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diff --git a/76817-0.txt b/76817-0.txt new file mode 100644 index 0000000..c14c71b --- /dev/null +++ b/76817-0.txt @@ -0,0 +1,26314 @@ + +*** START OF THE PROJECT GUTENBERG EBOOK 76817 *** + + + + + + DISEASE IN CAPTIVE WILD MAMMALS AND BIRDS + INCIDENCE, DESCRIPTION, COMPARISON + + + BY + HERBERT FOX, M.D. + + PATHOLOGIST TO THE ZOOLOGICAL SOCIETY OF PHILADELPHIA, DIRECTOR OF THE + WILLIAM PEPPER CLINICAL LABORATORY, UNIVERSITY OF PENNSYLVANIA + + + WITH A FOREWORD BY + CHARLES B. PENROSE, M.D. + + PRESIDENT OF THE ZOOLOGICAL SOCIETY OF PHILADELPHIA + +[Illustration: ZOOLOGICAL SOCIETY OF PHILADELPHIA. INCORPORATED 1859] + + PHILADELPHIA, LONDON & CHICAGO + J. B. LIPPINCOTT COMPANY + + + + + COPYRIGHT, 1923, BY HERBERT FOX + + + + + THIS BOOK + IS DEDICATED TO + CHARLES BINGHAM PENROSE, M.D., PH.D., LL.D. + IN GRATEFUL APPRECIATION OF HIS FRIENDSHIP + AND OF HIS GUIDANCE AND ENCOURAGEMENT + IN ALL MATTERS PERTAINING + TO THIS LABORATORY. + + + + + CONTENTS + + + PAGE + + FOREWORD—DR. CHARLES B. PENROSE 1 + + SECTION + + I. INTRODUCTION 17 + + Zoological Classification + + Numerical List of Autopsies Upon Which the Work is + Based. + + II. DISEASES OF THE HEART 48 + + III. DISEASES OF THE BLOOD VESSELS 66 + + IV. DISEASES OF THE BLOOD AND BONE MARROW 83 + + V. DISEASES OF THE LYMPHATIC TISSUES INCLUDING SPLEEN 114 + + VI. DISEASES OF THE RESPIRATORY TRACT 134 + + VII. DISEASES OF THE ALIMENTARY TRACT + + The Tube Proper 166 + + The Liver 222 + + The Pancreas 244 + + The Peritoneum 260 + + VIII. DISEASES OF THE URINARY TRACT 263 + + The Kidney + + IX. DISEASES OF THE FEMALE REPRODUCTIVE ORGANS 287 + + X. DISEASES OF THE MALE REPRODUCTIVE ORGANS 313 + + XI. DISEASES OF THE DUCTLESS GLANDS. + + The Thyroid 316 + + The Thymus 336 + + The Suprarenal 336 + + XII. DISEASES OF THE SKELETON AND ITS JOINTS 343 + + XIII. DISEASES OF THE CENTRAL NERVOUS SYSTEM AND SPECIAL SENSES 372 + + The Eye 402 + + XIV. CONSTITUTIONAL DISEASES 410 + + XV. THE RELATION OF DIET TO DISEASE BY E. P. CORSON-WHITE, + M.D. 415 + + XVI. NEOPLASMS 462 + + XVII. THE INFECTIOUS DISEASES. + + Tuberculosis 483 + + Mycosis 558 + + Streptothricosis 567 + + Miscellaneous Infections 596 + + XVIII. ANIMAL PARASITES, THEIR INCIDENCE AND SIGNIFICANCE, BY F. + D. WEIDMAN, M.D. 614 + + + + + LIST OF TABLES + + + PAGE + + 1. The incidence of degenerative and inflammatory changes in the + heart 51 + + 2. The incidence of hypertrophy and dilatation of the heart with + principal associated lesions 57 + + 3. A condensation of the important features of Tables 1 and 2 63 + + 4. The heart-to-body-weight ratios 63 + + 5. The incidence of arteriosclerosis 71 + + 6. The differential percentage of the circulating leucocytes in a + number of different animals 84 + + 7. The various types of splenitis 126 + + 8. The incidence of the various types of bronchitis and of + pulmonary parasites 142 + + 9. The incidence of the various forms of pneumonia 150 + + 10. An analysis of cases of abscess and gangrene of the lung 156 + + 11. The incidence of gastroenterocolitis, its distribution and an + analysis of the causes 182 + + 12. An analysis of the inflammations of the alimentary tract in + Ungulata 196 + + 13. An analysis of the inflammations of the alimentary tract in + Marsupialia 200 + + 14. An analysis of the cases of pancreatitis, the associated + pathology and the details of the anatomy of various orders 252 + + 15. The weight of the thyroid body in relation to body weight 318 + + 16. The incidence of the various enlargements of the thyroid body 326 + + 17. The incidence of cases of degenerative bone disease in the + various orders 357 + + 18. The weight of the brain and the relation of this to the body + weights in 196 animals 388 + + 19. An analysis of pathological conditions in terms of diet 423 + + 20. An analysis of the diets used in the Philadelphia Garden 426 + + 21. The incidence of tumors 464 + + 22. An analysis of the breeding, captivity and visceral + distribution of neoplasms, of tumor-bearing animals 466 + + 23. An analysis of the incidence, character and distribution of + tuberculosis 486 + + 24. The incidence of parasites in the zoological orders 630 + + 25. The incidence of heterakis in pheasants 635 + + 26. The incidence of various parasitic orders and families 636 + + 27. The visceral distribution of parasites 639 + + 28. The occurrence of blood parasites in zoological classes 651 + + + + + FOREWORD + + BY + + CHARLES B. PENROSE + + +The work on which this book is based was begun in November, 1901. From +that date, systematic autopsies were made on animals dying in the +Philadelphia Zoological Garden. Previously autopsies had been made very +rarely and only on animals of especial importance and interest. +Pathological conditions were occasionally noted in animals subjected to +anatomical study. The work was strictly volunteer, for there was no one +on whom the Society had the right to call. Dr. Henry C. Chapman, a +former Director, whose interest was in physiology and comparative +anatomy, made nearly all the autopsies that were made before the +beginning of the present work. In the annual reports from the foundation +of the Garden in 1872, very few such examinations are recorded. In some +reports there are lists of important deaths, but no record of the cause +of death. + +This state of things was not peculiar to the Philadelphia Garden. It +existed in every zoological garden in the world. It exists in most of +them to-day. When an animal died it had no interest or value except for +its hide and bones. Rare specimens were sent to the Academy of Natural +Sciences from the Philadelphia Garden. The great majority, however, were +immediately destroyed, and thus during the twenty-nine years from the +foundation of the Garden, preceding this work, there have been lost many +opportunities—some of which will never recur—of increasing our knowledge +of pathology. + +This book gives results of the study of animals that have not been +subjected to experimental procedures and conditions, and though their +mode of life has not been that strictly natural to them, yet they have +not been influenced by any of the artificial procedures of the +laboratory which are usually followed in investigations on animals. +Though the object of the work was the pursuit of knowledge for its own +sake, yet results of practical value have followed: hygiene has been +improved; disinfection has been made scientific; epidemics have been +arrested; some diseases, notably tuberculosis in monkeys, and +spiropteriasis in parrots, have been practically eliminated. + +The value of the work is recognized by the keepers. Their interest has +increased and their morale has improved. The frequent deaths in a large +collection of animals are discouraging, and a good animal man must have +courage and optimism—traits that are stimulated by the knowledge that +every animal that dies is studied to determine the cause of death, and +to prevent its recurrence. + +Some results of this study are to be considered as “raw material,” while +others permit cautious or tentative conclusions. The first include— +visceral weights, incidence of certain lesions like anemia and hepatic +cirrhoses, occurrence of calculi and observations on weak hind quarters, +convulsions and constitutional diseases. The second include—eradication +of tuberculosis and spiropteriasis, the response of the mammalian and +avian heart to strain and disease viruses, the origin of pneumonia in +birds, the genesis of bronchiectasis, the nature of osseous degeneration +with relation to diet and alimentary tract, the comparative anatomy, +physiology and pathology of the female genitalia, the occurrence of +lesions in the thyroid comparable to those in man, the character of +kangaroo disease. + +Great praise is due Dr. Herbert Fox and his assistants Drs. F. D. +Weidman and E. P. Corson-White, for the splendid scientific spirit and +thoroughness with which they have done this work, with no adequate +remuneration, except the intangible reward appreciated only by the real +research worker. + +It is a mistake to think that all animals in the wild state are healthy. +The healthy wild animals that we see are the survivors, the sick and the +weaklings having died. Undoubtedly diseases are fewer than in captive +animals; but on the other hand wild animals are exposed to dangers to +which captive animals are not exposed—such as lack of care in sickness +and old age, starvation, and attacks of enemies that feed on them. The +maximum longevities in some species are probably in captive animals. It +is doubtful if a wild animal ever reaches the greatest age possible to +it. + +Many kinds of parasites have been found in wild animals captured only a +short time before arriving at the Garden, so that they must have existed +in the wild. Thirteen wild cats received from South Carolina within a +few days after capture were infested with intestinal, muscular, and +pulmonary parasites. Several years ago there were received from the +Island of Chincoteague, off the coast of Virginia, a number of native +birds recently captured, all of which had mould disease of the air sacs. +This happened on several occasions, so that it became necessary to +reject all birds from this locality. Among the birds were meadow larks +and cardinals. + +Hunters not infrequently kill animals with disease, and if more hunters +knew enough to recognize the disease there would be more recorded cases. +Sick animals are not as likely to be killed by the hunter as healthy +ones, as sick animals seek seclusion and do not move about. In many +localities of the United States white-tailed deer are infested with the +liver-fluke. Trout and other fish in remote mountain streams are found +with tapeworms. Round worms and other parasites infest the white +rhinoceros in the African forest. + +In many instances the parasites and the host, when in health, get on +very well together; but when the host weakens the parasites may give him +the finishing stroke. + +Though some morbid conditions described in this book are peculiar to +captivity, yet it seems reasonable to assume that many of the diseases +found in captive animals occur also in the wild. Some of the extinct +races of animals may have been wiped out by disease. + +Captivity causes numerous physical and mental disarrangements. +Unaccustomed, unnatural and unvaried food, change of climate and +environment, physical and mental degeneration from disuse of muscle and +brain, fear, ennui, nostalgia, lack of the exhilaration of chasing and +being chased, unsatisfied sexual feeling—all react harmfully on the +captive. + +No captive animals get their natural food; and though some, like the +carnivora, may get approximately their natural food, yet they do not get +it in the natural way. They have but little variety and may miss +elements important to their well-being. They get only certain cuts— +muscle and bone; they do not get blood, guts and glands. The lion’s meat +is handed to him. He does not tear down his prey; and one result is that +the jaws of the captive-bred lion differ decidedly in shape from the +jaws of the wild-bred lion. He gets his food regularly, with awful +monotony—twelve pounds of meat at 3.30 p.m. day after day; there is no +alternation of feasts and fasts, with consequent change in the balance +of the body reserves. + +Some animals, such as caribou, the moose, the black cock, the hoatzin, +the koala, do not long survive captivity, because it is impracticable to +obtain their natural food. Gastrointestinal disease is the commonest +disease of wild animals. Twenty-five per cent. of sick humans in +civilized communities also suffer from it. On the other hand, many +animals become accustomed to the new diet and thrive on it. + +Animals also often thrive in a climate very different from that of their +natural habitat. Some animals from warm countries, though kept outside +without any artificial heat, get on very well during the severe weather +of Philadelphia winters, when the temperature often drops to zero +Fahrenheit. For the past two years it has been the custom to put +outdoors all monkeys—of value—that are suspected of having tuberculosis. +The cheap monkeys are killed. The outdoor monkeys are kept in fair sized +cages—five feet square and six feet high—usually singly, though +sometimes two are together. The vervet, the grivet, the leonine macaque, +the yellow baboon, the Hainan gibbon and many others, have not only +survived the climatic conditions but have not succumbed to tuberculosis. +South American monkeys do not stand cold as well as Old World monkeys, +and cannot be kept out in severe winter weather. + +The monkeys that are kept indoors during winter have free access to the +outside through swinging doors and they often go out voluntarily in the +coldest weather. The same is true of other animals. A note made several +years ago (February 12, 1914) states: “Temperature last night was 1° F. +At 2 P.M. outside temperature 13° F., in carnivora house 25° F., +elephant house 38° F., giraffe house 39° F., monkey house 42° F. Two +Bengal tigers were voluntarily outside. Monkeys that have been out all +winter are: two Barbary apes, Hainan gibbon, lion-tailed macaque, yellow +baboon, grivet monkey, pigtailed macaque, and eleven rhesus macaques. +All the animals appeared comfortable.” + +The physical condition of the animal and the kind of cold—damp or dry— +have much to do with its ability to stand low temperatures. Monkeys have +passed through very severe winters without damage, and subsequently in a +less severe winter have had frozen fingers, toes or tail. + +The size of the cage or pen has not as much effect upon the well-being +of the animal as might be expected. Reptiles, birds and mammals do as +well in cages and pens of medium size as in very large ones. A deer or +antelope in a large enclosure does not use all its domain. It usually +has a favorite corner near the food, water and shelter, and stays there. +Nor has a large enclosure been found perceptibly to diminish mortality +from cage-mates. The stronger will follow the weaker until he gets him, +no matter what the enclosure. Even in the large flying cage for birds it +is necessary to keep out those of a scrappy disposition. From the point +of view of the public small enclosures are more satisfactory. + +Mental disease in captive animals offers a fascinating field for study— +now chiefly speculative. Many conditions are present to produce it—all +the conditions that cause prison psychoses in man. And many if not all +the insane and perverted acts of animals have their counterpart in the +human. Masturbation is very common in mammals. Eating of their own +feces, coprophagy, is not infrequent, and is especially notable in one +of the highest types—the Chimpanzee. Perhaps occasionally coprophagy may +be due to some defect in diet. There is no instinctive disgust at +excrement in the lower animals any more than there is in the uneducated +child. Nevertheless, eating feces cannot be healthful, and probably does +not occur in nature; and occurs only in the human with mental disease. + +Some of the insane acts of animals if prevalent in the wild would +probably cause the extinction of the race. Such are killing of the young +by the father and by the mother; killing of the female by the male, +usually during rutting time, in some instances reminding one of Sadism +in man. This kind of sexual killing does not often occur in the wild. +The female has a better chance to escape, and the male probably does not +feel so inclined to damage her when he chooses her himself as when she +is chosen for him by his gaoler. When the mother devours her young it is +usually shortly after birth. I have, however, the record of a Jungle cat +(_Felis chaus_) who ate two of her kittens when they were seven weeks +old. Some of the domestic animals devour their young; the sow often does +it, and occasionally the bitch. + +Sucking, gnawing and eating parts of itself or of a cage-mate is not +uncommon in a variety of animals. Bears lick their paws until they are +sore; a monkey may gradually gnaw away its tail from the tip to the +body; an ocelot (_Felis chibigonazon_) bit open his scrotum and devoured +his testicle; a Tasmanian devil (_Sarcophilus ursinus_) bit off one of +his front feet at the wrist; a monkey may gradually gnaw away its +fingers; and numerous other self-inflicted mutilations occur. Often +there is a local irritating cause, as skin disease, lice, or freezing. +But in many cases no local cause can be found, as no local cause can be +found for thumb-sucking or nail-biting in the human. + +The surgery done by monkeys on their frozen fingers and toes is +interesting. After the flesh has sloughed the monkey bites off the +protruding phalanges, apparently without pain, so that satisfactory +well-covered stumps are made. + +Animals often mutilate their cage-mates in an amicable way as +distinguished from fighting. A bear may lick its mate’s ears until the +hair and skin are gone. A monkey may eat its mate’s tail or patches of +its skin, the victim lying placidly while the process goes on. Many +animals are addicted to perverted acts on their own or their mate’s +sexual organs. + +It is probable that the phenomena just mentioned are due to confinement, +idleness and ennui, and that they do not often happen in nature where an +animal is kept busy seeking his food, fighting and avoiding his enemies, +attending to his mate or mates, and meeting the various vicissitudes of +his environment. + +It should be remembered, however, that the members of a wild species +vary in intelligence and temperament, as humans do. There are morons and +perverts among animals in the wild; but not being coddled by the normal +members of the species, they have a poorer chance than has the subnormal +human of surviving and of transmitting their peculiarities. + +Fear, ennui, loneliness and nostalgia, by affecting the minds of captive +animals, react on their physical condition. Some animals have the fear +of man bred in them. The young often show it from time of birth. This is +especially common in animals that have survived for generations in +proximity to man. It is one reason for their survival. The mother and +father may have become tame and gentle in captivity and yet the young +one may be a wild thing from birth. Such fear is sometimes +uncontrollable, an apparently slight cause making the animal dash itself +against the fence of the enclosure. It is not mere speculation to +discuss the physical effects of the emotions on the animal body. It has +been shown that fear, anger, and grief bring about distinct measurable +physical changes. Dr. Corson-White has found that the red corpuscles are +increased by over two million per cubic centimetre in the blood of a cat +frightened by a dog barking at it. The amount of blood sugar is also +increased. + +Such observations are suggestive in a consideration of the changes that +may occur in a captive animal subjected to acute and chronic fear. + +The monotony of a captive animal’s life is broken only by feeding, the +sight and sounds of others in the same building or nearby, and by +visitors. Many animals show their appreciation and pleasure when +visitors approach, and some of the more intelligent animals, bears and +monkeys and some birds, “show off” apparently to keep the visitors +there. When there is nothing doing, some stand swaying their heads, like +a weaving horse, or pacing the cage, inanely tagging at each turn the +side of the cage with the head or other part of the body—often so +persistently that a sore is produced. Nearly all animals are social and +suffer from loneliness when kept by themselves. This is true even of the +lowly forms. The keeper of the reptile house reported that a giant +tortoise became despondent and refused to eat when his companion, a +leopard tortoise, was taken from him, and that he braced up as soon as +the leopard tortoise was returned. It is not necessary that the +companion be of the same species, or even of the same family. A lion or +a tiger may be satisfied with a little dog for a companion, and there +was an African rhinoceros at the Philadelphia Garden that was very +discontented and unhappy when alone and became perfectly satisfied when +she was given a domestic goat as a cage-mate; and the huge rhinoceros +stood for a good deal of butting and bullying from the goat without +retaliating. A sympathetic keeper may do much to relieve the loneliness +of the animals in his care. + +Nostalgia, or homesickness, has been felt by all men. Some have died of +it. The tradition among writers is that it affects young people and +those who have been living nearest to a state of nature. In this country +the American Indian and the negro are affected more than the whites. +Much was written of it after the Franco-Prussian War and the American +Civil War. It is a real condition, capable in extreme cases of causing +death and of so weakening the sufferer as to make him more susceptible +to the invasion of other diseases. At the present day we hear less of it +among civilized people than formerly, perhaps because the conception of +home has been broadened by modern methods of intercommunication. The +wild animal’s conception of home is narrow; he comes directly from it +into an environment where he may see many other animals, but not one of +his own kind. Predisposing causes of nostalgia are stronger with him +than with the human. That home means a great deal to animals is shown by +the migration of birds—the return of the carrier pigeon, and of the lost +dog, and of the swallow, which returns every year to the same nesting +place. + +All animals long for the things of nature—open air, earth, grass and +water. They are thrilled when their feet touch the sod. Even the +hippopotamus gambols when he leaves his concrete house and his feet +touch earth and grass. + +The face and carriage of many animals cannot express feelings as in the +human, though it is not unreasonable to assume that animals may indicate +feelings by expression understood by their mates, though not understood +or even noticed by man. When they can express it in a human way their +feelings may be read. The dejection of nostalgia is especially shown by +anthropoid apes. Gorillas have been noted for it from the earliest +writers. The orang is prone to it, shows it by his attitude and +expression, and sometimes dies of it. + +It is stated in _A Handbook of the Management of Animals in Captivity in +Lower Bengal_, p. 130, that elephants have been observed to shed tears +abundantly if forced to leave their old home and surroundings. How much +other animals who cannot express homesickness may feel it, and how often +it is a cause of unhappiness, depression and predisposition to disease, +it is impossible to say. + +Most wild animals in captivity are sterile. The reason is not known. It +shows the profound effect of captivity. It would be difficult to +determine whether the sterility of a mating is the fault of the male or +the female. + +There is no apparent rule for sterility. Some families are always +sterile in captivity, others are fertile, even with very unfavorable +surroundings. The deer, horses, hippopotamuses, pigs, goats, sheep and +oxen, are good breeders; while antelopes, rhinoceroses, giraffes, +elephants, are poor breeders. Some members of a family may be good, +others poor. The lion and puma breed fairly well; the tiger, leopard and +jaguar, very poorly. Bears breed well, but the mother usually destroys +her young. + +We cannot mate wild animals and birds simply by putting males and +females together in the same cage. Domestic mammals and birds usually +mate under such conditions, but wild ones often refuse. Many mammals and +probably all birds that are not polyandrous or polygamous reserve the +right to select their mates, and if the sexes are put together by man +they may view each other with indifference or with animosity. There are +many males and females of the same species of mammals at the Zoological +Garden that will not consent to live together. A male monkey in a cage +with several females will very often select one female for his mate and +will have nothing to do with the others. + +Among monkeys fertility varies greatly. It is not practical to determine +the ratio among the various kinds, as some kinds are much commoner in +zoological collections than others. I think that in general the Old +World monkeys (_Cercopithecidæ_) are better breeders in captivity than +those of the New World (_Cebidæ_). The anthropoid apes are very poor +breeders indeed; of the many gibbons, orangs, and chimpanzees, that for +years have been captive in Europe and America, it is probable that only +the chimpanzee has bred, and that very rarely. + +Refusal to mate, sterility, infanticide by father and mother, and sexual +killing keep down reproduction in zoological gardens; and the number of +young ones is a good indication of the character of a garden and of the +provisions made for the happiness, comfort and health of the animals. + +With the birds in a zoological garden the conditions for nesting and +laying are not good. Caged birds have no material for a nest, no privacy +and rarely lay an egg. The outdoor water birds and the outdoor upland +birds with natural surroundings, with secluded retreats, lay and hatch +very well. Birds like mammals apparently are indifferent to publicity +when copulating, but seek seclusion for laying and nesting—from maternal +fear for the safety of the young. + +The sexual instinct in indoor caged birds in a zoological garden is +dormant. Very few copulate and very few lay eggs; pigeons and Mexican +conures (_Conurus holochlorus_) are exceptions to this general rule. + +Probably because the sexual instinct is dormant the males never fight +over the females among perching birds, and very rarely kill each other. +In some species of finches, however, as the chestnut-eared (_gn. +Amadina_), the females fight among themselves if there are not enough +males. + +Ovoviviparous reptiles breed more often in captivity than one would +expect; and egg-laying snakes often lay eggs, which of course are only +hatched artificially. + +Birds suffer less than mammals from the psychological effect of +captivity. The mental development of a bird is much lower. With few +exceptions, like the ruffed grouse, the bird accepts captivity easily +and becomes tame, though he will not stand being touched. He views his +keeper and visitors with indifference or friendliness. If a bird house +is bright, cheerful and sunny, all the inmates thrive and appear to be +happy. These conditions undoubtedly affect the health of the bird, as is +evidenced by their plumage; bright colors that are lost in a dark and +gloomy house are retained and developed when the house is cheerful and +sunny. There are some birds, however, that never retain their colors in +the captivity of a zoological garden. Among them are the scarlet ibis, +the American flamingo, and the roseate spoonbill. It has been suggested +that the loss of color is due to the lack of something in the diet, +mineral or organic, that the bird gets in its natural habitat. Tame +scarlet ibises living with the chickens about the dwellings of natives +in Venezuela retain their brilliant color. The material of the beautiful +red color on the under surface of the wings of the touracou contains +copper, yet these birds retain this color very well in captivity, even +after several moultings. + +The source of the copper has long been uncertain. In nature the birds +are fruiteaters, and their diet in captivity consists of bone meal, +zweibach, corn meal, white potatoes, eggs and carrots—foods that are +usually assumed to contain no copper; and no copper utensils are used in +the preparation of the food. Dr. John Marshall, however, writes me that +all the common cereals contain minute quantities of copper; and Dr. Leon +A. Ryan, _University of Pennsylvania Medical Bulletin_, June, 1907, +states that copper may be found in animal tissues. Dr. E. P. Corson- +White has found traces of copper in the bone meal used at the +Philadelphia Zoological Garden. The copper in the red color of the +touracou’s wing therefore comes from the food. + +It is probable that a bright and cheerful bird house does not influence +the color of birds by the direct action of light on the color as much as +indirectly by improving the health and spirits of the birds. Coloration +in birds is a very complicated proposition. It depends upon age, sex, +season, health, light, heat, moisture, mode of life, and food. No one +bird house can combine all the conditions necessary for the retention of +natural colors in every species. The desert species from a habitat of +intense light and dryness require for their color a different +environment from the forest species, from a habitat of shade and +moisture. The suppression of sexual feeling in captive birds may +influence color. In nature the finest colors are attained by mating +birds. + +It may be said that all animals—except those of nocturnal habit—have a +feeling of joy and well-being in fine weather and bright surroundings +that reacts favorably on the general health. + +The variability of the breeding period induced by captivity in many +animals may be mentioned with sterility. It was shown some years ago in +the Philadelphia Garden by the European brown bear which in one year +gave birth on January 16th, and in the following year on July 25th. It +is another evidence of the profound effect of captivity on the captive +animal. I know of no observations of the effect of captivity on the +period of gestation. + +There is considerable mortality among captive animals from killing of +cage-mates. I do not refer to sexual killing, already mentioned, or to +fights over a female. Often males, with no females near, cannot be kept +together; probably sexual jealousy is at the bottom of it. Antelope and +deer are especially inclined to scrap. Even a large enclosure will not +save the weaker male; the stronger follows him with horrible +persistency, sometimes for days, around and around the enclosure, often +at a walk, but always on the offensive, at least during the day; until, +careless from weariness, the weaker is caught unawares and finished by a +horn-thrust in the side. + +Both birds and mammals often kill their mates when the mate is sick, or +“down” from injury or disease. All animals hate sickness and death, and +show their dislike by attacking or shunning it. Birds may get on happily +together for months until one becomes sick, and as he crouches in a +corner with ruffled feathers the others pick on him and finish him. The +same is true of mammals, the sick one being horned or tramped to death +by the mate with whom he had formerly been on most friendly terms. The +keeper often reports an animal “killed by its mate,” whereas the mate +has only given the _coup de grace_. + +This brutality is not universal. Rarely a parrakeet will stand guard +over his sick and dying mate; and we have seen a ratel—of a ferocious +family—stand guard over and resist the removal of his sick companion. + +The diagnosis of disease in wild animals is unsatisfactory; usually +impossible; clinical study as we know it in the human is impossible. We +know that the animal is sick, but not why. A certain group of symptoms +accompanies all diseases—dull, rough coat or feathers, refusal to eat, +weakness in the hind quarters, and finally getting down. They rarely +show symptoms of pain—or at least we cannot read the symptoms. The pain +of acute pancreatitis in man is violent, yet many animals die with it +and we cannot tell that they suffer. Animals do not suffer as much as +the human, and they stand the ravages of disease better than the human. +At autopsy we often wonder how the animal could have lived with the +conditions that are found. A monkey may be apparently well until a few +days before his death, though his lungs and abdominal organs may be a +mass of tubercle. A small red howler monkey (_Alonata seniculus_) was in +apparent good health, playful and lively until twenty-four hours before +his death from acute pancreatitis, though his stomach and intestines +contained fifty-one nematode worms, some of which were eight inches in +length. + +As diagnosis is unsatisfactory, so is treatment. Usually all we can do +is to treat symptoms; and by the time disease has advanced to the point +of becoming externally noticeable, it has usually gone beyond the reach +of medical treatment. It must also be remembered that drugs vary very +much in their action in different families of animals. Nux vomica will +not kill the gallinaceous birds of North America, and Tenant says that +in Ceylon the hornbill feeds on the fruit of strychnos nux vomica. The +pigeon is immune to opium. The _Felidæ_ are said to be unusually +susceptible to carbolic acid; veratrum viride is harmless to sheep and +elk, but poisonous to the horse; dogs can take with impunity large +quantities of cyanide of potassium. These statements are true when the +drugs are administered by mouth—the usual way of giving them to wild +animals. The action may be different if the drugs are administered +intravenously or subcutaneously. Variations in effect when they are +administered by mouth are often due to chemical variations in the +digestive secretions. It is probable that the action of cyanide of +potash on dogs depends on the amount of hydrochloric acid in the +digestive tract. + +When worms or their eggs are found in the stools vermifuges are used, +and with some animals especially liable to infestation by intestinal +worms, periodic doses of vermifuges are given as a prophylactic. +Turpentine is given to the zebra at fixed intervals for the round worm; +santonin, male fern and areca nut to the carnivora for the various worms +that are so common in the intestinal tracts of these animals. + +The work of the Laboratory of Pathology is throwing light on the subject +of diagnosis, and though from the character of the clinical material +diagnosis can never be as satisfactory as in the human, yet we may +fairly hope for improvement. Prophylaxis is our chief reliance, and +always will be. + + + + + DISEASE IN CAPTIVE WILD + MAMMALS AND BIRDS + + + + + SECTION I + INTRODUCTION + + “We have also parks and enclosures of all sorts, of beasts and birds; + which we use not only for view and rareness, but likewise for + dissections and trials, that thereby we may take light what may be + wrought upon the body of man.” + + +The purpose of a menagerie under the auspices of a zoological society +can scarcely be put into better words than those found in this quotation +from Sir Francis Bacon’s _New Atlantis_. Apt as this description of the +mythical island’s collection may be, it is but a reflection of the +teachings of Plato’s original legend of a perfected community, and the +practical applications of these teachings by Aristotle in his _Anatomy +and Physiology of Animals_. The history of human study shows a constant +investigation of lower forms of life, ever broadening in its scope, ever +more satisfying in its explanation of biologic problems and ever +increasing in value from an economic standpoint. + +If, however, all animals are to be subjected to “dissections and trials” +there inevitably will come under observation many specimens presenting +variations from the accepted mean or standard or even from an average +for their kind and therefore approaching what may be called +pathological. + +The desire to explain the abnormal has had the effect, during the half +century since Virchow defined cellular pathology and Darwin systematized +the world’s knowledge of comparative biology, of directing attention to +comparative pathology and of stimulating the study of veterinary +medicine. Moreover in the past twenty-five years much work has been done +and many isolated publications have appeared upon the diseases of wild +animals, notably Bland-Sutton’s work, _Evolution and Disease_ (1895), a +thoroughly scientific and most charmingly written book, but rather +elementary in its approach of the subject of pathology, and Wood +Hutchinson’s _Diseases of Animals_, a more or less popularly presented +treatise. I am unaware, however, of any systematic monograph upon the +subject wherein we may find data showing the character of pathology in +the various animal groups or the incidence of the various lesions. The +reports of some zoological gardens contain the result of medical and +pathological data collected for the report period. The publication of +greatest merit and value is that from the Zoological Society of London, +whose huge collection studied by a large official personnel makes it +possible to present valuable data. The New York Zoological Park uses its +material in a similar manner and has been able to explain some of the +knotty problems so frequently met in wild animal collections. + +Here at Philadelphia it has been our practice now for twenty years to +perform an autopsy upon every mammal and bird that dies, and upon all of +the large or important reptiles. There is no aquarium connected with the +Garden. The office of the society keeps a record of the arrival and a +general description of every animal so that a brief history of the +specimen is usually available. The keepers are required to observe their +charges regularly and closely and to report any abnormalities to the +officials of the Garden. Somewhat detailed discussions upon signs of +sickness will be given at appropriate places, where also a few remarks +upon treatment will be included, but as this work is not intended to be +a treatise on therapy and since this subject does not differ from that +referable to domesticated animals, little space will be devoted thereto. +Upon death a complete autopsy is performed and the findings are recorded +upon a printed form from which, when the histological, bacteriological +and parasitological studies have been completed, a set of cross index +catalogue cards are typed; these are divided into the principal +diagnoses and determinations. The report of the Zoological Society, +appearing at the end of their fiscal year, February 28th, contains a +résumé of the observations for the year, together with notes of +interesting cases and experimental work. + +There have accumulated the records of nearly six thousand autopsies and +upon them as a basis has been founded the following report of the +incidence and nature of pathological manifestations in the various +animal groups, using also as additional data, published reports from +other gardens. The book might be described as a collection of our +studies, parts of which have appeared as separate articles, but most of +which are entirely new, put together with as much connection as the +subject matter will permit. The zoological and pathological literature +has been consulted very extensively, but except for the reports of +zoological societies and the publications of special students, it +usually represents isolated notes by travellers and veterinarians so +that many articles may have been overlooked. Therefore no claim of +perfect completeness of reference is made, the statements resting +chiefly upon our own records. The subject will be approached from the +standpoint of description and incidence, but it is inevitable that +comparisons and contrasts must be noted. + +Into the realm of evolution[1] I shall not venture because I appreciate +a lack of adequate preparation for such an attempt, and because, even if +such were not the case, the material at hand is lacking in data upon +fishes, many kinds of reptiles and invertebrates. + +A direct and practicable application of these data will be in the +direction of explaining some of the pathological states in domestic +animals and man. There are indeed many disease entities or syndromes in +these groups for which no useful hypothesis has been advanced, while for +others a partial explanation has been offered, usually, however, +inadequate wherewith to form the basis of rational prevention or +therapy. Thus, for example, essential emphysema seems to be limited to +the animals of civilization; on the other hand, the anatomical basis of +exophthalmic goitre may be seen throughout nearly the whole animal +kingdom yet the clinical phenomena belong characteristically to man, and +are occasionally seen atypically in the dog. While it may be impossible +to give a complete comparative anatomy and physiology for each of the +pathological states, the attempt will be made to treat all subjects +analogically through the zoological orders. + +The experimental pathologist may find the records of the Garden useful +in his work. For example, he can know that rodents are not prominent +among the orders showing spontaneous arteriosclerosis, but that +nephritis occurs among them in about a quarter of natural deaths; or he +may learn that the Primates have a good cardiac reserve while the +Marsupialia have not. Too often experimental work is not based upon +facts including natural probabilities. + +A collection of pathological data such as is presented in the following +pages may be of assistance to veterinarians and managers of zoological +gardens in the diagnosis of sickness in animals, both wild and +domesticated. We do not presume to offer a system of veterinary +medicine, but it is possible to introduce certain objective findings of +practical hygienic and therapeutic value. Such observations are, +however, limited and in our experience at the Philadelphia Garden the +diagnosis of disease in a wild animal, excepting of course those which +are perfectly self-evident, is more often speculation and conjecture +than at all well grounded. It is not uncommon for animals to come to +autopsy presenting a perfect galaxy of abnormalities, yet the closest +antemortem observation failed to reveal unusual conduct or appearance. +On the other hand specimens are frequently opened whose organs fail to +contain any lesions discoverable even by careful study. Dr. Henry +Chapman, sometime prosector to the Society, once made a remark in this +connection—“Why do they die or how can they live so long.” Space is +given to this phase of the observation of wild animals in order to +emphasize the difficulties of interpreting their conditions, but of +course it should be understood that certain data of value may be gained +by close attention to the details of their normal behavior and to +changes which occur indicating that something is wrong. + +The naturalist and the trained animal keeper are, in our opinion, better +judges of a wild animal’s condition than is the veterinarian, unless he +be at the same time a zoologist and have long experience with a +menagerie. My own observation of dogs and horses leads me to think that +more acumen is needed to interpret the actions of wild animals since +they seem to have greater natural reserve, and of course in regard to +them there are many more variables since we see fewer specimens of each +species than we know familiarly among domestic varieties. The principal +objects for observation are, as in veterinary medicine, the eyes, the +hair and skin, the mucous surfaces, the droppings, the condition of the +abdomen, the appetite and the desire for water. Physical examination is +limited to tractable beasts and those which can be caught and handled +without danger to the personnel or unusual fright and damage to +themselves. In the interpretations of physical signs in tractable +animals, such as many ungulates and some monkeys, the experience of the +trained veterinarian is of the greatest value, but this fails amongst +carnivores and birds. It might be said that anesthetics could be used +for a thorough examination, but this would be undesirable for a +seriously sick animal and it is, in our experience, none too safe a +procedure although often perfectly practicable. Animals do not like to +be molested much as they may seem to enjoy attention, and when it is +possible it is our practice to avoid handling them. + +It might be contended that observations upon diseased states in captive +animals would not represent natural developments, in other words, not +that which occurs in the wild. Such indeed may be true in regard to the +infectious diseases, but since we are imperfectly informed as to the +pathology of the wild state, we are obliged to accept and use the best +substitute at hand. Moreover it seems perfectly fair to consider as +characteristic for an animal or group, the physical and even +physiological expressions of morbid agencies as we know them, even +though the animals be at the time under conditions not natural to them. +It would be perhaps incorrect to say that cirrhosis of the liver occurs +in .6 per cent. of animals in the wild as is the case for our autopsies, +since incorrect food and infections are potent in its causation; on the +other hand, our experience and some few data from naturalists and +pathologists make it conceivable that tumors occur to this number in +native states. The incidence of tumors in wild rodents is quite well +known. Degenerations and fibroses, the result of parasitism, are known +to exist throughout the entire animal kingdom. Further to illustrate how +pathology is distributed in wild life, Plimmer’s experience[2] with 500 +rats (_M. decumanus_) might be cited. He found the following: Tubercle 3 +times, tape worm cysts 10, Tryp. lewisi 49, empyema 2, tumor of jaw from +old injury 1, pleuritis and hydrothorax 1. Bacteria were found in 71 +rats, 40 times in the lungs, 31 times in the spleen; saccharomyces were +found 16 times in the lungs. Dr. W. L. Abbott reports to us personally +that he has repeatedly found coiled exproventricular worms in the wild +specimens he has collected. Not only are we informed of some isolated +and individual pathological states but the existence of epizoötics of +communicable disease among wild life is well authenticated. The simple +citation of the extermination of deer in one section of Colorado by +pleuropneumonia will suffice to illustrate this point. Other examples +are, however, interesting. The occurrence of changes in the jaw bone +almost certainly those of actinomycosis is reported by Blair, the +specimens being shot in the wild and believed never to have been near +civilization. The white-tailed deer of the Swan River Valley in Montana, +are known to be constant carriers of liver-flukes. + +It would seem therefore that it is not unfair to use material gathered +from animals under somewhat unnatural conditions as representing the +reaction of the zoological orders to pathogenic agencies. Such +conclusions must however be made very guardedly, for it is probable that +not over ten per cent. of the total number of mammalian and avian +species are to be observed in captivity. Because of the number of orders +and the great variety of genera included in the present study it is +probable nevertheless that the lesions are fairly representative of the +whole animal kingdom. + +However, the numbers and percentages given should be read to indicate +the probabilities and should not be interpreted as implying the +mortality relationships since different varieties have differing powers +of resistance to the same pathological state. The margin of safety in +any given group for one or several different disease entities cannot at +present be stated with any degree of precision but this factor is +doubtless very great. The work of physiologists suggests that there is a +reserve power in the human lung sufficient to sustain life until five- +sixths of the functionating organ is useless, and I shall quote a case +of an opossum wherein only one-tenth of the respirable surface seemed to +have remained; we have repeatedly seen both lungs of a monkey apparently +entirely solid. Such physical vital incompatibilities might be +exemplified by many other cases, but when one reviews the physiological +margin of safety, inexplicable and contradictory instances are equally +numerous. I have seen a male deer run a doe against the fence and butt +her, without result, whereas in an apparently similar occurrence the +animal would be dead in a short time. Numerous instances of slight +enteritis of a short stretch of duodenum or ileum have killed, with +almost nothing to be found microscopically, and on many occasions we +have been chagrined in being unable to discover the cause of death. The +capacity of self-healing is a variable one, but seems in direct +proportion to the quietness and seclusion possible for the animal and +inversely to the chance of bacterial infection. + +The effect of captivity has been the subject of much speculation. For +the preservation of health it would seem that animals require periods of +rest and activity, thorough elimination, possibly a moderate exercise of +their procreative functions, but most of all, appropriate food obtained +by the physical effort we term chase. All but the very last condition is +supplied in a measure in well managed collections. The degenerating +effect of the absence of chase must be admitted. An interesting and +suggestive example of this was noted by Mr. Jones at the London +Zoological Gardens. He observed the skull of a lion that had been in +captivity thirteen years, in which the canine area of the face and the +part of the skull acting as the insertion for the seizing and holding +muscles had undergone atrophy while the chewing muscles with their bony +bases had remained normal. Numerous examples of disease atrophy are on +record and those of a physical nature must have counterparts in the +realm of physiology. The size to which an animal will attain cannot be +estimated by the examples seen in menageries. Judging by the accounts of +collectors and hunters and upon the more reliable of the moving picture +displays of wild animals in their native haunts, it would seem probable +that under normal conditions of habitat the average size of wild beasts +is considerably in excess of that in park specimens. + +The effect of captivity may also be felt in the direction of reduced +resistance to infectious diseases. Brooks, of the New York Park, +expresses the view that captivity increases susceptibility to bacteria +and causes parenchymatous degenerations. In the latter direction it is +interesting to learn that Seligman of London claims to have seen sudden +deaths in wading and struthious birds from myocardial disease, without +valvular or other lesions, for which he holds the enervating effects of +captivity responsible. It is well recognized that a species may be +unusually susceptible to a disease that it has not encountered in its +phylogenic development. Man illustrates this peculiarity very clearly. +Europeans were found exceedingly susceptible to sleeping sickness when +they went first to the part of Africa inhabited by the tsetse fly, and +the American Indians died in hordes when they met the tubercle bacillus +for the first time. Judging by the ravages of tuberculosis in captive +monkeys a similar susceptibility probably explains the matter for there +are no entirely satisfactory records of this disease among them in the +wild state. + +In so far as general susceptibility to infection is concerned, it may be +in part due to one of the artificial conditions of captivity, that of +inbreeding. This influence is undoubtedly very great, both by chance in +families, and by intention on the part of dealers as well as the mating +which occurs in menageries. However, it is not known how far inbreeding +may go in the wild state so that one must be very careful about drawing +conclusions in this particular. Several years ago, at the time we +reported the neoplasms found at the Garden, discussion arose as to the +effect of inbreeding, and thereafter some observations were made in this +direction. With the exception of the hyperplasias of the thyroid, not +certainly of neoplastic nature, in a much mixed-up family of wolves, we +could find no evidence that inbreeding was responsible for tumors. +Plimmer and Murray of London, seem to imply that some of their inbred +animals are likely to have tumors; reference to this matter will be made +later in this book. In so far as diseases of the organic systems are +concerning those of the bones seem to be the only ones in which +inbreeding is significant. + +The individual resistance will be reduced of course by the unsanitary +surroundings incident to trapping, shipping and storage, but this need +not affect the figures or pathological tendencies of classes or orders. + +The effect of captivity is felt in another way. A very large percentage +of wild life perishes during the first weeks or months after its +capture, and in gardens the heaviest mortality occurs among the recent +arrivals. The London Garden figures that from thirty-three per cent. to +fifty per cent. of their total mortality is in animals that have not +been in the garden six months and that die because they are not yet +accustomed to their new surroundings. It seems to us, both from an +academic and a practical standpoint, that this is a long time and should +afford ample opportunity for the garden to study the specimen and for +the specimen to become acclimated. These early deaths are perhaps to be +ascribed in large part to failure of acclimatization but many are +doubtless the result of infection acquired in the wild, in transit while +in the hold of vessels, at quarantine, or in trains, or at the +establishments of dealers. We have seen a few deaths which have followed +behavior that might be likened to homesickness. Perhaps the age at +arrival has an influence upon the morbidity and mortality of wild +animals, for it is easily conceivable that the young and the very old +might adapt themselves to new surroundings with much less readiness than +the sturdy middle-aged adult. The age of animals upon arrival is very +rarely known, and can only be recorded as “young,” “fully developed,” +and “old.” This will have an effect upon statistics and when possible is +noted in the text, but this is not practicable to the extent we desire. +The meaning of “young,” “adult,” and “old” is not the same throughout +the animal orders nor even within orders. + +Mitchell[3] has attempted to gain concrete ideas of the expectancy of +life among animals by analyzing the records of the London Gardens. This +gentleman bases his figures upon known ages and the length of time in +captivity, from a combination of which data the specific viability and +the potential longevity may be estimated. Such results, he admits, can +only be approximate and they show within classes and orders, a decided +lack of uniformity. The terms “specific” and “potential” longevity, +coined by Sir Ray Lankester, apply, for the first, to the average length +of life as it is affected by external conditions and those incident to +procreation, while, if an animal be under ideal conditions it will +attain the potential longevity which is longer than the former. These +considerations have a biological and economic importance, while a +knowledge of the pathology shown by the various groups may help to +explain these durations of life. Contrariwise figures of the expected +longevity may assist us in evaluating youth and senility in the causes +of death but can hardly affect the comparative nature of the lesion. + +A résumé of Mitchell’s studies indicates that the higher apes have a +potential longevity and a hardihood much less than man but still upwards +of thirty years. As one investigates lower in monkeys, life periods +become shorter, while in the next order, Lemures, the length of life +rises. Carnivora have a reasonably good vitality, their potential +periods varying from ten years in the foxes to thirty-three years in +bears. Insect eating animals are short lived, three years being a +maximum. The Bat family shows great variations, the greatest life being +not over seventeen years. The Rodentia have long lives compared to their +sizes—twenty years in porcupines, fifteen years in squirrels, thirteen +in marmots, nine in agoutis and capybaras, and three in dormice (which +is also about the maximum for the rat). Hyraces live four years on the +average. Proboscidea, although reputed to live to great age, probably +rarely live a half century and may be said to have an expectancy of +twenty to thirty years. Perissodactyla (horses, tapirs and rhinoceroses) +while they may live half a century, have an average life of between +fifteen and thirty years. The closely related Artiodactyla fall into two +groups, a first comprising antelopes, sheep, goats and deer which rarely +exceed seventeen years, and a second consisting of cattle, camels and +giraffes, which vary in expectancy from eighteen to thirty years. The +smaller members of the Ungulata have in relation to size a relatively +greater viability, the ruminants, however, having on the whole a low +viability. Marsupials vary from a maximum of seven years in the opossum +to eighteen in the wombats, but none of this group has a good viability. +The Aves as a class or if compared according to dietary requirements, +have longer potential ages and better viability than mammals. Passerine +birds average twenty years and many live to sixty, while the Picariæ +approach the former figure but do not have such good viability. Psittaci +and Striges may live a half century but the resistance of the latter is +much reduced by any unfavorable surroundings. The raptatory birds live +fifty years, but their viability is variable. Herodiones have a maximum +expectancy of thirty years and good resistance, while their relatives, +Steganopodes, may live fifty years, and Odontoglossæ have a good +viability, up to twenty years. Anserine birds may live to be fifty, and, +unless conditions are quite unfavorable, have a good resistance. Columbæ +may under good conditions live to be fifty. Gallinaceous birds may only +be expected to survive twenty years, a figure also given for Fulicariæ. +Alectorides may live up to fifty years. Limicolæ, though they do not +thrive in captivity, may live thirty years. Impennes live poorly under +artificial conditions, the greatest record being twelve years, a figure +also holding for Crypturi. Struthiones, if the conditions be right, may +live fifty years. + +Because of the variable specific longevities, it is frequently difficult +to decide when an animal is senile. Man is said to be as old as his +arteries, and his span of life nowadays is in the neighborhood of half a +century. Parrots exhibit lesions of the vascular system comparable to +the arteriocapillary fibrosis of human beings, and their expected +longevity is about the same or a little greater. From a study of our +cases of this lesion in parrots it can be said to appear quite early in +life and not to lead to organic disease as it is alleged to do in man. +It is, however, interesting to note that in those animals which are +supposed to have the longest specific lives—elephants, snakes, anserine +and raptatory birds, parrots—there is relatively low mortality and fewer +infectious diseases are encountered. The last part of this statement +should be qualified by stating that anserine birds and parrots are quite +susceptible to mycoses, in all probability from musty food, which raises +their death rate, but as this is accidental and artificial, it can be +excluded from consideration. + +In a rough way there is a direct relationship between the size of an +animal and its longevity, but this is not close enough to be a reliable +guide; whales and elephants live a long time, but so do snakes and +parrots. Within orders this relation of size and expected longevity is +more easily seen but is not absolute. I cannot state, according to my +present studies, that there is an unqualified relationship between the +size and expected longevity of an animal and its pathological lesions. + +The immediate surroundings and the management of captive animals have a +very direct and important bearing upon the mortality and perhaps upon +the incidence of morbid processes but probably not upon the character of +the latter. A full knowledge on the part of the personnel of a +zoological society concerning the habits and habitat of every animal in +their keeping is essential, to which must be added a group of interested +keepers. In engaging the last, it should not be forgotten that certain +men have “a way” with animals and that others cannot manage themselves. + +The enormous literature at the disposal of the naturalists permits +executive officers to formulate a plan of housing and feeding with fair +accuracy for each kind of animal, but of course it is rarely possible to +obtain in sufficient quantity the natural food (_e.g._, ants for +anteaters). In so far as food is concerned it seems that with a few +exceptions like the one just mentioned, the substitutions made at the +zoological gardens are nearly satisfactory. The elements in which the +captive diet is poor are the inorganic salts and vitamins since Dr. +Corson-White, some of whose work is included in a later chapter, has +shown that for those animals which our statistics indicate as most prone +to have rickets and osteomalacia, the available phosphorus and calcium +are low, and one vitamin was also below the desired quantity. In this +regard, however, I am not at all convinced that diet alone will suffice +to explain these degenerative osseous diseases; I shall take this up +more fully later. Careful inspection of all food should be made and +cleanliness (sifting of cereals, protection of meat from flies, etc.), +is indispensable. The mortality among our carnivora has materially +decreased since the horse meat after butchering was placed in covered +galvanized iron pans. There are many problems of feeding, too numerous +to be covered in a survey of this sort, which must be solved, and it is +a credit to superintendents that this they have studied carefully. + +There are two problems in the management of animals upon which much +difference of opinion exists, namely the heating of houses and the +material of which cages are made. It seems to be the practice in many +gardens to keep animals very warm. Dr. Chalmers Mitchell states +unqualifiedly that adult animals do not have to be kept warm, and that +even an equable temperature is not demanded, variations in temperature +having a distinctly stimulating effect. However he maintains that they +should be kept dry and must be supplied with a shelter. This is in +accord with the experience at the Philadelphia Garden, since for many +years we have allowed access to the open air all winter to every animal +that could stand it. A large group of macaques has now lived entirely in +an open “band stand” cage for nine years with a lower mortality than in +the rest of the monkey collection, which is permitted to go indoors some +of the time. Occasionally one in poor health is frozen to death, and +healthy ones may lose fingers, toes, or a part of the tail, but the +general condition is so much improved that they present an attractive +exhibit to visitors. Unless a storm be of great severity, wild animals +are usually indifferent to it although they may seek their shelter. Snow +apparently is no source of fear to them, and many enjoy playing in it. +The general principles of the enclosure should be proper lighting, free +access of air, dryness and shelter in time of storm, the last so +arranged that the sleeping place is well protected. Appropriate +arrangements should be made for nocturnal animals, regardless of their +visibility to visitors, if their preservation is of importance. + +The hygiene of communicable disease has influenced everyone to use +concrete and metal for cages. These substances are without doubt most +simply kept clean, but they are heat-conducting and remain cold or damp +longer than wood or the ground. It may be claimed that the latter two +cannot be disinfected so well, but this need not militate against their +use. Wood can be disinfected by sunlight or by mechanical cleaning plus +disinfectants, by a blast lamp and by paint. The ground will disinfect +itself if allowed to lie fallow for a time, or it may be turned over +after sprinkling with lime. It is fair to note that the New York +Zoological Garden reduced their mortality, especially from verminous +pneumonia, by changing some deer herds to concrete paved enclosures; if +that were the only change made the result would be very significant, but +it should not be forgotten that another clean ground range might have +served as well to a herd from which the infected ones had died. My own +observations with guinea-pigs, rabbits, mice and dogs lead me to believe +that they thrive and breed better on wooden floors than on metal or +stone. + +I have tried to work out figures to show that more animals die when +housed in enclosures of stone and metal than when upon the earth or on +wood, but the attempt has been unsuccessful chiefly because of the +presence of epidemics and parasites, principally among the birds. The +attempt was further embarrassed because some members of an order are +housed on both floorings. However, there was no great advantage for the +metal and concrete floors even after the epidemic had been discounted. +This Garden does not have a great number of pneumonias, a disease said +to be favored by dampness and cold, but those that occur are chiefly +among the small mammals, on wooden floors and in the large bird house in +cages of concrete and metal. However, the construction of both these +houses permits the visitors to approach very close to the cage, a factor +that doubtless explains the disproportionate incidence of inflammation +of the lungs. In so far as outdoor fowl and ungulate ranges are +concerned, they should be changed frequently under the best conditions +since occasionally one will find groups doing badly until moved. +Moreover the ground becomes contaminated with parasites such as +esophagostomum and heterakis, infestation with which while not very +serious in itself, may lead to fatal infection with bacteria. + +The effect of animal parasites upon the morbidity and mortality of wild +beasts and birds in captivity is by no means clear, and Doctor Weidman +and I are inclined to be sceptical, with certain reservations of course, +of their great importance in the death rate. Doctor Weidman has kindly +agreed to contribute a chapter upon the general distribution of +protozoal and metazoal parasites with a summary of their probable +pathogenic importance. + +The groups known to have a decided pathological power might be divided +into the toxic, the tumor formers and the mechanically obstructive; +certain parasites have properties placing them in two of these classes. +The first group comprises the hemosporidia and hemogregarines, the +uncinaria and some of the cestodes, forms which produce hemolysis and +hemorrhages with varying grades of anemia. The importance of this group +is shown chiefly among the Aves, in which high grades of anemia are +occasionally met from malarial infections, but cats and dogs or even +herbivores also frequently suffer from hookworm. The tumor-producers are +chiefly echinococcus worms, the cysts of which may grow large enough to +occupy nearly the entire abdomen. A certain grade of anemia and general +ill health accompany this hydatid disease, partly the result of a toxin +and partly by damage to important viscera. Those parasites which +obstruct mechanically do so by their own bulk or by an accompanying +inflammation, incited by them as foreign bodies or by bacteria which +have gained entrance at the irritated point. This is exemplified by the +enormous collection of nematodes sometimes found in reptiles (a pailful +was removed from a python) and by the tightly coiled or tangled thread +and tape worms frequently found in birds. The effect of swelling by the +mucous membrane under the influence of worms is illustrated by the +infestation of the proventricle in parrots. Here spiroptera penetrate +into and under the glandular layer which swells and pours out mucus, the +total mass of nematodes, mucus and tissue obstructing the passage. + +Very many animals show parasitic infestation at postmortem, but the +percentage in which they can be said to be principal causes of death is +quite small, while that in which they play a rôle as activator of the +terminal condition is also small but indeterminate. The latter group +comprise, together with the anemias mentioned above, certain forms of +pneumonia, of hepatic and vascular lesions. Inflammations of the lungs +from ascaris and paragonimus are fairly well known; fortunately we have +been troubled less with this than have most gardens, possibly because we +do not have such large herds of herbivora susceptible to it. Hepatic +diseases from flukes, from coccidia and from amœbæ we have always with +us in small numbers, but they are unimportant excepting enterohepatitis, +a condition which appears in nearly all orders. This last disease, be it +purely amœbic as in dysentery of man and monkeys, or like blackhead of +turkeys and chickens or in the forms of quail disease, arrests the +attention at once and evokes a desire to explain the association of +large intestines and liver. Parasitic vascular lesions are relatively +unimportant. + +Taking parasitic infestations by and large, there are close similarities +throughout the entire animal kingdom, and the effects produced by a +given genus will be repeated almost exactly in several others. The +pathological pictures of anemia, of hepatic degeneration, of cystic +degeneration, of colonic ulceration or of fibroses are similar in +different hosts, only slight variations in the type of inflammation +being noted, for instance in reptiles and birds as against the mammals. +We have made rather close observations upon the effect of parasites in +the production of neoplasms, incited by Fibiger’s discovery of nematodes +in the rat’s stomach cancer, but, with the possible exception of a +papillomatous growth in the stomach of opossums from the action (?) of +physaloptera, we have been unable to establish such an etiological +relationship. A decision of the importance of parasites in any given +case is not without its difficulty, and we are inclined to reserve +judgment pending further analysis unless the effect of the invaders is +unequivocal. Leiper[4] does not seem to credit animal parasites with a +great effect on the mortality after a specimen has been in the +collection six months since all the intestinal varieties he studied came +from animals dying in that period. On the other hand the forms which +invaded the internal organs and tissues were, in his series, from +specimens resident several years in the garden. He seems to think the +conditions of life at the garden favor the expulsion of intestinal +worms. To what extent some intestinal worms may be commensal remains as +uncertain as the value of certain bacteria in the gut tract. In man +considerable importance has been ascribed to certain fermentative and +putrefactive germs in the maintenance of a reaction unfavorable to +strict pathogens and some observers have looked at them as possessing a +digestive power. In the digestive tract of the animals eating large +quantities of carbohydrate as cellulose, nature provides for its use by +rumination and by supplying a large hind-gut, by which means secondary +mastication and bacterial decomposition of the cellulose capsule insures +its full use. Possibly a similar usefulness may be finally ascribed to +some animal microbes or even larger metozoa. + +The rôle of vegetable parasites in the causation of disease among wild +animals seems as undoubted as it is in the human being and the +pathologic results are usually as clear, at least for the entities of +which we have exact data, based upon comparisons with man and domestic +animals. + +There seems to be no essential difference among mammals between the +pathological pictures of infectious septicemias, the mucous and serous +membrane inflammations and tuberculosis for example. They are +characterized by fibrinous, purulent or infiltrative inflammations which +may go on to necrosis or repair, by fever, by leucocytosis and by +evidences of resistance—all of these things occurring in a similar way +throughout the class. Of course not all animals are receptive to all +infections since specific racial and generic immunities exist, but the +basic response in terms of pathology is similar. There are no normal +means of judging the susceptibility of wild animals on their native +heath to the important pathogens of civilization, pneumococci, +streptococci, staphylococci, cholera bacilli, the typhocolon group, the +Friedlander group and others, but it is interesting to note that in +captive conditions they evince some receptivity to these germs or their +congeners. The pneumococcus takes a fairly heavy toll in zoological +collections every year and the Friedlander bacillus, not a very common +cause of human pneumonitis, has been seen here and at London. + +Among the birds, however, quite distinct differences in some +pathological processes occur, not only from the mammals but also within +the class. As a whole birds do not produce pus as we know it in man, +probably because of the absence from their leucocytes of a protein- +splitting ferment; their leucocyte-producing organs do not seem to +respond as readily to a virus, the place of purulent exudate being taken +by a coagulum or necrosis. The former varies from a clear gelatin-like +material seen upon serous surfaces to a thick mat or mass of coarse but +short fibrinous strands. Necrosis may succeed upon the latter or occur +so promptly as to appear like the original form of degeneration. It is +usually rapid, accompanied by a circumferential congestion but not +associated with active phagocytosis. Giant cell production is variable, +but when developed the appearance is like that of large syncytia. +Hemolysis is not marked in the simple infections but a hyperplasia of +the mononuclear nodes of the liver is the rule. The function of this +nodal increase is not quite clear. It has been always thought that the +scanty bone marrow would supply the necessary erythrocytes, but we have +seen these mononuclear areas full of pale red cells fitted with round +nuclei and without pigment. The fibrin mentioned above does not have the +delicate interweaving that we know in a fibrinous exudate in man. This +is interesting when we consider the composition of the blood and its +coagulation in the Aves. The cell upon which human coagulation seems to +depend, the platelet, is represented in birds by the thrombocyte, which +appears only up to about 50,000 per cubic millimetre. Coagulation time +is relatively short and the resulting clot is firm and irregular. +Perhaps this may have something to do with the nature of an inflammatory +exudate. + +The response to infection on the part of birds may to some extent depend +upon differences in anatomy, which are quite distinct, not only from the +mammals within which class the anatomy is more uniform, but also from +one avian order to another. These differences among the birds may be +exemplified by the large foramina between lungs and air sacs in the +water birds, a passage which permits infection, notably mycosis, to +spread from the first to the second. Again the close apposition of the +pancreas to the duodenum over a long stretch permits easy infection of +the former from the latter. Still again the large renal-portal vein in +the gallinaceous birds explains some of the infections of the liver +secondary to intestinal disease. The position of the lungs, deep in the +thorax and fitted into recesses made by the sharp anterior border of the +ribs and overlaid anteriorly by a rather firm air sac wall, makes it +difficult for these organs to expand and therefore renders even a simple +congestion a dangerous thing. The position of the ovary subjects the +shell-less egg to much danger from the intestinal area. + +These and many other peculiarities of anatomy affect the pathological +picture in birds. To be sure there are also noteworthy differences among +the Mammalia, notably in the intestinal and genital tracts, but the +pathologic response is not so varied as in the birds. When due allowance +is made for the kind of stomach and absorptive area, apparent +differences can be reconciled. For example, there is little confusion +experienced in comparing acute erosive gastritis or the follicular +enteritis of an omnivorous intestinal tract (man or pig), of a +sacculated stomach and absorptive tract (the marsupial), of a +carnivorous gut (cat) or a herbivorous compound stomach with its long +digestive and water-absorbing surface (cow or camel) and an expansive +muscular organ with a very extensive digestive area (seal). The type of +lesion seems the same, in that inflammation, pus, necrosis, granulation +tissue and cicatrices are comparable throughout the series. The size of +the hind-gut has been taken by Metchnikoff as an indicator of the +possibility of intoxication by degradation products of digestion. He +believes that the capacious colon of herbivora and the short small one +in carnivora explain the relatively greater life in the latter, because +here less stagnation and absorption can take place. A reference to the +expected lengths of life given before hardly substantiates this, and in +our later chapters there will be found no strong indication that animals +with large colons suffer with degenerative visceral changes more than +those with small ones; nay even the reverse may be found true. + +In regard to epizoötics the behavior of man and lower animals is similar +except perhaps that during an outbreak a smaller percentage of the +latter give evidence of individual immunity and whole groups are apt to +be carried off. Occasionally hygienic measures stay the ravages, at +other times nothing seems to avail. Fortunately it is sometimes possible +to sacrifice infective specimens and remove contagion. We have had few +serious outbreaks, unless one might call our former heavy infection with +tuberculosis in monkeys an epizoötic. The principal ones were an +unexplained water fowl disease which carried off one hundred and forty- +six birds, an imported epizoötic of quail disease which killed about the +same number, a few cases of blackhead among wild turkeys, and a small +group of cases of amœbic dysentery in monkeys and of thrush in passerine +birds, and a small number of tuberculous pneumonias in snakes. + +Pathology may be difficult upon an anatomical basis, but when we engage +to explain functional physiological defects we are surely embarked, with +a poor compass and weak rudder, upon an uncharted sea. One knows, of +course, that all animals require the same amount of food elements per +kilo of body weight, that man eliminates his nitrogen as urea and uric +acid, that monkeys do the same, that most other mammals destroy uric +acid and excrete allantoin, that birds and reptiles form uric acid but +chiefly urates, that there is an adaptation of alimentary tract and +diet, that herbivores have a high threshold for carbohydrates, that +there is a variable quantity of enzyme present in different organs and +in different animals, that vitamins, whatever they may be, are necessary +for the growth of young animals, that hormones exist whereby +correlations of parts are kept normal—but these things, rather than +being learned thoroughly from animals, have merely been substantiated by +comparisons with man. Constitutional diseases so-called, from which the +necessity to investigate much of this physiology originated, are little +known in the wild animal. Many cases of so-called gout have been +encountered and we have seen an instance of diabetes in a fox, but more +extensive experience is needed for definite practical comparisons. This +applies to thyroid and pituitary disorders and to the vague conditions +we have at times been obliged to call marasmus or inanition. + +Some attention has been given to the study of diets for the wild +specimens of our Garden, but no systematic observations have been made +or records kept upon purely physiological subjects. Reference will be +made at appropriate places to accepted comparative physiological facts, +but our statistics permit additions to such knowledge only in a limited +manner and in isolated instances. Doctor Corson-White has very ably +summarized the diet, alimentary tract and physiology of the zoological +groups with the pathology as found in our records. + +A word might be added here as to the destruction of animals by injury +from fighting and harassment by others in the cage. Fighting doubtless +causes death, especially when males are together, but it is our +experience that in cases of traumatic death search should always be made +to see if the resistance of the dead animal had not been reduced by some +disease. This is well illustrated in birds. Very frequently a specimen +will come to autopsy with its head feathers plucked out, or with a +billthrust in the wing or pelvic region. Such birds are not infrequently +suffering from malaria, or heavy intestinal parasitism or from organic +disease whereby the resistance and self-preservatory power has been +decreased. + +The foregoing survey of the approach to our subject reveals the +multiplicity of factors which affect the study of comparative pathology. +No one of them can be entirely omitted, no one is without some effect +upon the origin and expression of disease, and no one is fully +understood. Yet it is to be hoped that a study of our material, +accumulated under routine conditions and uninfluenced by any +experimental procedures, will demonstrate the natural response of +various zoological groups to morbific agencies. Perhaps reactively some +of the modifying conditions may thus be understood. It is also not +unreasonable to expect that alterations observed as natural responses in +a large number of specimens in nearly normal surroundings would serve as +more reliable guides to investigative speculation than would changes in +a few animals under artificial technical experimentation. We hope that +the few facts we have been able to record may afford someone a basis for +further biological studies. It is also to be hoped that something has +been learned which in the end will afford an explanation of the diseases +of man. Too great optimism in this direction should be guarded against +because the human being is indeed an animal _sui generis_ and, from the +standpoint of normal conditions of nature, a wild animal. + +The zoological classification found on pages 43–46 was compiled in 1903 +by Dr. A. E. Brown on the basis of the British System. With a few +exceptions the computations in the text are made on the basis of +zoological _orders_ since the number of specimens in families is often +too small and the complications of so many different figures would be +confusing. The tables will be found to correspond to the sequence of the +classification. Dr. Corson-White has, however, used for her analysis the +dietary groupings. A carnivore in her chapter implies strictly a meat- +eater, in the rest of the book one of the zoological group Carnivora. + +The Laboratory of Comparative Pathology at this Garden speaks for the +earnest desire on the part of the Directors to use the material to its +fullest extent, and I, acting for myself and my associates, wish to +record our appreciation of the facilities offered to us for study, and +for the broad-minded, scientific coöperation the Board has always +displayed. The President, Charles B. Penrose, M.D., Ph.D., LL.D., was +the active originator of the plan whereby this department was started, +and he has given to it continuously the support of his rich experience. +I wish to express for myself the deepest appreciation of his personal +interest in my studies, and assistance which has been constructive and +stimulating. Whether or not this present work prove useful to the extent +that is hoped, the results from the Laboratory are such as to make the +scientific world debtor to this gentleman. + +It is a duty, and a pleasant one, to record, though unfortunately in +memoriam, my association with Arthur Erwin Brown, A.M., Sc.D., Ph.D., +C.M.L.Z.S., for many years the Secretary of the Society and Executive +Officer of the Garden. Doctor Brown as teacher was ever ready to help in +the broad subject of biology, and I am proud to recall that he guided me +also as a friend. + +The first director of the Laboratory was Courtland Y. White, A.M., M.D., +who served from 1901 to 1906, retiring then to accept a position in the +City Laboratory. The foundation of the recording system is still in use +essentially unchanged from his plan, and is a credit to his foresight. +Our clerk and technician, Miss Harriet M. Phelps, has served the Garden +faithfully and well since 1906. The condition of the museum is very much +due to her interest and watchfulness. Thanks and appreciation for her +work are felt by every one, the author most of all. Dr. F. D. Weidman +has been our first assistant since 1911, and his work on parasitology +has been of the greatest value, practically and scientifically. It is to +be hoped that we shall be able to retain him indefinitely. Dr. E. P. +Corson-White has in recent years taken an assistant position with us, +armed for the work with a thorough knowledge of applied organic +chemistry and immunology, and has already obtained useful results. + + ZOOLOGICAL CLASSIFICATION + │ + + MAMMALIA + + PLACENTALIA + + PRIMATES + + _Simiadæ_ Anthropoid apes + + _Cercopithecidæ_ Old World monkeys (macaques, baboons). + + _Cebidæ_ New World monkeys (capuchins, howlers, + spiders). + + _Hapalidæ_ New World monkeys (marmosets). + + LEMURES + + _Lemuridæ_ Lemurs, Loris, Galagos. + + CARNIVORA + + _Felidæ_ Cats + + _Viverridæ_ Civets, Genets, Paradoxures, Ichneumons. + + _Hyænidæ_ Hyena. + + _Canidæ_ Dogs, Wolves, Foxes, Jackalls, Etc. + + _Mustelidæ_ Marten, Skunk, Weasel, Otter, Badger, Etc. + + _Procyonidæ_ Raccoon, Bassaris, Coati, Kinkajou. + + _Ursidæ_ Bear. + + _Otariidæ_ Eared Seal, Sea Lion.│These are grouped + │separately as suborder, + │PINNIPEDIA, illustrating + │water carnivores. + + _Phocidæ_ Common Seal, Walrus. │ „ + + INSECTIVORA + + _Tenrecidæ_ Tenrec. + + _Solenodontidæ_ Solenodon. + + _Talpidæ_ Moles, Shrews. + + _Erinaceidæ_ Hedgehog. + + CHIROPTERA + + _Pteropodidæ_ Fruit Bats, “flying foxes.” + + _Vespertilionidæ_ Common bats. + + _Emballonuridæ_ Snouty Bats, Free-tailed Bats. + + RODENTIA + + _Sciuridæ_ Squirrels, Spermophiles, Marmots. + + _Castoridæ_ Beaver. + + _Muridæ_ Rats, Mice. + + _Geomyidæ_ Pouched Rats, “Gophers.” + + _Dipodidæ_ Jumping Mice, Jerboas. + + _Heteromyidæ_ Kangaroo Rats. + + _Octodontidæ_ Capromys, Coypu. + + _Hystricidæ_ Porcupines. + + _Chinchillidæ_ Viscacha, Chinchilla. + + _Dasyproctidæ_ Agouti, Spotted Cavy. + + _Caviidæ_ Guinea-pig, Capybara. + + _Leporidæ_ Rabbits, Hare. + + PROBOSCIDEA Elephant. + + HYDRACOIDEA Cape Hyrax. + + UNGULATA + + PERISSODACTYLA (odd toed) + + _Rhinocerotidæ_ Rhinoceros. + + _Tapiridæ_ Tapir. + + _Equidæ_ Horse, Ass. + + ARTIODACTYLA (even toed) + + _Bovidæ_ Oxen, Antelopes, Sheep, Goats. + + _Cervidæ_ Deer, Moose, Elk. + + _Antilocapridæ_ Prong-horned Antelope. + + _Giraffidæ_ Giraffe. + + _Tragulidæ_ Chevrotains, Muis Deer. + + _Camelidæ_ Camels, Llama. + + _Hippopotamidæ_ Hippopotamus. + + _Suidæ_ Swine, Warthogs. + + _Tayassuidæ_ Peccaries. + + SIRENIA Sea-cow, Manatee, Durong. + + CETACEA Whales, Porpoises. + + EDENTATA + + _Bradypodidæ_ Sloths. + + _Dasypodidæ_ Armadillo. + + _Myrmecophagidæ_ Anteaters. + + + MARSUPIALIA + + MARSUPIALIA + + _Didelphyidæ_ Opossums. + + _Dasyuridæ_ Dasyures, Tasmanian “Devils.” + + _Peramelidæ_ Bandicoots. + + _Phascolomyidæ_ Wombat. + + _Phalangeridæ_ Phalangers. + + _Macropodidæ_ Kangaroo, Wallabies. + + + MONOTREMATA + + MONOTREMATA + + _Echidnidæ_ Echidna, Ornithorhynchus. + + + AVES + + PASSERES + + _Turdidæ_ Thrushes, Robins, Etc. + + _Sylviidæ_ Warblers, Kinglets. + + _Paridæ_ Titmouse. + + _Troglodytidæ_ Wrens, Mockingbirds, Catbird, Etc. + + _Pycnonotidæ_ Bulbul. + + _Crateropodidæ_ Babblers, Jay-thrushes. + + _Oriolidæ_ Oriole. + + _Motacillidæ_ Wagtails. + + _Dicruridæ_ Drongos. + + _Mniotiltidæ_ Chats, Warblers, “Woodwarblers,” Etc. + + _Cœrebidæ_ Sugarbirds. + + _Vireonidæ_ Vireos. + + _Laniidæ_ Shrikes. + + _Ampelidæ_ Waxwing. + + _Hirundinidæ_ Martins, Swallows. + + _Meliphagidæ_ Honeyeaters. + + _Tanagridæ_ Tanagers. + + _Ploceidæ_ Weavers, Whydah birds, Waxbills, Finches, Etc. + + _Fringillidæ_ Finches, Sparrows, Buntings, Grosbeaks, Etc. + + _Icteridæ_ Hangnests, Troupials, Grackles, “Blackbird,” + Etc. + + _Sturnidæ_ Starlings, Mynahs. + + _Corvidæ_ Crows, Jays, Magpies, Jackdaws. + + _Alaudidæ_ Larks. + + _Tyrannidæ_ Tyrans. + + _Cotingidæ_ Bellbird, Cock-of-the-rock, Etc. + + PICARIÆ + + _Upupæ_ Hoopæ. + + _Trochilidæ_ Hummingbirds. + + _Cypselidæ_ Swifts, “Chimney Swallow.” + + _Caprimulgidæ_ Night hawk, Whip-poor-will. + + _Coraciidæ_ Roller. + + HALCYONES + + _Alcedinidæ_ Kingfisher. + + _Momotidæ_ Motmots. + + BUCEROTES + + _Bucerotidæ_ Hornbill. + + TROGONES + + _Trogonidæ_ Trogons. + + SCANSORES + + _Picidæ_ Woodpeckers. + + _Rhamphastidæ_ Toucans. + + _Capitonidæ_ Barbets. + + COCCYGES + + _Cuculidæ_ Cuckoos. + + _Musophagidæ_ Touracous. + + PSITTACI + + _Loriidæ_ Lories, Lorikeets. + + _Cacatuidæ_ Cockatoos. + + _Psittacidæ_ Macaws, Conures, Amazons, Parrots, Parrakeets. + + STRIGES + + _Strigidæ_ Barn owl. + + _Bubonidæ_ All other owls. + + ACCIPITRES + + _Falconidæ_ Buzzards, Hawks, Falcons, Eagles, Etc. + + _Serpentaridæ_ Secretary Vulture. + + _Catharidæ_ Vultures. + + COLUMBÆ + + _Treronidæ_ Fruit pigeons. + + _Columbidæ_ All other pigeons and doves. + + PTEROCLETES + + _Pteroclidæ_ Sand grouse. + + GALLI + + _Tetraonidæ_ Grouse, Ptarmigans. + + _Phasianidæ_ Pheasants, Fowls, Turkeys, Quail, Etc. + + _Cracidæ_ Curassows, Guans, Etc. + + _Megapodidæ_ Brush turkey. + + HEMIPODII + + _Turnicidæ_ Hemipodes. + + FULICARIÆ + + _Rallidæ_ Rails, Porphyrios, Gallinules, Coots, Etc. + + ALECTORIDES + + _Aramidæ_ Courlan. + + _Eurypygidæ_ Sun bittern. + + _Gruidæ_ Cranes. + + _Cariamidæ_ Cariama “Crane.” + + _Psophiidæ_ Trumpeters. + + LIMICOLÆ + + _œdicnomidæ_ Thicknees. + + _Charadriidæ_ Plovers, Sandpipers, Curlews, Woodcocks, Etc. + + _Chionidæ_ Sheathbills. + + GAVIÆ + + _Lariidæ_ Gulls, Terns. + + _Stercorariidæ_ Jaeger Gull. + + PYGOPODES + + _Colymbidæ_ Loons, Grebs. + + _Alcidæ_ Auks, Murrs, Puffins. + + IMPENNES + + _Spheniscidæ_ Penguins. + + STEGANOPODES + + _Sulidæ_ Gannets. + + _Pelicanidæ_ Pelicans. + + _Phalacrocoracidæ_ Cormorants. + + _Anhingidæ_ Darter “Water turkeys.” + + TUBINARES + + _Procellariidæ_ Petrels, Fulmars. + + HERODIONES + + _Ardeidæ_ Herons, Bitterns, Egrets. + + _Ciconiidæ_ Storks, Ibises. + + _Plataleiidæ_ Spoonbills. + + ODONTOGLOSSÆ + + _Phœnicopteridæ_ Flamingoes. + + PALAMEDEÆ + + _Palamedeidæ_ Screamers. + + ANSERES + + _Anatidæ_ Swans, Geese, Ducks. + + STRUTHIONES + + _Apterygidæ_ Kiwis, Apteryx. + + _Casuariidæ_ Cassowaries. + + _Struthionidæ_ Ostriches. + + _Rheidæ_ Rheas. + + CRYPTURI + + _Tinamidæ_ Tinamous. + + _List of Animals subjected to + Autopsy giving the number of + each. These Figures are used to + obtain the percentages quoted + in the Tables and Text._ + + MAMMALIA + Primates 498 + Lemures 86 + Carnivora 481 + Pinnipedia 20 + Insectivora 6 + Chiroptera 5 + Rodentia 198 + Ungulata 365 + Proboscidea 3 + Hyracoidea 7 + Edentata 16 + Marsupialia 175 + Monotremata 0 1860 + ———— + + AVES + Passeres 1355 + Picariæ 87 + Striges 133 + Psittaci 689 + Accipitres 196 + Columbæ 157 + Pterocletes 0 + Galli 299 + Hemipodii 2 + Fulicariæ 35 + Alectorides 37 + Limicolæ 6 + Gaviæ 20 + Pygopodes 0 + Impennes 5 + Steganopodes 21 + Tubinares 0 + Herodiones 98 + Odontoglossæ 6 + Palamedes 5 + Anseres 317 + Struthiones 32 + Crypturi 5 3505 + ———— ———— + 5365 + + + + + SECTION II + DISEASES OF THE HEART + + +The heart is an organ whose duty, throughout the two classes considered +in this study, remains entirely identic, purely a physical one in +driving the blood through the corresponding vascular system. The physics +involved naturally differs between mammals and birds, but energy is +derived from the automatic power lodged in the cardiac musculature. +Whether this be neuromyogenic, as seems to be the case in all mammals, +or purely myogenic, as is probably the case for the birds in which +MacKenzie and Robertson[5] say there is no atrioventricular bundle, the +result is the same, since in both classes there is some continuity of +muscle fibres from auricle to ventricle. The gross anatomy varies little +if any more than the physiology, albeit there is proportionately greater +auricular capacity in the mammals than in the birds, and indeed there +are differences within the classes which cannot now be readily +explained; certain minor variations of valvular arrangement exist, such +as the absence of the membranous light tricuspid in Aves. + +When, however, one considers the cardiac power available for various +animals, the subject becomes one of greater breadth and complexity, for +no consistency obtains even within families, since the demand for +cardiac strength will vary more with habits than with zoological +relationships. Thus for example the domestic rabbit has a small heart +volume while the wild hare has a great one. Although, of course, the +size of an organ may not be an absolute measure of its efficiency (a +flea’s leg muscle has relatively greater power than a man’s), yet size +is the only physical gauge one has for estimating nature’s preparation +for expected demand. Perhaps this will be shown later when after +discussing the pathological anatomy of the heart in the wild mammals and +birds, we can study these changes in light of statistics upon the +relative size of the heart. + + +EXPRESSION OF CARDIAC DISEASE. + +The diseases of this organ are known only by their physical effects, +chiefly by causing physical or functional defects in other organs and to +a minor degree by purely physiological irregularities in the heart +itself (tachycardia, arrhythmia). All the latter and most of the former +are subjects discovered by observation during life and unfortunately +cannot be included in the study at hand. Both states are well known to +the veterinarian who diagnoses them with reasonable ease in animals that +can be handled; I saw one case of arrhythmia in a monkey for which no +adequate gross morbid explanation was found postmortem. Some of these +functional abnormalities are certainly caused by myocardial disease and +cardiac failure has occurred among many orders. An interesting +observation was made by Plimmer[6] on several large birds (ostriches, +storks, cassowaries) which apparently died from this condition; at +autopsy he found myocardial degeneration, or epicardial edema or only a +flabby heart. Lack of exercise was held responsible by this observer. +Such cardiac deaths have probably been encountered at this Garden but we +have accounted them to shock, or gastrointestinal disease; this matter +will be discussed on a later page. + + +CORONARY ARTERY DISEASE. + +If a degenerative sclerosis of coronary vessels be the cause of angina +pectoris then perhaps paroxysms of this kind occur, for we have seen +such anatomical changes in the heart of three widely separated varieties +of animals, a Nylghaie, a Hamadryas Baboon, a Macaque, and a Brown +Pelican. The history of these animals does not register anything +resembling the clinical picture of angina pectoris in man, and they did +not come to their death from the arterial changes in the heart alone +since sufficient other pathology also existed. + + +KINDS OF PATHOLOGICAL CHANGE. + +As an introduction to the strict pathology of the heart it might be well +to outline the headings of the scheme upon which it seems desirable to +study the subject. It is hardly profitable to take up seriatim the +ordinary general pathological processes as discussed in systems of +pathology for it is our purpose to show the distribution of basic +aberrations from the normal in terms of zoological position. To this end +one must consider the response of the heart (a) to damaging influences +and (b) to a demand for increased work. In the first group come +degenerations and inflammations, upon which may succeed an incompetency +in the form of dilatation. The response of the normal heart to any +physical demand greater than customary has usually been thought to lie +in the direction of hypertrophy, but on occasion it has seemed to be in +the form of dilatation, especially if the strain has been sudden and +severe. Starling thinks that the primary and normal reaction of the +heart to physical strain is always dilatation. The idea of hypertrophy +must not be confused with an understanding of the relatively large +hearts in animals whose habits demand great cardiac power, for then it +is their norm and might be called “physiological cardiac hyperplasia.” I +shall use the terms “increased muscle bulk” and “increased chamber +space” as preferable to hypertrophy and dilatation; this also focuses +attention upon the two features of an enlarged heart. + + +DEGENERATIONS AND INFLAMMATIONS. + +Degenerative changes in disease are recorded in our system as amyloid, +hyaline, fatty metamorphosis, granular and cloudy degeneration. While +there is perhaps between some of these conditions and true myocarditis a +matter only of degree, the records have been analyzed as filed and +perhaps some lessons can be learned from the responses of the various +zoological orders. In the accompanying Table 1 will be found the +distribution of degenerative and inflammatory lesions through the +zoological orders. The percentages speak for themselves but deserve as +well some consideration from the standpoint of normal heart value; this +will be taken up later after the other lesions have been discussed. + + TABLE 1. + _Table Showing Incidence, in the Orders, of Degenerations and Inflammations, + or in Other Words the Response to Infectious and Toxic Agencies._ + ════════════╤════════╤═══════╤════════╤════════╤════════╤════════╤══════════ + Heart of │Degener-│Myocar-│Pericar-│Endocar-│Total[7]│ Cases │Percentage + │ ations │ ditis │ ditis │ ditis │ │followed│in deaths + │ │ │ │ │ │ by │per order + │ │ │ │ │ │dilation│ + ────────────┼────────┼───────┼────────┼────────┼────────┼────────┼────────── + Primates │ 8│ 12│ 18│ │ 38│ │ 7.6 + Lemures │ 1│ │ │ │ 1│ │ 1.2 + Carnivora │ 19│ 14│ 11│ 10│ 54│ 5│ 11. + Pinnipedia │ 2│ 1│ │ │ 3│ │ _15._ + Rodentia │ 5│ 7│ 6│ │ 16│ │ 8. + Insectivora │ │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ │ + Proboscidea │ │ 1│ │ │ 1│ │ _33._ + Hyracoidea │ │ │ │ │ │ │ + Ungulata │ 3│ 9│ 8│ 2│ 20│ │ 5.4 + Edentata │ 2│ 3│ 1│ │ 7│ │ _44._ + Marsupialia │ 12│ 5│ 6│ 12│ 33│ │ 19. + Monotremata │ │ │ │ │ │ │ + │ │ │ │ │ │ │ + Passeres │ 4│ 4│ 9│ 2│ 19│ │ 1.4 + Picariæ │ 2│ 1│ 3│ │ │ 6│ 6.7 + Striges │ │ │ 1│ │ 1│ │ .8 + Psittaci │ 10│ 7│ 7│ │ 24│ │ 3.4 + Accipitres │ 2│ 19│ 8│ 7│ 36│ 1│ 18.3 + Columbæ │ 2│ 1│ │ │ 3│ │ 2. + Pterocletes │ │ │ │ │ │ │ + Galli │ 4│ 10│ 13│ 1│ 28│ 1│ 9.3 + Hemipodii │ │ │ │ │ │ │ + Fulicariæ │ 2│ │ 1│ │ 3│ │ 8.6 + Alectorides │ │ 1│ 1│ │ 2│ │ 5.4 + Limicolæ │ │ │ │ │ │ │ + Gaviæ │ 1│ 1│ │ │ 2│ │ 10. + Pygopodes │ │ │ │ │ │ │ + Impennes │ │ 1│ │ │ 1│ │ 16. + Steganopodes│ │ 1│ 2│ 1│ 4│ │ _20._ + Tubinares │ │ │ │ │ │ │ + Herodiones │ 1│ │ 1│ 2│ 4│ │ 4.1 + Odontoglossæ│ │ │ │ │ │ │ + Palamedes │ │ │ │ │ │ │ + Anseres │ 16│ 17│ 11│ 6│ 50│ 1│ 15.7 + Struthiones │ 2│ 3│ 5│ 1│ 11│ │ _34._ + Crypturi │ │ │ │ │ │ │ + ────────────┼────────┼───────┼────────┼────────┼────────┼────────┼────────── + Total │ 98│ 118│ 112│ 44│ 367│ 8│ + ════════════╧════════╧═══════╧════════╧════════╧════════╧════════╧══════════ + +In this and subsequent tables, figures in italics are for small groups +of animals coming to autopsy, usually less than one hundred, and from +which percentages may be misleading. The number of autopsies upon such +groups may be found by consulting the list given on page 47. + + +ENDOCARDITIS, MYOCARDITIS. + +Romberg said in his classical work on the heart that there is always +some form of myocardial disease with endocarditis. The 44 cases of +valvular disease detected at this Garden are 15 of chronic nature, 29 of +acute or subacute character. In the former, the chronic, 9 showed some +grade of muscular involvement, while 21 of the 29 acute cases of +valvular inflammation were accompanied by myocardial damage; the +percentages are 60 for chronic and 72 for acute, a relation that would +be expected if one credit the theory that many valvular inflammations +start at the root of the valves, but, at all events, they indicate that +after the acute stages have passed the myocardial damage may be +repaired. + +[Illustration: + + FIG. 1.—VEGETATIVE AND ULCERATIVE ENDOCARDITIS OF AORTIC VALVE. + OSTRICH (STRUTHIO AUSTRALIS). ORGANISMS ISOLATED CORRESPONDED + CLOSELY TO BAC. AFANASIEFFICHESTER. +] + +The large number of cases of endocarditis among the Carnivora, +Accipitres, Anseres and Marsupialia is noteworthy and can hardly be +explained by other argument than a special vulnerability of this organ +in these groups. However, the unusual number of cases in our only native +marsupial, the opossum, seems worthy of a special note since ten of the +twelve instances in the order Marsupialia affected this particular +animal. When seen these ten cases were acute in five instances, subacute +in three and chronic in two. The Streptococcus pyogenes was isolated in +three of the five acute cases; bacteriology of the others was negative +or not done. All of the acute and one of the subacute cases were +combined with some evidence of general septicemia. The type of lesion +was in no way peculiar, unless the facts that all were vegetative when +acute and markedly deforming when chronic, be noteworthy. In two chronic +aortic cases the valvular orifice was almost closed, yet the left +ventricle could not be considered as greatly hypertrophied and no +dilatation existed. In one acute aortic and mitral case, general +dilatation existed. The mitral was involved nine times, three times +alone, four times with the aortic, once each with the tricuspid and +pulmonary. Once the vegetations were limited to the mural endocardium. +Nine of these animals came from one enclosure over a period of two and a +half years, during which time other opossums died from similar bacterial +infections (pneumonia) despite repeated cleansing of the place. No +unusual number of cases of this or similar kinds occurred elsewhere in +the Garden at this time, but it would seem that we had in this cage a +continued bacterial infection. + + +UNUSUAL PERICARDIAL CHANGES. + +The appearance of a stiff gelatinous exudate in the pericardial sac has +attracted our attention on ten occasions (8 birds, 2 mammals). The +substance seems quite homogeneous and almost entirely acellular. One +specimen became solid on heating and another became turbid when put into +Kaiserling’s fluid. In two cases bacterial cultures were made; nothing +grew. It has not been associated with tuberculosis or tumors nor has any +one pathological lesion more than another appeared to accompany it. + +A peculiar lesion occasionally seen in birds is “uratic pericarditis” a +process not infectious at all, according to Plimmer, but due to renal +disease. It has been seen here in association with retention of urates +in the kidney, with gout of birds, and apparently quite independent of +any renal or constitutional disease. Both layers of the sac are pearl +gray or irregularly salted with a whitish granular material so that they +are entirely opaque; occasionally the distribution is spotty. The +deposit does not seem to penetrate the myocardium. There is at times +some involvement of other serosæ, but this is usually much less marked +than around the heart. It does not seem that this of itself should be +fatal, but it has been the most decided pathological factor in some of +the autopsies. + +Aside from pericarditic exudates, twenty-one instances of pericardial +effusion have been encountered. They offer little that is peculiar in +etiology, chemistry or cytology, but as there has been some question of +the position of the accumulation of the fluid in human beings, it might +be well to note the position in our material. It is recognized in +veterinary medicine that the cardiac dullness is increased especially to +the right, and that most of the fluid will be on that side and +posteriorly. At our autopsies on mammals this is the position usually +occupied by the fluid, the apex being covered by pericardium, unless the +quantity be great enough to make the sac taut, and this position is +retained whether the animal be laid upon the one side or the other; nor +does the fluid all leave the base of the heart when the body is placed +prone. The crown of the heart is nearly always well covered. In birds, +on the other hand, the fluid occupies the apical part of the sac, +probably due to the fact that this membrane is attached by its tip to +the transverse air sac wall which takes the place of a diaphragm, so +that the tip of the heart is always free and the pericardium of the base +fairly closely applied to the epicardium. This holds good even for the +birds whose cardiac apex is normally attached to the pericardium by a +fibrous band. + + +HYPERTROPHY AND DILATATION. + +The response of the heart to a continued demand upon its working +capacity will, as already indicated, lead to increased muscle bulk or to +larger chamber size. Whether hypertrophy be purely the building of a +bigger engine or be accompanied by, or due to, muscular disease as had +been suggested by certain authors, was a question to which an answer was +hoped, but it would seem that the solution is no nearer than can be +obtained in human pathology. Fifteen of the 34 cases showed some degree +of myocardial damage. Some of the other cases may have been instances of +so-called essential hypertrophy, enlargements due to hard work or to low +grade hidden infection. Aubertin[8] ascribes such cardiac muscle +increase to overwork under the stimulus of intoxication from intestinal +sources or from irregular constitutional functions. For information +concerning this and pathological enlargements one may consult the Table +(2) of Hypertrophies and Dilatations; in advance the method of charting +must be known. Since it is usually impossible to decide what may be the +single important factor in the cardiac disease, all of the accredited +factors have been listed with the hope that the resulting figures would +be significant. Thus an animal may have recorded pericarditis, nephritis +and arteriosclerosis—who shall say which was primary or most potent in +the cardiac change. + +Essential hypertrophy is limited to those cases for which there was no +concomitant pathology that might have been responsible for the +overgrowth. There was one in a carnivore (fox) and one in a raptatory +bird (buzzard). Idiopathic dilatations on the other hand are much more +common, but they still bear a relation to the apparent vulnerability of +the heart. Their distribution is as follows: Primates 1, Carnivora 1, +Pinnipedia 1, Ungulata 1, Marsupialia 4, Anseres 1. These may be cases +such as Plimmer described, of cardiac failure, indicated by dilatation, +the result of inactivity. Besides these special instances and the ones +accounted for in the list, there were three acute dilatations apparently +due to shock, two ungulates and one marsupial, probably incidental to +fright when being caught by the keepers. + +The association of secondary dilatation with hypertrophy is only evident +in three instances. One case and perhaps the most interesting, is that +in which the principal antecedent pathology was thyroid hyperplasia and +nephritis; the dilatation was perhaps agonal or shortly before the last +struggles. It would seem that all of the dilatations occurred shortly +before death because long standing passive congestions and dropsies of +cardiac origin are exceedingly rare; only one certain case is recorded +(carnivore). + +Let us now examine the Table (2) according to orders and then as to +causation. The Primates’ heart is apparently well able to increase in +size in response to increased work, a demand most often made by +pulmonary, pleural and pericardial diseases. Two of these cases occurred +in animals suffering with pulmonary tuberculosis sufficiently extensive +to impede cardiac action while in another case the tuberculous lesion +was mild but a pericarditis existed. When the right hand columns are +inspected it would seem that on occasion dilatation may occur; one of +the tuberculous pulmonary cases had a dilated heart. The slothful lemurs +apparently have no call upon their cardiac mechanism. + +Carnivora with their large organ, which, it would seem, should be +prepared for excess work either simply as a reserve or as an inherent +ability to grow, present in about equal numbers, hypertrophy and +dilatation. It is admitted that there are within this order, genera of +differing habits, but analysis of the canidæ, felidæ and ursidæ for +examples, in the first place, offer too few specimens for conclusions +and, secondly, have upon trial actually shown nothing definite, so that +we are forced to use the larger group, the order. It is interesting to +note that long continued infection is in this order the most potent +factor in enlargements of the heart. Four of the ten cases show +myocarditis. Nephritis does not seem very important in relation to +cardiac muscular increase, but occurs with great frequency in +association with dilatation. Three of the cases of hypertrophy were +associated with thyroid disease and two of these showed dilatation as +well. The general causes of chamber distention are more diverse, and we +see associations that do not appear with hypertrophy, namely +arteriosclerosis and diseases of the chest. + + TABLE 2. + + _Table Showing Incidence per Order of Hypertrophy and Dilatation, and + the Principal Associated Lesions Believed to Have Etiological + Importance._ + + ═════════════╤═════════════════════════════════════════════════ + Heart of │ Hypertrophy + ─────────────┼─────┬────────┬────────┬────────────────┬──────── + „ │Total│Percent.│Valvular│Arteriosclerosis│Diseases + │ │ for │Disease │ │ of + │ │ Order │ │ │Thoracic + │ │ │ │ │ Serosæ + ─────────────┼─────┼────────┼────────┼────────────────┼──────── + Primates │ 4│ .8│ │ 1│ 3 + Lemures │ │ │ │ │ + Carnivora │ 10│ 2.1│ 1│ │ + Pinnipedia │ │ │ │ │ + Rodentia │ │ │ │ │ + Insectivora │ │ │ │ │ + Chiroptera │ │ │ │ │ + Proboscidea │ │ │ │ │ + Hyracoidea │ │ │ │ │ + Ungulata │ 4│ 1.2│ │ │ 1 + Edentata │ │ │ │ │ + Marsupialia │ 1│ .6│ 1│ │ + Monotremata │ │ │ │ │ + Total Mammals│ 19│ │ 2│ 1│ 4 + │ │ │ │ │ + Passeres │ │ │ │ │ + Picariæ │ 1│ 1.1│ │ 1│ + Striges │ │ │ │ │ + Psittaci │ │ │ │ │ + Accipitres │ 8│ 4.1│ │ 4│ 1 + Columbæ │ │ │ │ │ + Pterocletes │ │ │ │ │ + Galli │ 2│ .7│ │ 1│ + Hemipodii │ │ │ │ │ + Fulicariæ │ │ │ │ │ + Limicolæ │ │ │ │ │ + Gaviæ │ │ │ │ │ + Pygopodes │ │ │ │ │ + Impennes │ │ │ │ │ + Steganopodes │ │ │ │ │ + Tubinares │ │ │ │ │ + Herodiones │ │ │ │ │ + Odonotoglossæ│ │ │ │ │ + Palamedes │ │ │ │ │ + Anseres │ 2│ .6│ │ │ + Struthiones │ 2│ _6.2_│ │ │ 2 + Crypturi │ │ │ │ │ + Total Birds │ 15│ │ 0│ 6│ 3 + ─────────────┼─────┼────────┼────────┼────────────────┼──────── + Total │ 34│ │ 2│ 7│ 7 + ─────────────┴─────┴────────┴────────┴────────────────┴──────── + + ═════════════╤════════════════════════════════════════════════════════ + Heart of │ Hypertrophy + ─────────────┼─────────┬───────┬─────────┬─────────┬───────┬────────── + „ │Pulmonary│ Renal │ Chronic │ Acute │Thyroid│Myocardial + │ Disease │Disease│Infection│Infection│Disease│ Disease + │ │ │ │ │ │ + │ │ │ │ │ │ + ─────────────┼─────────┼───────┼─────────┼─────────┼───────┼────────── + Primates │ 3│ 1│ 1│ 1│ │ + Lemures │ │ │ │ │ │ + Carnivora │ │ 2│ 6│ 1│ 3│ 4 + Pinnipedia │ │ │ │ │ │ + Rodentia │ │ │ │ │ │ + Insectivora │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ + Proboscidea │ │ │ │ │ │ + Hyracoidea │ │ │ │ │ │ + Ungulata │ │ 4│ │ │ │ 2 + Edentata │ │ │ │ │ │ + Marsupialia │ │ 1│ │ │ │ 1 + Monotremata │ │ │ │ │ │ + Total Mammals│ 3│ 8│ 7│ 2│ 3│ 7 + │ │ │ │ │ │ + Passeres │ │ │ │ │ │ + Picariæ │ │ 1│ │ │ │ + Striges │ │ │ │ │ │ + Psittaci │ │ │ │ │ │ + Accipitres │ │ 3│ 1│ 1│ │ 5 + Columbæ │ │ │ │ │ │ + Pterocletes │ │ │ │ │ │ + Galli │ │ 1│ │ 1│ │ 1 + Hemipodii │ │ │ │ │ │ + Fulicariæ │ │ │ │ │ │ + Limicolæ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ │ + Pygopodes │ │ │ │ │ │ + Impennes │ │ │ │ │ │ + Steganopodes │ │ │ │ │ │ + Tubinares │ │ │ │ │ │ + Herodiones │ │ │ │ │ │ + Odonotoglossæ│ │ │ │ │ │ + Palamedes │ │ │ │ │ │ + Anseres │ │ │ 1│ 1│ │ 1 + Struthiones │ │ │ 1│ 1│ │ 1 + Crypturi │ │ │ │ │ │ + Total Birds │ 0│ 5│ 3│ 4│ 0│ 8 + ─────────────┼─────────┼───────┼─────────┼─────────┼───────┼────────── + Total │ 3│ 13│ 10│ 6│ 3│ 15 + ─────────────┴─────────┴───────┴─────────┴─────────┴───────┴────────── + + ═════════════╤═════╤═══════════════════════════════════════════ + Heart of │ │ Dilatation + ─────────────┼─────┼────────┬────────┬────────────────┬──────── + „ │Total│Percent.│Valvular│Arteriosclerosis│Diseases + │ │ for │Disease │ │ of + │ │ Order │ │ │Thoracic + │ │ │ │ │ Serosæ + ─────────────┼─────┼────────┼────────┼────────────────┼──────── + Primates │ 4│ .8│ │ 1│ + Lemures │ │ │ │ │ + Carnivora │ 11│ 2.2│ │ 1│ 2 + Pinnipedia │ │ │ │ │ + Rodentia │ 8│ 4.2│ │ │ + Insectivora │ │ │ │ │ + Chiroptera │ │ │ │ │ + Proboscidea │ │ │ │ │ + Hyracoidea │ │ │ │ │ + Ungulata │ 11│ 3.│ │ │ 4 + Edentata │ 2│ _12.5_│ │ │ + Marsupialia │ 8│ 4.5│ │ │ + Monotremata │ │ │ │ │ + Total Mammals│ 44│ │ 0│ 2│ 7 + │ │ │ │ │ + Passeres │ 1│ │ │ │ + Picariæ │ │ │ │ │ + Striges │ │ │ │ │ + Psittaci │ 1│ .1│ │ │ + Accipitres │ 1│ .5│ │ │ 1 + Columbæ │ │ │ │ │ + Pterocletes │ │ │ │ │ + Galli │ 2│ .7│ │ 1│ 1 + Hemipodii │ │ │ │ │ + Fulicariæ │ │ │ │ │ + Limicolæ │ │ │ │ │ + Gaviæ │ │ │ │ │ + Pygopodes │ │ │ │ │ + Impennes │ │ │ │ │ + Steganopodes │ │ │ │ │ + Tubinares │ │ │ │ │ + Herodiones │ │ │ │ │ + Odonotoglossæ│ │ │ │ │ + Palamedes │ │ │ │ │ + Anseres │ 5│ 1.5│ │ │ 1 + Struthiones │ │ │ │ │ + Crypturi │ │ │ │ │ + Total Birds │ 10│ │ 0│ 1│ 3 + ─────────────┼─────┼────────┼────────┼────────────────┼──────── + Total │ 54│ │ 0│ 3│ 10 + ─────────────┴─────┴────────┴────────┴────────────────┴──────── + + ═════════════╤════════════════════════════════════════════════════════ + Heart of │ Dilatation + ─────────────┼─────────┬───────┬─────────┬─────────┬───────┬────────── + „ │Pulmonary│ Renal │ Chronic │ Acute │Thyroid│Myocardial + │ Disease │Disease│Infection│Infection│Disease│ Disease + │ │ │ │ │ │ + │ │ │ │ │ │ + ─────────────┼─────────┼───────┼─────────┼─────────┼───────┼────────── + Primates │ 1│ │ │ 1│ │ 1 + Lemures │ │ │ │ │ │ + Carnivora │ 2│ 4│ 1│ 2│ 3│ 2 + Pinnipedia │ │ │ │ │ │ + Rodentia │ 3│ 2│ 2│ 4│ │ + Insectivora │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ + Proboscidea │ │ │ │ │ │ + Hyracoidea │ │ │ │ │ │ + Ungulata │ 1│ 2│ 2│ 2│ │ 1 + Edentata │ 1│ │ 1│ │ │ 1 + Marsupialia │ 1│ 3│ 2│ 2│ │ 1 + Monotremata │ │ │ │ │ │ + Total Mammals│ 8│ 12│ 7│ 11│ 3│ 10 + │ │ │ │ │ │ + Passeres │ │ │ │ 1│ │ + Picariæ │ │ │ │ │ │ + Striges │ │ │ │ │ │ + Psittaci │ 1│ │ │ │ │ + Accipitres │ │ │ │ 1│ │ 1 + Columbæ │ │ │ │ │ │ + Pterocletes │ │ │ │ │ │ + Galli │ │ │ │ 1│ │ 1 + Hemipodii │ │ │ │ │ │ + Fulicariæ │ │ │ │ │ │ + Limicolæ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ │ + Pygopodes │ │ │ │ │ │ + Impennes │ │ │ │ │ │ + Steganopodes │ │ │ │ │ │ + Tubinares │ │ │ │ │ │ + Herodiones │ │ │ │ │ │ + Odonotoglossæ│ │ │ │ │ │ + Palamedes │ │ │ │ │ │ + Anseres │ │ 2│ 1│ 2│ │ 1 + Struthiones │ │ │ │ │ │ + Crypturi │ │ │ │ │ │ + Total Birds │ 1│ 2│ 1│ 5│ 0│ 3 + ─────────────┼─────────┼───────┼─────────┼─────────┼───────┼────────── + Total │ 9│ 14│ 8│ 16│ 3│ 13 + ─────────────┴─────────┴───────┴─────────┴─────────┴───────┴────────── + For meaning of italics see foot note Table 1. + +The rodents seem to have no power to increase muscle bulk, but a +sufficient number of cases of dilatation occur to make one conclude that +this is their method of response to unusual strain. Pulmonary disease, +mostly of infectious nature, and myocardial degenerations are the +principal causes. + +The next order to show cardiac enlargement is the Ungulata where +nephritis is the most frequent association with hypertrophy and disease +of the pleura and pericardium with dilatation, or the reverse of the +factor value in the Carnivora. These animals, fairly well prepared for +flight, with moderately large hearts, seem more often to show dilatation +than hypertrophy. + +Two Edentata (armadillo) showed dilatation but no hypertrophy. + +Marsupials behave somewhat like rodents in that the heart does not seem +to increase muscle bulk, but our records do not explain this clearly. As +already mentioned four cases had no sufficient internal reason for +dilatation, but as one was probably the result of shock three only +remain to be accounted for. Nephritis seemed to exist in all three, but +two of them had kangaroo mycosis of the jaw and a general chronic +infection. + +If now our attention be given to the Aves we find the highly specialized +Passeres and Striges not represented and their closely related well- +organized orders Picariæ and Psittaci with only an isolated single case. +This is the more interesting since the last order suffers reasonably +often with arteriosclerosis. Accipitres, the birds of pugnacious habit +and carnivorous diet, seem well able to increase their muscle upon +demand, but do not often suffer dilatation. Vascular and renal diseases +stand out most prominently in the etiology, and one-half of them show +myocardial change. The Galli, which includes both ground and flying +birds, are represented but fail to exhibit any unusual accompanying +disease. Anserine birds apparently have a low power to increase the size +of the heart, but most often allow it to dilate. Struthiones, large +stalking and rapidly travelling birds, apparently have a good margin of +safety in their cardiac mechanism. + + +SUMMARY OF LESIONS ASSOCIATED WITH HYPERTROPHY AND DILATATION. + +Analysis of the associated pathology will reveal that among the mammals, +renal disease, chronic infections and diseases of the thoracic serosa +are most often responsible for hypertrophy, and that something over one- +third of the hearts showed myocardial damage. Among the Aves +arteriosclerosis and renal disease are most important in enlarging the +heart; half of the cases had myocarditis. In so far as dilatation in +mammals is concerned, renal disease and acute infections are decidedly +more important than other influences, even than the next in order— +chronic infections and pulmonary diseases; only one-fifth of the cases +had myocardial disease. Acute infectious disease is the most potent +cause of dilatation in birds; only two of the eight cases had +degeneration of the heart muscle. + + +COMPARISON OF MAMMALIA AND AVES. + +If a comparison of the incidence of increased muscle bulk in the two +classes be made[9] it will be found to occur two and one-half times more +often in mammals, while dilatation occurs nearly ten times more often +among the mammals than among the birds. Hypertrophy is accompanied by +myocardial change in 44 per cent. of the cases, whereas muscular +degeneration was only seen in 24 per cent. of the dilatations; this +change is conspicuously lacking in the Primates, Ungulates and +Marsupials. The usual teaching has been that dilatation, which means +enlargement of chambers and thinning of walls or at least no thickening +thereof, implied an inability on the part of the heart to keep up with +increased demand—a decompensation. If Starling be correct that +dilatation is not a degeneration of pump value but merely one of +adaptations to increased demand, then this method is more characteristic +of mammals than of birds. There is, however, the reserve power to +increase the muscle bulk inherent in the mammalian, not possessed or +needed by the avian heart. The large-hearted class Aves certainly dilate +their blood pump less frequently than mammals and indeed have less +cardiac disease. + +An analysis of the incidence of hypertrophy _versus_ dilatation shows +that hypertrophying power resides in the Primates, Accipitres and +Struthiones, their hearts relatively seldom dilatating. Lack of such +power and consequent dilatation resides in Rodentia, Ungulata, +Marsupialia and Anseres. Hypertrophying power lies therefore chiefly in +the heart of average size for its class, dilatation occurring in the +small heart. (See page 63.) + + +AVIAN HYPERTROPHY. + +There is little to be learned from the nature and anatomy of the +hypertrophies and dilatations except perhaps their character among the +birds, in which the physics of the circulation is somewhat peculiar. In +this class both the hypertrophy and distention are predominatingly left- +sided, a state probably explained by the pressure against which the pump +must work in flight because then the lungs and the viscera are somewhat +compressed by the pressure of an excess of air in the pneumatic sacs. At +all events while concentric hypertrophy was mentioned once, it is +difficult to estimate the degree of increase in the right chambers +because they are not uncommonly well filled when diastole occurs at +death. Grober[10] asserts that the normally large heart (or what I have +called “physiological hyperplasia”) shows a “hypertrophy” of the right +ventricle because of the extra work entailed in flying. This is +certainly not the case in the material we have seen under pathological +conditions. Right sided increase might be expected if pulmonary or +serous membrane affections were prominent, but left-sided increase, +following arteriosclerosis and nephritis is the actual finding. The best +examples of concentric hypertrophy are in the dogs with thyroid disease +and the best examples of concentric dilatation in ungulates suffering +shock. + + +SUMMARY. + +The foregoing pathological data can now be summarized by grouping the +facts under the headings of absolute and relative vulnerability of the +heart. By the former is meant the actual number and quality of lesions +in the various orders, but here at once one comes upon the irregularity +of examples of zoological and pathological character, and if one trust +entirely to the percentages, fallacious conclusions might be reached. +Basing judgment upon the incidence of pathological lesions in mammals +and birds, it is evident that the former has greater vulnerability, as +13 is to 6.2. This is noteworthy as we shall learn that the bird has a +larger and apparently better prepared heart than the mammal. Attempts to +discover the order or kind of animal having the greatest or lowest +vulnerability are difficult for the reason given above. Thus, for +instance, Pinnipedia, Proboscidea, Edentata, Gaviæ, Impennes, +Steganopodes, and Struthiones present the highest percentages of cardiac +lesions, but the total specimens examined are so few that these figures +may well be misleading. (See Tables 1 and 2.) If, however, figures mean +anything in such small groups, these are the animals which have the +greatest cardiac vulnerability. They have little in common in regard to +zoological relationships and habits; four of the seven orders are rather +slothful and three are active. It is much better to limit our +observations to those orders from which sufficient examples have been +subjected to autopsy and upon which we have some standards for +comparison in the heart-body weight ratio. It so happens that in the +above seven orders I was unable to obtain any reliable figures of heart +weight. Table 3 is a combination of data from Tables 1 and 2 for the +principal orders from which we have enough material (at least one +hundred autopsies) and for which it is possible to obtain as comparative +standards figures indicating the weight of the normal heart in kilograms +of body weight; Table 4 gives these ratios for normal hearts. The +information about the weights was obtained from some of our own figures +and the references given in the footnote.[11] There are no extensive +data upon weights and measures in exact terms, such as body weight, so +that we are limited to the numbers quoted in parentheses besides the +orders in the table. The ratios might be modified slightly by a greater +number of examples, but they show certain things by comparison of the +classes; in a rough manner the heart ratios correspond to the pathology. + + TABLE 3. + _Table Containing a Condensation of the Two Foregoing Tables and + Showing Figures for Degenerations, Hypertrophy and Dilatations for + Orders Having the Largest Number of Autopsies._ + ═════════════════╤═════════════════╤═════════════════╤═════════════════ + │ Degenerations, │ Hypertrophy │ Dilatation + │ &c. │ │ + ─────────────────┼─────────────────┼─────────────────┼───────────────── + Primates │ 7.6│ .8│ .8 + Carnivora │ 11.│ 2.1│ 2.2 + Rodentia │ 8.│ 0.│ 4.2 + Ungulata │ 5.4│ 1.2│ 3. + Marsupialia │ 19.│ .6│ 5. + │ │ │ + Passeres │ 1.4│ 0.│ 0. + Picariæ │ _6.7_│ _1.1_│ 0. + Striges │ .8│ 0.│ 0. + Psittaci │ 3.4│ 0.│ .1 + Accipitres │ 18.3│ 4.3│ .5 + Columbæ │ 2.│ 0.│ 0. + Galli │ 9.3│ .7│ .7 + Herodiones │ 4.1│ 0.│ 0. + Anseres │ 15.7│ .6│ 1.5 + ─────────────────┴─────────────────┴─────────────────┴───────────────── + + TABLE 4. + _Table Showing Weight of Normal Heart in + Relation to Body Weight. Number of Specimens + used to Determine Weight Quoted in Parenthesis._ + ════════════════╤═══════════════════════════════ + Average Heart of│Grams per Kilogram of Body.[12] + ────────────────┼─────────────────────────────── + Man ( 4)│ 5.67 + Primates ( 4)│ 6.56 + Carnivora ( 6)│ 6.78 + Rodentia ( 5)│ 5. + Ungulata (10)│ 5.8 + Marsupialia ( 3)│ 5.1 + │ Average 5.82 + Passeres (43)│ 19.8 + Picariæ ( 9)│ 21.3 + Striges ( 4)│ 7.33 + Psittaci ( 6)│ 8.89 + Accipitres ( 7)│ 12.32 + Columbæ ( 4)│ 14.47 + Galli (16)│ 11.08 + Fulicariæ ( 3)│ 23.82 + Limicolæ ( 2)│ 8.78 + Anseres (14)│ 11.8 + Struthiones ( 1)│ 12.7 + │ Average 13.84 + ────────────────┴─────────────────────────────── + For meaning of italics see foot note Table 1. + +However, there are many reasons why great caution should be used in +evaluating the relative size of the heart. Welcher showed in his work +that the proportion is greater in small and young animals than in large +and adult ones. All the authors quoted agree that in birds and to less +degree but still clearly in mammals, there is a direct relationship +between the bodily activity of an animal and its cardiac bulk. This is +fairly well shown in the list of avian heart ratios, but not so clearly +in the mammals. What shall be considered the most active mammals—the +monkey, perhaps, with his tendency to be occupied constantly, yet we +find the greatest heart bulk among the Carnivora, animals prepared for +travel and struggle, and the smallest among the Rodentia, quiet and +timid animals. The avian order showing the greatest cardiac ratio, the +Fulicariæ, shore birds, is made up of some quiet hiding varieties, and +of some capable of very prolonged flight; the most constantly active +fliers (Passeres) also have a high cardiac weight proportion. The +inactive owls have the smallest heart bulk. + +The contrast between the average heart-to-body weights of mammals and +birds is striking, the latter having two and one-half times as much as +the former, 5.8 _vs._ 13.8. Since this is the most prominent and best +supported statement in the table of weights, it may be used to compare +with the incidence of the pathology as seen in the two classes. + +Degenerations and inflammations occur in mammals and birds as 9.5 is to +5.5.[13] + +Hypertrophies occur in mammals and birds as 10.3 is to 4.3.[13] + +Dilatations occur in mammals and birds as 2.4 is to .28.[13] + +In other words, mammals are much more susceptible than birds to +degenerative and inflammatory processes, show an ability to increase the +muscle bulk two and a half times as great and are liable to chamber +distention nearly ten times as often. It might also be put that birds +cannot or do not need to increase their muscle, and that the chamber and +muscle balance is more perfectly arranged. + +While in the preceding pages hypertrophy has been discussed rather from +the standpoint of its value as a compensating and reserve capacity, and +dilatation as a degenerative or decompensatory process on the part of +the cardiac mechanism, it may be that dilatation of the mammalian heart +is the usual method employed by the class in response to increased +demand. It seems certain, however, that the originally and normally +larger heart, both mammalian and avian, more often uses an increase of +its muscle to this purpose. + +Hypertrophy was accompanied by myocardial disease in 44 per cent. of the +cases, while dilatation showed this change in only 24 per cent. This +supports the theory that dilatation is a normal response of the +myocardium under strain and the belief held in many quarters that the +muscle increases its bulk because some of it is damaged. + +The differences between classes are not so conspicuous between orders. +However, the large heart of the carnivores increases both its muscle and +chambers, while the small heart of the rodents and marsupials more often +dilates. Analysis of the avian orders is inconclusive and somewhat +contradictory. Let it suffice to say that the birds which fly most, with +exception of the ducks, have a relatively low vulnerability, and the +soaring carnivorous Accipitres and the largest birds, Struthiones, +apparently have a high susceptibility to damaging influences and enlarge +their muscle bulk in response to increased work. + +Aneurysms of the heart are quite rare; only two have been seen. They +were both located at the apex of the left ventricle in birds; they did +not rupture. Myocardial damage is evident in both cases but the cause is +not clear; parasites could not be demonstrated. Plimmer reports a case +of cardiac aneurysm at the apex from infestation of the heart muscle by +sarcosporidia. + + + + + SECTION III + DISEASES OF THE BLOOD VESSELS + + +The gross anatomy of the blood vascular system is constructed upon the +same general scheme throughout mammals and upon a comparable basis in +birds. Microscopically there is little variation throughout the orders +unless it be in the relative proportion of muscular and connective +tissues. The origin of the great vessels at their cardiac base and their +distribution to the pulmonary and to the greater circulations in no way +differ in these two classes in that it always consists of an efferent +pathway to the lung and a root vessel above the aortic orifice. The +former has usually quite a distinct origin on the right side, but in +some birds the posterior wall of the pulmonary artery may overlie the +entire aortic base; this, however, is not the rule for birds. The aorta +in most mammals remains a separate and distinct vessel for some +distance, after which it gives off the innominate and subclavians. In +the birds on the other hand, the stretch immediately above the aortic +valve is usually ballooned out somewhat, into a sort of sac or ampulla +from which the subclavians and descending aorta arise. This forms a +structure of rather trident shape, the lateral prongs being the +subclavians, the middle and posterior being the aorta proper. In some +birds the aorta may have the length of a centimetre or more then +dividing into the left subclavian and right aorta from which the right +subclavian comes off. + +There is definitely more support to the heart and vascular roots in +mammals than in birds, in the latter class these structures lying quite +free between the lateral air sacs and well in front of the lungs. Nor is +there the richness of mediastinal areolar and fatty tissue in the winged +creatures. + +The vessels of mammalia retain a considerable wall throughout nearly +their entire length. At first the wall is thin compared to the calibre +of the vessel while the arteries smaller in calibre, have a heavy wall. +In birds the arterial stalk at the heart is supplied with very heavy +walls, but after the second branching the relation of wall to calibre +seems to continue about the same. In this class the stalk vessels have +wall to calibre relation of 1 to 3 (measurements in 2 Passeres, 1 +Psittaci, 1 Accipitres) whereas in mammals the relation varies from 1 to +5 to 1 to 7 (observations on 2 carnivores, 1 ungulate, 2 rodents). In +mammals the consistency of a normal artery wall remains much the same, a +firm, resilient, yellow-white tissue, quite opaque and standing open +upon cross section. In birds this description covers the main stalk, the +aorta in the abdomen and the first part of the carotid and iliacs. When +these characters are lost, the arteries become semitranslucent bluish +strands so that they are difficult to follow in the muscles of the neck +and extremities. This is particularly true in the Passeres, Picariæ, +Galli and Columbæ while in the Psittaci, Accipitres, and Anseres the +arteries are distinctly whiter than the veins but yet quite soft. In the +Herodiones and Struthiones, thick walled vessels may be followed as far +as the second joint in both extremities. These differences depend in +part upon the grosser construction of the central arteries in Aves and +in part upon the larger amount of elastic tissue in them than in the +secondaries and smaller vessels, and than in comparable mammalian +vessels. + +It is impracticable to go into the minutiæ of histology in the different +orders, which indeed varies but little, although attention might be +directed to the facts that in all central vessels the relative amount of +elastica is greater than in smaller ones and that muscular tissue seems +to exceed in the latter. Considerable work has been done upon the amount +and arrangement of muscle bands in isolated genera, but no comprehensive +data are at hand upon orders. The strands of muscle do not seem arranged +so regularly as in mammals; the pulmonary artery of the cat, for +example, has a muscle arranged like an oblique band in waves or festoons +along the length. The mammals as a class seem more richly supplied with +arteries and veins than do the birds, and the square area of the +vascular system is likewise larger. This is distinctly different from +the amount of heart bulk as given in the discussion of kilogram-heart +ratios so that one might say that the birds are “overhearted and +undervesseled.” + +In so far as the physiology of the two classes is concerned it is +obvious that a different regulatory system is necessary because, aside +from the variations of pressure incidental to pulmonary, muscular and +visceral work, there remains the altering pressure within the air sacs +of Aves, a force different under states of rest, of running, of deep +water swimming and of flying with or against the wind. Part of the +internal air pressure variation is cared for by the ability a bird has +to respire the air in its sacs and bones, but in prolonged exposure to +the pressure under water or during protracted flight some compensatory +mechanism doubtless exists. This seems to reside in part in the heavy +elastic quality of the arterial stalk and the very rich venous supply of +the abdomen, including the renal-portal system and the distensible +pelvic veins. Just where the governing power for this mechanism resides +is as much a matter of debate as in the case of the human being, but +certain researches would place it in the caudate lobe and pituitary +body. + +Having discussed these general comparative data we can now pass to a +consideration of the pathology seen at this Garden. The subject will be +studied from the standpoint of the vessels as a system and the changes +peculiar to it. Naturally the most important lesions affect the great +stalks and the principal trunks, from which the processes may continue +into the smaller vessels. The essential alterations are inflammatory and +degenerative, of which the latter are by all odds the more important. +The former are either involvements of the vessel walls by frankly +infectious processes, or less easily proved to be bacterial in origin, +as is the case with periarteritis nodosa. Acute arteritis and phlebitis +are constantly encountered and present nothing unusual. General nodal +periarteritis has been seen in the lower animals, Lupke having +reported[14] before the German Pathological Society a big outbreak in +cows, but it is less common than among men; we have not discovered it +here. + + +THROMBOSES. + +Thrombosis is practically always a parasitic or an infectious process +although at times considerable difficulty is encountered in explaining +the source of the worms or bacteria. Thus, for example, the iliac or +femoral thromboses which are at the bottom of intermittent claudication, +are frequently quite vague in origin. We have had one such case in a +deer in which a partly occluding thrombangeitis existed in both femoral +arteries and veins. Mesenteric thrombosis, a serious condition in cattle +and horses from infestation with sclerostomum or strongylus, has not +been proven at the Garden, but we have seen one case of numerous +thromboses of the venous radicals in the jejunal wall apparently due to +some nematode larvæ; the specimens were so soft by decomposition that +determination was not attempted. There occurred a thrombosis of the cava +and aorta originating from a necrotizing cloacitis, apparently +streptococcal in nature, in a Demoiselle crane. The clot, while not +totally occlusive, extended nearly as far as the heart in the vein and +the abdominal aorta. There is also on record a thrombosis of the vena +cava and right pulmonary vein in an American beaver, harboring +Hepaticola hepatica in the liver, with a fibrosing pneumonia due to this +parasite. Another case in which parasites seemed to take a hand +concerned a common raccoon with tapeworms (sp.?) in the small intestine +and microscopically discoverable parasitic parts in the lungs; these +organs were the seat of extensive congestion and venous thrombosis, the +latter containing really enormous numbers of diplococci. The parasites +probably paved the way for bacterial invasion. A frank case of septic +thrombotic aortitis was noted in a Rice Grackle, the infectious focus +apparently being a vegetative “tricuspid” valvulitis. + + +ARTERITIS. + +In addition to these cases, productive inflammatory changes were +discovered five times affecting vessels in or near frank inflammatory +processes. The animals affected with this productive process were three +birds, a rodent and an elephant. In the case of two birds and the rodent +the process was associated with chronic intestinal lesions, while in the +elephant it was found as an endarteritis obliterans in large vessels of +the lung of chronic pulmonary tuberculosis occurring in this animal. +These instances serve as examples of the truly productive inflammatory +processes affecting vessels and illustrate the distribution through the +animal kingdom. Pathogenetically there are no essential differences, and +histologically they correspond to the forms seen in man. Had every piece +of tissue been subjected to microscopy wherein such lesions might have +existed, more examples might have been discovered, but these processes +excite no peculiar secondary effects so that attention is not drawn to +them directly. The only noteworthy difference between mammals and birds +is the fragile character of the clots in the latter class. This is +peculiar because the principal response of this class to an infectious +irritant is coagulation necrosis, liquefying enzymes apparently being +absent or small in quantity. + +Fatty deposits in the aortic intima are by no means uncommon in the +human subject and are encountered at all ages, even in youth at a time +when progressive arteriosclerosis does not accompany them. There is a +belief in many quarters that this fat may be laid down and then removed. +Such deposits are exceedingly rare in wild animals; when they occur it +is in small indefinite patches and not the bands or rows as found in +man. + + TABLE 5. + + _Table Showing the Incidence of Degenerative Arterial Disease, the + Percentage in Animals Subjected to + Autopsy and the Principal Associated Pathology._ + + ════════════════╤═════╤══════════╤═════════╤═════════╤══════════ + │Total│Percentage│ Due to │Aneurysms│Myocardial + │ │ of order │parasites│ │ disease + │ │ │ │ │ + ────────────────┼─────┼──────────┼─────────┼─────────┼────────── + Primates[15] │ 3│ .6│ │ │ 3 + Carnivora │ 16│ 3.3│ 5│ 7│ 1 + Ungulata │ 13│ 3.5│ 2│ │ 1 + Marsupialia │ 3│ 1.8│ │ │ + Total │ 35│ 1.8│ 7│ 7│ 5 + │ │ │ │ │ + Passeres │ 3│ .22│ │ 2│ + Picariæ │ _2_│ 2.2│ │ │ + Psittaci │ 13│ 1.8│ │ 1│ + Striges │ 3│ 2.2│ │ │ 1 + Accipitres │ 13│ 6.6│ │ 1│ 4 + Galli[16] │ 5│ 1.6│ 1│ │ 4 + Steganopodes[16]│ _5_│ _25._│ │ │ + Herodiones │ 1│ 1.│ │ │ + Palamedes │ _1_│ _20._│ │ │ 1 + Anseres │ 11│ 3.4│ │ 2│ 4 + Struthiones │ _7_│ _22._│ │ │ + Alectorides │ _2_│ _5.4_│ │ │ 1 + Total │ 66│ 1.8│ 1│ 6│ 15 + ────────────────┼─────┼──────────┼─────────┼─────────┼────────── + Grand Total │ 101│ 1.8│ 8│ 13│ 20 + ────────────────┴─────┴──────────┴─────────┴─────────┴────────── + + ════════════════╤══════════╤═══════╤═════════╤══════════ + │Valvulitis│ Renal │ Chronic │ Chronic + │ │disease│pulmonary│infectious + │ │ │ disease │ disease + ────────────────┼──────────┼───────┼─────────┼────────── + Primates[15] │ │ │ │ 1 + Carnivora │ │ │ 1│ 5 + Ungulata │ 1│ 2│ 3│ 2 + Marsupialia │ │ │ │ + Total │ 1│ 2│ 4│ 8 + │ │ │ │ + Passeres │ │ │ │ + Picariæ │ │ │ │ + Psittaci │ │ 6│ 3│ 2 + Striges │ 2│ │ │ + Accipitres │ 2│ 5│ 2│ 4 + Galli[16] │ │ 2│ 1│ 2 + Steganopodes[16]│ 1│ 3│ │ + Herodiones │ │ │ │ + Palamedes │ │ 1│ │ + Anseres │ 1│ 4│ 1│ + Struthiones │ │ 1│ 2│ 3 + Alectorides │ │ 1│ │ + Total │ 4│ 25│ 9│ 11 + ────────────────┼──────────┼───────┼─────────┼────────── + Grand Total │ 5│ 27│ 13│ 19 + ────────────────┴──────────┴───────┴─────────┴────────── + For meaning of italics see foot note Table 1. + + +DEGENERATIVE ARTERITIS OR ARTERIOSCLEROSIS. + +Whether or not it be exact to speak of the more protracted forms of +vascular disease usually called arteriosclerosis or atheroma as +degenerative, such changes form the most pronounced features of the +lesions, and we have made such a separation at this laboratory. Here is +not the place to engage in the academic discussion of the nature of the +process, but I wish to state that collectively the changes as seen in +such lesions in the lower animals are more degenerative than productive, +and that we have never seen true ulcerative atheroma as it not +uncommonly appears at the autopsy table in any large hospital. This +disease of the vascular walls has long been attributed to alcohol, gout, +syphilis and other such prolonged intoxications to which we might apply +the light term of “toxins of civilizations.” Too little credit, or +discredit has been given to chronic intestinal disorders, overeating, +and overdrinking of ordinary fluids, to entirely incorrect diets, and to +chronic bacterial diseases. Even though the exact counterpart of the +disease in man does not occur in lower animals, we shall see the +probable association with food and with habits, in a manner discordant +with former teaching of the causation of the disease. + +The group to which the name degenerative arteritis has been applied is, +as has already been indicated, more productive than the analogues seen +in the human being, but indeed it is questionable whether the lesions +even in the lower animals are not more degenerative than productive. +Since, however, chronic arteritis is always associated with damage to +the elastic and muscular fibres of the media as well as with fatty +change and overgrowth of the intima, all the deforming and degenerative +cases will be classed together. + +The general picture in mammals is one of diffuse rather than of plaque- +like thickening, but well outlined raised or depressed areas are +encountered. In the aorta and larger branches one may find irregular +streaking and loss of elasticity with fairly clear, pale yellow or gray, +flat sections of distinct opacity. Rarely these may contain calcareous +matter, a change most often seen in the carnivores. The lesions are very +largely limited to the aorta; 26 or 76 per cent. of the 35 cases had +this distribution alone. The arch seemed never to be affected alone, and +indeed it is rather commoner to find opaque patches stretching along the +thoracic or even abdominal portion; this is especially true of the +Ungulata. + +[Illustration: + + FIG. 2.—ARTERIOSCLEROSIS AND ATHEROMA. THORACIC AORTA. JACKAL (CANIS + AUREUS). THIS WAS CONTINUED TO THE MESENTERIC AND ILIAC VESSELS. +] + +There have been also in mammals five cases of mesial change which have +given rise to the picture described by Mönckeberg and usually entitled +by his name. However, the noteworthy differences between the wild animal +and the human cases are the absence of advanced calcification in the +media under the concavities and the prominence of the changes in the +aorta near the heart to be found in the former. These few cases do not +permit an association of the arterial disease with any particular +pathology in other parts. + +Considered minutely, the outstanding lesion in the class Mammalia is the +separation of the elastic fibres by fluid and debris, apparently derived +from the degenerated muscle fibres, associated with a decrease of round +and elliptical nuclei. Globules and hyaline pink staining material are +often collected between split-up elastic strands, which fibres in some +cases seem quite numerous, in others reduced. In the intima heaping-up +of cells and fibres is very moderate in degree while usually one finds +only subendothelial edema. When the process has advanced far, the +microscopy is like that of well developed human lesions. Arterial +degeneration due to parasites gives a different picture in that medial +degeneration is far advanced and some fibrinocellular activity is seen +upon the intima when this tissue remains. When, however, the infestation +has proceeded to weaken the wall sufficient for it to give way into an +aneurysm, little or no vestige of the true arterial wall is left. + +In the Aves the distribution and anatomy of this process present some +differences. The aorta is as usual most conspicuously the seat of +change, but it is noteworthy that the dilatation or ampulla immediately +above the aortic valves and from which the main vessels spring, is +practically always free of lesions which are on the other hand most +marked in the thoracic and abdominal sections. One’s attention is +usually attracted to the aortic surface by its roughness although +visibly there may be no plaques, but upon close inspection a mottled +opacity may be detected. This all seems due in the few cases subjected +to tissue section, to hyperplasia of endothelia, with or without fibre +increase. The media may show muscular granularity or no change at all. +At the stage when plaques are formed, fairly well outlined, firm but +rather brittle, raised areas are detected, seated upon a distinctly +opaque gray wall. The remainder of the vessel may be smooth and elastic +but sometimes, in the Accipitres for instance, a general resistance to +pressure and tension is found. Microscopically such a vessel will show a +media the seat of ruptured muscle fibres, split-up or broken elastica +and some debris, while the intima is covered with active and distinct +fibrocellular exudate. + +I have for comparison divided the cases into those in which the +superficial productive character was prominent and those seemingly +entirely a degeneration of the media, that is with inactive intima. In +mammals 77 per cent. of the cases were of the degenerative type while in +birds 50 per cent. were of this kind. The exact importance of this +difference is not easy to evaluate, but with the facts that the bird has +a greater elastic supply for its large vessels and a greater wall to +calibre ratio, it is interesting. The aorta alone was affected in half +of the birds, the remainder showing lesions in the carotids and +femorals. + +The tendency for the media to degenerate would lay the basis for +concavities on the intimal surfaces after the type seen in Mönckeberg’s +sclerosis. A number of cases of this variety have been encountered, but +instead of being better developed in the vessels of extremities as in +man they have presented more definite pictures in the aorta and +pulmonary vessels. Examples will be quoted under the discussion of the +various orders. + +[Illustration: + + FIG. 3.—ARTERIOSCLEROSIS, ATHEROMA AND ANEURYSMAL DILATATIONS IN + THORACIC AORTA. WILD CAT (FELIS RUFFUS). +] + +Primates are not often affected with degenerative arterial disease, two +of the instances observed showing this change confined to the coronary +vessels. As might be expected the myocardium in both was affected, and +in one animal had a definite concentric hypertrophy. A very interesting +case was encountered in a Lion-tailed Macaque (_Macacus silensis_). His +heart showed distinct fibrosis of the conducting pathways from auricle +to ventricle and of the papillary muscles. No atheroma was present in +the aorta, but in the pulmonary distinct sacculations of the Mönckeberg +type were found. Mesial degeneration was apparently responsible, but no +calcification had occurred. Death was due to acute gastritis. + +Carnivora present about half the cases seen in mammals and 16 per cent. +of the total. Five of the sixteen cases owe their origin to parasitic +arteritis and were combined with aneurysms. As will be noted by +consultation of the list there is no outstanding accompanying pathology, +a fact which makes parasites more important. One case of mesial +degeneration, resembling the Mönckeberg type was observed in the +thoracic aorta of a bear. + +Ungulata are generously represented, thirteen cases being recorded +distributed rather unevenly between the odd-toed (1 or 8.5 per cent.) +and even-toed groups (12 or 2.9 per cent.). The single case in the first +group occurred in a Zebra (_Equus burchelli_) wherein was found about +the middle of the thoracic aorta a diffuse thickening of media and +intima in a circular plaque approximately two centimetres in diameter; +it was by no means so well developed as similar lesions in the even-toed +ungulates. This recalls the expression of doubt by Zinserling as to the +occurrence in the horse of arteriosclerosis similar to that in human +beings. + +The lesions in the Artiodactyla are both in plaques and diffuse, the +aorta and its branches sometimes being quite wrinkled but beset with +firm elevations with and without calcification. These changes are fairly +definite and, although they never attain the development seen in man, +resemble the stage of wrinkling and roughness in the preulcerative stage +of the human analogue. Two of the cases were associated with dilatations +of the mesenteric vessels and with periarteritis, a picture strongly +suggesting parasitic infestation; in one case ineffectual search was +made, in the other no record is made of the parasites. Renal disease +occurred only twice and myocardial damage only once. Chronic pulmonary +disease, present thrice, took the form of tuberculosis twice and pleural +adhesions with atelectasis once. + +Marsupialia present three quite interesting cases, a Tasmanian Devil +(_Sarcophilus ursinus_) and two Kangaroos (_Macropus_). The first showed +distinct sacculations in the ascending aorta, suggestive of Mönckeberg’s +sclerosis but equally resembling several small or incomplete aneurysms. +The underlying vessel was opaque and stiff, continuing so to the middle +of the thoracic portion. The other marsupials showed distinct mesial +damage with early calcification and a roughened intima; once the +pulmonary artery was involved. + +It will be noticed that the orders Rodentia and Lemures are missing from +those showing arterial disease although we have a reasonable number of +autopsies upon them. + +Passeres are hardly good exponents of vascular disease, an interesting +thing in view of their large heart, heavy vessels, and flying habits. It +is, however, striking that two of the three birds of this group had +aneurysms of the aorta, one of which ruptured just above the origin, +partly into and partly outside the pericardium. Despite several +microscopical sections we were unable to find the tiny ends of the +breach and any evidence of parasites. In the other case a vegetative +growth occurred on the intima near the dilatation. + +[Illustration: + + FIG. 4.—ARTERIOSCLEROSIS IN AORTA. OTTER (LUTRA CANADENSIS). THERE IS + RELATIVELY LITTLE INTIMAL CHANGE, THE MEDIA BEING FIBROTIC AND + ALLOWING THE INTIMA TO BE DEPRESSED IN SMALL CONCAVITIES. +] + +The Picariæ were represented by a Hornbill and a Toucan. The former +presented roughened yellowish elevations for two centimetres above the +aortic valve; this seemed the only involvement. The Toucan had a few +small scattered but deep yellow plaques in the same location. + +Psittaci, although failing to be accredited with a high percentage of +arterial disease, nevertheless present some striking and interesting +changes. In the first place, the central vessels are not so +conspicuously the principal seat of atheroma as is the case in many +other orders, and the lesions are not so productive. It is usual to find +flat areas of opacity, perceptible as easily by section through the wall +as by holding up the opened vessel to the light, the seat of the density +being in the media. This can be followed into the wing arteries and, +upon microscopic section, these smaller vessels will show mesial +degeneration, thus being comparable to arteriocapillary fibrosis of man. +However frequent this picture may be, there are also instances of +overgrowth in the intima, prominences over opacities or raised plaques +at the points of branching, lesions which correspond to the activity of +the inner coat. It is interesting that renal disease, chronic pulmonary +and general infections occur in a goodly proportion of these birds. + +Striges is an order of little importance. The lesions in the two cases +consisted of rather prominent plaques in aorta and large branches. + +Accipitres stand out as giving the greatest percentage of any order of +which we have had a fair number upon which to make comparisons. Their +arterial lesions are frequently accompanied by renal, myocardial and +valvular disease. Mesial and intimal alterations are about equal in +degree, irregular patches going on to softening without ulceration, and +early calcification being quite prominent. The sickle at the branching +of the renals is a favorite site of deposit. Like the parrots their +arterial damage is not confined to the aorta, but may be found in the +carotids, femorals or small wing arteries. The most common situation is, +however, in the lower thoracic and renal regions. + +Galli, represented by five specimens, seem to have their vascular +disease accompanied very often by myocardial and infectious disease. +Their arterial pathology consists of raised gray patches in the aorta +only. + +Steganopodes give the highest percentage among avian orders, but this +must be held _sub judice_ because of the small number of specimens +subjected to autopsy. Renal disease occurred in three cases. Their +lesions are in the form of yellow opaque streakings in the aorta and its +branches, in one case following the carotid half way up the neck. +Plaques are not common, and when they occur are streaky and illy +outlined. + +Herodiones, represented only by a heron, are negligible. This bird +showed a diffuse thickening with early thrombotic deposits attached to +the intima. + +Palamedes are represented by a Screamer which showed around the orifices +of the renal arteries an early fatty deposit and mesial opacity. + +Anseres present a considerable number of cases which are accompanied by +cardiac, renal and general pathology. The character of the lesions is +like that of the Accipitres and the distribution differs in only one +particular. In four of these eleven cases the elevations or opaque areas +were limited entirely to the stretch of aorta which might be compared to +the arch in mammalia, that is the part with which the right subclavian +is in closest contact and which bends almost directly backward to become +the thoracic aorta. This excludes the ampulla just above the aortic +valves. There seems no real reason for this and it may be accidental. + +[Illustration: + + FIG. 5.—AORTIC ARTERIOSCLEROSIS. SARUS CRANE (GRUS ANTIGONE). THE + LESIONS ARE ELEVATED AND IRREGULAR. +] + +Struthiones, with seven specimens having arterial disease in the great +vessels alone, seem to have no especial characters unless these be in +the heavy furrowing and stiffness of the wall, with opaque, elevated, +indefinite patches, seen mostly in the descending aorta; once a long +tough and partly brittle stretch was found in the carotid. + +Alectorides, with a relatively high percentage, present irregularly +outlined fatty and finely granular patches in the intima of the lower +aorta and abdominal vessels, and, in two cases, as far as the vessels of +the lower extremities could be followed. + +The orders Columbæ and Fulicariæ are missing from the list of Aves +having arterial disease, yet a reasonable number of autopsy records are +at hand. + + +SUMMARY ON ARTERIOSCLEROSIS. + +Having discussed the orders separately, a review of the whole situation +is desirable. Chronic arteritis, or as it is usually called +arteriosclerosis, is common to very many zoological orders, and its +principal lesions are comparable throughout the two classes under +consideration. A statement as to its incidence would best be made by +adopting an arbitrary number of observations as the desired minimum upon +which to draw conclusions, and I shall adopt one hundred as such a +figure. Accepting this as reasonable, a review of the table indicates +that the order of percentage incidence is: Accipitres 6.6, Ungulata 3.5, +Anseres 3.4, Carnivora 3.3, Striges 2.2, Psittaci 1.8, Marsupialia 1.8, +Galli 1.6, Primates 0.6, Passeres 0.22; the other orders have less than +one hundred specimens each. There is no doubt that carnivorous birds +have the highest incidence of chronic arterial disease. Next in order +come three varieties with nearly equal incidence, the ungulates, +anserine birds and carnivorous mammals. These orders have little in +common unless it be that in nature they are often engaged in prolonged +or strenuous effort, as in fight or flight. We possess no measurement of +their vascular supply but by consultation of the table giving heart +weights (page 63) it will be found that three of them have values below +that of the class in which they belong; the Carnivora alone have a +greater heart-to-body ratio than the average for its class Mammalia. Nor +do these orders have any direct dietetic relationship. The expected +longevity of these groups does not permit one to discover any reason for +arterial changes except perhaps that they have a reasonably good +viability under park conditions, and therefore many have a longer +opportunity to develop vascular disease. It so happens, however, that +the first four groups are the most likely to suffer from +gastrointestinal inflammation, of dietetic or bacterial origin. + +It is interesting, but not easily explicable that the orders of great +activity, Primates and Passeres, are at the end of the list; their food +is very largely carbohydrate in character. Just why Lemures, Rodentia +and Columbæ should be missing is not quite clear, because orders of +comparative habits and food are included. + +A review of the concomitant pathology reveals the fact that nephritis +more often accompanies these processes than any other single condition. +Among the chronic infectious disease in the table is included chronic +enteritis; this group falls well behind the renal diseases. The +relatively small number of cases of valvulitis speaks rather against an +active infectious origin of the vascular lesions. + + +ANEURYSMS. + +Aneurysms have been observed all over the world and in nearly all the +larger orders. The London Garden has had an unusually large number to +report, the most striking being that described by Seligman in the 1906 +Report of the Society, in a tiger thirteen years in captivity which had +fourteen sacculations from pea to plum size scattered along the aorta. +Even with the number of cases on record and those collected here it +would be unwise to draw deductions as to their incidence or as to the +possibilities of vascular dilatation in any given order. Horses have +aneurysms occasionally, cows and dogs rarely, according to Rievel. I +can, however, state that there has not occurred in our experience a +large growing pulsating aneurysm in the aortic arch region comparable to +the condition so well known in man. The literature to which we have had +access gives a definite impression that parasitism of vessel walls is +the most important factor in the causation of ectasia, and that simple +non-parasitic arteriosclerosis is relatively unimportant. Two of our +seven cases seem to have been free of parasites but the notes cannot +entirely assure one of this. The distribution of cases at this Garden is +found in Table 5. + +[Illustration: + + FIG. 6.—PARASITIC ANEURYSM IN THORACIC AORTA. PARADOXURE (PARADOXURUS + LEUCOMYSTAX). PARTLY SACCULAR, PARTLY DISSECTING ANEURYSM WITH OPEN + THROMBOSIS AS INDICATED BY THE GLASS ROD. PIECES OF WORM FOUND IN + WALL. COULD NOT OBTAIN WHOLE SPECIMEN, SPECIES UNDETERMINED. +] + +A dilatation of the first part of the arch in a seal to a size which +might be described as an aneurysm caused us to make such a diagnosis, +correctly enough from the size and shape of the vessel but possibly +worthy of reconsideration in light of the fact that no damage to the +wall was found. At the heart and in the descending arch the diameter +measured 4–5 cm., while the first part of the aorta measured 7.5 cm. +This great irregularity in width could not be found in other seals +albeit this section of the arch is usually a trifle larger than its +origin and descending portion. The cava in seals is also large, but in +this particular animal it measured 6 cm. across at the liver where there +is a normal dilatation. These two spaces are looked upon as normal +reservoirs for blood during diving, but the case in question seemed to +have excessive “aneurysmoid” enlargements without mural disease. London +reports an aneurysm of the aorta in a seal.[17] + +Aneurysms are not so common in birds, the incidence being in comparison +with mammals as 1 to 2.2. Two seats are prominent for their development: +the sinuses above the aortic valves and the first part of the subclavian +vessels; two of the six cases occupied the first position, two the +second, while one other lay in the arch of the aorta, the last in its +descending thoracic portion. Those developing over the valves seem to +arise from simple degenerative arteritis; those that occupy the other +locations are apt to be surrounded by plaques on the intima. Aneurysms +in birds reveal by microscopy some trace of all the vascular coats and +seem not to construct an adventitia from surrounding areolar tissue. The +veins have presented no peculiar pathology, except in tumors which will +be taken up later. A Derby’s Tyran showed a phlebitis and periphlebitis +of the left subclavian vein, of mycotic nature, which led to death by +rupture and hemorrhage. + + + + + SECTION IV + DISEASES OF THE BLOOD AND BONE MARROW + + +The production and physiology of the circulating blood seem closely +similar in the two classes under consideration, although the anatomy is +not the same in birds and mammals, variations also occurring within the +latter group. Pathological responses follow comparable lines in that +hemolyzing agencies, be they hemosporidia, absorptions from metazoan +parasites or bacterial toxins, produce a reaction in erythropoietic +centres, and positively chemotactic viruses call forth increases in the +colorless elements. We have also observed a decrease of leucocytes in an +Orang Utan suffering from influenza, a finding analogous to that in the +human attack. There is, however, a much less ready response on the part +of birds to any leucocyte-stimulating influence, in this class the +mononuclears seeming to bear much of the burden assumed by the myeloid +cells of Mammalia or at least appearing on the stage very quickly so +that any increase of the latter is overshadowed by them. Perhaps this +apparent difference may be further explained by the greater number of +colorless blood cells, structures which might be called the principal +secondary defences of the body and constantly at the disposal of the +organism, normally present in the birds’ blood; they amount to 25,000 +per cubic millimetre in birds, while in the mammals very few varieties +have half this number. On the accompanying Table (6) will be found a few +differential leucocyte counts now known to us. + + TABLE 6. _Differential Percentages of Leucocytes._ + _The Figures are based upon Counts of Two Hundred Cells upon Two Slides unless + Otherwise Specified. Blood Films were taken from Apparently Healthy Animals in the + Exhibition Cages._ + ════════════════╤════════════╤═══════╤═══════╤═══════╤══════════╤══════════════════ + Animal │ Polymor- │ Small │ Large │Eosino-│ Special │ Notes + │phonuclears.│Lympho-│Mononu-│philes.│ │ + │ Per cent. │cytes. │clears.│ Per │ │ + │ │ Per │ Per │ cent. │ │ + │ │ cent. │ cent. │ │ │ + ────────────────┼────────────┼───────┼───────┼───────┼──────────┼────────────────── + Potto │ 20.│ 67.│ 7.1│ 5.9│ │ + Perodicticus │ │ │ │ │ │ + potto │ │ │ │ │ │ + Rhesus Macaque │ 30.2│ 61.4│ 5.6│ 2.8│ │ + Macacus │ │ │ │ │ │ + rhesus. │ │ │ │ │ │ + │ (Av. 5 counts) │ │ │ │ + Raccoon-like Dog│ 62.2│ 32.│ 2.│ 3.8│ │ + Canis │ │ │ │ │ │ + procyonoides. │ │ │ │ │ │ + Swift Fox Canis│ 65.│ 18.│ 13.│ 1.│ 3 per │ + velox. │ │ │ │ │cent. Baso│ + Dingo Canis │ 77.│ 15.4│ 3.8│ 3.8│ │ + dingo. │ │ │ │ │ │ + Timber Wolf │ 76.5│ 15.5│ 3.5│ 4.5│ │ + Canis │ │ │ │ │ │ + mexicanus. │ │ │ │ │ │ + Wild Cat Felis │ 55.8│ 34.│ 7.│ 3.8│ │ + ruffus. │ │ │ │ │ │ + Gray Ichneumon │ 52.6│ 44.4│ 2.3│ .7│ │ + Herpestes │ │ │ │ │ │ + mungo. │ │ │ │ │ │ + Indian │ 66.│ 20.│ 14.│ 0.│ │ + Paradoxure │ │ │ │ │ │ + Paradoxurus │ │ │ │ │ │ + niger. │ │ │ │ │ │ + Large spotted │ 60.│ 31.2│ 1.2│ 7.6│ │ + Civet Viverra │ │ │ │ │ │ + megaspila. │ │ │ │ │ │ + Ocelot Felis │ 79.│ 15.6│ 3.5│ 1.9│ │ + pardalis. │ │ │ │ │ │ + Texas Skunk │ 44.1│ 46.3│ 4.3│ 5.3│ │_a._ There are + Mephitis │ │ │ │ │ │several grades of + mesomelas. │ │ │ │ │ │eosinophilic + │ │ │ │ │ │granulations, + │ │ │ │ │ │ranging from very + │ │ │ │ │ │fine to very + │ │ │ │ │ │coarse. They are + │ │ │ │ │ │entirely discrete, + │ │ │ │ │ │however, and the + │ │ │ │ │ │eosinophile cells + │ │ │ │ │ │are quite distinct + │ │ │ │ │ │from the + │ │ │ │ │ │homogeneous + │ │ │ │ │ │neutrophiles. + Tayra Felis │ 75.6│ 19.2│ 4.1│ 1.1│ │ + tayra. │ │ │ │ │ │ + White nosed │ 60.│ 20.│ 18.│ 2.│ │_b._ The + Coati Nasua │ │ │ │ │ │protoplasm of the + narica. │ │ │ │ │ │leucocytes shows + │ │ │ │ │ │practically no + │ │ │ │ │ │stain. Mitotic + │ │ │ │ │ │figures are + │ │ │ │ │ │frequent among the + │ │ │ │ │ │polymorphonuclear + │ │ │ │ │ │cells. The small + │ │ │ │ │ │lymphocytes show + │ │ │ │ │ │basophilic + │ │ │ │ │ │granules. + Crab eating │ 45.│ 42.│ 2.5│ 10.5│ │ + Raccoon. │ │ │ │ │ │ + Procyon │ │ │ │ │ │ + cancrivorous. │ │ │ │ │ │ + Ring tailed │ 39.2│ 54.7│ 4.3│ 1.8│ │ + Bassaris │ │ │ │ │ │ + Bassariscus │ │ │ │ │ │ + astutus. │ │ │ │ │ │ + Kinkajou Potos │ 47.4│ 42.5│ 6.│ 4.1│ │ + caudivolvulus.│ │ │ │ │ │ + Common Raccoon │ 46.│ 42.9│ 7.4│ 3.7│ │ + Procyon lotor.│ │ │ │ │ │ + Texas White │ 67.│ 19.│ 11.│ 3.│ │ + footed Mouse │ │ │ │ │ │ + Peromyscus │ │ │ │ │ │ + leucopus. │ │ │ │ │ │ + Kangaroo Rat │ 55.│ 33.│ 6.│ │ 5 per │_c._ Many + Perodipus │ │ │ │ │ cent. x │leucocytes were + richardsoni. │ │ │ │ │ cells. │noted, with deeply + │ │ │ │ │ │staining nuclei + │ │ │ │ │ │filling up most of + │ │ │ │ │ │the cells. The + │ │ │ │ │ │protoplasm was + │ │ │ │ │ │colored a deep + │ │ │ │ │ │brown. These were + │ │ │ │ │ │called x cells + │ │ │ │ │ │pending + │ │ │ │ │ │investigation. + Polecat Mustela │ 42.4│ 54.6│ 2.1│ .9│ │ + putorius. │ │ │ │ │ │ + Common Opossum │ 44.│ 39.│ 7.│ 9.│ 1 per │_d._ Polynuclears + Didelphys │ │ │ │ │cent. Mast│quite large, with + virginiana. │ │ │ │ │ cells. │deeply staining + │ │ │ │ │ │nuclei which are + │ │ │ │ │ │in many instances + │ │ │ │ │ │entirely separate + │ │ │ │ │ │and distinct. + Bridled Wallaby │ 58.3│ 38.8│ 2.│ 4.2│ │ + Onychogalea │ │ │ │ │ │ + frenata. │ │ │ │ │ │ + Six banded │ 57.1│ 23.2│ 6.3│ 13.4│ │ + Armadillo │ │ │ │ │ │ + Dasypus │ │ │ │ │ │ + sexcinctus │ │ │ │ │ │ + Elephant Elephas│ 15.│ 47.4│ 7.6│ 5.8│ (Bilobed │_e._ The ordinary + indicus. │ │ │ │ │ 23.8) │polymorphonuclears + │ │ │ │ │(Basophile│are very few in + │ │ │ │ │ .4) │number, and those + │ │ │ │ │ │seen have nearly + │ │ │ │ │ │all a faint + │ │ │ │ │ │acidophilic or + │ │ │ │ │ │basophilic + │ │ │ │ │ │character. The + │ │ │ │ │ │eosinophiles are + │ │ │ │ │ │quite distinct and + │ │ │ │ │ │their granulations + │ │ │ │ │ │are large and + │ │ │ │ │ │globular. The + │ │ │ │ │ │cells called + │ │ │ │ │ │bilobed are + │ │ │ │ │ │unusual and can + │ │ │ │ │ │probably best be + │ │ │ │ │ │accounted for as + │ │ │ │ │ │directly dividing + │ │ │ │ │ │small lymphocytes. + │ │ │ │ │ │The staining + │ │ │ │ │ │properties and + │ │ │ │ │ │shape of the + │ │ │ │ │ │nuclei of the + │ │ │ │ │ │bilobed cells are + │ │ │ │ │ │most closely + │ │ │ │ │ │related to the + │ │ │ │ │ │lymphocytes. They + │ │ │ │ │ │are not always + │ │ │ │ │ │regular, however, + │ │ │ │ │ │but may be almost + │ │ │ │ │ │as irregular as + │ │ │ │ │ │the polynuclears. + │ │ │ │ │ │In practically + │ │ │ │ │ │every instance, + │ │ │ │ │ │however, a + │ │ │ │ │ │connecting isthmus + │ │ │ │ │ │may be found + │ │ │ │ │ │between the + │ │ │ │ │ │spherical nuclear + │ │ │ │ │ │portions. No + │ │ │ │ │ │mitotic figures + │ │ │ │ │ │seen. The + │ │ │ │ │ │protoplasm is + │ │ │ │ │ │homogeneous and + │ │ │ │ │ │pale blue or lilac + │ │ │ │ │ │in relatively + │ │ │ │ │ │large amount. No + │ │ │ │ │ │granules were ever + │ │ │ │ │ │seen. + ────────────────┴────────────┴───────┴───────┴───────┴──────────┴────────────────── + +It would seem, from a general observation of simple and infected wounds +and from a few blood counts, that the response of leucocytes in the +lower animals is greater than in monkeys and man. The ease with which +animals endure a wound and the rapid local pus formation about an +infection speak for an easy mobilization of their cellular defenders; +their connective tissue elements seem equally well brought into play. In +so far as birds are concerned perhaps the normally large number of +leucocytes and the participation of local tissue cells in response to +irritation is a preparatory protective mechanism because of their +relatively small amount of bone marrow which may not be able to mobilize +new cells rapidly; many of the birds, notably those prepared for long +flight, have much of their osseous system given over to air space. The +number of red blood cells is also greater in Mammalia, which show a +variation from 4,000,000 per cubic millimetre in some small genera to +12,000,000 per cubic millimetre in some ungulates, while birds vary from +2–5,000,000 per cubic millimetre. Despite these fundamental differences +in the classes, pathological changes of anemia, leucocytosis and +leucemia are comparable; polycythemia in lower animals is unknown to me +but may of course occur. + + +ANEMIA. + +As in human pathology this condition may be divided into the group that +follows some disease which damages the red blood cells or their source, +called secondary, and those cases not preceded by such a condition, +called primary. Formerly this latter group, known as progressive +pernicious anemia, was copiously represented, but study has discovered +that worms, inorganic poisons and infections can produce a picture of +grave anemia so that the formerly large group has dwindled. We now +conceive a primary anemia to be one without discoverable responsible +antecedent pathology, therefore a disease of the bone marrow itself. +There is one variety, hemolytic anemia, which seems to be an +intoxication of the bone marrow with solution of red cells, but the +affected tissue puts up some struggle against the poison. In another +primary, the so-called aplastic anemia, no activity at all is shown by +the marrow, no young cells appearing in the circulation. Clorosis, or +green sickness of young persons, is a primary anemia and presents itself +as a moderate cell reduction with a disproportionately low hemoglobin +percentage. As a disease entity this does not occur in the lower +animals, so far as I am aware, but a very few hemoglobin estimations and +a reference to the literature would indicate that well marked hemoglobin +anemia does occur. + +In so far as the pathology of anemia is concerned we are obliged usually +to judge by the appearance of the blood and tissues, the yellowish +pallor of the mucous membranes, the condition of the marrow and the +amount of pigment; severe rapid cases show hemorrhages and prolonged +cases have fatty degeneration of the parenchymatous organs. For a +decision of the primary or secondary nature we must judge the +accompanying pathology and the condition of the bone marrow. + + +SECONDARY ANEMIA. + +Secondary anemia can be laid in general to insanitary housing or +inappropriate diet over a long period, to chronic bacterial infection of +low grade, to the action of blood parasites or those of the bowel which +either suck blood or elaborate an absorbable toxin, or to single great +or repeated small hemorrhages. We shall now consider the cases at the +Garden. Perhaps many other animals have had a substandard blood, but +these are the cases in which the gross appearance attracted close +scrutiny in this direction. London has had much anemia, probably from +their reported heavy infestation with parasites, but this factor has +with us apparently played a small rôle in the production of anemia. + + +IN MAMMALIA. + +In so far as the Primates are concerned the one outstanding cause of +anemia is degenerative disease of the osseous system. In both rickets +and osteomalacia there is an irregular hyperplasia of the marrow, which +is usually more marked in the latter. In osteomalacia one finds +irregular areas of congestion or even hemorrhage besides masses of a +gelatinous fatty tissue while scattered about are pink spots where the +marrow is better preserved. In rickets, on the other hand, the tissue is +more uniformly congested and less sharply separated from the endosteal +osseoid material or the irregular epiphyseal spongiosa. The fibroid or +osteoid growth of osteomalacia seems to be fairly well differentiated +from the marrow tissue although it may send strands into the canal and +across the spongy area. Histologically there is not a distinct +difference in the appearances nor do they differ from the human +analogue. In those cases which develop late in life the red cell centres +are very few in number but usually active. In the blood, one finds a few +nucleated and stippled cells, but not much change in size and shape of +the erythrocytes. + +It does not seem that the anemia can be the cause of death, for among +our thirty-nine cases of osteomalacia and rickets, the prosectors have +thought it of sufficient importance to record in the diagnoses but +eleven times. There are usually complications of pneumonitis or +enteritis to finish the animal before the poverty of the blood will do +so, and our records show only a Black Spider Monkey (_Ateles ater_), a +Silky Marmoset (_Leontocebus rosalia_) and a macaque (sp.?) with +osteomalacia and grave secondary anemia. It would seem, however, that +hemoglobin anemia must exist, for, despite one record of 40 per cent., +Fleischl, no excess of pigment deposit is noted in the spleen, liver or +marrow. + +Carnivora have shown a moderate number of diseases of the skeleton but +the occurrence of a marrow involvement seems less frank, although the +anatomical changes are similar. However, there are three grave secondary +anemias recorded in eleven carnivores suffering from osteomalacia and +rickets. Another prime cause of low blood value in this order is +gastrointestinal inflammation; in seventeen cases of anemia, of +secondary nature, five showed gastroenteritis of severe grade or +protracted character. Perhaps the most prolific single cause of this +blood change is parasitism, six of the seventeen cases showing +infestation, five of which are nematodes and two cestodes, one showing +both. The details of these are worth recording. Two young Jungle Kittens +(_Felis chaus_) from the same litter died of enteritis with a noticeable +anemia; they harbored in their upper small intestine ascarids, and one +of them had a few hookworms (sp.?). A Kinkajou (_Potos caudivolvulvus_) +died from a general mild infection, emanating from a pneumonia perhaps, +and showed a heavy infestation with tænia (sp.?). An American Wild Cat +(_Felis ruffus_) died from acute catarrhal enteritis and anemia; the +parasitological findings included Filaria fasciata, adults in abdominal +and gluteal muscles, larvæ in the blood; Dibothriocephalis felis, +Ascaris mystax and Uncinaria canina in the small intestines. While the +blood was thin and pale and some pigmentation existed, the condition +could not be called a picture of grave anemia. A noteworthy finding was +the deep pigmentation of almost the entire intestinal wall. Ascaris +mystax was found in an under-sized inbred gray wolf, killed because of +poor coat; there was a marked anemia and atrophy of the skin. An Ocelot +(_Felis chibigonazon_) gave a picture of anemia due to uncinariasis, but +is not so instructive as the following. A Swift Fox (_Canis velox_) +exhibited clearly a case of progressive secondary anemia from uncinaria, +and the history is worthy of a brief recital. + + + Muscles atrophic, greenish black over abdomen. Fat absent. Lung is + blotched by darker red markings where parenchyma contains distinct + excess of frothy pink watery fluid. No fluid or adhesions in + pericardium. Heart is contracted, and muscle is pale yellow and firm. + The only abnormality consists of slight yellowing of musculature. The + abdomen shows great omentum firmly adherent to fundus of bladder. No + fluid or other adhesions in abdomen. The liver is normal in size, + smooth in surface and has sharp edges, is friable and bright orange + yellow. The section surface is glistening, smooth and dry. Organ is + poor in blood content, greasy and breaks easily. Bladder is large, + contents fluid green bile; duct patulous. Spleen normal. Kidney is + small and smooth, diminished in bulk, normal location, smooth surface, + and pale yellowish gray, consistency, soft, flabby. Ureters normal. + Mouth and teeth normal. Stomach contains scanty brown fluid. Duodenum— + Mucosa bile-stained, contained a solitary nematode worm. In its lower + portion it becomes filled with a blackish red fluid, and its mucosa + becomes studded by heavily outlined punctate hemorrhages whose + positions are best seen through serosa. Jejunum similar in condition + to duodenum and contains four small nematode worms. At one point, + i.e., where the worm is located at beginning of ileum the blood + staining of mucosa is strictly in neighborhood of the worm. + Capillaries nowhere congested. Ileum contains slight amount of + brownish black material, mucosa normal. Large intestine and rectum + normal. Pancreas normal. Lymphatics normal. This is a case of death by + anemia as result of bites of hookworms. There were certainly more than + four worms present antemortem since no males were found, and this may + be explained by a possible diarrhœa which has flushed them out. This + idea is borne out by empty condition of gastrointestinal tract. Animal + Parasites—Uncinaria canina. The four small nematode worms above + mentioned conform in all respects to the given anatomical points of + uncinaria. All four specimens are perfectly formed females. The + location of the hooks was easily determined and established as being + in the most dorsal portion of buccal cavity, and as projecting forward + and ventrally in two groups of three each in same manner as described + heretofore in similar infestations in foxes. The large nematode worm + found in duodenum is, from its possession of three lips and its + general form, an ascaris. The mustache, however, which is so commonly + seen in ascaris worms from this region is absent. Postmortem blood of + heart shows red cells granulated and almost worthless for histological + study. Nucleated reds, however, are absent but other points valuable + in settling the question of anemia cannot be determined. + + Lung.—There are no abnormalities in supporting tissue. Alveolar walls + are markedly congested. Bronchi normal and show no trace of larval + hookworm infestation. Air sacs contain many red blood cells together + with a few heart-failure-cells. Congestion of lung. + + Liver.—No excess of fibrous tissue. Finer details of structure cannot + be made out owing to advanced autolytic changes. The only possible + pathological changes consist of localized areas where liver cells have + fused to form notable masses of pink granular material suggesting + local necroses. Autolysis. + + Intestines.—Four sections are present and all show essentially the + same character of changes. Interstitial tissue between muscular tissue + and submucosa loosely arranged as though separated by edema. + + On luminal side of muscular mucosa is a distinct zone of striking + tawny yellow color with hematoxylon-eosin combination. This zone is + smooth homogeneous and contains a few spindle and stellate cells with + no capillaries and with little or no fibrillation. It abuts upon the + fundi of the crypts. Interstitial tissue of mucosa is loose and + infiltrated with round and spindle cells in its deeper portions. Here + it is also congested but congestion is most marked toward lumen where + masses of free blood cells occur in interstitial tissue, within lumina + of crypts and within lumen of intestine itself; no parasites or ova + are found. Epithelium of crypts has granular cytoplasm; goblet cell + formation frequently seen; cilia well preserved. Edema; Subacute + catarrhal enteritis Hemorrhage. + + +Six instances of nephritis, four parenchymatous and two diffuse, are +recorded in the total of seventeen cases of secondary anemia in +carnivores. Except in the skeletal disease the marrow is very mildly +affected, some edema and reddening grossly and moderate hyperplasia +minutely, being the only noteworthy changes. + +The next order is that of the Ungulata wherein we have found but two +cases of frank anemia, an Isabelline Gazelle (_Gazella isabella_) and an +Aoudad (_Ovis tragelaphus_). The former had several lesions of different +etiology and nature so that an impoverishment of the blood is not +astonishing: parasitic (?) cyst in lung, chronic infective arthritis, +calcareous tuberculosis, congestion and edema of lungs, osteomalacia, +and osteofibroma of maxilla. The condition of the aoudad was too +indefinite to permit conclusions. + +The marsupials are represented by two common Opossums (_Didelphys +virginiana_) and a Rufous Rat Kangaroo (_Aepyprymnus rufescens_), two of +which suffered also from rickets. The condition of the bone marrow was +unfortunately not recorded, but in other rachitic marsupials this tissue +follows the changes seen in other orders. One opossum had a hypertrophic +gastritis with numerous Physaloptera turgida, a worm frequently +associated with chronic thickening of the mucosa; there was also an +early portal hepatic cirrhosis with enlargement of the spleen. + +Among the Rodentia we have had anemias in a Beechy’s Gopher (_Citellus +grammurus beecheyi_) and a Southern (_Sciurus niger niger_) and Western +Fox Squirrel (_Sciurus rufiventer_). The first had a myeloma also, and +will be discussed later. One of the squirrels had osteomalacia, while +the other suffered with diarrhœa and showed hydropic degeneration of the +kidneys, conditions probably due to acute intoxication. + + +IN AVES. + +The class Aves is represented by the orders Passeres, Psittaci, Columbæ, +Herodiones, Gaviæ, Picariæ, Striges, Galli and Accipitres; the first +four are well represented, but in the other orders only one or two cases +have occurred. The causes of anemia in birds are essentially those +discussed for mammals with the provision that greater attention must be +paid to parasites, particularly those of the blood. Several slightly +varying protozoa inhabit the blood corpuscles of birds, and numerous +embryos may circulate after they escape from a parent lying in some +organ or tissue. The rôle of blood parasites, intra- or +extracorpuscular, in the cause of death or of anemia is, however, +somewhat paradoxical. Plimmer seems to credit a heavy infestation with +great value in the cause of death. In the human being an infestation of +one cell in a hundred is a fair grade of malaria; such a relation is +apparently common in birds, and we have repeatedly seen a much heavier +seeding while Plimmer reports as many as 70 per cent. of the +erythrocytes to be carriers of hemogregarines (he has seen 92 per cent. +in reptiles). Can then the effect upon hemic function and vital +resistance be great? It has been our practice to interpret the finding +of circulating protozoa or of larval metazoa as merely reducing the +resistance of the birds so that they succumb more readily to incorrect +food, strange environment or infection. + +It is perhaps well to show the state of our records in the Passeres by a +table. + + Passeres—Secondary anemia associated with intestinal or visceral + parasites 11 + + blood parasites 9 + + intestinal inflammation 6 + + skeletal diseases and chronic infection (osseous) 3 + + nephritis 4 + + miscellaneous and unassociated anemias 8 + + (entries in this line not included under any + other heading) + + Total cases 37 + +In the first group, two of the birds showed cestodes, one a tænia, the +other not examined for identification; three showed coiled filaria in +the air sacs, two, tropidocerca in the proventricular wall and five had +coiled filaria in the serosa of the stomach. The second group was +infested five times with Halteridium and five times with embryo filariæ. +Anemia was associated with gastrointestinal inflammation alone only +once, the remaining five cases having other finding of greater +significance. The three birds of the next group concerned one with +tuberculosis, one with mycosis and one with a long continued abscess. It +seemed worthwhile to separate four cases of anemia in which nephritis +was a prominent association, in three indeed being the only other +diagnosis. While it is impossible to state that either is dependent upon +the other, and they may of course be coincidental, it is nevertheless +noteworthy that such an obscure relation occurs here as well as in human +pathology. In one of these birds seen recently there was in all +probability a distinct hemoglobin anemia suggested by jaundice, pallor +of the tissues, absence of pigmentations and the finding of large pale +erythrocytes in the heart blood. The last group is a mixed one including +some birds in which only anemia was diagnosed, others with prolonged +hemorrhages, two tumors, intestinal sand, congestion of the lungs and +the like. + +The parrots and their relatives are represented by nine specimens, among +which two had proventricular spiroptera, two had long standing +tuberculosis and two had osteomalacia. The notes of the other three are +not sufficient to warrant deductions. + +Herodiones showed eight cases of anemia, five herons, one bittern and +two storks. Parasites are noted in only three examples, herons, and it +is noteworthy that these all had flukes in the proventricle or +intestine; one also had ascarids in the proventricle. Two of this order +suffered with long standing inflammation following bone injuries. +Perhaps the outstanding features of this order are the erythrocytic +picture and the condition of the spleen. The red blood cells seem very +fragile or soft, for one often encounters in their fresh or stained +preparation vacuoles or rifts in the protoplasm surrounding the nucleus. +At first we thought these were hemosporidia, but repeated attempts at +their coloration and the absence of pigment granules seem to warrant an +assumption that they are artefacts. In five of the seven instances there +is very definite evidence of present or past activity of the spleen. We +have not always considered it sufficiently prominent to call it a +splenitis, but follicular activity is commonly discoverable, and two +cases of definite fibrosis are recorded. The sun bittern (_Eurypyga +helias_) showed a chronic interstitial nephritis in the atrophic stage. +No other of the wading birds showed secondary anemia. There are seven +cases among the pigeons (Columbæ) where anemic tissues attracted our +attention. Three were associated with osteomalacia, in one of which the +marrow picture was that of an aplastic form being everywhere pale and +flabby without cells under the microscope; it is further interesting in +this case that there was a distinct but ineffectual attempt at bony +regeneration by the periosteum. In another case, this time brought to +death by an enteritis and cloudy swelling of the viscera, the marrow was +hyperplastic and red, there being activity in the basic staining areas +of the head and in the shafts. (Notes of the third case scanty.) None of +the seven cases seems to have been associated with animal parasitism; +one had tuberculosis. The other cases are obscure and not definitely +connected with other pathology. + +Ten more cases of anemia were scattered among seven orders. There is +nothing striking or even individual about them worthy of special +mention. + + +SUMMARY OF SECONDARY ANEMIA. + +A review of our records shows that among 5365 animal autopsies we have +recorded anemia of probable secondary character in 122 instances, 53 +(2.8 per cent.) mammals and 69 (1.9 per cent.) birds. The orders +represented, with the percentage for the order, are Primates, 25 or 5 +per cent.; Carnivora, 18 or 3.7 per cent.; Ungulata, 3 or .8 per cent.; +Marsupialia, 4 or 2.2 per cent.; Rodentia, 3 or 1.5 per cent.; Passeres, +37 or 2.7 per cent.; Psittaci, 9 or 1.3 per cent.; Herodiones, 8 or 8. +per cent.; Columbæ, 7 or 4.7 per cent.; Picariæ, 2 or 2.3 per cent.; +Striges, Galli, Gaviæ and Accipitres, each one case. A consideration of +their associated pathology reveals the fact that four changes are +prominently associated with secondary anemia, to wit: gastrointestinal +inflammation, 26 times (15 mammals and 11 birds); parasitism, 29 times +(7 mammals and 22 birds); osteomalacia, 24 times (18 mammals and 6 +birds), and nephritis, 18 times (12 mammals and 6 birds); a few of these +cases overlap, but this is rather the exception than the rule, and this +does not militate against the importance of the connection with anemia. +It will be noted that practically all the important orders of animals +are represented, including species from all over the globe. There is, +however, no especial relation of anemia to the kind of diet or digestive +tract. Conclusions as to the meaning of these figures of incidence are +hardly justifiable. In so far as the blood picture is concerned we can +only record the qualitative appearance and the effect upon tissues. It +cannot be stated that to external observation a secondary anemia +presents any distinguishing features that a specimen in poor condition +may not exhibit. The monkeys formerly dying of tuberculosis had not +infrequently pale buccal mucosa and skin around the eyes, but upon +examination of their viscera, blood or marrow the quality of their blood +could not be called greatly substandard. Slide smears of secondary +anemia in many specimens would occasionally show stippling or a moderate +number of nucleated cells with anisocytosis and poikilocytosis. This is +much more frankly exhibited in the Aves, wherein displaced karyolytic or +pyknotic nuclei are very common. Mention has been made of the rifts in +the protoplasm, seen in Herodiones, and this has been observed in other +orders. Perhaps the most striking change is the increase of young +erythrocytes and of thrombocytes in the winged creatures. The nucleus of +the former reminds one of that of the human plasma cell. + +The condition of the bone marrow corresponds with fair accuracy to that +which one is accustomed to see in the human being. Certainly this holds +good for the mammals, while among the birds, the few observations upon +which we feel like relying indicate a nodular erythropoiesis of rather +striking character. In the areas of reddening as seen grossly there will +be found under the microscope an orderly arrangement of large red cells +with loose chromatic nuclei about a very much larger cell of the same +type, apparently the primary erythroblast. Outside of this group, red +cells such as appear in the circulating fluid, are rather irregularly +distributed in a marginal zone. I have seen small areas like this in +apparently normal marrow, but the central grouping was not so large as +in the anemic cases; it thus appears that we probably have the anatomy +of erythropoiesis. + +The deposition of pigment in the birds is in much coarser granules than +among the mammals, in the former case large masses sometimes obscuring +several liver cells or apparently blocking a lymphatic sinus; the +Kupffer cells do not seem to be heavily laden. + +The extramedullary formation of blood cells has been a matter of +considerable interest and study in the human being, and as far as it +concerns the circulating mononuclears, the general opinion seems to be +that such a histogenesis exists. A decision in the negative is perhaps +reached by the majority in the case of erythropoiesis, and as far as my +observations go, this holds for all mammals. It seems worth while, +however, to record an occasional finding in some birds, especially +anemic ones, which may be of importance in their erythropoiesis. The +adult red cell is a clearly formed ellipse with a distinct, deeply +stained, sharply outlined nucleus of a shape corresponding to that of +the whole cell. Young red cells have a more nearly circular outline but +almost truly circular nucleus, the short diameter being at least +proportionately greater than is the corresponding short diameter of the +whole cell; this is also the nucleus whose internal structure resembles +that of the human plasma cell. Groups of such cells have been seen in +the interstices of the liver, sometimes as many as twelve, in a rather +orderly formation. An excess seems at times visible in the spleen but +not in orderly arrangement. Observations are under way toward +determining the relation of this finding to the amount of marrow, the +condition of the blood and the habits of the bird. + +Primary Anemia. + +As already specified primary anemia is apparently causeless, aside from +the assumption that it is a disease of the marrow itself. Since there +are only four cases, representing three orders and they cannot be +grouped as could the secondary variety, the individual instances will be +discussed separately. + + + Ring tailed Bassaris (_Bassariscus astutus_). Adult died after two + weeks’ stay in the Garden with a history of general failure of + condition. The diagnosis at autopsy was primary anemia, fatty + degeneration of the liver, hemorrhages in intestines and spleen, + hyperplastic bone marrow. The external appearance is of general good + condition, fair skin, mucous membranes pale. Lungs collapsed, and + gray-red. There are several small hemorrhages scattered irregularly + throughout respiratory tissue. Lymph Nodes—small, soft mottled gray- + red. Pericardium had slight excess clear fluid, and no adhesions. + Heart normal in size, and of pale brown color. The liver of normal + size, smooth surface and sharp edges, of a pale brown color, soft and + friable. Has indistinct markings like yellow brown mottlings on + section surface. gall-bladder contains some viscid brown bile. Spleen, + normal or slightly less in size, consistency firm, capsule pale pearl + gray, apparently not thickened. There are numerous small hemorrhagic + spots on section surface. Interlying pulp is homogeneous deep red. + Follicles not visible. Kidney, normal in size and shape. Trabeculæ + faint. Capsule smooth, strips easily, smooth surface, and brown. + Consistency soft. Medulla prominently striated, cortex homogeneous + salmon pink. Stomach contains a little glistening mucus. Mucosa pale, + flat yellowish, slightly opaque. There is a recent clot lying in some + mucus just above pyloric valve. There is, however, no open vessel + nearby. From pylorus to anus lumen contains some rather fresh smeared + out or slightly clotted blood and mixed in with mucus. Mucosa is flat + translucent, submucosa slightly injected in a mosaic fashion, + otherwise gut wall is negative. No recognizable food present. + Follicles not visible. Mesentery glands small, soft, pale yellow. + Bones seem entirely normal. Marrow of long bones is firm, bloody. + Marrow of ribs also deep red. Blood in intestinal tract is probably a + recent slow oozing from intestinal walls, and was probably the last + straw. Cause of this anemia could not be determined. Blood preparation + not made because it was too long after death. Liver shows moderate + fatty infiltration of marginal areas. Pigment is scarce, only a few + granules being present in the Kupffer cells, not more than is often + seen without marked anemia. There is a slight increase in interstitial + nuclei but not in fibres. No obstruction or increase of bile ducts. + + Kidney.—Very mild swelling of tubular epithelium but no exudative + processes. Glomeruli show a few vacuoles but capsular space is + negative to pigment. Bone marrow (Femur) fairly cellular in + construction, but fat well mixed. Cellular areas well arranged, + active, most of cells are small members of the larger mononuclear + variety. Small lymphocytes abundantly represented. Most of the larger + cells are non-granular, with centrally placed nucleus. Megakaryocytes + fairly numerous, nuclei seem closely jammed into centre. No + recognizable certain nucleated red blood cells, moderately number + stippled cells, few adult red cells. Eosinophiles and basophiles quite + few. Pigment small quantity. + + +This is a case of primary anemia of moderate severity and short +duration, and probably of hemolytic character if one may judge by the +bone marrow, although excessive pigmentation of the liver and kidneys +was not found. Unfortunately the spleen was not minutely studied, nor +was the central nervous system investigated. Atrophy of the intestinal +tract did not exist. + +Two cases occurred among the monkeys, but one example will answer, since +the two were essentially the same. + + + The case to be cited was that of a Japanese Macaque (Macacus + fuscatus). ♀ Young, weight three pounds two ounces, exhibited in the + Garden about four months, and apparently in good shape until two weeks + before death when it rapidly became emaciated. + + DIAGNOSIS.—Aplastic anemia, chronic atrophic gastritis. Atrophy of + heart muscle, fibrosis of liver, slight local cloudy swelling of + liver. Perilobular diffuse nephritis (subcapsular type). Congestion of + spleen. Fibrillar fibrosis of spleen. Hemosiderin pigmentation of + spleen. Local amyloid infiltration of spleen. Calcareous infiltration + in medulla of adrenal. + + Coat only fair, body emaciated. Pale muscles, fat scanty. Respiratory + tract normal throughout save for slight emphysema. The Pericardium + showed no fluid or adhesions. Epicardium glistening and slightly + thickened. Heart pale in color. Abdomen shows no fluid or adhesions. + Liver slightly decreased in bulk, smooth surface and sharp edges, + hard, and rusty brown. Gall-bladder distended, contained green fluid. + Spleen firm and normal in size. Capsule smooth, shape normal. Section + surface, dark reddish brown, trabeculæ distinctly visible. Kidney, + normal in shape, capsule smooth, strips easily, smooth surface, + glistening, pinkish gray, consistency hard. Section surface, poor + demarkation between cortex and medulla. R. Adrenal, thick orange + yellow cortex, solid small brown medulla. Mouth and teeth normal. + Stomach distended, contains gas and small quantity yellowish mucus. + Mucosa everywhere normal. Postmortem blood examined, stained by + Romanowsky, but red cells were disintegrated possibly by laking so + examination is not satisfactory. Histological Sections: Heart shows + normal epicardium quite free of fat. Myocardium peculiar in that + fibres immediately under epicardium show marked broadening in a very + narrow rather sharply indicated zone where nuclei are extremely large + although not especially chromatic. Transverse markings here easily, + although faintly recognized, have very indefinite borders, their + longitudinal fibrillæ being ranged in form of a coarse reticulum. This + comes about from frequent and extensive lateral anastomoses with + fellow fibres giving appearance of a syncytium. In deeper parts, + fibres are of more normal size but nuclei are still large and fibres, + now cut in transverse section do not appear to anastomose so freely; + there appears to be a slight excess of fibrous tissue in their deeper + parts. Arteries quite normal. Atrophy with regeneration. + + Liver.—Capsule and interstitial parts on whole normal. Perilobular + fibrous tissues largely missing, but where remaining show an + overgrowth occurring in peculiar zonal arrangement and of old adult + almost hyaline type. Its fibres are often arranged strikingly in + whorls. Bile ducts, arteries and veins quite normal. Parenchymal cells + of normal size, finely granular, prominent normal nuclei and contain + small quantities of finely granular, golden brown pigment not really + as abundant as commonly seen in severe anemias. Blood capillaries + narrow, contain small quantities R.B.C., and Kupffer’s cells very + frequently contain fine granules like those of parenchymal cells but + of a greener tint. In a few isolated areas parenchymal cells + distinctly more swollen than others and many show disintegration of + nucleus. Hemosiderin pigmentation. Perilobular fibrosis. Slight local + cloudy swelling. + + Kidney.—Capsule smooth, interstitial fibrous tissue of organ proper + highly fibrosed in peripheral parts, but slightly in deeper. No + lymphocytic infiltrations anywhere or sclerosis of vessels. Tubular + epithelium highly atrophic in subcapsular regions where tubules are + narrow. In deeper parts epithelium is at times so swollen as to + occlude lumina, where they are coarsely granular and occasionally show + some karyolysis, a pink hyaline or finely granular material. Tufts + never show fibrosis, normal size. Bowman’s capsule heavily thickened. + Chronic diffuse nephritis (subcapsular type). + + Spleen.—Slightly hyalinized capsule, normal thickness. General + reticulum of pulp slightly fibrosed and poor in lymphocytes. Sinuses + broad, crowded with red blood cells, but only small numbers of + lymphocytes. Coarse granular blood pigment abundant, showing greenish + cast on focusing. Malpighian follicles normal size, slightly fibrosed, + and in several instances show a deposit of smooth pink material + between cells. Congestion. Fibrillar fibrosis. Hemosiderin + pigmentation. Local amyloid infiltration. + + Adrenal.—Organ appears normal in all respects save for presence of a + few small irregular areas of calcification in medulla. These occur + apart from any recognizable necrotic or fibrous areas. In one place + one appears to lie within lumen of blood vessel. No fibroses or + special congestions anywhere in organ, and cells show normal details + and normal numbers of vacuoles. Calcareous infiltration of medulla. + + Stomach.—Muscular tunic normal. Submucosa thin, has densely arranged + bundles of smooth, pink character. Mucosa distinctly thinned, shows + comparatively few regions holding acid cells, consisting for most part + of peptic type of gland. These are short and of broader calibre + towards lumen than deeper, suggesting a hyperplasia of luminal + portions; stroma richly infiltrated with lymphocytes, not fibrosed or + congested. Epithelium of crypts has rarefied appearance, shows no + special degenerative changes. Chronic atrophic gastritis. + + Bone marrow appears as widely separated large, fat globules with + intervening granular edematous material and no hematopoietic elements. + Blood capillaries numerous and highly congested. + + +Although the notes fail to discuss the gross appearance of the bone +marrow, the amount of alteration in its microscopy and the relatively +small output of pigment in the liver, seem to substantiate the +determination of aplastic anemia; it is unfortunate that the blood +smears could not be used in the decision. At all events the condition of +the intestinal tract, of the heart, liver, spleen, and adrenal, justify +us in classing the case as one of primary anemia. The next and last +instance is of the same type, although I am inclined now to differ from +the diagnoses made at the autopsy table, that of aplastic anemia, and to +place it in the hemolytic variety. The rapidity of the fatal attack, the +redness of the marrow, the excessive pigmentation, and the prominence of +recent degenerative lesions in the organs are much more like the changes +of a primary hemolytic intoxication than of an aplastic anemia. + + + Gray Fox (_Canis cinereo_). ♂ Weight four pounds, adult, was in the + exhibition two years, but in good condition until two weeks before + death, when it stopped eating and rapidly fell away. + + DIAGNOSIS.—(Aplastic) Primary anemia. Zenker’s Hyaline of heart and + skeletal muscles. Mucoid degeneration of bone marrow. Congestion of + bone marrow. Atrophy of hemopoietic elements in bone marrow. + + Hemosiderin pigmentation of liver. Atrophy of liver. Congestion of + liver. Congestion and fatty infiltration of kidney. Patulous lumina in + adrenal and absence of pars glomerulosa. + + External appearance of coat good. Decomposition advanced in + intestines. Skin and subcutaneous tissue faintly yellow. Poorly + developed, dark muscles and fat. Respiratory tract normal throughout. + Pericardium glistening, transparent, and pale, with no adhesions. + Heart a little too pale, consistency slightly soft. Normal or slightly + increased size of liver, with smooth surface and sharp edges, + consistency friable, and of a brownish red with rusty coloring. Spleen + normal. Kidney normal in size, shape, location, and consistency. + Capsule strips easily, and of a faintly yellow, under general red, + coloring. Adrenal normal. Mouth and teeth normal. Stomach, serosa and + wall normal. Mucosa shiny, autolytic, muddy red. Ileum, agminated + follicles swollen. Feces from colon examined microscopically. Pancreas + normal. Bone marrow tibia and femur gelatinous and red, not slightest + trace of yellow. Blood films from heart’s blood show poikilocytosis + and anisocytosis; only one nucleated red. + + Microscopic Notes.—Heart has torn but normal pericardium. No + abnormalities of interstitial tissue or vessels. Fibres of normal + width but show transverse markings irregularly since cytoplasm becomes + hyaline and swollen in many places along its course. Nuclei prominent, + slightly pyknotic. Zenker’s Hyaline. + + Bone marrow consists of a matrix of granular or fibrillar mucoid + tissue within the delicate reticulum of which highly developed + capillaries are placed, together with stellate spindle and sealring + cells. In a few places only are myelocytes recognizable and then in + decreased numbers. Plasma cells sometimes found containing much blood + pigment. + + Liver.—Capsule normal; perilobular fibrous tissue only slightly + overgrown, moderately infiltrated with lymphocytes and heavily with + blood pigment. Arteries, ducts, veins, normal. Parenchymal cell a + little smaller than normal with nuclei of normal type, and crowded + with fine granules of blood pigment. Latter lie in usual + pericanalicular position. Blood capillaries narrow, moderately + congested and Kupffer’s cells also contain abundant pigment granules. + + Thyroid.—Interstitial framework shows no fibrosis or cellular + infiltrates. Blood vessels normal. Acini fairly uniform in size, none + ever attaining large proportions, but some being distinctly below + normal. They are uniformly filled with a very pale pink hyaline + material which in some way gradually increases in color intensity + toward one side, attaining in a few examples usual intensity of + colloid. Lining epithelium is low cuboidal, shows no special + hyperplastic features or atrophy. + + Kidney.—Capsule normal. Interstitial tissue normal. Blood vessels + slightly congested. Tubular epithelium granular, disintegrated and + frequently contains numerous fat globules and obscured nuclei. Lumina + of about normal size containing variable quantities of pink granular + detritus. Glomerular tufts normal in size and appearance. Subcapsular + space and Bowman’s capsule normal. + + Adrenal.—Capsule and pericapsular tissue normal. Parenchymal cells + throughout poor or practically free of vacuoles, such appearing in + only limited portion of pars vesicularis. Interstitial framework and + vessels normal. Structure of columns in pars vesicularis is peculiar + in that they extend quite to capsule with no intervening pars + glomerulosa, and again in that most peripheral parts are expanded at + times showing a lumen, while deeper parts show broad cells extending + fully across the column. Pars reticularis contains no pigment and + medullary cells quite normal. Skeletal muscles show comparatively few + fibres with transverse markings. Most are swollen, hyaline, lumpy, and + have pyknotic nuclei. Interstitial parts show no inflammatory change. + + Tissues treated by Prussian blue test for iron. Kidney, adrenal, heart + found to contain none. Spleen, liver contain abundance. That in spleen + responds to test showing that it is all iron containing. Two kinds of + pigment found in liver. In periphery of lobule as much contains iron + as that which does not, while in deeper parts iron predominates. Many + times both kinds are recognized in one cell. On the whole it is the + finest granules which contain more iron (are bluer) while iron free + pigment occurs in bile canaliculæ. That in Kupffer’s cells stains + strongly blue. + + +SUMMARY OF PRIMARY ANEMIAS. + +A review of these instances of grave anemia brings one to the conclusion +that there is a strong similarity to the disease in man. Perhaps we have +constructed a picture that is too narrow for the animal kingdom in +general, but surely these few instances deserve to be distinguished from +the secondary cases already presented if for no other reason than that +no associated etiological condition was exposed. It was hoped in +studying the anemias of lower animals, and this hope extends over all +the subject of this book, to be able to throw some light upon causation. +The thought of incorrect diet came at once, but we are confronted with +the paucity of cases among our records. Moreover, secondary anemia from +digestive and dietetic troubles is clear, but how we can use this +argument for an essential change in hematopoiesis and natural +hematolysis, is far from evident. It will be noticed that I have +studiously avoided grouping any case with parasites among the primary +cases, nor will there be found any evidence of generalized infectious +disease. Most of the reported instances of pernicious anemia in the +lower animals have been associated with one or other of these factors, +although certain authors (Kitt, Hutyra and Marek) maintain that a +causeless variety probably exists. + + +LEUCEMIA. + +This condition is fairly well recognized by veterinarians as occurring +among domesticated animals, but in the records of this Garden it has +occurred rarely, indeed only once in a mammal and but five times in +birds. It is interesting that, in the wealth of material at the disposal +of Plimmer and his associates, only one case, a polecat with lymphatic +leucemia, is noted, and but very few avian instances. Herewith is +submitted the protocol of our single mammalian case; perhaps we have +missed others of a mild grade dying during the early stages because +their resistance to infection was reduced. Unfortunately, perhaps +because of the postmortem changes, but more likely because it appeared +at first as if we had to do with a case of generalized tuberculosis, the +bone marrow in this case was not examined. Nevertheless the infiltrative +character of the lesions, the absence of distinct tumors and the +numerous mononuclears in the blood as seen in sections seem to justify a +diagnosis of leucemia, in all probability of the lymphatic type. There +follows this case one with similar gross and microscopic picture which +has no visible increase of leucocytes, but a very distinct myeloid +picture in many places. + + + Common Opossum (_Didelphys virginianus_). ♂ Adult. No evidence of + illness. Found dead. Lymphatic leucemia (involving all viscera and + lymph nodes). Diffuse nephritis. Both lungs have become entirely + involved in a firm, gray-yellow mass not adherent to any serous + surface. Practically no normal lung tissue is left. This seems like + tuberculosis but no tubercle bacilli could be found in a good smear. + Estimation of the normal cubic capacity of an opossum lung was made to + be about five cubic inches. In this case not over one-half cubic inch + remained respirable. Bronchial lymphatic glands were enlarged, firm, + yellow gray, with no recognizable lymphatic tissue. Heart muscle was + firm and flaccid, pale and striated. Liver very large, firm and tough, + with smooth surface and sharp edges. Color pale brown. Section surface + glistening, dry, smooth, opaque. Common bile duct patulous. Spleen, + slightly increased, firm, tough consistency, capsule smooth. Section + surface, smooth, firm, brown-red, pale pulp, prominent follicles, and + trabeculæ faintly visible. Right kidney, slightly decreased, normal in + shape. Capsule smooth, strips with difficulty, tears surface. Surface, + granular, color brown, consistency firm. Thickness of cortex, narrow + irregular, markings irregular and obscure. Small mass of fibrous + material in cortex about 3 × 3 mm. like those in lungs. There are also + numerous pale yellow gray areas in cortex and outer medulla, round and + streaky, distorting the striated architecture. Right adrenal converted + to a yellow gray mass like lungs. The mesenteric and retroperitoneal + lymph nodes are firm, gray-yellow. This includes those under diaphragm + and around cœliac axis. + + The histology of the organs may be described together. The infiltrate + described is a densely packed mass of large cells with large, well + staining nuclei and a very narrow rim of protoplasm. It is not limited + by any definite wall or septa. It has no interstitial tissue. There is + no blood supply in the densest masses but the walls of the blood + vessels remain intact wherever the mass surrounds them. In the lungs + it has involved all structures indiscriminately, and has destroyed + practically all of the respiratory surface. It seems to follow by + preference the peribronchial space. A few glands may be seen in the + centre of this mass, but they are rapidly undergoing degeneration. In + the liver the infiltrate is chiefly beneath the capsule extending + inward but a very short distance. There are no large masses as in + other organs but small infiltrates are seen at the portal areas. The + spleen shows a diffuse excess of pulp cells and many of the cells + above described, the difference being only in the size of the nucleus + which is smaller in the pulp cells. There are very small round cells + relatively. Follicles are absent, connective tissue not altered. Note + states follicles prominent; this is due to nodal hyperplasia of the + large mononuclears above described. The parenchyma in the kidney is + anemic, the epithelium is slightly pigmented but this is probably not + abnormal. Between the tubules especially of the outer layer of the + medulla and medullary ray but also in the cortex and around the + glomeruli are diffuse, irregular, infiltrating masses of the cells as + described above. In some places in the kidney hyaline casts are being + formed probably due to the degeneration of the epithelium by pressure. + There are a few distentions of the tubules. The capsular space is + free. In the neighborhood of the collections the capsules are a trifle + thicker than normal. Lymph nodes, similar to spleen in that most of + the bodies are thoroughly overrun with the large mononuclears. The + sinuses, both marginal and internal, are practically obliterated by + these cells. In the blood vessels of the lungs and liver there are + many large mononuclears, perhaps not as large a number as might be + seen in leucemia, but decidedly in excess of normal. + + Common Marmoset (_Callithrix jacchus_). ♂ Adult. Had cage paralysis + for two months before death and declined gradually from that time. + + DIAGNOSIS.—Bronchopneumonia. Myeloid hyperplasia of bone marrow. + Myeloma in pancreas. Fatty degeneration of liver. Constipation. + Nematodes in cecum. Animal is thin, skin bare in spots. Both lungs are + pale pink with large areas of deep red consolidation. Heart is + dilated, increased in size with firm, red-brown muscle. Liver is firm, + red-brown, with smooth surface and sharp edges. Section surface is + glistening, smooth and moist. Lobular outlines are clear by reason of + pale lines. The gall-bladder is normal in size and contains fluid pale + green bile; duct patulous. Spleen is normal in size, smooth capsule, + soft, purple pulp, follicles small and faint, trabeculæ fairly + prominent. Kidneys normal in size and shape. Capsule smooth. Section + surface smooth and brown and firm. The glistening section surface has + a narrow cortex, swells slightly, with prominent striæ. Intestines + throughout are pale on serosa. Wall thin. Mucosa flat, pale pink. + Contents creamy mucus in the upper intestine. Large intestine contains + large masses of very firm feces. Cecum is distended with feces and a + great quantity of nematode worms. They are not attached to mucosa nor + does mucosa seem altered because of their presence. Skeleton and + muscles.—Long bones of extremities break easily, but with snap. Skull + can be dented with fingers. Bone marrow of femur bright red. + + MICROSCOPICAL NOTES.—Liver shows moderate degree of fatty degeneration + with capillary congestion. Kidneys negative. Some postmortem change in + last two organs. Spleen, marked congestion. Hyperplasia of large lymph + cell type, particularly in follicular centres. Blood destruction + moderate. Bone marrow seen in condition of marked activity of myeloid + type. Aside from enormous crowding of strands there does not seem to + be any atypical cell. Intestines show practically no change. Same + condition holds in pancreas. In several places in pancreatic ducts + cross sections of nematodes may be found. In among lobules of pancreas + is a well encapsulated cellular mass without particular architecture. + It consists of cells of large lymphocyte or endothelioid series. There + are numerous cells of size and staining characters of small + lymphocytes. There are no megalocytes but there are some + indistinguishable from myelocytes. This may be an intrapancreatic + lymph node. One small lymph node found in section; it shows a picture + quite like the marrow except for megalocytes. Blood vessels do not + show an excess of leucocytes in free or coagulated blood. + + +Perhaps this latter case belongs to the aleucemic leucemias or +pseudoleucemias. These two conditions are recognized by the difference +in circulating leucocytes, a piece of information not at our disposal. +The whole subject of hemato-lymphatic affection must remain unsettled in +so far as a diagnostic name is concerned, for in very few cases has the +blood of our animals at autopsy been in a state permitting reliable +observations upon stained smears, because of coagulation, lysis or +decomposition. After considering a few more of the diseases of the blood +and marrow, the lymphatic apparatus will be considered. But there is a +borderland to which a word might be devoted at this time, that group to +which various names—Hodgkin’s disease, pseudoleucemia, general +adenopathy, adenie, aleucemic leucemia—have been applied and which has +been accepted as occurring in the domesticated animals. Since I have +been occupied for several years in a study of this clinicopathological +complex in the human being, such cases have been searched for most +diligently, but without success. The New York Zoological Park records a +case of Hodgkin’s disease, without specifications, in 1901, and at the +London Garden a pseudoleucemia was found. The paucity of leucemia and of +the aleucemic adenopathies in lower animals and their relative frequency +in man excite speculation as to their interdependence; but more of this +under the lymphatics. + + +AVIAN LEUCEMIA. + +The class Aves is rather better represented in the group of leucemias, +but here the well known infectious disease may confuse the picture. The +birds affected were Psittaci 3 (1 parrot, 1 parrakeet, and 1 amazon), +Herodiones (stork) 1, and Galli (Gambel’s quail), 1. There was no close +association of these cases either in time or housing. One of the parrots +and the stork had a picture suggesting that given by Warthin for avian +leucemia while the remainder presented greater evidence of a generalized +infection, such as Moore described, associated with the finding of the +B. sanguinarium; this organism was isolated once, but no secondary cases +succeeded upon the death of this bird. It seems hardly profitable to +quote protocols of this relatively unimportant condition, especially +since it is fairly well known. + +The separation of the two groups just specified might be discussed, +however, for it is by no means certain that they are or are not +different. When a pathological picture of leucemia gives a decided +impression of an acute infection there are very prominent involvements +of the viscera but no lymph nodal masses. On the other hand, in the +cases with nodular masses corresponding to the scanty lymph tissue of +birds, there is much less infiltrative involvement of viscera and less +parenchymatous degeneration. This suggests that they are different +processes, but an analogous contrast may be found in the pathologic +anatomy of acute and chronic leucemia in man, and I am inclined to view +them as stages of the same disease. In one of our infectious cases noted +above the lesion was certainly myelogenic for the infiltrate in the +organs and the cells in blood smears showed an enormous number of +eosinophilic and basophilic polynuclears greatly in excess of normal. +The study of two of our cases confirms the picture as given for +lymphatic and myeloic leucosis by Ellermann[18], but material +corresponding to his lymphoidocytes or erythroleucotic group has not +come to our attention. Cells with deeply staining basophilic protoplasm +and a lymphoid nucleus are certainly to be found with reasonable ease in +the avian marrow normally and, more than this, can be detected by +careful search in nearly all cellular infiltrates of organs not leucemic +in nature. Perhaps, as Ellermann states, they are collateral stages in +normal erythrogenesis. + + +THE BONE MARROW. + +Since the foregoing conditions so vitally concern the bone marrow, it is +but natural to give to this structure a separate consideration. From +what is known of the origin, physiology, anatomy and regeneration of the +marrow from the work of Ponfick, of Neusser, Bunting, Selling, Werigo +and many others, it seems highly probable that the principal conclusions +reached in the study of human medicine and experimental pathology, apply +to the whole group of animals here under discussion. The peculiar +arrangement already mentioned as encountered in the marrow of birds +differs little if any from the erythropoietic centres seen in man after +experimental anemia, although it may be somewhat more orderly. +Myeloblasts or megakaryocytes are not numerously present in any order, +but seem more prominent in the mammals than in birds. In so far as the +mononuclear groups are concerned, one can state with reasonable +certainty that they differ little throughout the animal kingdom. They +occur in islands, strands, or infiltrate—like groups, are mixed granular +and non-granular in character and, with exception of the frankly +oxyphilic cells, are distinctly basic in tinctorial affinity. In a case +probably myeloma, soon to be discussed, there is not a single +acidophilic or multinucleated cell to be found in two sections. As might +be expected from the greater eosinophilic content of the circulating +blood in the Aves, greater numbers of such cells are to be found in the +marrow and they are, understandingly enough, sometimes found in distinct +nodes and groups containing mono- and polynuclear varieties. Concerning +the platelets, no sufficient data are at our disposal to warrant a +general statement. In the avian marrow they can be made out quite +clearly, as in the blood, and have a greater diameter and a sharper, +more chromatic nucleus than in the higher mammalian blood. Mast cells +are quite common in lower mammals and birds, in whose blood they +maintain an appreciable percentage, while in the marrow they stand out +clearly. It is noteworthy, in the light of Graham’s statement that the +hemic basophile is but a degeneration form of the eosinophile, that in +the bird’s marrow, large mono- and polynuclear cells with both kinds of +granules easily may be found by Romanowsky stain. An increase of +eosinophiles, seen in avian as well as in human parasitism, is not +necessarily accompanied by basophilia. + +Hyperplasia and atrophy of marrow in the lower mammals follow much the +same conditions as in higher groups. During acute general infections, as +by the paracolon bacillus in carnivores, it is common to find a distinct +increase in the mononuclear centres, while in suppurative lesions a +polynucleosis results. The bird, however, responds less readily with +leucocytes, judged by cross sections of blood vessels and the activity +of the marrow. The latter may show a myeloid picture, but mononuclears +without granules, with deeply staining nucleus and protoplasm, are +usually more numerous; two cases recently studied, one of tuberculosis +and one of pneumonia with general congestion, had similar bone marrow— +pale homogeneous red with distinct mononucleosis, more outspoken, +however, in the former case. Pigment is not common in the avian marrow. + +The relation of the marrow to general conditions has been mentioned in +the foregoing pages, but perhaps the following diagnoses will illustrate +other connections seen among our records: + +Bactrian Camel (_Camelus bactrianus_).—Hydatid disease of lung and +liver. Hemorrhagic enteritis. Atrophic bone marrow. Calcified areas in +thyroid. + +American Gray Wolf (_Canis mexicanus_).—Cretinoid. Hemorrhagic external +pachymeningitis with craniotabes. Secondary hyperplasia of thyroid with +colloid. Chronic lymphatic hyperplasia. Chronic interstitial nephritis. +Chronic enteritis. Osteogenesis imperfecta. Hemorrhagic bone marrow. +Concentric hypertrophy and dilatation of heart. + + +MYELOMA. + +Perhaps no pathological condition has given rise to more varied opinions +than the tumor-like hyperplasias of the bone marrow, growths resembling +bone sarcoma with and without giant cells—myeloma, chloroma, +pseudoleucemia ossium and many others. In brief only two cases occur in +our series which could be admitted to this category. There have been +osteomata, but they were so clearly local tumors that they cannot be +included in myeloid neoplasms that are assumed to be systemic in nature. +Here is not the place to engage in a discussion of the correct +classification and nomenclature since there are included only the +aleucemic newgrowths usually assumed to originate from blood-making +cells. The first case seems to be a myeloma because of the involvement +of many bones and the infiltrates in the liver. Judging by the cross +section of blood vessels there is no leucemia, but of course this is not +final, although somewhat supported by the normal size of the spleen and +lymph nodes; lymphatic structures need not be enlarged in myeloid +leucemia although they usually are. + + + Beechy’s Gopher (_Citellus grammurus beecheyi_). Adult ♂ . Gradual + loss of power in limbs beginning about two weeks ago. No other + symptoms. + + DIAGNOSIS.—Multiple myeloma. Anemia. Acute parenchymatous nephritis. + Chronic ulcerative gastritis. + + External Appearance.—General condition fair, hair in good condition. + Fully developed animal. Muscles contained no fat. + + Respiratory Tract.—Thymus, large soft gray homogeneous. Both lungs are + distended, pale, homogeneous, yellow pink, boggy, do not crepitate, + but contain no edema. Lymph nodes, small soft anthracotic. Pericardium + contained no fluid. + + Abdomen.—No adhesions. Size of liver normal or slightly small, firm + and pale brown-red. Architecture irregular showing areas of perfect + homogeneity and others where lobules are clear outlined by paler + interstices. Gall-bladder distended, contains brown fluid. Common bile + duct, patulous. Spleen, normal or slightly small, consistency soft, + capsule smooth, location normal; section surface, homogeneous pale + pulp, faint trabeculæ. Kidney normal in size and shape, capsule + smooth, strips easily, smooth brown surface; section surface + glistening, opaque; consistency firm; thickness of cortex normal and + of medulla normal; homogeneous cortex, glomeruli not visible. + + Adrenal.—Narrow, brown, opaque cortex; pale brown, opaque medulla. + Bladder, small quantity of cloudy urine showing albumin, bile and many + granular casts, few hyaline casts. Teeth carious broken; mouth pale. + Stomach distended; serosa and wall pale, contained gas; mucosa pale, + flat, translucent except in pyloric segment where it is slightly + thickened, irregular, opaque and there are several saucer shaped + depressions covered with black, shiny material; these seem like + sluggish ulcers. Intestinal tract throughout seems normal save for its + pallor. Few natural fecal masses in lower gut. + + Skeleton and Muscles.—All bones are irregular in thickness, very + brittle and show in their length irregular swellings made up of + periosteal growth and probably increase in marrow. The latter is pale + yellow with punctate hemorrhages. Skeleton seems too soft to give + support, but there is little deformity. + + Microscopy.—Bone section shows a myelomatous growth of costal marrow, + new myelocytes predominating. The cells are packed in disorderly + fashion through the marrow. They are chiefly lightly granular but a + few distinct promyelocytes are found. The hyperplasia is invading + cartilaginous bone with absorption. In some places cartilage is of + fetal type. Perichondrium is active but there is no round cell + infiltration. Ossification is imperfect at costochondral junctions. + Kidney shows granular and vacuolar degeneration of epithelium with + flattening of tubular lining. Nuclei are for most part normal. + Epithelium of tufts and Bowman’s capsule is likewise granular and + vacuolated. Distal and discharging tubules seem to be most affected. + No well defined casts are found. + + Liver.—The fine markings mentioned in the notes correspond to areas of + infiltration of large pale mononuclears without granules. There is no + fibroblastic or polynuclear increase around them. Very small necroses + seen in hepatic lobules. Very slight increase of connective tissue is + noted. + + +This seems to be a tumor of true myelocytic origin; none of the cells +was of the plasma type as usually depicted. The second case stands in +the files as a myeloma, yet the full description and slides have been +mislaid. It is cited briefly for record. + + + Samoli Ostrich (_Struthio molybdophanes_). Adult ♂ . Would not eat for + three weeks. + + Diagnosis.—Tuberculosis of lung, liver, spleen, kidney, mesenteric and + cervical lymph glands. Myeloma of periosteum of pelvis. + + Skeleton and Muscles.—Large tumor mass lying on inside of pelvis + measuring about ten inches by twelve inches with a thickness of about + four inches. It is sharply defined and separated from adjacent muscle + by a capsule. Inner border is directly below the peritoneum, and outer + border lies directly on bony pelvis. Traced to its origin it seems to + come from pelvis yet tumor peels off bone easily, leaving a rough + surface. The tumor is soft and succulent, of a red gray color and + contains some fat and much irregularly placed masses of bony tissue. + + + + + SECTION V + DISEASES OF THE LYMPHATIC TISSUES INCLUDING SPLEEN + + +Since we have followed diseases of the blood from the simple anemias to +a place where mononucleosis in the circulatory system and in the fixed +tissues is the prominent feature, another step reaches the area whence +most of these cells emanate—the lymphatic system. The anatomical and +physiological position of the lymphatic circulatory apparatus is closely +analogous in the classes under discussion, and it stands in an +anatomico-clinical sense, closer to the hematopoietic system than to any +other structures, throughout the whole animal creation. This anatomical +division of the circulation is closely comparable, for pathological +purposes, in the mammals whereas in the birds one finds noteworthy +variations. In the class Aves lymphatic radicals are extremely numerous, +the plexuses in the extremities and thorax perhaps being complemental +for the rather scantily supplied blood vessels. About the fibulo-tibial +and femoral muscles the tiny lymph vessels form an extraordinarily dense +and intricate lacework, a replica of which may be found in muscles of +the upper limb, while in the pelvis and thorax a rich plexus is +distributed around both kinds of blood vessels and also lies within the +walls of air sacs. The air sac walls in the chest display lymphatic +lines very well in birds that have been for many years exposed to +railway dust, the natural pearl gray glistening membrane looking as if +black pepper had been evenly dusted over it. The lymph glands or +compound nodes so easily discovered in mammals are practically absent in +birds. Along the large thoracic vessels and in the pelvis of some +anserine and struthious varieties, small illy defined masses of +lymphatic tissue may be discovered by careful search but they do not +possess nodal arrangement and capsule. Lymph follicles on the other +hand, are quite numerous in the respiratory, and especially, the +intestinal tract. Groups of follicles may also be found in the lining of +the upper ends of these tracts in such situations that the names +faucial, pharyngeal, or even tubal tonsils are justly applied. I do not +find any reference to a lingual tonsil in birds, but this structure is +found, with of course many modifications, down as far as the monotremes. +The lymphoid tissue of the nasopharyngeal region is so placed in animals +as to be exposed to aerial and food infections, just as it is in man. It +is, however, noteworthy that chronic inflammations leading to +hypertrophy or to obstruction have not come to our attention. There is +only one diagnosis of chronic tonsilitis in our records, a determination +based upon the nodular red-brown prominence of the tonsillar region, but +there were no true hypertrophy and areas of fibrosis combined with +necroses as seen in human medicine; this case concerned a Chacma baboon. + + +HYPERPLASIA. + +In so far as the reaction to infectious or toxic agents is concerned +there seems to be a fairly uniform character through the mammalian +groups, but in the Aves there are a few differences worthy of mention. +It is at once admitted that these observations upon birds are based upon +a very few sections of isolated lymphatic tissue, but they are supported +by records of the changes in nodes in mucous membranes and viscera, and +by those in the spleen. The first and perhaps most noteworthy difference +is in the paucity in birds of large mononuclears of the endothelial +type. Their position in chords, sinuses and germinal centres is taken by +deeply staining mononuclears, of the size and general character of large +lymphocytes as seen in the blood. The hyperplasia in the follicles is +much more dense but it is outdone by that in the chords. Since the nodal +tissue of birds is not so sharply delimited by some sort of capsule, it +is but natural that the hyperplasia should be diffuse; in the intestinal +wall it may extend laterally twice or thrice the width of the normal +follicle. Necrosis, unless the disease be mycotic, tuberculous or +parasitic, is uncommon. + +It may be well to discuss for a space the reaction to infection of the +thoracic and intestinal lymphatics in mammals. The amount of +lymphadenoid tissue in the mediastinum is very great in some mammals, +notably the Ungulates, while in others, the Rodents and Primates, for +example, it is not so plentiful. Nevertheless the gross and minute +changes are usually of the edemato-exudative type—large, pink, soft, +moist glands. In the abdomen, on the other hand, one usually finds well +outlined, firm, yellow nodes in the mesentery and behind the peritoneum. +This is not only to be discovered in various chronic diseases of the +intestine but even in acute, so-called toxic enteritis seen in +carnivores from food poisonings. One must therefore ask if the local +nodes abundant in the intestinal mucosa do not take up the poisons which +cause the acute hyperplasia and are in turn backed up by the stalk +glands. Even in so acute and overwhelming a disease of the intestine as +hog cholera (which we have not had here) the glands retain their general +structure, although hemorrhagic, while in late stages they become firm, +sharply outlined and pigmented. In birds there may be swelling of the +omental bursæ, but as there are no lymph glands no masses are found. + +The response on the part of the lymphatic tissues as a system, or some +large section of this system, is shown in the following figures. It is +our practice to include in the diagnosis general acute or chronic +lymphadenitis or inflammation of a large drainage area. Acute changes +have been mentioned 103 times, in which the important orders are +represented as follows: Primates 21, Carnivora 46, Ungulata 15, Rodentia +3, Marsupialia 13, Pinnepedia 4. Chronic changes are mentioned 43 times +as follows: Primates 7, Carnivora 19, Ungulata 14, Marsupialia 1, and +Pinnepedia 2. This great proportion among the Carnivora does not +indicate that they have more lymphatic structures for such an advantage +is probably possessed by the Ungulata, but perhaps should be interpreted +as an evidence for this order of the ready response to irritation on the +part of the tissues in question. They probably suffer more, as we shall +see later, with inflammation affecting drainage tracts. The hyperplasias +or inflammations included in the figures above most often accompany +gastroenteritis, pulmonary diseases or long standing infectious +processes such as arthritis, while there are also lymphatic enlargements +both local and general, associated with skeletal degenerations +(rachitis-osteomalacia) and with thyroid disease. The former may be +described as lymphadenitis, the latter as lymphatic hyperplasia. + +Unlike lymphadenitis, a condition associated with some definite +infectious or toxic cause, systemic hyperplasia of the lymphatic tissue +may be apparently primary and causeless. In a pathological and clinical +sense alike these hyperplasias are protean in their manifestation, +making a satisfactory classification extremely difficult. For our +purposes they are divisible into acute and chronic, associated with an +increased number of circulating lymphocytes and without such a +lymphocytosis. + +The first, acute systemic lymphatic hyperplasia, is known in man as +status thymicolymphaticus, a well recognized condition chiefly +encountered in youthful males having some of the stigmata of the +opposite sex. There is no record, nor have I any recollection of a +pathological state in a wild animal comparable to this condition. + +If acute generalized lymph node increase be associated with +lymphocytosis, acute lymphatic leucemia exists; there is no case in our +records. Chronic enlargement of lymph nodes with increase of circulating +mononuclears is chronic lymphatic leucemia; a case of this has been +cited under leucemia. + + +LYMPHOMATOSIS. + +Chronic enlargements of the lymphatic tissues without leucemic blood +present a bewildering number of varieties, the best known names of which +are Hodgkin’s disease, aleucemic leucemia, pseudoleucemia and +lymphomatosis. On occasion they are at first localized tumors, being +generalized only late in the course; under these circumstances they are +usually classed with neoplasms in the form of leucosarcoma and +lymphosarcoma. Examples of lymphatic disease answering the above +description are limited to two, but even these must be explained in +certain particulars. There has already been quoted under leucemia a case +of a common Marmoset (_Callithrix jacchus_) which was probably aleucemic +leucemia of the myeloid variety; the enlargement of lymphatic nodes was +trifling. The case to be cited answers in most respects to the +descriptions of systemic lymphomatosis, but there were found two +conditions, enteritis and parasitism, which might be responsible for +sufficient general toxemia to stimulate lymph nodes and follicles to a +state of active growth. Even accepting these two cases as examples of +this group, it is very plain that chronic systemic primary lymphatic +hyperplasia is an exceedingly rare entity in wild animals. There has +been no case resembling Hodgkin’s disease of man. + + + California Hair Seal (_Zalophus californianus_). Young ♂ four months + old. Appeared to be in good health, no loss of flesh or activity. + + DIAGNOSIS.—Lymphomatosis. Fatty degeneration of kidneys. Emphysema. + Chronic follicular and catarrhal enteritis. Nematodes in intestines. + + External appearance good. Both lungs distended and are tense; it seems + almost like a spastic dilatation—a simple emphysema—beneath pleural + surface are many minute petechiæ. Lung mottled red and gray. This + color is present on section. Lobules clearly outlined and separable + with fingers. Bronchi and vessels widely open, the latter containing + small amount of fluid blood. Lymph nodes—Mediastinal, tracheal and + those visible in neck are variously but definitely enlarged, firm, + irregular and roughly nodular, both in appearance and to touch. On + section they are red and gray, follicular border not preserved and + merging with medulla; connective tissue visible; gray juice expressed. + Pericardium normal. Epicardium, glistening, transparent and pale. + Heart position, size and interior normal. Abdomen contained no + adhesions or fluid. Pale brown-red, firm liver with smooth surface and + sharp edges; markings not clear; section surface smooth; watery blood + expressed from section. Gall-bladder normal, contents limpid, brown. + Common bile duct patulous. Somewhat enlarged spleen, soft, yet + resilient; capsule smooth; section surface pulp homogeneous brown- + purple; follicles gray, slightly enlarged, clear, sharply outlined; + trabeculæ faintly visible, more prominent where they are near + follicles. Kidney normal in size, shape and location, with smooth, + pale brown surface; capsule smooth, strips easily, section surface + glistening, consistency soft yet resilient; thickness of cortex + slightly wide, of medulla normal; individual lobules clear yet no + increase of connective tissue between; pyramids quite pale; top of + medulla a little darker; cortices, pale, striæ quite faint and seem + irregular; glomeruli not visible. R. Adrenal—In upper pole are two + cysts about 1.5 and .8 cm. across; no scar at this point. L. Adrenal— + Wide pale purple, regular homogeneous cortex under very dense capsule; + medulla reddish brown, homogeneous, quite bloody. In left adrenal is a + pale gray, fairly well outlined area between medulla and cortex at + upper pole about 3 mm. across. + + Stomach.—Contains glass and stones; mucosa, soft, smooth, flat, yellow + and pink, translucent rugæ; cardia about normal; pylorus, valve + prominent but probably not hypertrophied. Duodenum—Beginning at + pylorus and extending through to ileum where follicles commence, + intestine contains small amount white, creamy material, serosa + negative, mucosa smooth flat, pale pink, translucent. There are small + nematodes, probably uncinaria, some of which are attached quite + firmly. Here and there throughout the gut are bits of thickened mucosa + or submucosa, 2–5 mm. across. Some of these have a tiny opening from + which clear fluid can be expressed. Ileum shows smooth flat + translucent mucous membrane; empty; individual follicles faint but + discernible. Colon reddened mucous membrane, nematodes and little + mucus. Pancreas, soft, normal in size and position, color pink gray. + The lymphatics of peritoneal cavity are all enlarged; most of + retroperitoneal are also. Regional lymph glands are also enlarged. The + description given for mediastinal answers here. The glands of + mesenteric stalk present chain of sausage-like masses. Glands in + mesentery are but slightly affected. Glands within and without + peritoneum at kidney are especially enlarged. Large gland behind + stomach and pancreas and in front of upper end of spleen is much + enlarged, thick and roughly circular; it shows much fibrosis. The + regional glands are distinctly enlarged but proportionately not so + much as the internal ones. Smear of juice expressed from peritoneal + glands shows large and small lymph cells in about proper proportions. + There are a few plasma cells. No granular cells. + + Smear from bone marrow shows enormous number of premyelocytes and mast + cells. Polynuclears in their early stages are not numerous. Small + groups of lymphocytes, lightly packed together, noted here and there. + Blood smears unsatisfactory. + + Microscopical.—Lung shows distended vesicles with considerable + congestion of septa and in some places red blood cells in alveoli. + + Kidney.—Glomeruli contracted, relatively anemic; capsule negative; + epithelium throughout in state of granular degeneration probably + fatty; connective tissue not increased. + + Intestines.—Show slight hyaline change in muscle fibres and nodular + degeneration and disappearance of protoplasm, leaving bare nuclei and + outline of the cells; submucosa loose; mucosa shows infiltration of + round and plasma cells, diapedesis, degeneration and desquamation of + epithelium. Section of ileum shows a hyperplasia of lymph follicles + with active centre in which large endothelial cells predominate. Small + swellings in submucosa consist of chronic granulation tissue, but + there is no foreign body and no evidence of preëxistence of a lymph + follicle. + + Lymph nodes loosely arranged but in places solidly small lymphoid; + chords and sinuses contain chiefly small lymph cells in which are some + mast and plasma cells; follicles small and loose, and centres contain + chiefly large lymph and plasma cells; connective tissue not increased + yet there are some fibroblasts in follicles. + + Spleen.—Shows almost entirely hemorrhagic pulp; blood destruction not + active; follicles large and made up of about equal mixture of small + lymph, plasma and large lymph cells; connective tissue prominent + probably because of excess of blood around it. + + +LOCAL HYPERPLASIAS. + +In this group and touching the purely hyperplastic, come the +hypertrophies of the lymphadenoid tissue of the nasopharynx; this can be +disposed of by stating that no true chronic hypertrophies have been +seen. With most cases of gastroenteritis in ungulates, and many in +carnivores, there is a swelling and redness of the tonsillar region but +an exudative or necrotizing process does not occur. + + +THYMUS. + +The thymus is rarely visible in our specimens but when found has usually +been normal. An increase in size and a decrease of consistency of this +organ is noted in marasmus (inanition) from failure of care of the young +by the parent, but so far as can be determined this has not been +adequate to cause tracheal compression. In a few cases of rachitis in +the canines, the organ is large and pale along with the rest of the +lymphatic system. In one of the tumors of the mediastinum to be +discussed, the suspicion arose that the growth originated in the thymus; +adenomata and sarcomata have been described in the lower animals. + + +TUBERCULOSIS. + +Tuberculosis of the superficial lymph glands is rare as an independent +lesion in the lower animals. Dr. C. Y. White was fortunate in seeing a +monkey with a chain of fibrocaseous nodes in the cervical region, upon +which before death he offered the suggestion that it was of tuberculous +nature. In Primates almost all drainage glands exhibit some miliary or +caseous process. One monkey rejected upon the tuberculin test had what +was apparently a primary lesion in the glands at the tracheal +bifurcation. In the Ungulata, lymphatic tuberculosis assumes two forms, +the caseous and the cellular. The former is generally understood while +the latter is more uncommon. It is occasionally seen in the “fungous +tubercle” of cows, but we have seen it in deer and in another order, +Carnivora. In the latter, tuberculosis being uncommon, examples in the +lymph nodes were noted but twice, once caseous and once solid; this +latter was made up of firm, homogeneous yellow pink masses of glands in +the mediastinum, showing under the microscope solidly packed epithelioid +and giant cells. + +Lymphatic tuberculosis in the birds is rare; only one case is recalled +(unfortunately record cannot be found) as small yellow, discrete firm +nodules in the mediastinum and neck. The minute picture was of a solid +arrangement of large vacuolated mono- and polynucleated cells which were +so packed with bacilli that the preparation could not be decolorized. + + +TUMORS. + +The neoplastic enlargements are represented by a lymphosarcoma of the +mediastinum in a Dorcas Goat; there were secondary growths in the liver, +the kidney and several isolated lymph glands. Secondary growths from +original tumors not in the lymphatic system are curiously rare, +certainly much less frequent than is found in the human being. In +ninety-two tumors which are known to give metastases, only three +involved the lymphatic glands and only one of these could be considered +as involving nodes not in the ordinary drainage pathway. + + +THE SPLEEN. + +The spleen is an organ whose exact position in the scheme of things +remains mystifying through the whole series of animals. Its functions +have been arrived at largely by exclusion, somewhat by conjecture and +speculation, while the acceptably proven duties are indeed few. Although +this is not the place to enter into a discussion of all the points at +issue concerning the anatomy and function of the organ, a few facts +might be mentioned of comparative and perhaps pathological value. While +the spleen has been looked upon always as the origin of blood cells in +the embryo, cases in man are on record where no spleen was discovered, a +condition suggesting that its absence is not incompatible with life; +that such is the case is obvious for experimental or therapeutic removal +of the organ is well known. + +It was suggested by Virchow that at times the spleen assumes the duty of +the bone marrow and the swelling of the viscus in certain anemias seems +to support this statement. However, there is no physical relationship +between the size of the animal and that of the spleen, nor between the +available quantity of bone marrow, the obvious richness of circulating +blood and amount of lymphatic tissue. This is well shown in the water +mammals which have a great deal of blood in vessels and viscera yet +their spleen is relatively smaller than birds of somewhat comparable +size (the ostrich, for example). The Carnivora and Rodentia among the +mammals, have quite large spleens proportionately, while comparable +birds, Accipitres and Striges, have relatively small ones, and an +absolutely small amount of marrow. + +Another anomalous example of the function of this tissue is found in the +hematopoiesis of birds. While there seems to be some evidence that in +the spleen and liver red blood cells may be formed, there is perhaps at +most times sufficient bone marrow to keep the blood cells at a proper +number. There is no inverse relation between the amount of bone marrow +and that of splenic bulk; that is in diving birds with their hollow +bones the latter is no greater than in gallinaceous birds which have +abundant marrow in all the skeleton. + +It has been suggested that the spleen supplies an activator for +pancreatic ferments. This receives a sort of support from the greater +size of the organ in carnivores and smaller relative size in ungulates, +since in the former concentrations of digestive enzymes are more often +needed. Because of the greater excretion of iron in splenectomized +animals or those being starved, Fischer has thought that the spleen has +some power to metabolize this element; this receives some support from +the statements concerning the size of this organ in the carnivorous +orders. From experimental studies it appears that some relation exists +between the lymphocytes and resistance to implanted tumors. If one apply +this idea to the amount of lymphatic tissue and the incidence of +spontaneous new growths, it is found that no definite relationship is +discoverable either in terms of size of spleen or richness in lymphatic +nodes. Carnivores, rodents and marsupials show a high tumor incidence +and have a good lymphatic supply. Aves, on the other hand, with a poor +nodal apparatus and a variable splenic bulk, show many fewer tumors than +do the mammals. The mononuclears of avian blood rise normally as high as +60 per cent., of which 40–45 per cent. are of the small size. + +The size of the spleen is subject to great variation not only within +orders but actually within genera; it even seems that one sometimes sees +two or three members of a species kept in the same enclosure, maybe with +the same disease, maybe without any obvious disease, yet with definite +variation in the size of the organ. This irregularity is recognized by +veterinarians (Hutyra and Marek) who ascribe it to some unknown disease, +past or present, and to normal variation. The lack of uniformity is seen +more clearly in birds than mammals. In the former it might be due at +times to low grade or inactive parasitism or, conjecturally, to toxins +from incorrect diet; we shall see later that infection and intoxication +seem to have a different effect. Some writers have mentioned the +possibility of an idiopathic splenomegaly (?), a condition associated in +youthful human beings, with anemia and lymphadenopathy, and occasionally +going over into a sort of leucemia. The existence of such a condition is +difficult to admit or deny; we have met nothing which could not be +aligned in some fairly well defined group. Birds have a relatively +larger spleen than mammals and in addition the organ seems to respond +more actively in infections or intoxications, since it may reach, under +active stimulation, a size ten times that of the normal organ. + + +ENLARGEMENTS OF SPLEEN. + +Acute enlargements of the spleen, be they of congestive or +“inflammatory” nature are quite common among the lower animals, a fact +that is recognized in veterinary medicine. Congestions of the spleen are +most often seen during acute infections and diseases of the heart and +liver. The diagnosis has been made among mammals proportionately more +than in birds, 27 or 1.5 per cent. to 35 to 1 per cent. + + +REASON FOR CONGESTIVE ENLARGEMENTS. + +Perhaps this is partly due to the circulatory anatomy since in the +former the arterial and venous supply is usually by one large vessel of +each kind, whereas in birds the splenic branch of the cœliac axis breaks +up into several small arteries and the venous return is accomplished by +numerous venules some of which reënter the posterior cava almost +directly, others joining with the mesenteric to form the portal; by this +arrangement a more elastic system is assured. The same condition is +found when analyzing the records of chronic passive congestion; in +eighteen recorded cases, fourteen were mammals and four birds. In these +cases the principal associated pathological lesions were pleural and +pulmonary in seven, cardiac in three, renal in three and hepatic in +four. While the anatomy of the splenic blood supply may help to explain +the small number of congestions in Aves, it will not answer for the +inflammations which occur in large numbers in this class; this will be +discussed in the following pages. + +Hemorrhage and infarction of the spleen are not very common, there being +eleven of the former and ten of the latter and all occurring with the +same indication or history of infectious disease; in one case, an +opossum (_Didelphys virginiana_) an injury probably caused a massive +hemorrhage shaped like an infarct. It is, however, curious that of the +twenty-one cases only five occurred in birds, of which only one +hemorrhage was in the shape to which the term infarction is best +applied. There have been, as one might expect, a few cases of infected +infarction, with abscess. It is perhaps worth noting that no case of +hemorrhagic cyst or inspissated coagulum has been seen. Only one case of +rupture is recorded secondary to acute splenitis during an acute +septicemia. + + +INFLAMMATIONS. + +It has been the practice at this laboratory to classify splenitis in +three ways, (1) acute diffuse splenitis—general congestion with perhaps +small hemorrhages, swelling but retention of general architecture and +with no undue prominence of the follicles; (2) follicular hyperplasia— +where this is the prominent gross and minute finding, the pulp being +less pronouncedly involved; (3) acute splenic tumor—where the organ is +greatly enlarged but with loss of the usual markings. Perhaps this +separation is not warranted upon a strict etiological basis, and yet as +we shall see it holds true fairly well in the toxic and infectious +lesions. Moreover, from the following list it is evident how the various +orders call upon the splenic tissue in disease. + + TABLE 7. + _This Shows the Percentage of Various Forms of Splenitis in the Animals + Coming to Autopsy._ + ═════════════════╤═════════════════╤═════════════════╤═════════════════ + │ Acute Diffuse │ Follicular │ Acute Splenic + │ Splenitis. Per │ Splenitis. Per │Tumor. Per cent. + │ cent. │ cent. │ + ─────────────────┼─────────────────┼─────────────────┼───────────────── + Carnivora │ 7.│ 3.│ 1.3 + Primates │ 2.5│ 4.9│ 2. + Ungulata │ 2.4│ .3│ 1.2 + Rodentia │ 2.6│ 4.7│ 1. + Marsupialia │ 9.2│ 3.│ 3.7 + Pinnipedia │ _33._│ │ + Proboscidea. │ _33._│ │ + Edentata │ _12.5_│ │ _6.2_ + │ │ │ + Passeres │ 3.│ 3.│ 3.8 + Psittaci │ 6.5│ 2.3│ 4.1 + Anseres │ 5.2│ 7.2│ 5.2 + Herodiones │ _1._│ _6._│ _2._ + Galli │ 2.6│ 1.5│ 4.7 + Struthiones │ _10._│ _10._│ _1._ + Accipitres │ 7.5│ 3.7│ 1.6 + Gaviæ │ │ │ _5._ + Picariæ │ _4._│ │ _1.3_ + Striges │ 6.8│ 3.4│ + Fulicariæ │ _3._│ 6.│ + Steganopodes │ │ _10._│ + Columbæ │ .7│ .7│ + ─────────────────┴─────────────────┴─────────────────┴───────────────── + For the meaning of italics see foot note Table 1. + +The points to draw from this chart are first the greater variety of +lesions seen in the birds, which apparently make greater use of the +organ in defence, and the preponderance of acute diffuse hyperplasias in +mammals. It is noteworthy that the Primates and Marsupialia show more of +the acute hypertrophy of the spleen going under the name of tumor. It +would be interesting and valuable to be able to discover exactly what +determines and constitutes the conditions usually termed hyperplasia and +inflammation of the spleen and an attempt was made in this direction by +tabulating the data from Table 7 in terms of each diagnosis, classifying +these latter also as infectious and toxic. The results of this effort +are not conclusive, and while they permit of some discussion of the +lesions, do not allow finished conclusions. The figures obtained by +study are not illuminating. One can state, however, that in infections, +either specific or not specific, more elements of the spleen were +engaged in the process than when the condition did not resemble a +communicable disease, but might be called toxic. Under the former +condition the diagnosis of splenitis or acute tumor predominated, while +under the latter follicular hyperplasia is more often recorded. +Anatomical alterations in these two groups are described in the +definition given in a previous paragraph and deserve no special +discussion except in so far as they concern the changes in the avian +splenic tumor when under magnification. + +Microscopically there is a total loss of the relations in the acute +splenic tumor of birds, the chords and follicles being replaced by a +rather regularly arranged mass of small and large mononuclears, granular +cells of the circulating types and red blood cells; pigment always seems +increased. Endothelial cells do not take part in the general mass of the +organ but along lymph and blood vessels their bulk and number are +increased so that if the packing be not too dense one may find double +lines of these cells passing through the hyperplastic tissue. There is, +however, a group of seven cases (six birds) to which the term +endothelial hyperplasia in the spleen has been applied. All of them show +an unusual prominence of the vascular linings and of the follicular +centres and perivascular areas; besides this there is a moderate general +hyperplasia. An examination of the history and autopsy results in the +birds indicated that they had all suffered with some rather protracted +intoxication and showed a moderate anemia (four of the spleens were well +pigmented). + +The more chronic changes of this organ, be they moderate or of a grade +to which one must apply the term fibrosis, are rather uncommon when one +considers the number of animals with prolonged infection, anemia, +skeletal diseases and hepatic cirrhoses; these are the conditions that +take a prominent place in the associated pathology and history. There is +no essential difference in the organ throughout the animal kingdom, and +one may find as far down as the struthious birds analogies to the +processes of domestic and human animals. + + +SPECIAL SUBJECTS—AMYLOID. + +Amyloid changes in the spleen have occurred in the following orders: +Primates, Carnivora, Rodentia, Marsupialia, Passeres, Galli, Gaviæ, and +Anseres, fourteen cases in all. This infiltration is usually ascribed to +long continued suppuration or chronic infection, every one admitting, +however, that once in a great while a case is seen wherein no cause can +be discovered. In this laboratory we have a high percentage of cases +without adequate accompanying pathology so that we have called six of +the above cases primary or idiopathic. The gross appearance of the +spleen is in all these cases that of an enlarged, firm, homogeneous body +without the sago spots usually described for this change. +Microscopically the infiltration occurs first in the vessel walls, +thence spreading to the sinus walls and reticulum. Joest in discussing +this infiltration[19], states that it is comparatively rare among the +domestic animals, where it may appear under the usual conditions or as a +primary affection; it seems at times to follow unsuitable feeding. +According to this author, the “sago” type is more common than the +“bacony;” this has not been our experience. The most conspicuous example +is given here. + + + European Badger (_Meles meles_) Adult ♀ . Gradual failure for two + weeks. + + DIAGNOSIS.—Amyloidosis. Chronic parenchymatous nephritis. Emphysema of + lungs. + + Muscles atrophic; fat scanty. Heart is dilated and muscle is red- + brown. Aorta is jaundiced and there is a small patch of atheroma near + the anterior leaflet of aortic valve and about 5 mm. above it. Abdomen + contains a slight amount of clear fluid, no adhesions. Liver is normal + in size, smooth surface, sharp edges, firm consistency, yellow color. + The section surface is glistening, smooth and moist. The spleen is + very hard, greatly enlarged (25 × 6 × 2 cm.) and lies across the + abdomen over the intestines. It is pale red and very bacony. In iodin + the tissue stains a mahogany brown. The kidney is normal in size. (5½ + x 3 cm.). The capsule is smooth and strips easily leaving a smooth, + yellow surface. Organ is firm. The section surface is glistening, has + a relatively narrowed cortex and relatively wide medulla. The + glomeruli are barely visible but stain a mahogany brown in iodin. The + adrenals are 12 × 10 × 4 mm. The cortex is wide, dull yellow and + regular. The zone beneath fades into the cortex although rather + abruptly. The centre of both glands is occupied by an irregular pale + yellow, sharply outlined nodule suggestive of solid medulla, tubercle + or tumor. The zone between cortex and this is gray, irregular and + firm. This is practically a normal figuration. The stomach is empty, + mucosa apparently normal. Intestines were not opened but serosa seems + normal; when opened after Kaiserling fixation they seem normal. The + pancreas is normal in size, firm and pale. Lymphatics of the mesentery + are slightly enlarged, soft, homogeneous pale yellow. + + HISTOLOGICAL NOTES.—Lung seems somewhat atrophic and there are some + vesicular ruptures. One small patch of amyloid found in blood vessel + wall. Liver shows slight capillary congestion and granularity of + parenchyma. There is a marked blood vessel amyloid deposit not only in + interlobular spaces but in intralobular capillaries. Spleen, no trace + of splenic tissue recognizable in section. It is composed of more or + less eosin-staining material surrounding single, or small collections + of round or plasma cells. Kidney shows marked amyloidosis of glomeruli + and slight deposit in blood vessel walls and in the increased + connective tissue. There is a general moderate fibrosis; irregular + tubules; low epithelium and hyaline casts. Heart muscle fibres are + small and stain deeply. No amyloid in section. No pigmentation + although section is suggestive of brown atrophy. Adrenal is + practically negative. There seems to be slightly more connective + tissue than normal but parenchyma may be considered normal. At one + place in the cortex there are some structures of deep layer included + in vesicular layer. This seems like a structural malformation. + + +NECROSES. + +Focal necroses of the spleen affecting chiefly follicular centres but +also chords, are not at all uncommon in avian spleens, especially where +parasitism occurs, not only with hemic protozoa and embryos, but also +with intestinal or visceral nematodes and trematodes. + + +SPLEEN IN ANEMIA. + +The spleen in the anemias shows much less definite change than one would +expect. In the secondary form of anemia among mammals one finds a slight +excess of pigmentation and an occasional fibrosis but often the size of +the organ is recorded as normal. When the impoverished blood seems +secondary to skeletal degenerations there is a diffuse or follicular +enlargement. In the birds, on the other hand, there is nearly always +some grade of enlargement which is due in the well studied examples to a +richness of blood cells. There may be a slight increase in follicles, +but these bodies are usually small and solid. In two instances a +prominence of large endothelial cells was discovered. Pigment is seldom +increased, but it may be very excessive. + +In the primary anemias little more than the above is to be found. +Fibrosis is more evident and perhaps pigmentation less so, but the +variations are more of degree than kind. The spleen in leucemia can only +be discussed upon the case already reported (_q. v._). + +[Illustration: + + FIG. 7.—EUROPEAN BADGER (MELES MELES). PRIMARY AMYLOIDOSIS. THE + ENORMOUSLY ENLARGED SPLEEN IS SEEN LYING ACROSS THE STOMACH BELOW + THE LIVER, WHICH ORGAN IS EXCEEDED IN SIZE BY IT. +] + + +SPLEEN IN HEPATIC FIBROSES. + +The fibroses of the liver are not infrequently associated with some +enlargement of the organ under discussion. At this laboratory hepatic +cirrhoses are divided into Portal, Biliary, Fatty, Perilobular and +Vascular. By a study of the spleens in these cases a few facts have been +obtained. In mammalian portal cirrhoses there is usually a very moderate +but definite increase in the size of the spleen due to connective tissue +increase in the trabeculæ and reticulum, with very small compact +follicles. Among the birds the organ seldom shows more that a moderate +congestion and diffuse hyperplasia. In the mammalian biliary cirrhoses +there is almost without exception a definite enlargement due to fibrosis +and follicular hyperplasia. Among the birds the process is very far from +uniform, there being just as often no change, as a congestion and +hyperplasia, or as a mild fibrosis; it is notable, however, that +pigmentation is commonly met in this class. No noteworthy change is met +with in the spleen of fatty hepatic cirrhoses. We have no record of +cyanotic induration of the spleen accompanying a similar condition in +the liver. When the condition of perilobular hepatic fibrosis has been +met a distinct increase of the splenic pigment is usually found. In +reviewing the facts in this paragraph one is forced to the conclusion +that, with the exception of the frank infective cases, there is no +definite relation of the splenic changes to those in hepatic cirrhosis, +a fact made perhaps the more significant in view of the idea held in +some quarters that the primary change in this pathological process +occurs in the spleen. + + +PERISPLENITIS. + +Perisplenitis of an acute or fibrosing variety as a part of peritonitis +or as the result of an injury to the splenic region, has been +encountered on numerous occasions and offers nothing worthy of comment, +but the so-called “sugar-icing” spleen, associated with perihepatitis +and general peritoneal thickening, and with an obscure relation to +tuberculosis has not been seen. As we shall learn later peritoneal or +massive intestinal tuberculosis is not common in the lower animals. A +diffuse fibrous thickening of a pearl gray glistening appearance, has +occurred in five monkeys harboring the Filaria gracilis in the +peritoneum. + + +TUBERCULOSIS. + +In tuberculosis of this organ the capsule is almost invariably thickened +over the nodules, but not over the whole organ and rarely in the diffuse +variety. There is almost always, however, in this prolonged infectious +disease some reaction on the part of the spleen, particularly when +several other viscera are involved. In such cases a low grade of general +hyperplasia and fibrous tissue increase is found. This is especially +true in the Primates and Carnivora in long continued pulmonary +tuberculosis, and it is in this form that one does not often see +tuberculous lesions proper in the spleen itself. Tuberculosis of the +spleen is not very common in adult human beings and domesticated +animals, while in the young it is seen in a fairly high percentage of +cases. In the wild animals this organ seems much more susceptible to the +settling of tubercle bacilli as will be attested by the facts to be +cited, and yet there are some conspicuous exceptions to this statement. +Just why certain groups, or orders should show splenic tuberculosis very +frequently while others fail to do so is far from clear. + +The appearance of the lesion is fairly comparable throughout the animal +kingdom, variations among the Aves being chiefly in the more frequent +occurrence of the diffuse tuberculous splenitis. Miliary, caseous and +conglomerate masses occur separately or together and without very +distinct relation to other pathological involvements. + +The relative incidence of tuberculosis in the spleen is set forth in the +section devoted to this infection, but may be mentioned here in a +general way. The organ is about equally susceptible to the disease in +mammals and birds according to the figures, but the high percentage for +the former is due to the frequency with which tuberculosis is met in the +Primates. With this order deducted there is no doubt that the avian +spleen has a greater vulnerability for the tubercle bacillus than has +the mammalian organ. Rodentia as a mammalian order stand next to the +Primates, whereas the Carnivora and Ungulata relatively seldom show +splenic tuberculosis. Among the Aves one finds that Columbæ, Galli and +Accipitres have the highest splenic susceptibility, but beyond this one +hardly dare venture because of the irregularity in the number of +specimens seen at autopsy. Suffice it to say that a greater number of +cases of tuberculosis are seen in the spleen of the class for which the +intestinal origin of tuberculosis appears most important. + +In the cases of actinomycosis and its congeners, such as the Kangaroo +maxillary mycosis, which we have seen at the Garden, no specific changes +have been seen in the spleen, unless a single or double nodule of the +same variety as the original focus may be considered specific. Such was +found in two cases, one a tapir with low grade inactive actinomycosis, +the other a kangaroo with maxillary streptothricosis. Two deer came to +autopsy with a gross picture suggestive of anthrax; no bacilli could be +found in the semifluid spleen, but a member of the hemorrhagic +septicemia group was found. The latter group of infections has been +fairly well represented, although not in epizoötic form, and the almost +invariable splenic change has been that already discussed as diffuse +splenitis. Three secondary tumors are recorded, two cancers and one +renal adenoma. + + + + + SECTION VI + THE RESPIRATORY SYSTEM AND ITS RELATED STRUCTURES + + +It is customary to divide the descriptions of normal and diseased +conditions of the upper entrance to the body into respiratory and +alimentary parts, the nose, nasopharynx and larynx belonging to the +former, the mouth, buccal cavity and pharynx to the latter. As a matter +of fact they can for most purposes be considered as the structures +contained in the anterior head and furthermore their pathological states +are more often followed by extensions into or implications of the +respiratory organs proper than of the alimentary tract. From a +comparative standpoint the incidence of specific infectious diseases and +of the involvement of accessory nasal sinuses present the most +interesting subjects. There are several infections, believed to be +specific, observed among domestic mammals and birds but their actual +individuality has hardly been unexceptionally proved. This refers to the +communicable rhinitis of cows, pigs, rabbits, and birds, especially +parrots, the follicular catarrh of horses, and croupous nasopharyngitis, +all of which have been ascribed to a particular virus, without finished +evidence in many instances. Some of these diagnoses doubtless cover or +are confused with the early symptoms and signs of the disease of protean +manifestations, distemper, and indeed the Bact. septicus and relatives +of the bird cholera organisms are reported as being responsible for +them. No intention of excluding well recognized entities like bird +diphtheria, foot-and-mouth disease or influenza, exists. I shall refer +below to small groups of epizoötics which do not conform strictly with +word pictures drawn by Hutyra and Marek, Moore, or Ward and Gallagher. + + +RHINITIS, SINUSITIS. + +The nature of inflammations of the nasopharynx suggests at once that +there may be some anatomical reason for their distribution and +character. A general review of the anatomy of the mammalian and avian +nasopharynx reveals the relatively greater space in the former, +especially in the passage from the nose to the pharynx, and emphasizes +the exposure of the opening of the upper larynx in the bird, lying as it +does in the posterior part of the tongue and surrounded by the +constrictores glottidis. A dissection of the accessory nasal sinuses +exposes the relatively large size of these spaces in the lower mammals, +and the capacious openings into the nasal cavities.[20] In the Primates +and Lemures the anatomy more closely resembles that of man, the sinuses +being relatively smaller and the communicating passages narrower. In the +bird on the other hand, while the sinuses may be extensive in some they +are usually small, yet in all the communication with the turbinate area +is by a narrower slit or tortuous canal, frequently, as in Galli, +running from below upward into the maxillary sinuses. The extent of the +turbinate and the richness in mucosa is probably greater in all mammals +than in birds; certainly this seems true of Carnivora and Ungulata +_versus_ Accipitres and Galli. + +If the seriousness of a rhinitis be dependent upon the extent of +involvement of the sinuses and the blocking up of their outlets it would +be expected that the variety of animal having the smallest drainage +channels would show the greatest evidence of these diseases. Our records +would indicate that 32 birds (.96 per cent. of the autopsies upon Aves) +had rhinitis whereas only 7 mammals (.39 per cent. of autopsies on this +class) presented the condition. Extension to the sinuses occurred in +only one-third of each of these figures, a complication which in turn +produced generalized infection more often in mammals than in birds as 4 +is to 3. These figures are perhaps too small for conclusions but it +would seem that rhinitis occurs more often in birds with their small +sinuses and channels while sinusitis and general infection occur more +often in mammals with their large sinuses and extensive turbinate +apparatus. The most conspicuous orders represented are, in line of +numbers Anseres 12, Psittaci 7, Accipitres 5, Carnivora 3. Nine of the +twelve waterfowl were part of an epizoötic which will be discussed under +specific diseases. + +Bacteriologically the mammalian cases that have been worked out were due +to _Streptococcus pyogenes_ in several instances, including the +generalized cases, and to a mixture of streptococci, golden +staphylococci and members of the colon-aerogenes group. In one case in a +tapir a member of the B. septicus group was found. Moulds were +discovered in three avian cases and filaria in one. No pentastomum or +œstrus has been discovered. In thirteen instances the lungs have been +involved, apparently secondary to the nasopharyngeal disease. + +There have been two small outbreaks of an acute nonspecific infection— +that is not suggestive of cholera, psittacosis or infectious enteritis— +among the parrots in which during a short time 4 and 6 parrots died with +nasopharyngosinusitis as the prominent lesion. One outbreak was studied +bacteriologically without definite result. There was no uniform internal +pathology unless, in one outbreak, congestion of the cerebellum may be +mentioned. Fowl diphtheria and its associated condition from which a +satisfactory separation has not been accomplished, epithelioma +contagiosum, has happily given us little concern, so that it is not +possible to record any instructive facts upon its cause or differential +diagnosis. There was recorded in the 1911 Report of the Society the +occurrence of two fatal cases in cassowaries from which it was possible +to isolate the B. columbarum and one bird with the same clinical +appearances whose recovery seemed to be due to the use of human +diphtheria antitoxin. In light of more information and consideration of +the accepted variability of this disease, it is possible that this bird +may have recovered without the injections or with the use of normal +serum. Nowadays it is possible to obtain antiroup serum which is stated +by Blair of New York to be efficacious. The disease has been observed in +a wild turkey and an Abyssinian Ground Hornbill, beside the two +struthious birds mentioned above. + + +MYCOSIS. + +Mycotic disease of the nasopharynx seldom restricts itself to this +cavity, usually extending by continuity to the esophagus, or by +inspiration to the lungs whence it spreads to the air sacs. This +condition of the upper passages has occurred here only in Psittaci and +Accipitres although it is reported by veterinarians as occurring in +Anseres and Struthiones. In the first order four birds were affected, +two showing extension to the esophagus and a like number having +pulmonary and serous membrane involvement. These cases were all due to +aspergillus whereas those next to be mentioned were caused by an oidium +close to the “albicans” variety. In four Mississippi kites the prominent +changes were found in the pharynx and esophagus down as far as the +proventricle with only a few rather trifling lesions in the nasal area. +Infiltrative and necrotizing processes characterized the action of the +oidium while that exerted by the aspergillus was more superficial and +extensive. In one case of a parrot the whole nasal cavity was completely +filled with a yellow gray exudate whereas the esophageal wall of the +kites was thoroughly infiltrated by a gray-brown, friable, necrotic +mass. Attempts at treatment were made in the case of the latter, using +potassium chlorate and saline solution on cotton swabs. The result was +entirely negative and the applications seemed to have no effect upon the +course of the infection. + +There are on our records in addition to the above, several cases of +necrotizing processes about the head seeming to emanate from wounds to +the mucosa by foreign bodies, by decomposition of pieces of food in +crevices or by damage by masses too large to be swallowed. In the few +instances where we have tried bacteriology, no definite result has been +obtained unless the frequent occurrence of organisms bearing a +resemblance to Bact. necrophorus be important. This organism however may +be found in many necrotic processes in animals; I do not look upon it as +specific in the locations just cited. + +Mammals as a class do not present many inflammatory conditions around +the anterior head, aside from the specific diseases like distemper (?), +actinomycosis, Kangaroo disease and the like. Monkeys occasionally have +acute coryza, which may indeed seem transmissible to others but it +seldom leads to any serious consequences and is untreated, except by +segregation. Tuberculous lesions are not recorded. There has been no +glossitis aside from lesions involving the pharynx. The tonsils have +been discussed under the lymphatic apparatus and it only need be +repeated here that inflammation and hypertrophy of these organs are +exceedingly rare. Specific or individual diseases of the salivary glands +are also rare although these organs may be involved by extension. This +general region is not often affected with tumor, unless the jaw be +included which bone is the seat of several tumors in antelopes and +opossums. Aside from these we have seen an epithelioma of the tongue in +a black bear (_Ursus americanus_). + + +LARYNX. + +The larynx is an organ of fairly uniform construction through the +mammalian orders but is conspicuously different in the Aves where it is +double. The upper end of the trachea in the latter class is surmounted +by a cartilaginous box lying beneath the root of the tongue through +which an anteroposterior slit-like opening forms the glottis; there is +no epiglottis. This is only an air passage, the voice being made in the +syrinx or lower box which lies at the bifurcation of the trachea. The +structure of the upper box is quite simple with its lateral plates +controlled by the glossal muscles and two external retractors but the +syrinx is very complicated and variable in the different orders and even +in the same family. It possesses an internal and external set of muscles +and in some birds can be opened at one point to permit air to pass to +the cervical or thoracic air sacs. Detailed discussion of its anatomy is +hardly profitable since there is nothing peculiar about its diseases. On +one occasion only have we seen distinct pathological change—what was +probably an extension of mould disease from it to the cervical air sac. +It is involved in true tracheitis and bronchitis but even these are rare +in birds. + +The larynx on the other hand is constantly reddened in cases of +pharyngitis and may be the seat of mould colonies. Edema of this +structure is, however, not very common, it being recorded but twice in +birds in association with nearby inflammation and five times in mammals; +in the latter cases three were of acute infectious nature, one was a +tumor and the other osteomalacia. It is common to find the laryngeal and +tracheal mucosa swollen and wet in chronic bone degenerations without +the condition being severe enough to call it edema. + + +LARYNGITIS. + +Acute laryngitis of active catarrhal or purulent nature has been met +five times in mammals and twice in birds while more chronic lesions have +occurred only in the former, four times. Tuberculous laryngitis has been +observed in a cockatoo and a lemur; they are interesting enough to cite. +There are no cases recorded among monkeys despite the large number dying +from the disease; this implies of course that no suspicion of its +existence was had at postmortem but perhaps some would have been +detected had every larynx been subjected to microscopic section. A +citron-crested cockatoo was found when posted to have general miliary +tuberculosis. The bright red rim of the glottis attracted attention and +upon slitting open the organ, pinhead size, sharply outlined yellow +tubercles were found on both sides. A black and white lemur was killed +because of a positive tuberculin test. He was in good condition and +exhibited as his only lesions retropharyngeal lymph nodes with +precaseous miliary nodules and small miliary tubercles on the +epiglottis, true and false vocal chords and in the mucosa of the main +ventricle, each lesion being surrounded by a narrow sharply injected +zone. This seems like a recent double implantation since the +retropharyngeal glands probably do not drain toward or from the larynx. +The larynx has been the seat of only one tumor, a squamous cell cancer +in an Azara’s agouti. The tumor caused ulceration and edema of the whole +mucosa sufficient to produce fatal asphyxia. + +The trachea is of relatively little comparative or pathological interest +aside from its inflammations which however are so closely associated +with bronchitis that they will be included under that heading. Perhaps +the most important condition of this tube is its infestation with +_Syngamus trachealis_ since this leads to inflammations not only of the +related mucosa but predisposes to pulmonary infection. The occurrence in +the Galli is well known but perhaps it is not so well recognized that +this worm occurs also in crows (Passeres) and swans and geese (Anseres). +For the diagnosis of this condition it is customarily stated that a +frothy mucus in the mouth is very suggestive; this is true in the cases +seen here but in addition a mucopurulent stomatitis is exceedingly +common and when the two are combined the picture is almost confirmatory. +Although worms are credited with considerable weight in the production +of pneumonia in Ungulata, they have only been seen once within the +tracheal tube. + + +THE BRONCHI. + +The bronchi will be discussed as a separate part of the respiratory +system in so far as possible since they present a very decided +difference in anatomy between mammals and birds and because the +incidence of their disease is other than will be found for the lungs. +However, distinction has been made between changes in the grosser tubes +and those in the finer bronchioles, especially because capillary +bronchitis so-called is really a pneumonitis in which the mucosa of the +larger passages need not participate. The mammalian tubes are not really +greatly different in their construction, passing through ever smaller +branchings which give an increasing square area of tube capacity and +more extensive mucous surface. The avian main bronchus breaks up very +shortly after entering the lung into a varying number of spaces lined +with low epithelium lying upon a fibrous support and without cartilage. +These spaces then open into secondary air spaces of a size visible to +the naked eye which are in turn surrounded by microscopic alveoli. The +largest spaces, first mentioned, continue to grow smaller toward the +lower part of the lung where they usually communicate with one or other +of the various ostia of air sacs. Bronchial diseases in birds must +therefore be limited at the place where the bronchi lose the +cartilaginous rings since below this the surface functionates as +pulmonary tissue. + + +BRONCHITIS. + +The accompanying list, Table 8, will show the distribution of bronchitis +not accompanying pneumonia or due to mycosis. It is striking that +carnivorous animals are more prone to bronchitis than any other order +(the struthious birds are too few to be important). There is a very +decided preponderance of mammalian cases over avian, there being not +only more cases but proportionately more orders affected. The character +of lesions in the mammals is nearly always catarrhopurulent or freely +purulent while ulcerative changes are not uncommon. Peribronchial +infiltrates are seldom found without some evidence of pneumonia; nor is +it common to meet the pale lines extending from bronchi between the +lobules, such as are seen in human streptococcal disease. Avian +bronchitis is usually hemorrhagic or catarrhal and with exceeding rarity +becoming purulent; when this occurs the cause is frequently found to be +tuberculosis or mycosis. Inflammation of the larger passages is nearly +always accompanied by pulmonary congestion, a serious condition in birds +as will be seen later. A few of these cases have been studied +bacteriologically with no definite result, nor have these cases occurred +in such groups that an epizoötic was suggested. Bact. avisepticum, Bact. +canisepticum, Bact. coli, Bact. aerogenes mucosum, and Ps. pyocyaneus, +Streptococcus hemolyticus and non-hemolyticus and staphylococci have +been found. + + TABLE 8. + _Showing the Percentage Incidence of Bronchitis and of Parasites in the + Autopsies upon the Various Orders._ + ════════════╤═══════════════════╤═══════════════════╤═══════════════════ + Orders │ Simple Bronchitis │ Verminous │Inactive Parasites + │ │ Bronchitis and │of Lung (Encysted) + │ │ Pneumonitis │ &c. + ────────────┼─────────┬─────────┼─────────┬─────────┼─────────┬───────── + „ │ Cases │Per cent.│ Cases │Per cent.│ Cases │Per cent. + ────────────┼─────────┼─────────┼─────────┼─────────┼─────────┼───────── + Primates │ 7│ 1.4│ 3│ .6│ 5│ 1. + Lemures │ │ │ │ │ 1│ 1.2 + Carnivora │ 14│ 2.9│ 8│ 1.6│ 8│ 1.6 + Insectivora │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ + Rodentia │ │ │ 2│ 1.│ │ + Ungulata │ 5│ 1.3│ 2│ .5│ 10│ 2.7 + Proboscidea │ │ │ │ │ │ + Hyracoidea │ │ │ │ │ │ + Edentata │ │ │ │ │ 2│ _12.5_ + Marsupialia │ 3│ 1.7│ 2│ 1.1│ 3│ 1.7 + Monotremata │ │ │ │ │ │ + │ │ │ │ │ │ + Passeres │ 4│ .29│ 7│ .5│ 2│ .16 + Picariæ │ │ │ │ │ │ + Striges │ │ │ │ │ │ + Psittaci │ 4│ .58│ │ │ │ + Accipitres │ 1│ .5│ │ │ │ + Columbæ │ │ │ │ │ │ + Galli │ │ │ 1│ .3│ │ + Hemipodii │ │ │ │ │ │ + Fulicariæ │ │ │ │ │ │ + Alectorides │ │ │ │ │ │ + Limicolæ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ │ + Impennes │ │ │ │ │ │ + Steganopodes│ │ │ │ │ │ + Herodiones │ 1│ 1.│ │ │ 1│ 1. + Odontoglossæ│ │ │ │ │ │ + Palamedes │ │ │ │ │ │ + Anseres │ 2│ .67│ 3│ 1.│ │ + Struthiones │ 1│ _3.3_│ │ │ │ + ────────────┴─────────┴─────────┴─────────┴─────────┴─────────┴───────── + For meaning of italics see footnote Table 1. + +A review of the active verminous lesions of the bronchi and the +pneumonitis to which parasites lead, shows again the highest number +among the Carnivora, with negligible percentages among the Aves. The +forms concerned are, when determined, ascarides, strongylus, hepaticola, +fasciolopsis, cytoleichus, pneumonyssus and paragonimus; these will be +discussed later. The lesions in the bronchi are mucocatarrhal or +hypertrophic; occasionally actual ulcerations are seen. What is more +important however is the peribronchitis leading to interstitial +pneumonitis and to bronchiectasis of the smaller bronchi, or to areas of +atelectasis by total occlusion of some small air passage. This pathology +is fairly well recognized among veterinary pathologists but there are +two points which seem worthy of special emphasis, namely, the relative +mildness of the changes in the larger bronchi and the importance of the +worms as causes of pneumonia. In regard to the first it can be pointed +out that the trachea and its branches need not be altered at all while +the middle sized bronchi present a mottling of small recent congestion +with pigmentations from old hemorrhages, together with slight +unevennesses of the surface. Small bronchi on the other hand are the +seat of ulcerative internal processes and quite marked peribronchitis, +as indicated by round and connected tissue nuclei or perhaps polynuclear +increase under active acute inflammation; it is in the latter case that +acute pneumonitis is present. + +To what extent do the parasites predispose to pneumonia? Compare for +this purpose the two columns of Table 8 showing active and inactive +pulmonary parasitism. In Rodentia and Galli alone do we note that active +parasitism is effective, there being no passive cases. In all the other +orders, animal invaders of the lung are more often encountered as +quiescent or encapsulated bodies, therefore as findings incidental to +the autopsy and perhaps not concerned in the cause of death. In Ungulata +the inactive parasitisms are five times as frequent as the active +inflammatory lesions. It might be added that the list is made up of +cases wherein we saw parasites whether determined or not, an explanation +of the apparently small number of cases; there were many more in which +such invaders were suspected but not found and therefore excluded. + + +BRONCHIECTASIS. + +Bronchiectasis affecting the smallest tubes, or bronchiolectasis, is not +at all uncommon in verminous pneumonitis and is explained as due to the +degeneration of the wall, the surrounding progressive ulceration, to +accumulation of inspired air and its retention by the obstruction. There +is described a generalized bronchiolectasis, chiefly in young human +beings, due to a destructive bronchiolitis; this has not been seen. + +Non-verminous bronchiectasis of the middle sized bronchi such as is seen +in human chronic bronchitis, simple or tuberculous, is quite uncommon. +Widening of the bronchial lumen may be divided, as I see its +pathogenesis, into (a) that due to congenital weakness of the walls, (b) +that due to obstruction permitting air to pass into but not out of a +bronchus because of a ball-valve obstruction or weakness of expiratory +power, (c) that due to external pressure by tumors or distortion by +fibrous tissue either within the lung or pleura and (d) that due to +inflammatory weakening of walls, augmented by loss of supporting +pulmonary tension, accummulation of secretion and the dilating effect of +inspiration preparatory to and incidental to coughing. How important the +last three auxiliary factors may be in the cases explicable under a, b, +c, can easily be speculated upon and may vary in different cases. + +Bronchiectasis is reasonably common with pulmonary diseases of man, +particularly of chronic character, but is certainly not frequent among +animals. Under the first group (a) we can record one case, a Siberian +tiger which died of enteritis and its complications to which were added +a mild inactive bronchitis and a bronchiectasis of diffuse distribution. +The lungs were irregular in shape, dull, gray-red in color and gave a +variable boggy and vesicular sensation to the fingers. On opening the +lung, dilatations of the bronchi were found, affecting chiefly the +larger secondaries but apparently not the bronchioles. Parasites were +not found nor were inflammatory reactions apparently adequate to explain +the distentions, so that we looked upon this case as congenital. Cases +coming under the headings b and c are not recorded. Inflammation almost +certainly represents the most important single factor in the +pathogenesis of this lesion and could be demonstrated in two cases, a +Clouded Leopard (_Felis nebulosa_) and a Red River Hog (_Potamochærus +porcus_). While I feel that parasites probably laid the foundation for +the dilatations in these cases, none were found after, in one case at +least, a very thorough search, although in the second animal a single +cyst of _Cysticercus tenuicollis_ was found in the peritoneum. In both +animals there was a low grade interstitial pneumonitis and +peribronchitis with dilatations of the middle sized and end bronchi, +these being supplied with thick walls but containing very scanty +secretion. + +We have on record chronic ulcerative pulmonary tuberculosis in six +primates, two carnivores and nine ungulates. It is highly probable that +among this number some cases of ulcerative bronchiectasis occurred but +if so they were not conspicuous enough to mention in the diagnosis and +in only two protocols do I find a discussion thereof, once in a monkey +and once in a carnivore. All the cases of our records were diffuse +ectasias, fusiform, or irregular and none of the distinct saccular +variety. + +From the foregoing facts it would seem that in human cases more weight +should be laid to the effect of the dilating power of coughing and its +preparatory exertions. While I am aware that the comparative incidence +of human and lower animal bronchiectasis cannot be based upon the meager +figures at our command, these dilatations certainly can be expected in a +general autopsy service more in man than in lower animals. Chronic +bronchitis is relatively rare, aside from the verminous varieties. I +have seen little retained exudate in the bronchi, probably because +quadrupeds seem with ease to raise and swallow the secretions. Nor do +animals give vent to paroxysms of coughing such as the human being feels +forced to do. Suggestive deductions from these points are that +inflammation is the principal factor in acquired bronchiectasis and that +the retention of secretion with violent inspiratory efforts are potent +in man for the dilatation of the tubes. + + +THE LUNGS. + +The essential respiratory organ of the animal body, the lung, is all +through this kingdom a structure intended to expose the blood to free or +combined atmosphere in order to permit gaseous interchange, therefore +being arranged so that there is a close apposition of the two factors, +separated only by such cells and membranes as may be necessary to +protect the circulation; perhaps these anatomical elements possess at +the same time some vital force to further the exchange of useful and +useless matter. In the two classes under discussion there is no +difference whatsoever in the primary factors of respiration albeit some +variations exist in reference to oxygen and carbon dioxide interchange, +moisture of the air, and the physics of inspiration and expiration. The +chemical variables have in our limited knowledge of comparative +physiology apparently little effect upon morbid anatomy but it is +probable that some pathology may be in part explained on physical +grounds. + +The mammalian respiratory box is a relatively elastic affair, but +collapsed at the end of expiration which is largely a passive or recoil +process. The avian thorax is believed to be normally a tensely distended +space from which air is expelled by pressure of the pectoral contraction +upon the broad sternum driving the latter back upon the air sacs which +in turn drives it from the lungs. Also by this means, air is distributed +through the bones and air spaces, a measure necessary in flight, +especially in a head wind when tracheal inspiration is said to be +suspended at times. The communications of the lungs, air sacs and bones +make it possible for birds to breathe internally when the trachea is +closed and externally as well if a bone be opened. The balance of air +pressure in the lungs and related spaces is dependent upon the patency +of the ostia communicating between the bronchial ends and the air sacs, +from which the bony cavities obtain their supply. Should all these be +closed there is first a standstill of current and a limitation of the +respiration of the lungs. Fortunately it is extremely rare that this +occurs for it is obvious that it is incompatible with flight, and with +life indeed. The principal effect upon the lungs of obstruction to the +passages seems to be expressed in congestion but in how far this is due +actually to the closure of foramina and how far to the cause of +obstruction is sometimes difficult to evaluate. It should be remembered +that the air sacs are usually looked upon as mucous surfaces continuous +with the bronchial wall, there being a deep layer to each membrane +possibly continuous with the serous membranes. In mould disease of the +lungs there is very commonly a colony lying in the ostium supplying the +anterior, lateral and posterolateral cavities. + +The lungs in birds are not free as in mammals, being fitted into the +troughs made by the anterior ridges of the ribs, to the serous covering +of which they are lightly attached by delicate fibres running between +the two. This more or less definite fixation, together with the pressure +of the air in the sacs give the free play of the lungs a limited +excursion. They are naturally very elastic by reason of a good supply of +elastic fibers and large air spaces, a condition aided by their +attachments to the supports of the diaphragm and to the insertions of +the air sac walls. Notwithstanding this elasticity and the great +capacity of the organ for blood, it seems as if congestion of the lungs +is a very serious matter, since from the foregoing review of anatomy, +accommodation of excess blood and any consolidation must be difficult. +As a matter of fact the mere excess of blood known as active congestion +seems able to kill small varieties. + + +CONGESTION OF LUNGS. + +Birds of flight seem to have little resistance to this condition and +often it is the only diagnosis one can make at autopsy. The causes of +this condition include exposure, dust, gorging (?), indigestion, +enteritis and infection in birds while in mammals acute gastrointestinal +disease stands out as the most prominent accompaniment. To what extent +dust and exposure operate I do not see, although they are frequently +mentioned as causes. The overfilling of the crop, esophagus and +proventricle, the turgescence incident to gastric indigestion or the +pressure of foreign bodies in large amount are supposed to operate by +exerting pressure on the anterolateral air sacs with closure of their +ostia and also by right lateral torsion of the heart with twisting of +the very delicate pulmonary veins. + +I have sought to show that protozoa or embryo nematodes in the blood +might embarrass the lungs to a state of congestion, a thought suggested +by some findings in the London Gardens, but only about ten per cent. of +our cases of hemic parasitism are accompanied by it. + +The incidence of congestion of the lungs not due to stasis as from +cardiac diseases, is 2.4 per cent. in mammalian autopsies, in only 7 per +cent. of which figure did it represent the principal morbid anatomy, +whereas in birds it occurred to the extent of 7.6 per cent. of +postmortems, in 17 per cent. of which it was the sole or principal cause +of death. This seems to bear out the feature of delicacy of the +pulmonary vascular mechanism in these latter animals. This condition +seems to be indicated by simple dyspnœa in birds, relief for which has +occasionally been afforded by removal from the exhibition cages and +protection separately in a warm dry room; this is partly hypothetical of +course and congestion is to be looked upon as serious, particularly in +passerine birds. + + +PNEUMONIA. + +Pneumonia as a clinical disease is a relatively uncommon, although quite +serious sporadic condition in animals. However accompanying the +specific, more or less epizoötic diseases such as influenza, distemper +and the choleras it may be a frequent and quite pronounced complicating +feature of the case. Pneumonia _per se_ has exacted a reasonable toll in +this Garden but unfortunately recognition being impracticable, diagnosis +and treatment have not progressed. Nor has it been practicable to group +our cases pathologically because of the lack of history and the +difficulty of making bacteriological observations at many autopsies. +Fortunately we have had practically no epizoötic pneumonias, an +experience shared with other gardens judging by their published reports. +Etiologically, and of course this applies to non-verminous, non-mycotic +and non-tuberculous cases, the pneumococcus has stood out prominently as +a cause with a few additional cases due to the streptococcus and the +Bact. aerogenes mucosum group; London reports four cases in monkeys due +to the Friedlander bacillus. Some time ago Doctor Weidman subjected our +pneumonias to an analysis and was able to show that there is no +parallelism between the seasonal incidence of pneumonia in man and +animals, rather indeed that the Garden is more apt to have a greater +number of cases in the summer, a sort of “closed season” for man. This I +am inclined to interpret as connected with the larger number of visitors +during that season. Doctor Weidman was further able to show that the +only real examples of lobar fibrinous pneumonia strictly comparable to +the human infection occurred in the Primates. I have uncovered one in a +lemur and one in a carnivore. The pneumococcus has been far and away the +greatest producer of our pneumonias, in two typed cases being of the IV +variety. There will be given below a summary of the pathological types +of pneumonia encountered, to be followed by some notes upon the +principal gross and minute anatomy in special orders. Table 9 will show +the numerical distribution of types among the orders. All the principal +mammalian orders are represented while the birds seem relatively less +susceptible to the disease and, except the Passeres, show a trifling +incidence. + + TABLE 9. + _Showing the Number of Cases of the Various Forms of Pneumonia Found in Each + of the Orders._ + ════════════╤═════════╤═════════╤═══════╤══════╤══════════╤═══════╤═══════════ + │Fibrinous│Catarrhal│ Acute │Septic│Hypostatic│Chronic│Pleurogenic + │ Lobar │ │Inter- │ │ │Inter- │ + │ │ │stitial│ │ │stitial│ + ────────────┼─────────┼─────────┼───────┼──────┼──────────┼───────┼─────────── + Primates │ 4│ 22│ 2│ 1│ 1│ 2│ 2 + Lemures │ 1│ 3│ │ │ │ │ + Carnivora │ 1│ 34│ │ 4│ │ 1│ + Insectivora │ │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ │ + Rodentia │ │ 6│ │ 3│ │ │ + Ungulata │ │ 14│ │ 5│ 1│ 1│ + Proboscidea │ │ 1│ │ │ │ │ + Hyracoidea │ │ │ │ │ │ │ + Edentata │ │ 1│ │ │ │ │ + Marsupialia │ │ 13│ 1│ │ 1│ │ + Monotremata │ │ │ │ │ │ │ + │ │ │ │ │ │ │ + Passeres │ 1│ 59│ 2│ 2│ │ │ + Picariæ │ │ │ │ │ │ │ 1 + Striges │ │ 3│ │ │ │ │ 1 + Psittaci │ 1│ 15│ │ │ │ 1│ + Accipitres │ │ 1│ │ │ │ │ + Columbæ │ │ 2│ │ │ │ │ + Galli │ │ 2│ │ │ │ │ + Hemopodii │ │ │ │ │ │ │ + Fulicariæ │ │ 1│ │ │ │ │ + Alectorides │ │ │ │ │ │ │ + Limicolæ │ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ │ │ + Impennes │ │ │ │ │ │ │ + Steganopodes│ │ │ │ │ │ │ + Herodiones │ 1│ │ │ │ │ │ + Odontoglossæ│ │ │ │ │ │ │ + Palamedes │ │ │ │ │ │ │ + Anseres │ 1│ │ │ │ │ │ + Struthiones │ │ │ │ │ │ │ + ────────────┴─────────┴─────────┴───────┴──────┴──────────┴───────┴─────────── + +Primates present a definite group of variations from the other orders, +notably in having four clear cases of lobar fibrinous pneumonia, and in +certain histological findings. In reference to the lobar cases, a review +of their history does not indicate that any might have been surely +diagnosed by their symptoms, and only possibly by signs in one case +during the stage of red hepatization; unfortunately no temperature +records are at hand. In one case it was possible to see a group of +alveoli with the fibrin collected in a strand which, according to +classical description, passes through the septum to the adjoining +alveolus. + +There were two cases, a Chimpanzee (_Pan niger_) and a Galago (_Galago +maholi_) with a microscopical picture suggestive of those we met in the +influenza epidemic, and indeed the lung of the former resembles grossly +the lung of influenza pneumonia. The spotty areas of watery purple color +correspond under magnification to celluloedematous semisolid sections +showing a sanguineous exudate, few polynuclear cells and many swollen +epithelia. The microscopic picture of the bronchocatarrhal pneumonias +shows conspicuously thickened septa decidedly wider than one is +accustomed to see in human cases and apparently due more to round cell +infiltration than to congestion or polynuclear increase. + +Bronchopneumonia or capillary bronchitis with zones of cellular edema in +the vicinity is a rather usual picture in the deaths from degenerative +bone disease. It cannot be said that there is anything very peculiar +about it, although a frequent note met in the autopsies describes spotty +areas of hemorrhage and nearby atelectasis. + +The case of lobar pneumonia found in a ring tailed lemur (_Lemur catta_) +showed very delicate fibrinous reticulum and relatively few cells in the +exudate, a picture apparently due in part to beginning resolution since +the whole upper left lobe was in a stage of gray hepatization. + +The peculiarity of the Carnivora seems to lie in the reaction of the +epithelia, these cells being quite large, swollen and occasionally much +vacuolated. Such a picture was most pronounced in the terminal +bronchitic pneumonias in cases which might be called distemper. Many +instances of pseudolobar catarrhal or bronchopneumonia are recorded but +we also observed the fibrinous lobar form at the stage of red +hepatization in a Texas skunk (_Mephitis mesomelas_). Concerning the +orders Rodentia and Edentata no especial notes seem necessary for their +inflammatory reactions are essentially like the others in that +epithelial cells are much swollen and prominent. + +Pneumonias of Ungulata are well known to pathology and offer in +causation and microscopy little that is peculiar. It might be emphasized +however that the gross appearance of the bronchocatarrhal variety +closely simulates that of lobar pneumonia, therefore to be called a +pseudolobar form, in that extension to various parts of a lobe seems to +occur. Moreover in the bronchitic varieties associated with enteritis, +with or without infectious foci in the pharynx or larynx, there may be +two or even three stages of the pneumonitic process in one lung or lobe. +It seems that this pseudolobar appearance occurs definitely more often +in ungulates than in the other orders. + +[Illustration: + + FIG. 8.—NORMAL AVIAN PRIMARY AND SECONDARY ALVEOLI. NOTE THE DELICACY + OF THE SEPTAL PROLONGATIONS THAT BOUND THE PRIMARY ALVEOLI, ALL OF + WHICH ARE WIDELY OPEN. +] + +[Illustration: + + FIG. 9.—EARLY BRONCHOPNEUMONIA OF SUPERFICIAL ORIGIN. NOTE SOME LITTLE + EXUDATE IN SECONDARY ALVEOLUS. WIDE SWOLLEN SEPTA AND BOTH ALVEOLI + REDUCED IN SIZE. +] + +Marsupialia offer two rather easily grouped classes of bronchopneumonia— +one associated with enteritis and one secondary to “Kangaroo disease” of +the jaw; they differ in microscopy correspondingly. The simple +bronchitic and peribronchitic infiltrate and superficial exudate +occurring with enteritis or with a general infection is relatively +diffuse, giving in some instances the impression of an interstitial +process and showing notably swollen septa; there may be fibrin but this +is exceptional and scanty. When mycosis of the jaw has been the origin +or occasion of the infection the picture is that of frank aspiration +pneumonia, therefore more like a septic infarct. However the amount of +fibrin is sometimes very great and whole alveoli will be filled with it, +perhaps accompanied by red cells, polynuclears and epithelia. Epithelial +cells however play a small part in the minute anatomy. Hemorrhage and +edema are prominent but true abscess formation and gangrene are not. +Possibly the animals die too soon for the latter to develop. + +Pneumonia in Aves aside from that due to moulds is apparently much less +common than among the Mammalia, one order only, the Passeres, showing an +incidence comparable to the important orders of the latter class. The +other orders, and this applies particularly to those of which we have an +adequate number, are quite insusceptible to simple pneumonia, none of +them showing over two per cent. There are listed for Aves three +instances of lobar fibrinous pneumonia. These cases can be described +together since in all the findings were about the same. A whole lung or +goodly portion thereof was uniformly involved in a red or gray +consolidation of rather fine granular character which on section study +seemed to be made up of the same lesion all over, with fibrin a +prominent part of the exudate. The coagula were largely within the +secondary alveoli but the primaries also contained it. The microscopic +section may not have represented the process at all places, and since +the arrangement of fibrin is similar in definitely catarrhal lesions, +these may of course have been instances of pseudolobar pneumonia. + +Our data are too few to draw any conclusions as to the behavior of the +various orders but one note may be permitted. The passerine birds have a +great tendency to dense cellular infiltrates while parrots show more +coagulative or fluid exudates. + + +PRODUCTION OF INSULAR PNEUMONIA IN BIRDS. + +Insular consolidations in which catarrhal and infiltrative processes are +prominent, the bronchopneumonias, seem to arise in two ways. One course +of events apparently follows infection _via_ the bronchial mucosa, the +other _via_ the blood stream and a study of the resulting lesions may +help toward an understanding of the development of pneumonia in man. + +When infection unquestionably has been superficial, that is _via_ the +bronchus, the first thing to happen is a swelling of the septal +prolongations dividing the primary alveoli and an extension of their +ends farther into the secondary alveoli with the result that the inlet +to the primary air sacs is narrowed and the space in the secondaries is +reduced. Upon the surfaces there then develops the usual catarrhal +exudate while in the deeper parts marked congestion makes its +appearance. Fibrin may develop and be mixed with the cells both in the +larger and smaller alveoli but it is more evident in the former. (Figs. +8, 9, 10.) + +[Illustration: + + FIG. 10.—LATER BRONCHOPNEUMONIA OF SUPERFICIAL ORIGIN. NOTE GREATER + EXUDATE, GREATER SWELLING OF SEPTA. PRIMARY ALVEOLI PRACTICALLY ALL + CLOSED. MUCH OF LUNG HAS BECOME CONSOLIDATED. +] + +[Illustration: + + FIG. 11.—INSULAR PNEUMONIA, BEGINNING AS CELLULAR INFILTRATION OF + DEEPER PARTS OF SEPTA AND OF INTERSTITIAL TISSUE. FOUR AREAS OF + DENSE AIRLESS CONSOLIDATION. ALL SECONDARY AND MANY PRIMARY ALVEOLI + WIDELY OPEN. +] + +The other process by which insular pneumonia develops seems to begin in +the septa of the smaller alveoli and in the perivascular areas. This has +been looked upon as hematogenic or pleurogenic. The first change occurs +in the surroundings of the primary alveoli where there appears a +richness of nuclei, of round, moderately well stained character, among +which one may see a few granular and red blood cells. Soon the epithelia +of adjacent alveoli increase in number and a fibrinocellular exudate +appears, at first probably in the smaller sacs. However when the lesion +is intensive the course of events must be rapid for the identity of a +group of primary alveoli is soon lost and the exudate may extend to the +larger air space. (Fig. 11) In severe or late cases a decision as to the +course of origin is often impossible. The most instructive point of this +part of the study is the closing of primary alveoli by the swelling of +their septal ends and the early occlusion of the secondary alveolus by a +catarrhofibrinous or even pus-like material. It is quite possible that a +similar course of events transpires in the pathogenesis of human +pneumonia, the superficial avian form being comparable to the aspiration +form, the interstitial form comparable to the septicemic variety. + + +ABSCESS AND GANGRENE OF LUNG. + +Abscess and gangrene of the lung are degenerative processes dependent +upon embolism, or inspiration of infective matter and it is usually +assumed that gangrene succeeds upon abscess when the blood or air supply +of a part of the pulmonary tissue has been obstructed mechanically or by +inflammation. A review of our material adds little to the etiology or +pathogenesis of these two lesions, well recognized as they are by +veterinarians. As opposed to human beings, lower animals probably suffer +more from them, for an explanation of which one can probably look to the +B. necrosis or necrophorus, an organism quite common in feed, and +acknowledged to be of great importance as a secondary invader during +specific infectious diseases. It has been found in embolic abscesses and +in the organs in calf diphtheria and similar other conditions. It has +been cultivated here twice, once from a lung abscess, once from Kangaroo +disease. It doubtless occurs in human necrotizing processes but is +seldom emphasized or even heard about; possibly none is due to it or its +congeners. + + TABLE 10. + + _Table giving Analysis of 20 Mammalian and 3 Avian Cases of Abscess and + Gangrene of the Lung_ + + ════════════╤═══════════════╤════════════════╤════════ + Animal │ Causative │ Pneumonia, │Abscess + │condition upper│septic or other │ or + │ respiratory │ │Gangrene + │ tract │ │ + ────────────┼───────────────┼────────────────┼──────── + Sooty │Negative │Catarrhal │Gangrene + Mangabey │ │pneumonia │ + Cercocebus │ │ │ + fuliginosus │ │ │ + │ │ │ + Rhesus │Negative │Septic from │Abscess + Macaque │ │suppurating │ + Macacus │ │gland │ + rhesus │ │ │ + Am. Wild Cat│Aspiration │ │Gangrene + Felis ruffus│vomitus from │ │ + │violent │ │ + │gastroenteritis│ │ + │ │ │ + │ │ │ + │ │ │ + Puma Felis │Acute purulent │No │Abscess + concolor │nasopharyngitis│ │and + │ │ │gangrene + │ │ │ + │ │ │ + Ichneumon │Negative │Sepsis, scalp │Abscess + Herpestes │ │wound │ + mungo │ │ │ + │ │ │ + │ │ │ + Raccoon │Negative │Pneumonia │Abscess + Procyon │ │followed by │ + lotor │ │sepsis │ + │ │ │ + │ │ │ + Skunk │Cellulitis face│Sepsis, very │Abscess + Mephitis │and neck │mild │ + mephitica │ │ │ + Puma Felis │Perforating │Secondary │Abscess + concolor │abscess around │terminal │ + │jaw │pneumonia, │ + │ │sepsis │ + │ │ │ + │ │ │ + Porcupine │Negative │Enteritis, no │Abscess + Erethizon │ │special sepsis │ + dorsatus │ │ │ + │ │ │ + │ │ │ + │ │ │ + Kangaroo Rat│Negative │Right sided │Abscess + Perodipus │ │bronchopneumonia│ + richardsoni │ │ │ + │ │ │ + Squirrel │Abscess under │No │Abscess + Sciurus p. │eye and in │ │ + carolinensis│masseter muscle│ │ + │ │ │ + │ │ │ + │ │ │ + Mule Deer. │Actinomycosis? │Arthritis. │Abscess + Mazama │nasopharynx │Myositis │and + hemionus │ │Tenosynovitis │gangrene + │ │ │ + │ │ │ + Axis Deer. │Negative │Negative │Abscess + Cervus axis │ │ │ + │ │ │ + │ │ │ + │ │ │ + │ │ │ + │ │ │ + │ │ │ + Tapir. │Abscess of │Died from │Abscess + Tapirus │parotid │enteritis │ + indicus │ │ │ + │ │ │ + │ │ │ + │ │ │ + Gazelle. │Negative │Sepsis from │Abscess + Gazella │ │infected wound │ + isabella │ │ │ + │ │ │ + │ │ │ + Kangaroo. │Negative │Catarrhal │Abscess + Macropus │ │pneumonia │and + rufus │ │ │gangrene + │ │ │ + │ │ │ + │ │ │ + │ │ │ + │ │ │ + │ │ │ + Kangaroo. │Kangaroo │Sepsis │Abscess + Macropus │mycosis of jaw │ │ + rufus │ │ │ + │ │ │ + Kangaroo. │Kangaroo │ │Abscess + Macropus │mycosis of jaw │ │ + giganteus │ │ │ + │ │ │ + Kangaroo. │Negative │Sepsis from │Abscess + Macropus │ │infected wound │ + robustus │ │ │ + Devil. │Negative │Negative sepsis │Abscess + Sarcophilus │ │ │ + ursinus │ │ │ + │ │ │ + │ │ │ + Crow. │Negative │Filaria in │Abscess + Gymnorhina │ │blood? │ + leuconota │ │ │ + Heron. Ardea│Negative │Negative │Abscess + tricolor │ │ │ + ruficollis │ │ │ + │ │ │ + │ │ │ + Goose. Anser│Syngamus in │Negative │Abscess + fabalis │trachea │ │ + │ │ │ + │ │ │ + │ │ │ + │ │ │ + ────────────┴───────────────┴────────────────┴──────── + + ════════════╤═════════╤══════════════╤══════════════ + Animal │Single or│ Position │ Bacteria + │Multiple │ │ + │ │ │ + │ │ │ + ────────────┼─────────┼──────────────┼────────────── + Sooty │Massive │Upper part │Streptothrix, + Mangabey │single │lower lobe and│necrosis + Cercocebus │ │adherent part │bacillus. + fuliginosus │ │upper lobes │ + │ │left side │ + Rhesus │Single │Occupied │ + Macaque │ │nearly all │ + Macacus │ │right middle │ + rhesus │ │lobe │ + Am. Wild Cat│Bilateral│Right middle │ + Felis ruffus│ │lobe, left │ + │ │lower lobe, │ + │ │left bronchus │ + │ │ruptured, │ + │ │right middle │ + │ │lobe ruptured │ + Puma Felis │Bilateral│Right upper │Streptococcus + concolor │ │and left lower│pyogenes. + │ │lobe abscesses│ + │ │biggest, right│ + │ │middle also │ + Ichneumon │Bilateral│Scattered │ + Herpestes │ │small │ + mungo │ │abscesses, │ + │ │under pleura │ + │ │especially │ + Raccoon │Bilateral│Probably all │ + Procyon │ │lobes, right │ + lotor │ │middle │ + │ │contains │ + │ │largest │ + Skunk │Single │Left lower │ + Mephitis │ │lobe, single │ + mephitica │ │small │ + Puma Felis │Bilateral│Numerous small│ + concolor │ │abscesses, │ + │ │irregularly │ + │ │scattered │ + │ │through both │ + │ │lungs │ + Porcupine │Bilateral│Multiple small│ + Erethizon │ │scattered. │ + dorsatus │ │Parasitic? No │ + │ │notes │ + │ │parasites or │ + │ │bacteria │ + Kangaroo Rat│Single │Left lower │ + Perodipus │ │lobe, small │ + richardsoni │ │abscess, │ + │ │record scanty │ + Squirrel │Multiple │Left lung │ + Sciurus p. │ │scattered, │ + carolinensis│ │small │ + │ │abscesses, │ + │ │parasites not │ + │ │seen │ + Mule Deer. │Bilateral│Scattered both│ + Mazama │ │lobes under │ + hemionus │ │pleura, upper │ + │ │right inferior│ + │ │tip gangrenous│ + Axis Deer. │Single │Apparently │Streptothrix. + Cervus axis │ │primary │ + │ │streptothrix, │ + │ │abscess in │ + │ │cardiac tip of│ + │ │upper lobe │ + │ │with extension│ + │ │toward hilum │ + Tapir. │Bilateral│Multiple │Staphylococci. + Tapirus │ │subpleural pus│ + indicus │ │pockets, │ + │ │surrounded by │ + │ │catarrhal │ + │ │pneumonia │ + Gazelle. │Bilateral│Multiple │ + Gazella │ │subpleural and│ + isabella │ │internal, both│ + │ │lungs about │ + │ │the same │ + Kangaroo. │Double │Lower middle │Pneumococci + Macropus │left │left lobes, │streptothrix. + rufus │ │seat of a │ + │ │ruptured │ + │ │gangrene │ + │ │surrounded by │ + │ │pneumonia, │ + │ │right lung │ + │ │pneumonic │ + Kangaroo. │Bilateral│More on right │Streptothrix, + Macropus │ │side, sharply │cocci. + rufus │ │outlined │ + │ │abscesses │ + Kangaroo. │Single │Abscess and │Streptothrix + Macropus │ │atelectasis, │ + giganteus │ │right middle │ + │ │lobe │ + Kangaroo. │Single │Lower right │ + Macropus │ │lobe │ + robustus │ │ │ + Devil. │Multiple │Largest middle│Probably + Sarcophilus │ │of right lung,│streptothrix. + ursinus │ │many small │ + │ │scattered │ + │ │abscesses. │ + Crow. │Multiple │Scattered tiny│ + Gymnorhina │ │abscesses, no │ + leuconota │ │worms seen │ + Heron. Ardea│Single │Upper pole, │ + tricolor │ │right lung, no│ + ruficollis │ │apparent │ + │ │antecedent │ + │ │cause │ + Goose. Anser│Single │Lower half │ + fabalis │ │right lung │ + │ │occupied by │ + │ │abscess, which│ + │ │has penetrated│ + │ │air sac │ + ────────────┴─────────┴──────────────┴────────────── + +The distribution of abscess and gangrene in the lungs in terms of the +antecedent disease, therefore its causation, may however be of interest. +The lower animals move more in the horizontal position, they seldom +cough, they are subject to several different diseases with principal +lesions in the anterior head (diphtheria, actinomycosis, etc.) but not +to chronic lymphatic infection, they push their snouts into all kinds of +filth thereby probably taking into the nose and throat many objects +which can find their way to the bronchi, and finally they are not +subjected to various instrumental operative procedures when they chance +to have a focus of pathology in the nasopharynx. For these reasons the +position of abscess and its sequels may be instructive. It has recently +been stated that abscesses of the lung in human beings following +anesthesia for infections of the upper respiratory tract, occur most +often in the upper parts of the lung whereas those following pneumonia +develop more in the lower lobes. For the animals of this series, these +facts are not borne out. In the accompanying list will be found our +acceptable cases of abscess and gangrene. Little can be said about +incidence save the fact that the highest percentage and number occur in +the Carnivora. It will be found that the right lung is affected nine +times predominatingly while the left lung is affected seven times. The +lobe most often singled out for an isolated lesion is the lower left, +the right middle being the next most often affected. These figures +concern the mammals alone, the three birds being considered too few to +discuss. It cannot be said from these figures that there is in animals +any definite distribution of pulmonary abscess and gangrene. + +Nor do these figures correspond to those appearing in literature of +human pathology. In man inspiration of foreign bodies, including +bacteria-laden mucus, usually carries them into the right lung because +of the larger and more directly vertical bronchus to that side. Emboli +go as a rule also to the right lung more than to the left because of the +greater size of the pulmonary artery and more direct blood current to +that side. In these animals right side lesions are more numerous but the +left lower lobe is the principal segment of the lung to be affected. The +cases are too few and the anatomy too variable to permit any deductions. +There is in the affected animals no uniform anatomical peculiarity which +would explain the predominance of the right lung as a whole or the left +lower lobe as a unit. + + +PNEUMONOKONIOSIS. + +Pneumonokoniosis, because of its importance in industrial diseases, has +been subjected during recent years to considerable intensive study in +human medicine, from which activity some interesting and useful +information has been obtained as to its genesis and effect upon the +function of the lung. This condition is of course a purely environmental +one, the degree and particular kind of “dusting” being dependent upon +the duration and nature of exposure of the particular individual. This +Garden is situated beside an active railroad trunk line so that the +opportunity for coal dust inhalation is continuous. The degree of +anthracotic pigmentation of the lungs and related serous membranes is +really negligible and with one questionable exception, we have not seen +fibrosis due to this cause in any animal. The one exception, an amazon +presented and living in the Garden but three months, at necropsy showed +an interstitial chronic bronchitis and pneumonitis stretching out from +the hilum, all of the affected area being deeply pigmented. The picture +was comparable to what might be expected from a second degree +anthracotic fibrosis of Landis and Pancoast. Many specimens come to +autopsy with some grade of pigmentation, but none, except the one above, +with resultant fibrosis. The degree of anthracosis is usually so slight +that it has been considered important enough to include in the diagnosis +but eighteen times and curiously enough seventeen of these were observed +in birds. Were there more cases it might be profitable to plot their +exhibition period but the use of this small number might lead to error; +the average length of exhibition of the birds was about a year. It is +common to observe some black specklings of the air sacs, as if pepper +were dusted on them as has been said before, but even this is rarely +marked. It is most often seen in the Anseres, Psittaci and Struthiones +but a goodly number of cases occur in the long-lived Passeres. + +The distribution of the pigment is essentially the same throughout +Mammalia—peribronchial, submucous and in the lymph nodes at the root of +the lung. In the birds it is first seen in the subepithelial spaces of +the septa of the small alveoli where they project into the secondaries, +later accumulating in the connective tissue of the main septa. +Collections under the pleura and at the root of the lung are rare, the +dust usually spreading out along the air passages into the air sacs. + +Other forms of pneumonokoniosis are unknown. Although animals must +inspire much dust from dry feed and from floors it must be caught early +and removed by snorting or by the lymphatic drainage. It seems fairly +well accepted that dusts are dangerous to the degree that they contain +inorganic substance and as these animals are not exposed to concentrated +mineral or metallic dusts, no effects are seen. + + +INFARCTION OF LUNG. + +Infarctions of the lung, while not at all common, are interesting +because of their incidence in the Carnivora and in the distribution. The +figures concern the mammals only since the decision for or against +infarct in the birds is very difficult because of the frequency in this +class of hemorrhage with pulmonary congestion. There were eleven single +or double non-septic infarcts, of which seven occurred in Carnivora, one +in an ungulate, two in Primates and one in a rodent. The existence of +parasites was excluded in most of the cases but could not be entirely in +all. Eight of these infarcts were on the left side, five of these being +in the lower lobe. + + +EMPHYSEMA. + +Emphysema of the atrophic and chronic vesicular types with the soft, +fluffy, pigmented or pale pink organ has not occurred in the animals +under observation. Acute vesicular emphysema, such as is seen in chronic +bronchial and cardiac diseases, has been encountered several times. +Cardiac lesions were found four times, nephritis eleven times, acute +enteric conditions seven times, hepatic diseases seven times. Two cases +of wide spread amyloid disease showed a deposit of this substance in the +alveolar walls. It is quite common to find some grade of emphysema in +monkeys dying from osteomalacia and rickets. The process is then most +prominent in the upper lobes and along the free anterior margins. The +incidence in the orders is Primates 5, Lemures 2, Carnivora 2, +Pinnipedia (drowning) 1, Rodentia 1, Ungulata 4, Marsupialia 4. The best +example was found in a Skunk (_Mephitis mesomelas_) having a general +infection, emanating from the cranial sinuses, and cardiac dilatation. +Emphysema does not seem to occur in birds for only one was seen which +seemed to present this condition. This was a Bald Eagle (_Haliæetus +leucocephalus_) with chronic renal and enteric disease and cardiac +hypertrophy. The lungs were tensely distended under their serous +covering and showed a few small bullæ anteriorly. Unfortunately a +histological preparation is not at hand. + + +TUMORS. + +Tumors of the lung are moderately common, both of primary and secondary +origin. Thus we have seen three primary and six metastatic growths in +mammals and one of each kind in birds. The primaries were: carcinomata +in a civet (_Viverra tangalunga_), a bandicoot (_Thylacomys lagotis_), a +kangaroo (_Macropus rufus_), and a lorikeet (_Glossopsittacus +concinnus_). The secondaries were: carcinomata in a black bear (_Ursus +americanus_), a polar bear (_Ursus maritimus_), a lion (_Felis leo_), +and a dasyure (_Dasyurus maculatus_); sarcomata in a prairie wolf +(_Canis latrans_), and a raccoon-like dog (_Canis procyonoides_); +adenocarcinoma in a chestnut-eared finch (_Amadina castanotis_). + +The histological character of the primary cancers would place them in +group of the nodular and infiltrative types of Kauffman. They all seem +to have taken their origin from the smaller bronchi, the usual starting +point. The growths were small in the civet and bandicoot and strongly +suggest that the tumors arose in bronchi occupied by parasites; such +bodies could not be demonstrated. It is the usual thing to find in cases +of parasitism of the bronchi that if there be no ulcerative destruction +of tissue the epithelium undergoes some form of hyperplasia, and even +structural metaplasia in the air tubes supplied with cuboidal or +cylindrical cells. Epithelia many layers deep have been encountered, +usually arranged in orderly fashion but frequently “papillomatoid,” +suggesting the epidermal layers yet not so far as to show protoplasmic +bridges. Distention of various degrees, affected by the contents of the +tube and the surrounding inflammation, are common. Such a picture +naturally resembles epithelioma and indeed growths of this nature are +reported as due to verminous pneumonitis. + +There are, especially in cats and dogs, small scattered adenomatoid +growths[21] under the pleura and in the pulmonary substance, thought to +originate in the alveolar epithelium and occasionally growing to large +size; the case in the kangaroo may have had this origin. _It was the +only primary tumor to give metastasis_ (to the spleen and gastric wall), +the secondaries being decidedly adenomatous in character. + +Metastatic growths come from the following originals: two from the +thyroid, well known to give pulmonary embolism in dogs; one each from +the breast, uterus, adrenal, intestine and kidney. The form assumed is a +gray and red mass lying under the pleura or an isolated nodule in the +substance. Sarcomatosis, the form apparently spreading out from the +hilum and growing in isolated grayish tubercular masses, has not been +seen. + + +THE PLEURA. + +The pleura is a tissue apparently quite susceptible to infection in +mammals and so closely associated with the air sacs in birds as to be a +part of the same membrane, therefore the two being affected together. +Throughout the higher class all orders give copious examples of the +involvement of the pleura, principally of course as an accompaniment or +a sequel to pneumonitic or bronchitic processes but also as a part of +acute infectious diseases, such as hemorrhagic septicemia, +pleuropneumonia and the like. However two orders present such a number +of instances of pleuritis that they deserve notice. The seals, +Pinnipedia, of which we have twenty autopsy records, showed inflammation +of this membrane four times, three of which were dependent upon +pulmonary infection and one apparently due to general septicemia with +trifling damage to the lung proper. One of the first cases had gone on +to empyema of the classical type, a shrivelled dry almost carnified lung +with a thick fibrinopurulent covering. The lung of the seal is well +divided into lobules, the external surface being generously supplied +with lymphatic channels under the pleura, an arrangement which should +carry away infection one would think. Perhaps this high percentage of +pleurisy in our Pinnipedia is but accidental. The marsupials, while +having a notable percentage of pleurisy both among all the cases and in +relation to the number of postmortems, are not so striking from the +etiological standpoint since practically all of these have suffered with +Kangaroo mycosis or pneumonia. In over half the cases of this infectious +disease some grade of pleuritic exudate has been observed, only one, +however, going to the stage of empyema. + +One cannot speak so definitely of pleuritis in birds since this tissue +merely represents in them the covering of the lung and is firmly +attached posteriorly to the ribs and anteriorly to the air sacs. +Exudates show as collections upon the air sac side of the combined +membrane, pleuritis proper in birds being an infiltrative affair coming +through the pulmonary tissue and therefore being a part of pneumonitis. +I notice a tendency in a few articles to write of pleuritis when the +process is confined to the thorax but this gives the impression that the +disease is peculiar. There seems no difference in the gross and minute +appearance between thoracic serositis and panserositis. The course of +procedure seems to be from the anterior or mesial pulmonary ostia into +respectively the cervical and thoracic air sacs and this seems to hold +good whether the infection be mycosis or fowl cholera or fowl pest. +There are records of 104 cases of serositis in birds of which 45 were +among parrots, the remainder being well distributed among the various +orders; only two each occurred in Galli and Anseres, orders prominently +affected under domestication. This high percentage of pleuroperitonitis +among parrots and their congeners can only be explained upon the ground +of a continued infection of our stock by the virus of fowl cholera and +by mould. One case of undoubted fowl cholera occurred recently and as +the records are reviewed a few are discovered where the organism was +found. The virus must be of low grade for we have had no severe and +devasting epizoötic. Mycosis is constantly with us no matter what we do +in hygienic measures. There was a small group of cases of pulmonary and +serous membrane mycosis combined with staphylococcus infection which +carried off six birds. The pathology of this group was interesting +because one could follow the infection of the bacterium. The anterior +pulmonary ostium was surrounded or covered by a mycotic mass and +spreading downward from this was a grayish yellow turbidity of the air +sac walls with a delicate sticky or almost mucilaginous exudate +extending into the lateral abdominal and posterior sacs. + +[Illustration: + + FIG. 12.—ENDOTHELIOMA OF PLEURA. LEOPARD (FELIS NEBULOSA). +] + +[Illustration: + + FIG. 13.—ENDOTHELIOMA OF PLEURA IN FIG. 12. DETAIL OF ONE OF THE WARTY + EXCRESCENCES. +] + +There is on record one tumor of the pleura, an endothelioma, in a +Clouded Leopard (_Felis nebulosa_). It was the usual plate-like +thickening with warty excrescences. No metastases occurred. (Figs. 12 +and 13). + + + + + SECTION VII +THE ALIMENTARY TRACT. PART 1.—PHARYNX, ESOPHAGUS, STOMACH AND INTESTINES + + +The portion of the anatomy that we now approach varies in construction +almost as much through the animal kingdom as do the external shape and +covering of the various orders and much more than do the other systems. +The reason for this is obvious, an arrangement accommodative to the +differing food chiefly, but not a little to the ease with which animals +obtain and assimilate their nutriment. It would be impracticable to +describe all the variations of the orders discussed in this study, but +since certain gross and minute differences are of importance in +comparative pathology they will be discussed at the appropriate places. +It is my purpose to present in a subsequent section a discussion of food +in captivity from the standpoint of its quality and quantity in relation +to pathology. + +Doubtless the quality of food is the largest factor in the production of +disease both of the alimentary tract and elsewhere, but I am not at all +sure that the quantity may not be equally important, in certain groups +at least. Thus, for example, the ungulate has nearly always available in +bedding a substance that he can and will eat, and the prevalent idea +that an animal will eat only as much as is good for him seems not to +hold at all times, since overfilled rumens are only too common. It might +be thought, however, that captivity creates a sort of pica, or that +enforced idleness is conducive to gorging. The use a few lines above of +the word “doubtless” may have arrested the attention of some, yet when +the whole subject is reviewed it seems entirely justified. Plimmer puts +incorrect food at the head of the list of the causes of enteritis, +Brooks emphasizes the importance of certain grasses and musty fodder, +systematic writers detail among the principal causes of gastritis +spoiled food, and in zoological gardens specific disease like hog +cholera and enterohepatitis are relatively uncommon while nonspecific +gastroenteritis is the most frequent diagnosis in causes of death. + +The other factors to which enteritis is ascribed are animal and +vegetable parasites and mechanically operative foreign bodies, the last +being unimportant. Just how important the first mentioned are is a +matter of some question which must be subjected to considerable study +before any solution can be expected. + +If for no other reason than that the gross and minute pathological +anatomy of gastroenterocolitis is the same through the mammals and birds +(aside from a few specific lesions like enterohepatitis, typhoid fever, +etc.), while the food and bacteria vary, it would seem probable that the +ultimate cause is the same, a poison which can be formed alike in the +carnivorous and herbivorous gut, and not dependent upon bacteria, but +upon the chemistry of the food or of the intestinal mucosa. To put the +matter more simply, the lesions being the same under nearly all +conditions is not the cause the same, and is it not a poisonous product +from food or the intestinal lining. It is profitable here only to +mention the marked similarity of enteric lesions under the differing +conditions and in different orders. We shall study chartwise, the +various forms of inflammation from the cardia to the anus in terms of +their anatomical diagnosis and most probable etiology in an attempt to +throw light upon the matter, and later present the physiology. System +requires, however, some attention first to anatomical order so that a +brief review of the esophageal and pharyngeal conditions is indicated. + + +PHARYNX. + +The buccal-pharyngeal cavity in mammals is used chiefly as a passage way +for food and as the place where some of them triturate and insalivate +the bolus. Certain orders, Primates, rodents and marsupials, use this +cavity thoroughly at the first mastication, others use it little at +first but may ruminate, the ungulates, while strict carnivores use it +very little. The Aves use their pharynx almost exclusively as a passage, +and, despite the presence of a certain amount of salivary gland tissue, +probably do not digest any substance in this cavity. The crop or +ingluvies is a sac to permit of salivary digestion but is really a +storehouse to allow rapid feeding without overfilling of the +proventricle. The esophagus extends from the pharynx to the cardiac +opening of the stomach in mammals and widens into the glandular stomach +or proventricle in birds, the upper end of which lies in front of the +lower third of the left lung behind the heart. + +Inflammations of the buccal, pharyngeal and esophageal walls are +relatively common in certain orders especially ground birds and grazing +ungulates. This would seem to be explained on the basis of injury to the +mucosa by sharp or pointed objects picked up while feeding. The +character is usually necrotizing, but need not be, and the bacteriology +is not specific. Definite infectious diseases like diphtheria and +actinomycosis are not included here, but it might be mentioned that the +second disease cited is believed to be started by the penetration of the +organisms into wounds made by sharp grasses. Certain orders, notably +Ungulata, Passeres, Psittaci and Struthiones, are quite susceptible to +mycotic infestation and we have seen an outbreak of thrush in Kites +(Accipitres). It is, however, interesting and possibly significant of +peculiar protective powers in the upper alimentary tract, that strict +carnivores have failed to show ulcerative, purulent or necrotizing +inflammations of the mucosa from the mouth to the cardia. There has been +no important data upon ingluveal indigestion or esophageal obstruction. +Birds especially, and occasionally mammals, gorge themselves or take too +large a bolus, but it seems as if this is only fatal where some distinct +important pathology is present which has reduced their resistance. In +the lower esophagus one has to deal with worms in connection with the +proventricle in birds, but no mammals seem to have suffered with +temporary or permanent strictures. “Crop-binding” has occurred in the +following orders: Psittaci, Galli; and overfilling of the esophageal +dilatation was seen in Accipitres and Herodiones; Columbidæ with their +double crop were not affected by this abnormal collection of food in the +esophagus. + + +DILATATIONS OF ESOPHAGUS. + +The mammals have shown three dilatations of the esophagus interesting +enough to detail briefly: + + + Mongoose Lemur (_Lemur mongoz_) ♂ . Sacculo-fusiform dilatation of + esophagus, probably congenital, with adjacent fibrosis of lung. In + poor condition for several years but recovered satisfactorily from a + bad cut inflicted by cage-mates. At autopsy the general condition is + poor, hair missing in spots, all skin dry and atrophic with patches of + keratotic dermatitis. All tissues anemic, muscles lusterless. Right + lung collapsed, brown and pink, spotted with anthracosis. Left lung + pushed forward and to left by a mass in the posterior mediastinum. + Lower lobe in its posterior portion is adherent to esophageal mass. + Lower half of this lobe beginning where bronchus ends and extending + over anterior-posterior surfaces shows marked fibrotic processes and + at one point in tissue between end of bronchus and adherent esophagus + there is no lung tissue remaining. No recent consolidations. Bronchial + lymph nodes, small, firm homogeneous pale brown with specks of + anthracosis. Heart contracted, normal in size, firm red-brown. Aorta + is firmly adherent to esophageal mass where bronchus crosses it. The + lower half of the esophageal from the hilum of the lung to the cardia + is the seat of a dilatation, fusiform for the most part, but with a + saccular portion anteriorly. This latter presses the left bronchus + upward and heart forward. The wall of the tube is slightly irregularly + thickened but there is no cicatrix and mucosa shows slight + hypertrophic condition. A large mass of food occupies the dilatation. + Stomach is empty save for gas. Mucosa is soft, smooth, pale pink. + Duodenum shows slight swelling of the rather pale yellow submucosa and + mucosa, but the tips of the villi are injected. Intestine contains + only a little slimy mucus. Large intestine contains a mass of + constipated feces. The esophageal dilatation seems to have been + congenital although it is barely possible that the fibrosing + pneumonitis and pleuritis may have aided and caused it by traction. It + has been doubtless the cause of the animal’s inanition. + + Black Bear ♂ (_Ursus americanus_). Sacculate dilatation of esophagus + with chronic esophagitis. Chronic hypertrophic gastritis. Chronic + lymphadenitis. Fatty degeneration of liver. Acute catarrhal enteritis. + Had been vomiting more or less, nearly every day for two months and + did not eat for six days before death. Mouth, pharynx and esophagus + are full of macerated, unrecognizable food. Pharynx seems normal. + Larynx is yellow, mucosa rough and slightly thickened in places + especially just above the vocal chords. No excess of mucus. Esophagus + in neck is dilated. Mucosa is rough, irregular yellow brown. This + dilatation proceeds downward so that at thoracic opening tube is twice + normal size. Upon entering thorax this dilatation turns to right and + in irregular saccular form extends to diaphragm compressing heart and + lungs to left. The main course of it then recrosses the midline, aorta + being slightly twisted as it regains position in front of vertebræ. + The wall is irregularly thickened from pseudomembranous patches and + some hypertrophy of mucous and submucous layers. Muscle and serous + coats are considerably thinned. The sac is full of macerated food and + gas. The right lung is compressed small resilient red gray. No + adhesions in either pleura. On section the lung tissue is found to be + slightly edematous, red gray, compact and while not atelectatic yet + crepitates much less than normal. Left lung is the seat of passive + congestion in lower lobe and lower half of upper lobe. The upper half + of lobe is compressed and subcrepitant like the right lung. Lymph + glands of neck and thorax are much enlarged firm with large irregular, + clear outlined follicles and brown firm homogeneous pulp. The aorta + shows slight roughening, the intima being smooth and homogeneous. + + Lion ♂ (_Felis leo_). Ten and one-half months old. Cystic + parenchymatous goitre, dilatation of esophagus, ulcerative enteritis. + Acute glomerular nephritis. Chronic hyperplasia of spleen. Fatty + infiltration of liver. Bronchopneumonia (from pressure of goitre). + Ascaris in intestines. Had lump on neck for several weeks, ate very + little and seemed to have hard work to get anything down. Stopped + eating toward the last and vomited water and foam. There is a small + ulcer with everted lips just below left incisor on lower lip which the + keeper says is of several months’ duration. The thyroid is much + enlarged and forms a large mass in the upper chest and extends far up + in the neck. Because of this mass the lungs are pushed far down in the + chest. Heart also lies very low. The thyroids are enormously enlarged + and cystic, the right measuring 13 × 8.5 × 5 cm. and the left + 19 × 9 × 5 cm. The lungs are pale pinkish white. Air content increased + in places, decreased in others. No hypostatic congestion. The lungs + seem normal except at the apex where they are collapsed probably from + pressure on lung by enlarged thyroid which dips down into the chest + for at least three inches filling entirely the apex of the chest. One + bronchial lymph gland was about the size of a walnut, the rest were + normal. The heart seems normal except for its slightly low position. + The abdomen contains about 300 c.c. of deep yellow highly albuminous + fluid. No adhesions. The liver is softer than normal, glistening, + smooth, moist and very yellow particularly at the edges. The gall- + bladder contains a green mucoid bile and the duct is patulous. Spleen + and kidneys are normal. Mouth and pharynx are normal. The esophagus is + much dilated above the thyroid. The enlarged thyroid pressing upon it, + has acted as a distinct obstruction. In this pouch was a large amount + of food probably (from the history) eaten two days before. The + esophagus below this point was normal except for the presence of thin + mucus. Stomach empty save for two small bits of meat. The duodenal + walls are much thickened, mucosa covered with small ulcers many with a + hemorrhagic base; there were present also a few small, round worms. + + +[Illustration: + + FIG. 14.—DILATATION OF ESOPHAGUS. LION (FELIS LEO). DILATATION + PROBABLY DUE TO OBSTRUCTION BY ENLARGED THYROID BODY. IN + ILLUSTRATION DISTENTION OF ESOPHAGUS CAN BE SEEN IN THE FORK OF THE + THYROID LOBES. +] + +Here are presented three different dilatations, the first probably +congenitally started and aided by pulmonary fibrosis, therefore +secondarily a traction diverticulum, the second probably entirely +congenital, and the unusual third case due to obstruction by an enlarged +thyroid. In this connection might be mentioned small saccular +diverticula in the proventricle of a Fire Finch (_Lagonosticta +senegala_), and at the pylorus in a Puma (_Felis concolor_). Neither of +these seemed of any significance and played no part in the death of the +animals; they did not seem to be artificially produced, by worms, for +example. + + +THE PROVENTRICLE. + +The proventricle or forestomach of birds, is the seat of active +secretion of the gastric juice in nearly all orders, although Jobert +believes that the mucosa of the gizzard may contribute some digestive +fluid, and there are active glands in this tissue in a few orders. The +proventricle does not act as a reservoir during digestion, but as soon +as the juices are well mixed with the bolus the food is passed on to the +gizzard. The organ has a rather free position, at least as far as its +left lateral and downward movements are concerned for the left lateral +abdominal air sac is free on that side of the gastric complex and the +left lateral thoracic also extends down the side of the proventricle. +Upward and anteriorly is the heart. Some of the cases of proventricular +spiropteriasis have shown very marked congestion of the left lung, +possibly due to the closure of the anteroinferior air sac aperture on +that side. Aside from parasitism, affections of this organ are not very +numerous. + +Infestation with spiroptera and with less dangerous worms was quite +serious at one time, but since routine examinations of all suspicious +birds has been practiced this parasitism has been under control. This is +a subject of especial importance to collections, and will be described +in a special section. The susceptibility of the proventricle to damage +seems from our figures to be very distinctly a matter of zoological +order. In so far as parasites are concerned, the parrot group stands +away ahead of all others having an incidence among autopsies upon +Psittaci of 16 per cent.; after them come the Picariæ with 9 per cent., +and Columbæ and Passeres each with 4 per cent. When, however, non- +verminous conditions are reviewed the anserine birds are found the most +susceptible, 3 per cent. of the autopsies upon this order revealing +proventricular lesions; after them come the Columbæ, 2 per cent., and +Psittaci, 1.5 per cent. In this group are included inflammations of all +kinds, dilatations and distentions and some lesser matters. + +This part of the stomach has been involved in our cases of fowl +diphtheria, showing a distinct mucopurulent inflammation with +penetration into the depths of the glands; no separation of the mucosa +occurred, but ulceration was seen. Perforation was observed thrice, +twice by ulceration around a worm while it was boring into the muscular +layer and once, in an ostrich, by the penetration of a nail. Obstruction +of this division of the stomach by impaction of food and stones is not +common, but does occur. The reason for such obstruction is usually very +obscure. Sometimes it seems due to the feeding of seeds and the like in +too finely divided form, whereby food and pebbles are taken up together. +Some of the smaller birds have had in times past too many small pebbles +in the cages, while others have had too large seeds, thus apparently +trying to use the pebbles to crush them. It would seem also that the +birds had really eaten too much and could not accommodate it in the +gullet and gizzard; this seems surely true in three or four Accipitres. +Most often, however, we have had to fall back upon the inadequate +explanation of pica or perverted appetite. + +Impacted proventricles and gizzards have been observed thirty-four +times, in eight of which it seemed the sole cause of death, and +therefore probably entirely due to foreign bodies in food. The theory is +accepted that dilatation and obstruction will not occur if the motor +power of the gastric wall be normal and no inflammation exist. In this +regard we can only discover five birds (the mammals will be discussed +later) with any distinct inflammatory or degenerative disease of this +part of the anatomy and two with lesions elsewhere which might affect +the musculature; this leaves the vast majority of gastric obstruction in +birds unexplained on basis of defective motor power, therefore probably +dependent upon the character of material consumed. The anserine birds +and parrots are most often affected by this form of obstruction. + +Acute or chronic dilatation of the forestomach and gizzard is very rare +in birds, it having occurred only thrice in our records, a finch, a +parrot and an owl; the causes were entirely unknown since the cavities +were not overfilled with food. + + +THE STOMACH. + +Impaction of the mammalian stomach is a diagnosis made but once in our +records, an Indian Antelope (_Antilope cervicapra_), and this is viewed +with suspicion. The rumen was undoubtedly tightly packed, being +distended to its fullest capacity with rather dry and not properly +softened grain. However, postmortem changes had advanced and therefore +observations in the whole body were not dependable. The bulk of food +which can be accommodated by the rumen is very large, and had this not +been dry and firm the condition might not have been interpreted so +seriously. Many animals come to autopsy with a well filled, indeed even +with a well packed stomach, but there is usually sufficient reason for +this or there is distinct pathology to account for death. + +All this of course implies a stomach of normal or approximately normal +dimensions since distention beyond this, or dilatation of the stomach, +is more definite. In veterinary medicine, gastric tympanites (rumen +alone or all stomachs, or the simple stomach) is ascribed to food that +ferments easily when taken in excess or in the presence of defective +motor power, to constrictions by scars and to obstructive tumors; +excessive feeding is sometimes mentioned but given a subordinate rôle. +Our records throw very little light upon the subject since only five +cases were observed. Four of these five seem to be due to acute +fermentation independent of gross physical obstruction, while one, a +Cape Hunting Dog (_Lycaon pictus_) showed an old chronic ulcerative +gastritis with both healed and active ulcers distorting the pyloric end +of the organ. Three of the first mentioned four were monkeys and one was +an ocelot. The stomach of the voracious monkey is at time of dissection +usually well filled, but in these cases there seems no doubt that gas +and excess fluid had distended the cavity enormously, in one instance +apparently assisting in acute cardiac dilatation. There were no obvious +reasons for assuming any damage to the gastric motor mechanism. + +[Illustration: + + FIG. 15.—ROUND ULCERS IN STOMACH WALL. COMMON OPOSSUM (DIDELPHYS + VIRGINIANUS). THERE IS GENERAL MODERATE CHRONIC GASTRITIS WITH ROUND + ULCERS NEAR THE CARDIA. +] + + +GASTRIC ULCERS. + +Gastric ulcer, so-called peptic or round ulcer of the stomach, having a +chronic course and leading to radiating scars of the mucosa is not +common in the lower animals, but frequent enough in the human being. The +form of ulcer in question has at present no adequate explanation, or at +least there is no one cause which will answer for all cases. Local +injuries from within or without the stomach, bacterial embolism, +entrance of bile through the open pylorus and many other factors have +been named in the causation but can seldom be used in any given case. In +the lower animals with their relatively frequent parasitic infestation, +another factor is added. In analysis of our statistics I have separated +ulcerative gastritis from parasitic and mycotic ulcerations and from +peptic ulcers; the first is discussed in later paragraphs. Parasitic +ulcers of the stomach occur chiefly in our native marsupial, the +opossum, and in some Carnivora; physaloptera, strongylus, ascaris, and +gastrophilus have been found. The kangaroos are frequently affected (8 +cases) with an acute or subacute ulceration of the gastric wall, without +much general gastritis. The lesion is peculiar in appearance. The +youngest ulcers are black or dark gray, flat necroses of the mucosa +alone and indeed the process very frequently penetrates no deeper. Older +lesions spread laterally and may be preceded by a very narrow congested +line but there is no raised edge nor does there seem to be submucous +infiltration. If the process be rapid a loose dirty slough may form. +Certain of the advanced cases of Kangaroo mycosis will present more +infiltrative lesions of the gastric wall leading to large and well +defined necrotic areas; they may at times penetrate the whole wall +outward. (See page 580.) + +True peptic ulcers have been found in Primates, 4; Carnivora, 5; +Pinnipedia, 2; Insectivora, Ungulata and Hyraces each one. The London +Garden reports that gastric ulcerations occur most often in Carnivora +and Marsupialia. Those in the last three orders of our list were small, +usually multiple and relatively superficial. The ulcers found in +Primates and Carnivora present the usual pictures seen in man. In one +example in each of these orders radiating scars of healed defects are +mentioned in the notes. None of them seems to have led to cancer, and in +only one, a wolf (_Canis lupus_), was the scar tissue sufficient to +cause definite impediment to the motility of the stomach. Six of the +fourteen examples appeared on the greater curvature, the remainder on +the lesser. Ten ulcers were in the pyloric division, the other four +being scattered. No other pathology is found common to these cases which +might be drawn into etiological association. + + +TUMORS. + +Tumors of the gastric complex are not at all common, there being only +the following to report: Primates, Hamadryas Baboon (_Papio hamadryas_), +diffuse adenoma; (none in Carnivora with the most ulcers); Marsupialia, +Red Kangaroo (_Macropus rufus_), malignant papilloma with metastases. +The former tumor, shown in Fig. 17, was a diffuse soft excrescence +beginning near the pylorus and stretching along the lesser curvature +toward the cardia. Histologically it was made up of glandular acini +growing in all directions but always maintaining normal relations of +cells and basement membrane. There were no metastases and other reasons +for death existed. The tumor of the kangaroo stomach was a true +epitheliomatous cancer with metastases to liver, spleen, and kidney. +Only one secondary tumor was observed, from a carcinoma of the lung in a +Red Kangaroo (_Macropus rufus_). + +[Illustration: + + FIG. 16.—MULTIPLE GASTRIC ULCERS. COMMON WOLF (CANIS LUPUS). CHRONIC + GASTRITIS WITH NUMEROUS IRREGULAR ULCERS OF THE PEPTIC TYPE. +] + +[Illustration: + + FIG. 17.—PAPILLOMA OF STOMACH. HAMADRYAS BABOON (PAPIO HAMADRYAS). +] + + +THE INTESTINE. + +Inflammation of the gastrointestinocolic tube is the most important +single condition with which handlers of animals have to deal, and +unfortunately it can seldom be diagnosed clinically, early and +accurately enough, to make treatment useful. At this Garden some +evidence of acute or chronic disease of the tube has been present in 31 +per cent. of our autopsies. The reports of other gardens would indicate +that their figures might be quite close to this. What is the cause of +this high mortality? Incorrect feeding, qualitatively or quantitatively +has been put at the top of the list by Plimmer, but he adds other less +important factors: Bacteria of infectious power, protozoa, foreign +bodies and parasites or their mural cysts. In order to evaluate +approximately how each of these acts let us review the causes as they +are generally known and later discuss the pathology as seen in the +various orders. + +(1) Overloading of the stomach by too much food or by rapid eating of a +hungry animal is of importance under certain domestic circumstances +where times of feeding are irregular or intervals are too long, but this +cannot occur in any well regulated menagerie. It is possible, however, +that overfilling might occur in certain Ungulata, which have hay and +straw nearly always available, if the food in their reach happens to be +particularly agreeable or tasty to them. + +(2) Insufficient mastication would seem to be important only in those +orders which depend upon this action to triturate, insalivate and +macerate their food, of which Homo, Primates, Ungulata and Marsupialia +are the principal ones. + +(3) Disturbance during and after feeding has always been believed to +affect digestion unfavorably, and it may be that visitors to a +collection exert such an effect; this factor is probably negligible. + +(4) The appropriateness of the food is a very important factor in the +health of an animal under captive conditions. Diet lists are made up by +officials largely according to the known habits and general physiology +of an animal, but the food offered can at best only approximate what the +wild beast obtains for himself. It does not follow because a selected +diet may seem to provide all the elements contained in the food +available under natural conditions that it actually does so, especially +since we are aware that some essential food factors, known under the +term vitamins, are necessary to best development. These substances vary +in closely similar foods, and seem to be higher in simple natural foods +than in prepared diets. We have seen in this Garden that the inorganic +constituents must be correctly represented in the food, else +degenerative osseous condition may develop. Inappropriate diet may +express itself at once after the receipt of an animal, by its sickness +or death, or after some time in the development of chronic tympanites, +chronic intestinal catarrh or bony deformities. + +(5) The physical condition of food is a matter of no small moment. The +taking of soft food in large quantities especially by herbivorous +animals, permits too short a sojourn in the gastric fundus and is often +followed by pyloric and duodenal disease. Too firm food may pack the +rumen, fundus or proventricle as the case may be, and be succeeded by +distention of these parts and catarrh of the pyloric and intestinal +area. The effect of foreign bodies mixed with food is difficult to +evaluate unless of course they be of such a nature (pointed metal and +the like) as directly to traumatize the mucosa. Many birds and mammals +come to autopsy with a relatively large number of stones and small +sticks in the stomach without any distinct evidence that they have been +hurt thereby. In the bird the stones may be so large and numerous as to +leave little room for food, or small enough to pass out into the +intestine where they undoubtedly may pave the way for bacterial action. +Smoothly polished pebbles in small quantity seem to have little effect +in mammals. Hair balls are not common and unless of large size are +apparently unimportant. Considerable sand mixed with food has a +distinctly irritating effect. It is perhaps best known as a chronic +gastric disorder of horses; we have seen it in zebra. + +(6) Spoiled food is obviously a very prime factor in inflammations of +the gastrointestinal tract. Its operations are illy understood except +perhaps when products of fermentation or putrefaction prevent digestive +action or are absorbed. If in small quantities not sufficient to cause +acute fermentative inflammation or intoxication, such substances +frequently taken may doubtless produce chronic catarrhs. Many animals +are fed upon vegetable mashes, or stews which can decompose, while bad +meat may occasionally be fed. We had a rather serious outbreak of +enteritis in small Carnivora from the use of fowl heads obtained at +hotels; some of these cases were shown to be due to B. paracoli, thus to +be looked upon as infections. Dirty food while not spoiled may carry +with it organisms of decomposition, or of infective qualities, or the +dirt may act as an irritative foreign body. We have found that for +delicate ungulates (antelopes) it is highly desirable to screen grain, +and that the grade of hay should be of the best. + +(7) Infectious conditions are of great importance under certain +circumstances but with the exception of hog and fowl cholera, the +dysenteries and a few other diseases, do not as a rule play a great part +in mortality as specific diseases unless of course an epizoötic appear. +The greater problem is to understand bacterial action in the face of +other factors. Are infectious germs introduced with food and drink in +every case of gastroenteritis or do some other factors activate those +already present in the gut tract? Unfortunately these questions cannot +be answered directly. We can, however, point out which groups of +bacteria are most common in some of the orders, which orders are most +susceptible to bacterial invasion and which to local lesions with +intoxication. The greatest problem in the field is the interrelation of +germs of various sorts in the intestinal tract. Certain varieties are +known to develop intoxicating aromatic substances, others to elaborate +or excrete fatty acids, still others to form antiferments but the +conditions existing in the various kinds of intestinal tracts are too +little understood to help very much in this study. + +(8) Animal parasites have long been considered as one of the causes of +gastrointestinal inflammation, a condition largely due to copying from +book to book of a few facts and more impressions. The sum of reliable +information to-day would seem to indicate that a few parasites—uncinaria +being the most conspicuous example of this type—draw considerable blood +from the mucosa, that a few, like uncinaria and dibothriocephalus, +elaborate an absorbable toxin, that some, notably ascarids, produce an +irritating substance, and that many possess the power in themselves or +by some excretion to act as antiferments. These factors, were they all +combined in one worm, might probably irritate the mucosa sufficiently to +produce inflammation, but it is not easy to imagine that they would +cause an acute specific condition. It is much more easily conceived that +with tiny hemorrhages or ulcerations of mucosæ, bacteria might get in +their work or if considerable ferment were neutralized, maldigestion, +flatulence or indigestive irritation would ensue. With certain worms +like esophagostomum there is considerable evidence to show that a +chronic fibrous disease of the intestinal wall arises, but in this case +the parasite resides in the mucosa and acts as a foreign body. It would +seem, however, that the most important influence that animal parasites +exert is to be found in the preparation of the mucosa for the action of +bacteria. Masses of parasites may of course physically obstruct the +lumen and lead to intestinal stasis and dilatation. + + +INFLAMMATION. + +In analyzing the cause of a gastroenteritis and its consequent effect +upon the wall of the tube and upon the viscera, certain physical, +chemical and physiological factors must be considered. Whether this may +be directly the effect of bacteria or poisons from worms or some other +factor seems of little moment since in any fully developed case, +symptoms and effects are comparable. Moreover it seems that pathological +anatomy, both gross and minute, is essentially the same from Primates to +struthious birds, the highest and lowest of the two classes here +considered. By this is meant that the acute congestive condition of the +gut tract with solution of the surface, to which we have applied the +name of toxic enteritis, seems to be met with in this form throughout +all the orders. So too catarrhal inflammations are the same to the naked +eye and under the microscope, due allowance being made for the fact that +mammals use polynuclear cells for exudative purposes while birds employ +mononuclears. Concomitantly with these conditions, a degenerative +process may be going on in the liver and kidney, and hyperplasias, +especially in the true infective processes, will be found in the related +lymphatic structures. + +The majority of students to-day place responsibility for gastroenteritis +upon the bacteria known to be present in the various intestinal tracts, +mentioning especially colon and proteus groups, streptococci, the +necrosis bacillus and anaerobes of the Welch class. In a few of our +studies of intestinal bacteria in cases of enteritis one thing has been +very definite and that is that in the intestinal content of animals +whose food is largely meat, Gram-negative bacilli have predominated, +whereas in herbivorous animals Gram-positive organisms have been most +numerous. From the observations of Kitt, Strassberger and some others, +the normal flora of domesticated animals is subject to wide variations +so that our observations must receive confirmation before they are +finally acceptable. We have on several occasions isolated from +carnivorous intestines Bact. paracoli, Bact. suipestifer and other +members of this group. We have no reliable cultural data upon the +herbivorous intestine and can only quote the Gram pictures as mentioned +above. On two occasions, an eland and an elk, a very large number of +forms corresponding to necrosis bacillus were seen; to this organism +Kitt gives considerable power in the production of necrotizing +processes. + + TABLE 11. + + _This table shows an analysis of all cases of gastroenterocolitis. The +left half of the table is an analysis of orders upon which one hundred +or more autopsies have been done, the right half of orders with fewer +than that number. The left half is expressed in percentages, the right +half in number of cases only since percentages might be misleading. Left +hand table: First column is percentage of gastroenterocolitis per order; +next five columns the percentages in which each of the factors in the +headings was believed responsible; the last three columns show the +participation of each of the divisions of the intestinal tract; thus +Primates had all told 24.8 per cent. of inflammations of which 7.2 per +cent. were in stomach, 18.3 per cent. in the intestines and 8 per cent. +in the colon; obviously many had all three sections affected. Right hand +table is constructed on a similar basis except that number of cases is +quoted, not percentages, and the total is put in the last column._ + + ════════════╤═══════════════════════════════════════════════════════ + │ Percentages in orders with sufficient autopsies. + ────────────┼─────────┬────┬────────┬─────────┬────────┬──────────── + │Per cent.│Food│Bacteria│ Animal │Physical│Undetermined + │ of │ │ │Parasites│Objects │ + │Autopsies│ │ │ │ │ + ────────────┼─────────┼────┼────────┼─────────┼────────┼──────────── + Primates │ 24.8│ 1.8│ 4.4│ 3.6│ │ 15. + Lemures │ │ │ │ │ │ + Carnivora │ 46.1│ 2.9│ 7.2│ 5.8│ .2│ 30. + Pinnipedia │ │ │ │ │ │ + Insectivora │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ + Rodentia │ 25.│ 5.│ 2.│ 2.│ │ 16. + Ungulata │ 24.8│ 6.6│ 2.2│ 2.│ .8│ 13.2 + Proboscidea │ │ │ │ │ │ + Hyraces │ │ │ │ │ │ + Edentata │ │ │ │ │ │ + Marsupialia │ 33.1│ │ 10.│ 10.1│ │ 13. + Passeres │ 23.6│ .1│ 4.5│ 1.8│ .15│ 17. + Picariæ │ │ │ │ │ │ + Striges │ 41.5│ 1.5│ 5.3│ .7│ │ 34. + Psittaci │ 36.6│ .3│ 10.7│ 3.7│ .15│ 21.8 + Accipitres │ 40.7│ │ 4.5│ │ .5│ 35.7 + Columbæ │ 17.8│ │ .6│ 3.│ .6│ 13.5 + Galli │ 38.6│ │ 5.3│ 19.6│ │ 13.7 + Hemipodii │ │ │ │ │ │ + Fulicariæ │ │ │ │ │ │ + Alectorides │ │ │ │ │ │ + Limicolæ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ │ + Impennes │ │ │ │ │ │ + Steganopodes│ │ │ │ │ │ + Herodiones │ │ │ │ │ │ + Odontoglossæ│ │ │ │ │ │ + Palamedes │ │ │ │ │ │ + Anseres │ 29.6│ .3│ 4.4│ 2.3│ .6│ 22. + Struthiones │ │ │ │ │ │ + Crypturi │ │ │ │ │ │ + ────────────┴─────────┴────┴────────┴─────────┴────────┴──────────── + + ════════════╤════════════════════════╤════════════════════════════════ + │sufficient autopsies. │Number of cases in orders with under 100 autopsies each. + ────────────┼───────┬──────────┬─────┼────┬────────┬─────────┬──────── + │Stomach│Intestines│Colon│ │Bacteria│ Animal │Physical + │ │ │ │Food│ │Parasites│Objects + │ │ │ │ │ │ │ + ────────────┼───────┼──────────┼─────┼────┼────────┼─────────┼──────── + Primates │ 7.2│ 18.3│ 8.│ │ │ │ + Lemures │ │ │ │ │ 8│ 2│ + Carnivora │ 21.│ 41.│ 6.6│ │ │ │ + Pinnipedia │ │ │ │ │ 1│ 1│ 1 + Insectivora │ │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ │ + Rodentia │ 7.│ 20.5│ 3.5│ │ │ │ + Ungulata │ 9.1│ 20.│ 2.5│ │ │ │ + Proboscidea │ │ │ │ │ │ │ + Hyraces │ │ │ │ │ │ │ + Edentata │ │ │ │ │ │ │ + Marsupialia │ 22.│ 21.│ 3.5│ │ │ │ + Passeres │ 1.2│ 22.│ 3.│ │ │ │ + Picariæ │ │ │ │ 1│ 10│ 4│ + Striges │ 6.│ 40.│ .7│ │ │ │ + Psittaci │ 1.7│ 35.4│ 1.3│ │ │ │ + Accipitres │ 5.2│ 39.│ 1.│ │ │ │ + Columbæ │ 4.5│ 13.5│ .7│ │ │ │ + Galli │ 2.6│ 21.6│ 19.6│ │ │ │ + Hemipodii │ │ │ │ │ │ │ + Fulicariæ │ │ │ │ │ 6│ 1│ + Alectorides │ │ │ │ 1│ 1│ 2│ + Limicolæ │ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ 1│ 1│ + Impennes │ │ │ │ │ │ │ + Steganopodes│ │ │ │ 1│ 1│ │ + Herodiones │ │ │ │ │ 1│ 3│ + Odontoglossæ│ │ │ │ │ │ │ + Palamedes │ │ │ │ │ │ │ + Anseres │ 2.5│ 27.7│ 6.6│ │ │ │ + Struthiones │ │ │ │ │ 7│ │ + Crypturi │ │ │ │ │ │ │ + ────────────┴───────┴──────────┴─────┴────┴────────┴─────────┴──────── + + ════════════╤═════════════════════════════════════════════════════ + │Number of cases in orders with under 100 autopsies each. + ────────────┼────────────┬───────┬──────────┬─────┬─────────────── + │Undetermined│Stomach│Intestines│Colon│ Total Animals + │ │ │ │ │ Showing + │ │ │ │ │Gastroenteritis + ────────────┼────────────┼───────┼──────────┼─────┼─────────────── + Primates │ │ │ │ │ + Lemures │ 13│ 4│ 19│ 3│ 23 + Carnivora │ │ │ │ │ + Pinnipedia │ 8│ 7│ 8│ 1│ 11 + Insectivora │ │ │ │ │ + Chiroptera │ 2│ 1│ 1│ │ 2 + Rodentia │ │ │ │ │ + Ungulata │ │ │ │ │ + Proboscidea │ 1│ │ 1│ │ 1 + Hyraces │ 2│ │ 1│ 1│ 2 + Edentata │ 2│ │ 1│ 1│ 2 + Marsupialia │ │ │ │ │ + Passeres │ │ │ │ │ + Picariæ │ 24│ 5│ 36│ │ 39 + Striges │ │ │ │ │ + Psittaci │ │ │ │ │ + Accipitres │ │ │ │ │ + Columbæ │ │ │ │ │ + Galli │ │ │ │ │ + Hemipodii │ │ │ │ │ + Fulicariæ │ 8│ 1│ 15│ │ 15 + Alectorides │ 10│ 2│ 13│ 3│ 14 + Limicolæ │ 1│ │ 1│ │ 1 + Gaviæ │ │ │ 2│ │ 2 + Impennes │ 3│ 1│ 3│ │ 3 + Steganopodes│ 8│ 1│ 10│ │ 10 + Herodiones │ 25│ 1│ 24│ 6│ 29 + Odontoglossæ│ │ │ │ │ + Palamedes │ 1│ │ 1│ │ 1 + Anseres │ │ │ │ │ + Struthiones │ 14│ 8│ 20│ 3│ 21 + Crypturi │ 1│ │ 1│ │ 1 + ────────────┴────────────┴───────┴──────────┴─────┴─────────────── + + +THE TABLE. + +Our records have been analyzed from the standpoint of diagnosis and the +most probable cause. The first will be taken up in discussing each of +the orders. The probable causes are divided into food, bacteria, animal +parasites, physical objects and undecided, in other words a +classification based upon the most prominent or definite evidences as +seen at postmortem combined when possible with antemortem observations. +When findings were inconclusive or contradictory, cases were called +undecided, naturally a very large group. Fermentative processes in the +presence of obviously undigestible material, are classified with food as +a cause. When evidences of septicemia existed in absence of the other +factors, it is held that bacteria were responsible. Cases were grouped +under animal parasites when these were the most definite findings. +Physical objects are relatively unimportant and self-explanatory. To the +etiological chart there are appended columns intended to show the +percentage or case incidence of the disease of the grosser subdivisions +of the gastrointestinal tract which indicate in a general manner what +part of the tube in the various orders is most susceptible to disease. +While of course conclusions must be drawn with great caution, there can +be little doubt, for example, that carnivores and marsupials have more +gastric disease than any other order, and that the high place for the +colon is held by the gallinaceous birds. This charting was suggested by +the work of Dr. Raymond Pearl upon statistics, wherein he takes as a +basis of classification the part of the body which succumbs to disease- +producing organisms or from which a disease starts. It cannot be stated +that there is a clear cut relationship between enteritis and the +expectancy of life. + + +MAMMALIA. + +The PRIMATES as an order have their share of inflammations of the +gastrointestinal tract and present points of interest. Acute digestive +disorders succeeded by acute dilatation of the stomach, or in less +fermentative cases by acute catarrh of the intestine, are not at all +uncommon. The reason for this is not discovered by reviewing the diet +and manner of feeding. The buccal pouches, distensible esophagus, the +freely movable stomach, and relatively elastic gastric wall would seem +to permit of very considerable dilatation to accommodate the large +quantities which the monkey sometimes crams into himself. Nine fairly +acceptable records of gastric overfilling exist and two of them seem to +have been followed by tympanites sufficient to embarrass respiration, in +one case there occurring an acute cardiac dilatation with myocardial +degeneration. The animals give no symptoms of this condition and in the +last case cited the beast, while old, ate well and was not distended the +evening before death. + +When acute gastritis exists (twenty cases) the animal seems uneasy but +does not vomit. On one occasion I was called to see a monkey which was +retching and seemed in pain. Lime juice was offered and taken, followed +by gentian and cardamon, which seemed to give some benefit. Somewhat +later this was repeated in another case, but observations where this +might be useful are rare. + +The pathology of gastric conditions offers little to contrast with that +of man. The enormous distensibility of the fundal pouch often suggests +to the observer the rumen of ungulates. Acute gastritis of one kind or +another and acute catarrhal enteritis are the most common lesions noted +in the Primates. Involvement of the intestine or colon need not carry +with it an increase of signs of illness, although at times one will see +an evidently sick animal with diarrhœa. Anatomically the lesions are +commonly restricted to the stretches of gut _above_ the ileum, it being +rather rare that this division or the colon is affected. Pathologically +the lesions are catarrhal with definite involvement of the follicles in +about one-third of the cases. In this order toxic and pseudomembranous +forms are quite rare and ulcerative lesions uncommon. Colonic disease as +a sequel to inflammation higher up is sometimes seen in the follicular +varieties, but takes a minor place compared to amœbic dysentery of which +we have had several cases; this will be discussed under a separate +heading. Degenerative disease of the skeleton is almost always +accompanied by a low grade of enteritis but not necessarily gastritis or +colitis. The pallor of the mucosa, while at times striking, may be +relieved by follicular spots and petechia or pigmentation. Often, +however, animals suffering from osteomalacia and rickets come to their +end by an acute inflammation of the gut tract. + +The bacteriology at our disposal allows no conclusions. Aside from a +case probably due to Ps. fluorescens and one with colon bacillus +abscesses in the liver, no reliable data are at hand. + +Reference to Table 11 reveals the fact that among orders with sufficient +autopsies to permit percentages, the alimentary tract in monkeys is in +the group of low figures, that the intestinal section is relatively more +often affected, and that the colon is more often diseased than in other +mammalian orders, and is exceeded only by the gallinaceous birds. + +The LEMURES, of which we have eighty-six autopsies, do not differ much +in anatomy from the Primates, however greatly they disagree in habits +and outward appearance; their diet is the same. Clinically the slothful +behavior of a normal lemur probably obscures symptoms and signs of +illness, for our antemortem notes with the exception of a few +observations of loose stools, fail to offer a lead as to diagnosis. This +order has a large incidence (twenty-three cases) of gastroenteric +conditions as shown in Table 11, but some explanation of the figures is +deserved. In the first place, only one case of acute gastritis occurred, +and this was apparently a part of a general infection, and if induced at +all by food this was only secondary. Indeed as one reviews the records +it does not seem that the lemurs are easily disturbed in their gastric +digestion. Acute and subacute inflammations from bacterial action seem +definitely more prominent since they take the catarrhal, follicular and +deep submucous form and are frequently associated with generalized +infectious processes. One amœbic case was observed and there was another +in which a heavy cestode and nematode infestation seemed to have paved +the way for bacteria. + + +CARNIVORA. + +The food of this order is received into the fundal part of the stomach, +the distensible but normally capacious left and superior two-thirds of +the organ. The general shape of the viscus, that of a gourd, permits a +fairly sharp separation of the fundal and pyloric sections, so definite +indeed that the pathology of the two parts was studied. The intestines +vary in length, but in the land carnivores are relatively short, narrow +in lumen and rich in wall. A cecum, or at least a blind end of the large +gut made by the insertion of the small intestine above the tip of the +colon, is suggested in all families, although, as in the bears, it may +be quite insignificant or rudimentary. Theoretically no stasis should +occur at this point. The colon is short in all carnivores and, like the +small gut, with a heavy wall. The comparative simplicity of the +carnivorous gut tract, the ability of many of these animals to disgorge, +the suggestion of high resistance of the upper end of the tract to +infection and the ease with which diarrhœa can clear out the tube, would +seem to warrant the expectation that inflammation would not be serious. +Such, however, is not the fact for, on the contrary, they have shown a +higher incidence than any other order for which we have adequate +comparison. Anatomically considered their stomach occupies the second +place in vulnerability, next to the marsupials, and their intestines the +highest place; this indicates of course that combined gastric and +intestinal disease has often occurred. Involvement of the colon occupies +the second place, in ordinate susceptibility, being exceeded only by the +monkeys, due to heavy parasitic infestation, but would occupy the first +place were the eleven amœbic dysenteries in monkeys subtracted from +their total, a subtraction which might be allowed since it represented +an epizoötic outbreak. + +Etiologically considered, it would seem as if the influence of incorrect +feeding were of little importance, and from one standpoint this is +probably the case. Acute fermentative or irritative processes are not +common at all, while more inflammatory pictures, catarrhal, erosive or +ulcerative, are the rule. There is another phase to the term incorrect +food, that is incorrect in its cleanness. During 1912–15 there was an +increasing mortality among the cats and dogs fed upon horse meat, mutton +and fowl heads. Early in 1916 the butcher shop was reconstructed and +thoroughly cleaned and covered galvanized pans supplied in which to +transport the food; these pans were scrubbed and scalded after use. +Since that time, infections inflammations of the stomach and intestines +have shown an ever increasing downward incidence, which result, there +having been no material changes in other directions, I do not hesitate +to ascribe to the improvement of butchering and dispensing engineered by +Dr. W. B. Cadwalader. + +Helminths seem to be of importance in this order both by reason of the +percentage of autopsies in which they presented the most probable or at +least most suggestive cause and because uncinaria and strongylus have +been seen attached to the wall and a large bulk of known irritative +cestodes have occupied the lumen. Physical objects, stones, bones, wire, +may cause irritation enough to activate bacterial action or may actually +penetrate the wall; the latter action is well known. In so far as +practical application of this is concerned, it teaches to feed whole, +unsplintered or ground bone. + +The distribution and character of pathological lesions according to the +region of the stomach is what might be expected from the shape and +physiology of its parts. True inflammatory processes are best, and in +some cases only seen in the pyloric half of the viscus, while the +changes in those few cases believed to be fermentative or irritative in +nature were largely confined to the fundus. Dilatation of the latter +part may be understood because there the muscular coats are about equal +to the mucous in thickness and one-half the width of those at the +pylorus, but why inflammatory processes should not be so developed in +the fundus is not clear unless the greater availability of mucus +protects the secreting wall. Not only does acute inflammation reach its +most definite form in the second part of the stomach, but the irregular +pigmentation, mammillated overgrowth and atrophy or ulceration of +chronic disease are likewise best seen in this part. + +Acute enteritis, of all varieties, is seen more beautifully in +carnivores than in any other order of mammals, and nowhere can it be +studied better. Its gross appearance is that of the text-book and its +minute character even more instructive. I have used a slide of acute +catarrhal enteritis in a lion for the illustration of this lesion for +the _Text-book of Pathology_ by Doctor Stengel and myself. However, as +is known to all who have paid any attention to enteritis, the postmortem +findings are usually much less definite than clinical observations would +warrant one to expect. The Carnivora not uncommonly show intestinal +congestion, mucous membrane swelling without edema or opacity, +congestion of the spleen, cloudy swelling of the liver and kidneys and +perhaps mesenteric lymph node edema. This picture we have viewed as a +toxic affair of some sort or a bacterial infection not yet far enough +advanced to produce catarrhal or ulcerative enteritis and septicemia. In +such cases the carnivorous intestinal mucosa offers instruction. The +epithelium is vacuolated or fringed on the free edge or may be missing +altogether. In the depths mucus formation is very active, and where it +is going on, round cells seem attracted, collecting in groups in the +villus or in the subjacent submucosa. Perivascular round cell increase +may be noted. Plasma cells and granular eosinophiles are common, but I +cannot state how important the latter are in the general picture because +of the frequency of parasites in carnivores. The central vessel of the +villus and the arterioles of the submucosa are injected. Lymph follicles +may or may not be enlarged, but if so usually fail to show a germ +centre. + +Colitis alone is not common in this order, but as an extension process +or involvement at the same time as the upper levels it occurs +occasionally. The only fact I wish to record and one which I would +emphasize because of having seen it recently in a human case of chronic +colitis, and since it does not appear important to systematic writers, +is superficial blood supply. The capillary network of the colonic villi, +while rich, is in the form of a fine plexus just under the epithelium. +In the cases studied these vessels become quite distinct and possess +much more definite walls, often bordered by mononuclears, while +connective tissue is more evident at the bases of the villi and deeper. +This may help in deciding the existence of a colitis. + +Bacteriologically the most instructive experience to report is the +discovery that a small outbreak of enteritis among small Carnivora, +chiefly cats, fed upon fowl heads was due to Bact. paracoli, or at least +this organism was found in the intestinal mucosa, spleen, and heart’s +blood of three cases. The type of enteritis was hemorrhagic and +follicular. There was also a case of septicemia apparently emanating +from enteritis due to Bact. suipestifer in a lion (_Felis leo_). These +facts bring strongly to attention the modern teaching that meat +poisonings of the Gärtner type are to be considered as infectious and +not of the so-called ptomaine group. + +PINNIPEDIA, while related closely to the Carnivora, are grouped in a +suborder in our classification and because of their restricted diet are +treated here in a separate paragraph. The tract is peculiar in the +strong tubular stomach sharply bent upon itself, the great length of the +small gut (upwards of a hundred feet in some genera), and the practical +absence of a cecum. Pathologically speaking, the most striking lesion of +these animals is ulcerative gastritis, a process usually most marked +along the posterior-superior surface, but not confined thereto. Upon +inspection the gastric mucosa, normally supplied with low regular rugæ, +is much distorted by swellings upon the top of which are irregular +ragged ulcers with rounded elevated but not frayed margins. The density +of the edges indicates much infiltration of the deep mucosa and +submucosa; this can be confirmed by microscopical examination. One +attempt to study this gastritis bacteriologically was fruitless. +Sections of one case showed streptothrix-like masses while in another +case bacterial colonies and yeast-like bodies were found in adjacent +lymph nodes. The genesis of this condition might lie in injury by fish +fins or by foreign bodies, of which large numbers are found at times (a +pint and a half of stones, marbles, and sticks were found in one +stomach). Gastritis has been the starting point of septicemia on two +occasions, and three times an acute exacerbation or new implantation of +infection occurred, with extension into the intestine. It is interesting +that all the deaths of Pinnipedia with gastroenteric conditions occurred +in the winter months. + +INSECTIVORA are represented by two common European Hedgehogs. In one +there were three shallow but shelving ulcers in the stomach which had +bled sufficiently to weaken the animal; free blood was found in the +intestine. The other specimen was diagnosed at postmortem as having +catarrhal enteritis involving nearly the whole small gut, but +histological section did not confirm this. + +As one descends the zoological scale the first gastrointestinal tract +prepared for the nutritional care of bulky food is to be found in the +RODENTIA. This order presents a great variety of shapes and arrangements +of the stomach, but the outstanding feature, with very few exceptions +(cf. spermophiles), is the development of the cardiac and fundal +divisions ostensibly for the reception of a large bulk of coarse food to +be digested at leisure. Some genera like the hamster (_Cricetus_) have a +stomach closely resembling the ruminants, while that of the spermophile +suggests the equine stomach. The pyloric end, variable in many ways, +greatly resembles the abomasum. So too the duodenum is large, loose and +distensible while the copious small gut ends in a very large cecum, +shaped at times in a manner which has led to the term “colonic stomach.” +The colon is variable and not always supplied with longitudinal bands +and sacculations. + +In regard to incidence of gastrointestinal disease, rodents occupy a +middle position in the table. The stomach seems a vulnerable section of +the tract. Dilatation of the left hand section is common, due, to all +appearances, to fermentative processes which have as a result the +softening of the mucosa so that even immediately after death it will +separate almost entirely. In these cases the pyloric part need not +participate but may remain flat, smooth, soft and pink. This condition +is slightly more common in the compound than in the simple stomachs. In +some of this order, especially rats and cavies, there is a fermentative +gastroenteritis expressed by injection and edema of the pylorus and +duodenum, and much frothy mucus. It was at first thought that some +relation might exist between this condition and the absence of the gall- +bladder, but it occurs in varieties possessing this structure. The +reaction of the intestine to irritation in this order is peculiar in two +ways, the occurrence of mucus and the activity of the lymphatics. In all +the inflammations from and including the stomach to the cecum, mucus is +conspicuous. At times it is thin or loose and mixed with contents, while +at others it forms a relatively close covering for the mucosa almost +like a false membrane. Rodentia are peculiar in the promptness and +clearness with which the follicles of the intestinal wall and mesentery +enlarge in inflammation. They appear as pale, well outlined or diffuse +opacities in the wall or as distinct plaques prominent on the surface. + +The PROBOSCIDEA are represented by one Elephant (_Elephas indicus_), in +which a mild catarrhal change was seen in the middle stretches of the +small intestine. This was of little importance as a cause of death, +there being several other diagnoses, and was probably a terminal affair. + +HYRACES, of which we have a total of seven examples, present two mild +involvements of the intestine but none of the stomach. It would appear +from the records that the intestinal condition had little to do with the +death of the animals, and unfortunately no microscopic slides were made. +Because of the curious formation of the large gut, notes of both ceca +were made in one case, and can be condensed as follows: “The upper or +anterior cecum presented a shaggy pearl gray mucous covering, closely +attached to the mucosa. This cavity and the posterior ceca were packed +with dry crumbling feces. Small thin-walled cysts were seen in the tips +of the lower ceca. Duodenum was congested and mucosa swollen. Stomach +contained dry, poorly digested food. No parasites were found.” + +The EDENTATA are represented by an Armadillo (_Tatu novemcinctus_) and +an Anteater (_Myrmecophaga tridactyla_.) The former had a prolapse of +the rectum accompanied by colitis but it is impossible to decide the +priority of the two conditions since the former is known to have existed +long enough to have permitted the latter to develop. The Anteater had a +distinct mucocatarrhal enteritis in which bacteria played a part since +involvement of the liver, spleen, kidney and lymph nodes also existed. +The beast was in good condition upon arrival, but did not become +accustomed to the proffered diet, and was distinctly anemic at death. + +The UNGULATA, so-called for their hoofed and horned character, are also +associated anatomically by the construction of their gastrointestinal +tract. However, the order of the list as given on page 44 does not +represent their historical development nor does it accord with +anatomical arrangement of the tube under discussion. The last three +families of Artiodactyla are perhaps the simplest in the construction of +this tube, or at least take an equal place with the Perissodactyla, +while the remaining families of the former suborder have a complex tract +of generally similar architecture. This whole order has, however, an +alimentary tract anatomically suited for the consumption of bulky +vegetable stuffs and shows an attempt at adjustment between the food, +the methods of mastication, the area of digestive surface, and the bulk +necessary for nutrition. The number of factors opened up by the many +variations between this complex tract and that of the carnivorous simple +tract is so great that I shall attempt only to contrast the anatomy and +pathology of the simpler ungulate tracts and the complex ruminant +apparatus. + +The simpler gastrointestinal tract is possessed by the Perissodactyla, +and by the following families of Artiodactyla, the Phachocœridæ, Suidæ +and Tayassuidæ. This consists of a stomach with a single cavity (some +Peccaries have partitions but no true septa with strict histological +differences) divided into esophageal, cardiac, fundal and pyloric areas, +dependent upon the nature of the lining epithelia and the absence or +presence of glands, as well as the nature of the tubules. The duodenal +section is ample and may be sacculated while the intestines are small in +calibre and rather sturdy in wall. The cecum is relatively very large, +well supplied by longitudinal bands and sacculations; the colon is +relatively short but quite capacious and sacculated. + +The ruminants and other remaining members of the Artiodactyla have a +compound stomach suited to the separation of coarse and fluid foods and +the retention of water, and so arranged that boluses of different +densities are distributed as needed. These divisions are histologically +as well as grossly different. The first three, comparable to the +esophageal section of the simpler stomach, are reservoirs or channels, +while the fourth or true digestive section, is divided into areas +corresponding to fundus and pylorus, possessing the appropriate type of +gland. The duodenum in this group is narrow, as is the rest of the small +gut, and has delicate walls. The cecum proper is short and of variable +width, but never as great as in the group first discussed, while the +colon, an intricately wound tube, is narrow and very long. Certain of +the first group (Peccaries) have a colon of this type, but it is not so +complicated as in true ruminants. + +These complications seem designed to permit of a long retention of +coarse food of low nutritive value per bulk for a time sufficient for +full digestion; reverse adaptation of large size of stomach and colon +may be explained on the same basis. Let us now examine these two groups +to discover their pathological reactions and the nature of the lesions. + + TABLE 12. + _Showing the Percentage Incidence of Various Forms of Inflammation in + the Alimentary Tract of Ungulata._ + ══════════════════════════════════╤═════════════════╤═════════════════ + Lesion │ Group A │ Group B + │ Perissodactyla │ Ruminants and + │ and Swine, Wart │ Relatives Per + │ Hogs, Peccaries │ cent. + │ Per cent. │ + ──────────────────────────────────┼─────────────────┼───────────────── + Acute fermentative gastritis │ 18.│ 2.1 + All other forms of gastritis │ 16.3│ 5. + Acute toxic or fermentative │ 1.6│ 2.3 + enteritis │ │ + All other forms of acute enteritis│ 1.6│ 8.4 + Chronic enteritis │ 0.│ 1.9 + Colitis and typhlitis │ 0.│ 3.1 + ──────────────────────────────────┴─────────────────┴───────────────── + +Ungulates as a class stand in a position equivalent to the Primates in +the incidence of gastrointestinal diseases. They show a conspicuous +percentage of cases apparently due to incorrect food and, coupled with +this, a high percentage of gastric involvement, being exceeded in this +respect by the marsupials only (there is an adequate reason for this—see +below). Cases ascribed to bacterial or parasitic agents are not +numerous. Analysis of the records of the two groups discussed above +brings out some interesting facts. Consultation of Table 12 shows +percentage comparisons, based on the number of autopsies, of lesions in +the various sections of the tract. Group A, that with the simple stomach +and the short capacious colon, is represented by forty-four specimens, +while Group B embraces 321 animals. Perhaps the use of these two widely +differing figures for comparison is open to some objection which might +be final and decisive were not the figures so definite. At a glance one +can see that Group A has involvement more marked high in the tract while +Group B has more disease in the intestine and colon. Certainly gastritis +is more common (five times) in the A than in the B group, while +enteritis is more common in B (over three times). No case of chronic +enteritis or of involvement of the colon is recorded in animals with a +simple stomach and a wide hind-gut. This may be read either in terms of +vulnerability of the stomach or in the degree of resistance of the +respective groups. + +Consideration of the local factors of the stomach brings to light at +once the fact that incorrect food entering the simple stomach could +attack the softer, less resistant glandular section of the fundal and +pyloric areas whereas the rumen and psalter of the compound organ, with +their stratified epithelium devoid of glands, act as barriers or as +places where detoxication of irritants might take place. In both groups +bulky food is packed to the left, the esophageal and cardiac section in +the simple form, the rumen in the compound. Soft or liquid food may pass +into the psalter and abomasum of the ruminant stomach almost directly +since it has not the force or bulk to push aside the valve-like fold of +wall at the junction of esophagus, rumen and reticulum. For this reason, +if for no other, the character of soft food supplied to this order must +be unexceptionable. + +It has not been possible to follow out the layering of diets as +Scheunert did when showing the course of various foods before they are +mixed at the beginning of the pyloric compartments. We have seen two +cases in ruminants which seem to indicate that soft food had passed into +the right side cavities of the stomach, there to cause irritation, while +the rumen remained quite normal. It seems, however, accepted by +veterinarians that excessive soft food may be followed by trouble in the +digestive stomachs, while excessive dry food may cause distention of the +left hand sections. So far as I know, the relative incidence of gastric +disorders in the above outlined groups has not been pointed out before. + +The pathological types of gastroenteritis do not present many unusual +features. Simple injection of vessels during digestion seems more +evident in this than any other order, while mucus production seems less +marked. The mucosa of the reservoir portions may, in simple overfilling +and fermentative distention (gastric tympanites), be quite normal or +dull red; when active fermentation has occurred it may be digested and +peel off. More or less true inflammation as seen in the digestive +stomachs is definitely better expressed in the compound ruminant organ +than in the simple equine variety where congestion and edematous +swelling with hemorrhage form the usual picture. True catarrhal changes +both gross and minute, are often well seen and ulcerative lesions are +not uncommon; ulcers are unusual in the simple stomach. These statements +hold good also for the small intestine. Enteritis affects the duodenum +and jejunum more in the Perissodactyla and swine than in the ruminants. +Ungulata do not react with hyperplasia of the mural lymphatics as do +many other orders, but the swelling of the mesenteric nodes is often +noteworthy. As might be expected this is more definite with catarrhal +changes and therefore best seen in the ruminants. In the colon, however, +the solitary follicles are often quite prominent in simple inflammation. +Histologically the greatest changes seen in this order are superficial +degenerations with mononuclear increase in the deep submucosa, mostly +arranged in perivascular fashion. The villi do not contain the large +number of cells seen in the Carnivora. + + +MARSUPIALIA. + +Consultation of the figures for this order in Table 11 arrests attention +at once because of the peculiar percentages found under the detailed +factors. Thus food is of no moment as a disturber of the alimentary +tract, while bacteria and parasites are high in importance. The gastric +segment is more often attacked than any other portion and slightly more +often than in the nearest order, Carnivora. These unusual figures +deserve explanation, to which purpose it will be necessary to consider +the anatomy of the organ and to discuss why bacteria and parasites stand +so high in etiology. + +Marsupials are divided into six families in our classification (see page +44) which in regard to their diet, range from largely carnivorous (the +first two) through those choosing mixed insects, fruits and vegetables +(the second two) to those eating vegetables and grain (the last two). +The stomach of these animals does not vary exactly according to their +diet, the first four, opossums, dasyures, bandicoots and wombats, +possessing an organ closely similar in outline and construction and +resembling the carnivorous variety, while the phalangers and kangaroos +have a stomach entirely different from the first four although somewhat +similar to one another. The first group has a round or irregularly +elliptical organ with the esophagus and pylorus close together along the +lesser curvature. The wombats have a bank of glands surrounded by a +capsule, near the cardia. The stomach of the first four animals is +divided into cardiac, fundal and pyloric parts by the construction of +their mucosa, the first mentioned division being a high, rounded pouch, +rumen-like, well to the left. The phalanger’s stomach is more elongated, +the two openings well separated and a fissure is found in the right end +of the lesser curvature which serves to separate the pyloric part from +the rest. The Macropodidæ all have a stomach resembling the human colon +in being elongated, with longitudinal bands gathering it into +sacculations. There is a distinct esophageal section to the left with a +blind sac suggesting an ungulate rumen, a long tubular fundal, and a +sacculate pyloric division. + +The small intestine of the order starts with the opossums as a stout +muscular and mucous tube fitted for meat eating, but as one proceeds to +study the families downward in the list this tube becomes more delicate +and longer. In the first two families the cecum is rudimentary and the +colon very short as in cats, but the length and capacity of these parts +increase through the bandicoots and wombats until in the strict fruit, +vegetable and grain eaters, phalangers and kangaroos, the cecum is long +and capacious and the colon relatively long and roomy. + + TABLE 13. + _Showing the Incidence of Gastroenteric Disease in the Two Forms of + Marsupial Intestinal Tracts._ + ═══════════════════════╤═══════════════════════╤═══════════════════════ + │ Group A │ Group B + │Carnivorous Stomach and│Herbivorous Stomach and + │ Intestines 103 │Intestines 73 Specimens + │ Specimens Per cent. │ Per cent. + ───────────────────────┼───────────────────────┼─────────────────────── + Acute gastritis │ 9.6 │ 15. + │ Bacteria Verminous │ Bacteria Verminous + Chronic gastritis │ 0. 13.6 │ 5.4 0. + Acute enteritis │ 2.9 │ 1.5 + Colitis incl. typhlitis│ 1.9 │ 4.3 + ───────────────────────┴───────────────────────┴─────────────────────── + +Table 13 contains an analysis of the forms of gastroenteritis as they +were described in the two groups of tracts, that resembling the +carnivorous, that similar to the herbivorous intestinal construction, +and according to the factor believed to be responsible. In the first +group gastritis of an acute nature occurred in 9.6 per cent. of the 103 +specimens. They were chiefly catarrhal in character and seem for the +most part secondary to verminous infestation; at least six of the ten +cases were associated with parasites. The process microscopically is +catarrhal and deeply infiltrative. Group B has a high incidence of +gastritis and here the evidence of bacteria or toxins is quite plain. +Several of the cases were in animals showing also Kangaroo disease of +the jaw with pneumonia or septicemia; the gastric lesion of +streptothricosis will be described under that heading. The character of +gastritis without jaw disease is somewhat different from that with it. +Pathologically the process is a congestive and superficially necrotizing +affair, forming upon the tips of the folds, small gray erosions or flat +shallow irregular ulcers, which upon histological study consist of loss +of tissue of the mucosa and some deep congestion with round cell groups +but no reaction deep in mucosa or submucosa. True catarrhal inflammation +has occurred, but not like in the opossums. + +Chronic gastritis in the simple stomachs is almost exclusively in +opossums harboring _Physaloptera turgida_, a worm which fastens itself +more or less firmly in the mucosa and probably, with the assistance of +bacteria, causes sufficient irritation to produce a hypertrophic change +in the deeper layers and a destruction of the glands where it holds and +a distortion of those nearby. One is reminded that Fibiger found +spiroptera to be responsible for adenocarcinoma in rats; no tumor +formation has been found in these animals, although one opossum with +such a stomach had an adenocarcinoma mammæ. Small hemorrhagic spots may +occur in the deeper layers, possibly where the worms have bitten. The +rugæ are irregular or interrupted by knobs and papillæ. + +Group B, stomachs showing chronic change, were all kangaroos. The three +cases resembled the infiltrating necrotizing lesions as discussed under +ulcers (page 175). The process showed an infiltration of the subsurface +tissues with a gray slough over the densest part. The mucosa as a whole +was irregularly rugous and spotted with red gray areas. + +Altogether one gets the impression that in the simpler stomach, reactive +inflammation is most prominent, while in the colonoid stomach +degeneration is greater than reaction. + +Intestinal lesions in marsupials are not common and not peculiar except +in that they carry out the pathological reaction as seen in the stomach. +The carnivorous intestine shows frank catarrhal changes, the herbivorous +presents congestions and superficial necroses. These two groups then +follow the descriptions as already given for carnivores and ruminants. + +The colon presented in the first group, simple catarrhal or follicular +change. In the second division the lesions resembled those in the +stomach; they were only once of the three instances associated with +streptothricosis. + + +AVES. + +The class Aves has been treated in the chart precisely as have the +mammals, but it is not possible to make the accurate diagnoses or to +separate groups of lesions according to anatomy as was done for the +latter class. Upon the average there is more gastroenteritis among birds +than mammals, but when looking for an explanation of this, it was +unfortunately necessary to enter in the “undecided” column of Table 11 a +very great number of cases. This column would be greater relatively were +it not for the parasites in parrots and gallinaceous birds, the entries +for which are high. Besides this fact and that the owl stands at the +top, the pigeons at the bottom of the list numerically, no further +general statements are allowable. There are several orders with high +values among those of which insufficient autopsies are at hand to cast +percentages. + +The avian alimentary tract seems to have developed according to the +character of food the different varieties of birds consume if one may +judge by the construction of the bill, the gastric musculature and the +intestinal wall. Zoological classification has only secondarily +considered this point, it being made incidental to the habits and +habitats of birds. For this reason the orders as outlined on pages +44–46, placed as they are in historical evolutionary position, represent +with few exceptions groups which have differing diets and, by the same +token, differing gastrointestinal tracts. Classifications based upon +habits of life (Raptores, Cantores, Natores), prove likewise too broad +or too heterogeneous, while systems making character of food the chief +criterion though apparently correct in reasoning and helpful in certain +orders, (Accipitres, Galli) are found to present copious exceptions; +moreover we are imperfectly informed of the exact diet that many +families require or resort to in absence of their preferred food. I +shall therefore discuss the chief diseases and distributions according +to our classification, preceding the discussion by a brief résumé of the +anatomical peculiarities of the avian alimentary tube. + +The first digestive burden falls upon the proventricle where the +principal juices are secreted while the muscular stomach or gizzard +assumes the duty of gastric mastication. The lateral muscular bellies of +its heavy wall grind the food and mix well the gastric juices. Its +mucosa probably supplies only lubricant. In birds whose food is hard, +corn and the like, this grinder is supplied with a dry horny internal +layer, while a thick, moist, soft, epithelial surface is sufficient for +carnivorous birds. All kinds of gradations exist between these extremes. +The mucosa of the proventricle is always soft, but quite deep to permit +the placement of compound tubular glands. + +The relation of size of these two parts is subject to many +variations.[22] The proventricle is larger proportionately in meat +eating, fish-eating and fruit eating birds, the gizzard having the +greater size in granivora and insectivora. In certain birds the mucosa +of the two is separated by a very soft thin zone, an important fact in +Psittaci since at this place spiroptera seem to penetrate to the +glandular layer of both organs. + +The duodenum begins in practically all birds, from a spherical cavity at +the pyloric end of the gizzard, to be accredited anatomically to both +sections. It passes downward, forms a long loop enclosing the pancreas, +its distal end lying under the liver and near the gall-bladder. Near its +end it receives the major bile and pancreatic ducts; smaller ducts from +the liver and pancreas may enter near the pylorus or elsewhere along the +loop. The small intestine is usually simple in its coils, but in the +birds that eat grain, grass and greens, may be long and complicated. So +too the colon, usually a very short segment, may be increased in the +just mentioned group while the ceca are only of any considerable length +in herbivorous birds. The length of the ceca is, according to Owen, +related to the availability of food and the need the bird may have for +exhausting the nutritive value of it. In carnivorous birds as in similar +mammals, the whole gut, but especially the hind-gut, is very short and +the ceca small or absent. But so they are in picarian birds which are +chiefly herbivorous, but may eat meat. + + +GASTRITIS. + +The double-muscle stomach, that with the two lateral plates and tough +epidermal internal coating, is seldom the seat of disease. An excess of +greens in the diet sometimes seems to soften or macerate the lining, +while an excess of pebbles may cause erosions. Upon severe irritation +this internal layer assumes the appearance of tanned leather and may +crack. The proventricle of such a gizzard seems rather resistant to +disease, particularly one would say, to infective processes, for +catarrhal or ulcerative inflammation is uncommon. The saccular stomach +with uniform muscular walls continuous with those of the proventricle, +such as is seen in raptatory birds and parrots, offers a somewhat +different picture. The internal membranes of these organs are definitely +softer, seeming to swell with great ease, and the glands themselves are +smaller both at the fundus and outlet, a construction which may favor +their closure by swelling from simple congestion and edema. Catarrhal +and ulcerative processes are definitely more common in such organs than +in the first type or true gizzard. + + +ENTERITIS. + +Enteritis of all orders is most outspoken in the duodenal loop, but a +determination of the lesion must be made with some care. All the signs +of intestinal inflammation—congestion, swelling and opacity, excess +mucus or mucopurulent covering—must be present to justify a gross +diagnosis of enteritis and even when these exist one fails at times to +confirm the finding by microscopical section. These changes may be +simulated by digestive activity so that it is but reasonable to demand +them all in a clear cut fashion before applying the term enteritis. +However, it is well known that cases in both human and veterinary +medicine giving a satisfactory clinical picture of this disease may fail +to show to the naked eye and under magnification the changes expected. + +In the human being, the carnivore and the ruminant, the ileum presents +the most definite picture of enteritis. In the bird, the duodenum shows +the prominent lesions, and with the exception of specific diseases like +blackhead, is always involved when the smaller coil of small intestine +is affected. This is true whether the enteritis be nonspecific or be +associated with cholera of chickens, ducks or parrots. + +The colon presents peculiar lesions in but few birds. Ulcerative and +necrotizing processes have been encountered in three orders, Psittaci, +Anseres and Herodiones, suggestively like the specific forms seen in the +ceca. Microscopy and one unsuccessful culture failed to reveal a mould +or protozoön. The condition appears as a gray white plaque in the +cloacal wall or it may spread up to the colon and around the urethral +orifices. At times it is superficial upon the mucosa and may be covered +by a pseudomembrane. + +The chief interest in the ceca centres about enterohepatitis either of +heterakis and amœbic origin or that supposed to be due to coccidia or +Bac. scoticus. This specific form has been encountered only in Galli +(three of the four families). It has been so well described by Hadley, +Smith, Morse and Cushman that it is unnecessary to discuss it since we +have nothing to add to its pathogenesis or pathology. At a later time +some attention will be given to our experience with Quail disease. What +is more interesting from a comparative standpoint, besides having a +bearing upon blackhead, is the discovery of heterakis in the ceca, and +hemorrhage and fatty change in the liver without amœbæ or coccidia in +either place (unfortunately no bacteriology was done), in a Sebastopol +Goose (_Anser domesticus_), a bird which has ceca not unlike the +gallinaceous varieties. This is a single observation and must be treated +expectantly. + +Microscopically the avian digestive tract in its various inflammatory +states presents a few noteworthy features. The primary reaction, +sometimes the only one, to irritation is injection of the vessels in the +villi or deeper mucosa. To this, however, is nearly always added a +granularity of the epithelium, without much evident mucus (goblet cell) +formation. When the epithelial degeneration is marked there appears a +round cell increase in the deep mucosa shortly followed by a similar +infiltration into the villi. True catarrhal enteritis as described for +the cats is not as common as some combination of the changes just +detailed, but when it occurs is best developed in the carnivorous avian +tract. The most striking cellular finding is the round cell of the +infiltrate. It is of the middle lymphoid size with clear protoplasm, or, +when late in the disease, may be small and so-called adult. +Polynuclears, unless eosinophilic, and endothelioid cells are rare. + +The foregoing are general remarks concerning the pathology of the avian +tract, and we are now ready to discuss briefly the reactions of the +orders. I shall, however, omit mention of those in the right half of +Table 11. + +Passerine birds are represented better than any other order because they +are more numerous in nature and therefore exhibited more generously in +collections. This order is not especially vulnerable as to its +alimentary tract, but this tube is often affected by tiny stones, bits +of rust from cages and by acute general nonspecific infections to which +these birds are quite susceptible. Upon many occasions intense +congestion with and without tiny hemorrhages in the duodenum are all +that can be found in the little birds and the diagnosis of enteritis is +put down. Only about one-tenth of these birds have shown more or less +definite catarrhal changes. Many birds have heavy infestation with worms +which may activate bacteria. + +The Striges and the Accipitres will be discussed together because of the +similarity of their tracts and their diets. The reaction of their +gastric complex has already been mentioned and what was written there +can be extended to the intestine. The type of lesion is catarrhal and +seems to be “meat bred” although this cannot be proven. They never have +given positive heart’s blood cultures so that the disease seemed not to +be septicemic. Liver and spleen have harbored colon and paracolon +bacilli. It will be noticed that they have the highest incidence of +gastric disease. + +Psittaci, birds with a tract similar to the last two but with a captive +diet of seeds, fruit and vegetables although they may eat small animals +and insects in the wild, present figures under bacteria and parasites +which explain the involvement of the alimentary organs. We have had two +acute outbreaks of what seemed to be fowl cholera, judging by the +pathology and the isolation of _Bact. gallinarum_ and we have frequent +deaths with the same gross anatomy from which bacterial isolation has +not been tried or was unsuccessful. At all events the enteritis of +parrots is often a definitely infectious affair. We have also isolated +_Bact. psittacosis_ on two occasions. Separation of the birds and +cleansing of the exhibition spaces seemed to stop the disease. The +lesions are hemorrhagic and superficially necrotizing in this group +whether or not they are septicemic. Some have also shown a follicular +appearance both grossly and minutely, one of which cases was associated +with _Bact. psittacosis_. + +The effect of animal parasites is chiefly exerted, for this group, in +the proventricle where the S_piroptera incerta_ occupies the lumen and +penetrates the mucosa or burrows under the inner lining of the gizzard. +Enteritis is not especially associated with this infestation, death +resulting more from inanition than infection; some few cases have had +enteritis, others pulmonary disease. + +Columbæ are not susceptible to disease in the parts under consideration. +This order seems to have some tissue resistance, for their lesions are +quite frankly catarrhal, more so than in most grain-eating birds. + +The figures set against the Galli are swollen by the number of cases of +enterohepatitis of one sort or another. Extracting these from the total +leaves the order among the lowest. Their lesions are congestive and +hemorrhagic, although they may show catarrhal cases. They seem to be +able to summon mucus more readily than many other birds. + +Anserine birds, though not very high in figures, present three +conditions worthy of note. In the first place, acute simple gastritis +occurs often, sometimes associated with foul green food, sometimes +without any apparent cause. From the number of times that foreign bodies +are present it seems probable that they contribute in some way. +Excessive stones and sand, bits of glass, collar buttons and the like +are sometimes found. Then the form of acute enteritis has always a +hemorrhagic tendency, at least in the submucosa, while the mucosa may be +swollen, opaque and covered with mucus. Upon histological study these +intestines show intense swelling by cellular infiltrate and +disappearance of the tips of the villi. The third observation concerns +what is apparently a subacute or chronic process although this is not +supported by microscopy. Certain birds will have a cast of mucus and +epithelial detritus rather closely adherent to the wall. Under the +microscope there may be slight evidence of chronic inflammation or there +may be little amiss. These birds have usually been large ones, and +several have come from the separate goose pens, not from the open lake +where many birds are kept. + +The struthious birds deserve a word. They have had a great deal of +enteritis and mostly of infectious nature. Two instances have arisen +from bird diphtheria, one from cholera and six from what later seemed to +have been anthrax but was not diagnosed at the time. The character of +the lesions in the struthious intestine tends to be hypertrophic and +superficially erosive if not ulcerative. The changes are found with +greatest clearness in the lower duodenum and small coil. + + +CONSTIPATION. + +Having discussed the inflammatory conditions of the gastrointestinal +tract we now come to the more or less definitely mechanical +abnormalities, whether or not they depend upon preëxisting inflammation, +and the subject of constipation will claim first attention. In the human +being this condition is the result of bad habits more than any other one +thing or all things together, I think it will be admitted. In the lower +animals perhaps no such thing as habit of defecation exists so that one +can with more certainty hold incorrect food, chronic catarrhs or +physical obstruction as responsible. Veterinarians look upon excess of +dry food and irregularity of work and food periods as the principal +causes of constipation. These factors do not hold in zoological +collections. As a matter of fact constipation is of minor importance in +this menagerie, but a certain few cases are worthy of note. It has been +mentioned in the diagnoses in only a little over 1 per cent. of the +total, and of these the records indicate its importance only ten times +(.2 per cent.); a few notes of these cases are appended. The first place +of incidence is taken by marsupials (six kangaroos and one opossum), the +second by ungulates (largely ruminants) and the third by Primates. It +will be noted that with exception of the opossum, herbivorous mammals +occupy the first places of incidence, carnivores falling well behind the +orders named. This condition is quite infrequent in birds and is usually +associated with the presence of seeds or parasites or with impaction in +the ceca. + +Primates, almost exclusively feeders upon carbohydrate and soft protein +food, have shown as causes of constipation two outstanding conditions. A +low grade of colonic catarrh with excessive pouchings of this tube has +had constipation associated with it three times. One of these cases had +small coproliths in the diverticula, one other a fecal concrement in the +cecum. Another group of these cases with evidence of delayed passage of +feces shows chronic peritonitis with adhesions, one of which seems +certainly due to filaria in the peritoneal sac. + +The seat of constipation in monkeys is practically always the colon. The +carnivores while occasionally showing hard fecal masses packed into the +colon, more often exhibit a constipation in the ileum. One case +presented a nearly empty colon with a long scybalum just above the cecal +valve. There is no peculiar associated pathology in the notes at my +command. + +Ungulata, showing next to the highest incidence, has its stoppage +chiefly in the colon, but the lowest stretch of the ileum may contain +balls of feces. In nearly every case one finds some grade of colonic +catarrh. In two instances, there being a proctitis, it seemed as if the +animal voluntarily restrained from defecating because of pain. The caput +coli is the seat of stoppage in the Rodentia. + +Marsupials give such a high relative incidence that especial search of +their records was made, without, however, very definite result. In three +of the seven cases an acute general infection existed, in one an acute +peritonitis which seemed to emanate from a small ulcer in the ileum, in +one an injury to the anal region was found while in the remaining two +the notes would suggest that the lower intestine was atonic, judging by +its distention, translucency and pallor. In five the stoppage took place +in the large bowel alone, in the others both divisions being affected. + +It is often difficult to establish a diagnosis of constipation in birds +because many varieties form a long rather dry mass in the lower small +intestine, to be moistened in the cloaca for discharge. Still again the +groups with capacious ceca are apt to have them filled normally with +firm casts. Diagnoses of fecal inspissation and stoppage in the smaller +tube have been made seldom, but one must consider also the obstruction +offered by excessive urate collections either in the cloaca or lower +ileum which will amount to a constipation if the cloaca be over-dilated +and dried urates mixed with dirt or feathers cover the anal opening. + +The causes of this condition in birds are usually mechanical, +inflammation being found in a small minority of cases. In the small +passerine birds, seeds, sand, or parasites form the commonest findings. +This is also true of parrots, while excessive urate collections are +noted for both these groups. The gallinaceous birds present two reasons +for fecal stoppage—disease of the ceca (see pages 205–6) and cloacitis +probably secondary to anal closure by excessive urate collection. Uratic +stones, varying from one to five millimetres in diameter, have been +found in the cloaca in several orders. In only one case, a pheasant, did +they cause ulceration and cloacitis. Sand, rust, grains and the like are +found frequently, and sometimes in groups of birds, indicating that the +specimens had not been put upon the correct flooring or caging. Unbroken +seeds may obstruct the lumen. + + +MECHANICAL OBSTRUCTION. + +Although the following is not constipation it is well to cite at this +place an experience which amounted to mechanical intestinal obstruction. +A number of finches were subjected to postmortem and found to have whole +white millet seeds in their intestines, this being the only discoverable +cause of death. Investigation revealed that during the night mice ate +the canary seed in the pans, leaving only the millet, which the hungry +birds consumed whole. Small birds can take a few millet and crack them +when eating leisurely, but apparently not when hungry. When the food was +removed at night the trouble ceased. + +Obstruction by sand is well illustrated by a peculiar form of pica, in a +goose, which is worth citing, and calls to mind the sand disease of +horses: + + + Canada Goose ♂ (_Branta canadensis canadensis_). + + DIAGNOSIS.—Masses of sand in entire intestinal tract. The general + condition externally and internally is good. The crop is distended + like a sausage, quite firm and the overfilling is obviously due to + sand in which very few stones, which could be called pebbles, are + found. This mass continues into the esophagus making the whole tract + impassable for food. The mucosa is a little pink and dirt-stained in + places but is not visibly inflamed. The gizzard is contracted over a + mass of sand but no food. Sand in more or less definitely packed + condition is found all along the gut tract, in one place in the small + coil it being quite as tight as in the crop and no lumen remaining. + Sand and bits of shale are found in ceca. The organs are apparently + healthy, slightly pale perhaps, but certainly not distinctly anemic. + No infection exists. The aorta, just above renals, has a 15 mm. × 2 + mm. pale opacity of same consistency as the rest of the vessel, just + perceptibly higher than surrounding surface. + + +“Sand disease” has occurred in a Persian Wild Ass (_Equus onager_) +causing in this case ulceration, perforation and peritonitis, a Common +deer (_Mazama virginiana_) and a Chapman’s zebra (_Equus burchelli +chapmani_). The collection of sand is always greatest in the caput coli, +but may coat the large bowel to the anus. + +Larger and more definitely obstructive physical objects are found in +both mammals and birds. We have on record a lion (_Felis leo_) and a +tiger (_Felis tigris_), which swallowed pieces of bone large enough to +be stuck in the small intestine and completely occlude it. Smaller +objects like buttons have been found even in the passerine tract. Worm +masses may occupy such a large part of the lumen of the tube as to +constitute a physical obstruction. This is definitely less important in +mammals than in birds, especially in the passerine order of the latter +class. + +Dilatation of the intestine aside from that occurring in connection with +fermentation, constipation or ileus, in other words chronic atonic +dilatation, has not been encountered. Acute dilatation has been found in +several orders under the picture known for domesticated animals. Its +pathology and incidence have already been discussed. + + +ILEUS. + +Ileus or acute intestinal obstruction may be divided for our purposes +into intussusception, volvulus, strangulation and paralysis from +interruption of mesenteric circulation. Examples of all these varieties +have been encountered and illustrative cases will be cited. In so far as +incidence is concerned, the Ungulata and Carnivora greatly outnumber all +other orders, showing seven cases each; the sum total in all other +orders is but eight. Upon re-reading some of the protocols I have, +however, excluded three invaginations in the carnivores, one each in the +ungulates and rodents, as probably being postmortem or shortly +antemortem occurrences; two had very early peritonitis but other things, +sufficient to account for death, were present. These deductions bring +the total cases of ileus in mammals to seventeen. Five cases in birds +will be discussed briefly. + +Primates present one case of volvulus, one of intussusception and one of +internal strangulation. The first displayed the entrance of four inches +of ileum into the colon with such swelling of the wall as to prevent +reduction. The exciting cause seemed to be an enteritis, the cause of +death a peritonitis. A white-collared mangabey (_Cercocebus collaris_) +was the victim of volvulus probably favored by an anomalous position of +the transverse and descending colon which lay to the right, the latter +traversing the abdomen obliquely from right to left to reach the pelvis. +The volvulus occurred in the ileum just above the cecum, the twisted +part being found adherent by the peritonitis. The third case is a +strangulation due to peritonitis from filaria and adhesions between +stomach and colon from a colitis and pericolitis due to cestodes, one of +which was found deeply implanted in the colonic wall. + +Two cases of intussusception are noted (after deductions above) for the +Carnivora. They both occurred in the ileum, one restricted thereto, the +other extending into the colon. In both a vague history of being “off +their feed” or giving evidence of intestinal trouble could be obtained +from the keeper. The three excluded cases had invaginations in the +middle and lower small intestines but not at the cecal valve. Volvulus +did not occur in the Carnivora. + +A paradoxure (_Paradoxurus hermophroditus_) died as the result of a +strangulation of a six-inch knuckle of gut which had passed through a +hole in the omentum. The animal had not been eating well for a month but +gave no signs by which this ileus could have been diagnosed. Perhaps it +had existed for sometime but only shortly before death had swollen +sufficiently to cause obstruction. + +Having excluded a doubtful invagination in a small rodent there remains +an interesting though somewhat obscure case in a porcupine (_Erethizon +dorsatus dorsatus_). This animal suffered with an acute hemorrhagic and +catarrhal enteritis while the colon seemed free of change until the +rectum was reached. Here was a stretch of a foot with the purple, +lusterless but translucent appearance of a strangulated intestine +although no involution or twisting remained. This was looked upon as a +volvulus which had untwisted a few hours before death. + +Intussusception was seen only once in the Ungulata, a tapir (_Tapirus +terrestris_) with chronic enteritis. Here the ileum had passed into the +colon for a distance of nine inches, it being much swollen and congested +but not gangrenous. Its condition warranted the idea that the process +was antemortem but a peritonitis had not arisen, death having occurred +from the slight extra shock in an animal suffering with chronic +malnutrition. Volvulus was encountered three times, two deer and a +zebra. The last was the animal already described that carried such a +heavy load of sand in the gut tract, a factor in the production of the +twist probably although this might have been aided by a fibromyoma of +the colonic wall. The location of the volvulus in this order was twice +in the dilated descending colon, the third in the jejunal area. This +last was a twist which resembled an internal strangulation because of +the intricate knot-like windings of the small bowel. + +The marsupials present two interesting cases. A rock kangaroo +(_Petrogale pencillata_) had chronic gastric ulcerations with local +peritoneal adhesions which apparently obstructed nearby coils of +intestine so that they became inflated and twisted over. An opossum had +a volvulus of the stomach which performed one and a half turns from left +to right; its protocol follows. + + + Common Opossum ♂ (_Didelphys virginiana_). Ileus. One and one-half + complete volvulus turns of stomach on duodenum. General condition + fairly good. Abdomen quite prominent, a condition found to be due to + great dilatation of the stomach which occupied the whole anterior part + of the abdominal cavity. The organ is blue and the vessels stand out. + Postmortem changes are occurring everywhere favored by the obstruction + to the circulation. The dilated stomach has undergone a volvulus upon + the third part of the duodenum making one and a half turns. The spleen + lies upon the right side well below the liver; it is swollen, soft and + deep purple. The duodenum in its upper half takes part in the + dilatation and beginning gangrene. The pedicle of the twist is made of + the duodenum, esophagus, edge of the mesentery and the middle part of + the pancreas; the end of the tail of the last is gangrenous. There is + no apparent obstruction lower down to explain the twist of the + stomach. + + +Among the Aves the following cases only are worthy of report. A parrot +(_Melopsittacus undulatus_) was found to have a tightly packed mass of +worms in the end of the duodenum above which the bowel was distended, +elongated, doubled on itself and of a deep red color; below this the +small intestine was empty. A closely similar condition was found in a +Screech Owl (_Otus asio asio_) the obstruction occurring just above the +end of the small gut. A Sparrow Hawk (_Falco sparverius_) had an +invagination two cm. in length, a short distance above the end of the +small intestine. No peritonitis existed but the presence of an acute +enteritis helps to explain the intussusception. + + +HERNIA. + +Hernia is not a common occurrence among the lower animals but our +experience is instructive in two particulars, to wit, its absence in the +orders preceding the Rodentia and the frequency of the traumatic +variety. There being no general remarks to be made upon the subject, it +seems well to give a summary of the findings in each of the seven cases. + +A Western Fox Squirrel (_Sciurus rufiventer_) showed a diaphragmatic +defect on the right side, a rounded opening with smooth edges, through +which a loop of intestine had passed, entering behind the liver and +reaching into the pleura as high as the pulmonary apex where it was +adherent; this was probably of long standing. Two more loops were found +wedged in the diaphragmatic hole, one of which was gangrenous. + +An Indian Antelope (_Black Buck_) (_Antilope cervicapra_) presented an +irreducible incarcerated but not strangulated umbilical hernia. The +peritoneum was fused with the aponeurosis at the ring but the gut was +not adherent at this point while it was attached within the sac outside +the muscle, thus forming the incarceration. Apparently the sac had +dissected between the muscular layers for it could be followed for +several centimetres in some directions. A Hog Deer (_Cervus porcinus_) +had apparently suffered an injury in the flank for at one point the +muscles were irregularly cicatrized and a rent was present through which +several loops of intestine and a band of omentum had escaped, being +adherent to fascia. No injury to the skin was apparent. + +Another Indian Antelope showed a clean traumatic rupture of the muscle +_and peritoneum_ in the right inguinal region _without_ penetration of +skin. An acute hernia had occurred which was lightly adherent to fascia +and an acute peritonitis was beginning. The bowel was however not +strangulated. + +An aoudad (_Ovis tragelaphus_) seems to have suffered an injury by a +pointed object (horn?) just to the right of the ensiform cartilage for +at this position there is a circular hole, with smooth healed edges, in +the aponeurosis, permitting the emersion of a peritoneal sac containing +omentum. All parts were adherent but no acute inflammation existed. + +What may have been a hernia or a relaxation of the transversus perinei +was observed in an Undulated Grass Parrakeet (_Melopsittacus +undulatus_). A bulge about the size of the finger end was seen +externally, beside and behind the anus. This proved to contain several +loops of bowel and a mass of fat. + +A lateral abdominal hernia was seen in a Barbary Turtle Dove (_Turtur +risorius_). It consisted of a peritoneal sac and two loops of intestine. +This protrusion, while firmly fixed in its unnatural position, was in no +way constricted. + + +RECTAL PROLAPSE. + +Prolapse of the rectum may in a sense be looked upon as a hernia or at +least as a relaxation of the anal and perineal muscles with protrusion +of parts normally situated intracorporeally. Although not frequent it +has been incurable in the animal, as it frequently is in man without +operation, a measure we have not adopted. Just what determines weakness +in the pelvic outlet is entirely obscure for indeed we have seen here +wounds and inflammations of the perineal area without prolapse of the +rectum and in none of the cases of prolapse did the pelvic floor seem +injured or diseased. It is but speculation to blame the annular muscles +of the anus. Tenesmus, or at least reasons for this straining action, +have been sought, with the result that in our cases lesions of the egg- +laying apparatus in birds and enteritis in mammals have stood out most +prominently. In no case have hemorrhoids been encountered nor has a +tumor pendant from the colonic mucosa, drawn the bowel toward the anal +opening. It might be added parenthetically here that hemorrhoids are +practically unknown for quadrupeds, Hutyra and Marek failing to mention +them independently and only one reference being found in the +_Jahresbericht fur Veterinär Medizin_ (Schmidt 1914–169); this case is +more like angioma than hemorrhoids. If tenesmus be active in the +production of rectal prolapse then it would have to be assumed that this +straining effort can be induced by enteritis since eversion of the +rectum has occurred with this disease in the absence of colitis, the +condition usually expected in the presence of tenesmus. The thirteen +cases have been seen in Mammalia, 8, (Carnivora, 2, Rodentia, 1, +Ungulata, 3, Edentata, 1, Marsupialia, 1) and Aves, 5, (Passeres, +Picariæ, Striges, Psittaci and Galli each one). Three mammals had +enteritis, one had foreign bodies in the bowel and one had many +ascarids; three had no demonstrable or suggestive causes. Two of the +five birds had enteritis high in the tract, one had uratic calculi in +the cloaca, and three had trouble in the egg-laying apparatus: one too +large an egg, one a broken egg and one a salpingitis. + + +DIVERTICULA. + +It is almost certain that in a human pathological service of fifty-five +hundred autopsies, one or more diverticula of the Meckel variety would +be encountered and perhaps several of other kinds. In our material only +pouchings or false diverticula of the colonic wall are recorded, and our +personnel has often spoken of the absence of these gross abnormalities +of the alimentary tract. The two cases, notes of which are given, are +instances of hernial pouchings of the colonic mucosa and serosa, a +condition which is well known in human medicine. It may be said to occur +in two varieties, one in which the pouchings have heavy walls formed by +a thickened mucosa, muscularis and peritoneum and one in which the +bulgings have delicate walls, then being small herniæ of the inner coats +through rifts in the outer. Such a division is probably unnecessary or +misleading since the latter may be only a forerunner of the former. +However the clinical evidence of the simple variety is scanty and may be +little more than constipation while the peritonitic variety gives a +clinical picture of pain, constipation and a mass in the left abdominal +area, then known as diverticulitis or pericolitis sinistra. In these +cases the colon is much distorted by the irregularity of its mucosa and +by inflammatory thickening of the muscularis and serosa. Diverticula +arise from defects of the muscular coat, or secondarily after +inflammation or prolonged constipation, by weakness of muscle, or as +hernial protrusions around the entrance of blood vessels where the +muscle is thin. Such sacculations permit feces to collect and continue +the inflammation, thus further weakening the gut and producing +constipation, the whole vicious cycle being favorable to the formation +of more sacculations; coproliths may form in the diverticula. The two +monkeys now reported seem to have varying grades of the same condition, +a long standing colitis with diverticula, constipation and the +collection of inspissated feces in the sacculations. These animals did +not have hemorrhoids. + + + Black Ape ♀ (_Cynopithecus niger_). Coprostasis. Coproliths in + diverticulum. Chronic colitis. Cor bifida. The large intestine is of + the same calibre as the small intestine should be when not distended. + The sacculations as seen before opening the organ are salient, forming + distinct pouches. In one or two cases they are so pronounced as to + constitute diverticula 7 cm. long. In two instances the serosa at the + fundi of these diverticula is markedly hyperemic and very thin. In + many cases the sacculations contain coproliths. The wall of the organ + is distinctly thickened, puckered, inelastic and opaque. Mucosa is + thrown up into coarse rugæ. + + Japanese Macaque ♂ (_Macacus fuscatus_). Chronic hypertrophic colitis. + False diverticula of colon. The large intestine contains a moderate + quantity of quite constipated feces. The serosa is smooth. The wall + shows at several stretches enlargements of the normal sacculations, + forming false diverticula. The wall of the gut in these herniæ is + thinner than in the surrounding parts; no ulcers exist; no local + peritonitis is present. The mucosa everywhere is irregular in + thickness, less translucent than normal and thrown into irregular + rugæ; tenacious mucus covers it. No ulcers. + + +TUMORS. + +Only one tumor was observed in the mammalian intestinal tract proper. +Dasyure (_Dasyurus maculatus_) Adenocarcinoma of the intestines. On +postmortem there was a pale diffuse thickening of the coats of the small +gut over a large area; numerous soft, light yellow, sharply +circumscribed, elevated (like secondary tumors) nodules in the liver and +spleen, and a pea-size whitish nodule around a bronchus in the right +lung. Histological section of primary growth not made but a cross +section of the intestine in the vicinity shows an adenomatous change +with considerable increase in the connective tissue. The nodules in the +liver, spleen and lung and the appearances of the abdominal lymph nodes, +found microscopically, are precisely similar. They consist of +irregularly arranged epithelial nests and distorted acini, around which +are sharply outlined spaces, filled with the remains of degenerated +blood or a granular material. The metastases are always sharply +outlined. + +Aves supply three papillomata which are interesting in that one occurred +in the proventricle, and two grew in the duodenum in the vicinity of the +upper biliary opening and presented within the lumen soft masses which, +while not occluding the passage, offered some little obstruction as +indicated by a slight distention above their location. In two, carefully +studied, no indications of parasites or of cancer could be found. The +birds concerned were an amazon, an owl, and a rhea. + + + + + SECTION VII + THE ALIMENTARY TRACT, PART 2. THE LIVER + + +A consideration of the liver is anatomically and physiologically the +next step in the discussion of diseases of the alimentary tract. While +this organ may participate in most of the pathological states of the +tubal part of the system, it is comparatively seldom the primary seat of +change and when damaged seems to be possessed of great accommodative and +reconstructive power. This must be true, and fortunately so, since we +ascribe to it the major detoxicating function of the body. Nevertheless +it is noteworthy that the largest solid organ of the animal body shows a +relatively low percentage of changes threatening to life. In the sense +of Pearl’s method of statistics, it does not “break down” easily. In +pathology it is the custom to list with great care all the changes, +gross and minute, in the liver, but with a few exceptions they are +secondary or incidental. They do however reflect many things, especially +referable to diet and to chronic infection from the intestinal drainage +area. It is in these directions that the organ will be studied in the +following pages. + +Anatomically the liver is situated in the right upper part of the +abdomen subjacent to the diaphragm in both mammals and birds, being held +in position by attachment to this transverse partition, by ligaments or +folds of peritoneum, and by the other abdominal viscera. Its general +relationships do not offer great variations since in all animals means +are afforded for a dual blood supply and an outlet for the hepatic +secretion, the bile, into the higher intestines. Naturally variations in +the size of the lobes are observed and there has been considerable +speculation as to their independence and association. From the +standpoint of comparative pathology, little can be ascertained to assist +in this matter unless the position of abscesses and hepatitis relative +to cholecystitis have a bearing; some discussion of this will appear +later. We have not observed any peculiar pathology of the lobes of +Spigelius and Riedel. In so far as the size and arrangement of the organ +is concerned a few general facts of significance may be mentioned. + +It was formerly thought that the liver varied inversely as the size of +the animal but Magnan[23] and others have shown that the matter is not +so simple. In the first place if there be an actual mathematical formula +it is that the liver varies in size inversely as the surface area of the +body, but this is not the whole story. It seems that the relation of +size of the organ to its weight is not constant and that it is better to +judge of the organic capacity by the latter. In herbivorous animals, +both birds and mammals, the liver is lightest per kilo of body weight; +next in weight are in order, fisheaters, meateaters, insectivora, +seedeaters, fruiteaters and omnivora. There is besides this a roughly +inverse ratio between the size of the liver and the length of the +intestine and in the class Aves inversely as the size of the lungs also. +From the immediately foregoing statements it is apparent that a +bewildering variation occurs and that only rough measurements of the +relative volume of the liver are available. An attempt was made in the +Marsupialia, which present all the variations given, to discover if any +peculiar pathology corresponded with the above groups; as it was +fruitless, no change from our zoological treatment will be made. + +Lobar arrangement varies from the relatively simple double avian type to +the manifold lobulations of the seal or the marsupial but I can find no +literature to indicate that lobes or lobulations have a direct effect +upon functions. There must be a difference of blood supply for in +certain infectious diseases like enterohepatitis and amœbiasis, the +cystic and extreme right lobes are more affected than the left parts of +the organ. In the bird this is not so difficult to follow since the +three divisions of the portal vein, while they combine at times in an +ampulla within the hilum of the liver, seem directed to certain lobes, +that from the left portal seeming to point toward the right side. The +avian portal system differs from the mammalian in having a large branch +from the renal area, the so-called renal-portal system, pass to the +liver, and by having a free anastomosis between the portal area and the +caudal vena cava whereby blood from the pelvic district may pass into +the general circulation without going through the liver. There is no +unanimity of opinion as to the function or importance of this +connection[24] and from the data collected here there is no peculiar +renohepatic pathology. + +The gall-bladder is not a constant organ in either mammals or birds and +indeed it may be absent or present in very closely related species (Two- +toed Sloth present, Three-toed Sloth absent). When present in mammals it +is usually a dependent bag while in birds it commonly lies upon the +cystohepatic duct, between the liver and the last curve of the duodenum, +in some varieties filling from the bottom, the inlet being guarded by a +valve. This cystic duct in nearly all birds, comes exclusively from the +right lobe while the hepatic duct, with which the cystic has no +connection, is formed by combination within the liver of radicles from +both sides. It passes to the duodenum well in advance of the cystic +duct, in some birds, _e.g._, the Struthiones, very near the pylorus, +that is on the descending limb of the duodenal loop. By this means +obstruction to the biliary stream is rendered difficult. The common duct +combines with one of the pancreatic outlets in most mammals but the +abdominal salivary gland in lower animals has more often patent separate +ducts or multiple ducts than it does in man. Birds have one to four +pancreatic ducts separate from the biliary openings. + +The gall-bladder is missing in most varieties of the following groups: +pigeons, parrots, wrens, ostriches, rheas, cuckoos, toucans among the +birds; most odd-toed ungulates, hyraces, Indian elephants, all deer, +peccaries, three-toed sloth, and many rodents. The varieties lacking +this reservoir are herbivorous in the main, true carnivores seeming +always to be possessed of such a structure. Among the important +herbivorous ungulates, Bovidæ, Tragulidæ, Camelidæ and Suidæ have this +bile reservoir almost without exception. Because of the interest now +being shown in the pathology of the gall-bladder and its passages and of +the pancreas, it was hoped that evidence of definite practical value for +human pathology would be at hand in our study if we divided the animals +into groups with and without a bile reservoir. The result is not +unequivocal but worthy of note; it is discussed on pages 238 and 255. + +Microscopically the well known lobular arrangement of the liver is +rather faithfully carried out among the mammals albeit the most +systematic and complete architecture is to be found in the pig while the +marsupial seems the most disorderly, thus resembling the avian organ. In +the latter class all the parts are indistinct, the cells having an +unclear outline, the tubules being intricately wound and the +interlobular connective tissue being scanty and not anastomosing in a +definite framework. The intralobular reticulum is especially difficult +to detect. Groups of cells are often found at portal spaces; these are +large and small mononuclears and granular cells, probably of the +hematopoietic system. It is possible that blood formation is performed +in the liver and spleen in some adult birds but such a function is +denied for the mammal except under very unusual conditions of bone +marrow atrophy. + +Glycogenic and fatty conservation is a function possessed by both +zoological classes as are the detoxicating and bile-producing powers. +However it is highly probable that urea and creatin in metabolism is not +cared for by the avian liver as it is by the mammalian, judging by the +researches of Paton and of Richet. + + +FAT DEPOSITS. + +The care of fat by the liver is very well shown by examining the +incidence of fatty metamorphoses through the various orders. In the +first place Mammalia show a slightly higher percentage of fatty change +than do Aves and should show a greater difference were it not for the +large number of cases in two orders of the latter. Among mammals, +lemurs, rodents and marsupials store fat in the liver more than other +orders but in the second and third, it is chiefly the carnivorous +varieties that have this property. Just why the slothful herbivorous +lemurs should be first on the list is not evident especially since the +grain-eating Ungulata are least apt to present fatty livers. With this +exception, mammals with plentifully available hydrocarbons in their diet +are most apt to show its deposit in the organ under discussion. Among +the birds the gallinaceous varieties stand far ahead of all others, the +passerines following next. Galli show the condition in association with +acute infections, chronic diseases and in health. Unless there be +distinct reason for it at autopsy, it may almost always be said to be +normal. Passeres, especially the smaller forms, frequently come to +autopsy with such excessively large livers, and indeed with a very large +pad of abdominal fat, and nothing else, that one is compelled to look +upon this overburdened organ as incapacitated by the deposit. These two +orders increase the percentage value for the birds. Striges, Anseres, +and Accipitres also show a good number of cases but there is among the +Aves no such clear relationship between food fat and fat infiltration as +may be found in the Mammalia. + + +AMYLOID DEPOSITS. + +Amyloid deposit is reported with reasonable frequency in domesticated +animals, causing in them a fairly definite entity, being as usual +related to the effects of long continued or repeated infectious disease. +Wild animals suffer from this condition but rarely and therefore to our +few cases will be given a short discussion separately. An Indian +Paradoxure (_Paradoxurus niger_) had patches of amyloid irregularly +distributed through the organ. The animal had a carcinoma of the head of +the pancreas, an obstructive biliary cirrhosis in a state of atrophy and +a chronic nephritis with arteriosclerosis. There was nothing peculiar +about the distribution of the deposit as there was in the next case, a +Badger (_Meles meles_) where amyloid was found around the interlobular +vessels and extending in the lobules along their canaliculi. This latter +case seemed without cause and we have considered it a primary +amyloidosis, the spleen, heart muscle, kidneys, intestines and other +structures being affected. (See Fig. 7.) A third mammalian case +concerned a Dasyure (_Dasyurus viverrinus_) which showed distinct +intralobular collections. Its cause was a chronic suppurative process in +the jaw bone. + +Avian livers are somewhat more prone to show amyloid deposits, eight +cases being on record. Four occurred in the Passeres, one each in +Columbæ and Impennes and two in Anseres. Three were associated with +chronic infectious disease and two with well established nematode +parasitism. The remaining three, classed as primary, were not related to +any other lesions, in two the amyloid liver being the only finding. + +The next abnormal deposition related to the physiology of the organ is +blood pigmentation. Normally hemic pigment is dispensed with very +rapidly but under unnatural conditions it accumulates. In only one order +is there any noteworthy percentage of hemosiderosis, the carnivores, the +remainder showing a very trifling incidence. + + +DEGENERATIONS. + +Going further into the physicochemical alterations of the liver brings +us to consideration of those changes known as degenerations— +parenchymatous, fatty, hydropic, hyaline, all of which we shall group +under one heading. They occur in a great variety of conditions and do +not appear to be specific, nor as the records are analyzed do they +appear to occur preëminently in any one disease of the lower animals. +The percentages are however higher for orders and families whose diet +contains relatively more protein, carnivores, the higher marsupials, +accipitrine, and wading birds. + + +ACUTE ATROPHY. + +A very important degenerative disease of the liver is acute yellow +atrophy or, better expressed, acute degenerative atrophy for it is a +total destruction of the whole or large parts of the parenchyma. It is +apparently toxic in origin being related to the toxemias of pregnancy, +to certain organic and inorganic soluble poisons; some cases arise +without discoverable cause. We have seen no cases in the mammal but two +in birds. Both were females, one in active ovulation, while the other +had no related pathology and the condition of the ovaries could not be +determined since they had been destroyed after death by rats. The +macroscopic and minute anatomy offers nothing new. Jaundice was present +but not intense. + + +HEPATITIS. + +True inflammatory lesions are to be defined as some form of +parenchymatous change to which are added congestion, infiltration of +round or polynuclear cells, stagnation in the bile ducts or perhaps +actual degeneration of their lining cells. It seems necessary to +stipulate these things because in the chronic forms, usually called +cirrhosis, it is necessary to have all of them, plus efforts at +regeneration, in order to determine it as a chronic progressive process. +Acute hepatitis is a rare condition in mammals except when it is +combined with septicemia or severe enteritis. In birds on the other hand +the liver is, aside from the intestinal wall, perhaps the most frequent +seat of pathology in the abdomen. This is because of its almost constant +involvement in infective enteritis, and in such conditions as fowl +cholera, fowl typhoid, coccidiosis and cecal amœbiasis, all of which we +have sporadically. When one searches for special distribution among the +orders, only one of them stands out as having a high percentage, the +Galli, an order which seems to have a very vulnerable liver. + +The macroscopic anatomy of hepatitis in birds is peculiar in showing a +definite swelling with spots of gray or yellow color, sometimes +coalescing to form irregular areas. These are much more definite than in +the mammalian organ where swelling and hemorrhage are the commoner +findings. These pale spots are of two origins. They may be focal +necroses of the hepatic cells, with or without circumferential +congestion or hemorrhage to make them stand out. In amœbic, coccidial +and typhoid livers such is the type of change. In septicemia and +cholera, the mottlings are made up of increased interstitial mononuclear +areas, with blood cells and shadow cells numerously present. I have seen +what was in all probability a stage of repair after both these kinds of +change. In the former, regeneration seemed to take place from adjoining +liver cells, there being in the section no evidence of increased bile +ducts to make new hepatic cells. It seemed also that phagocytes were +derived from blood cells and not from Kupffer’s cells. In the +infiltrative lesion disappearance of the liver cells from the groups +leaving compressed and deeply granular remnants was all that could be +determined. Regeneration seemed to be progressing in the manner just +outlined. + + +NECROSES. + +The degenerative and infiltrative areas of acute hepatitis are simulated +by focal necroses in livers not the seat of a general hepatitis from +which they can be differentiated only by the microscope. These small +areas of local tissue death are quite common in all pathological +processes but are most common in the liver, possibly because of its +exposure to toxins from the intestine. Their exact origin is not +determined, various explanations being given. The somewhat distinct +distribution in mammals _versus_ that in birds may help in the final +decision. In the former, focal necroses are more often encountered +midway in the anatomic lobule and around the central vein whereas a +perivascular location seems the usual position in the bird. + +Massive necroses of the liver may be of considerable importance in +veterinary medicine. They take their origin in several different ways. +The commonest in our records are those due to cecal coccidiosis and +amœbiasis (quail disease and blackhead) while from the primary seat of +these two infectious diseases, the cecum, may originate the virus of +nonspecific hepatic necroses. We have observed several birds, passerine, +psittacine and gallinaceous, which at autopsy showed a distention of the +cloaca, ceca, and lower small intestine with urates and slime but no +mural inflammation and a large area of necrosis in the liver. This +suggests perhaps a “white diarrhœa” but it did not occur in epizoötics +and other morbid anatomy of this specific disease was absent. These +frequent instances of association between the colonic area and the liver +seem to suggest the transfer of necrotizing organisms, just as amœbæ +travel, and to indicate measures to clean out the tract when birds +become “plastered.” Massive necroses also arise from mould disease, and +from infection with the necrosis bacillus, emanating from nearby +infectious foci, or _via_ the normal passageways from the intestine. +Massive areas of degeneration may form by the coalescing of numerous +foci, in any septicemic disease. + + +ABSCESS. + +In man, amœbæ, flukes, cestodes and biliary tract infection are the +commonest causes of purulent collections within the liver. In the lower +mammals parasites play practically a solitary rôle at least as the major +influence in localizing the collection, bacteria from the intestine +doing the rest. We have one case of massive abscess in a porcupine +suffering with septic pneumonia, the suppuration in the liver being due +to the colon bacillus, the general septicemia probably being from +distemper. Monkeys have shown more abscesses than any other order, three +being observed. One was due to infestation with trichocephalus which had +apparently penetrated from the colonic wall into the liver through +adhesions formed between these two structures. Another seems certainly +amœbic but these protozoa could not be found, while the third followed +an ulcerative enterocolitis of unknown cause. Two cats were seen with +parasitic abscesses; one harbored _Distoma_ or _Clonorchis sinensis_, +the other a nematode of ascaris type. + +The topographic distribution of these six hepatic abscesses was +interesting. The position of the abscess is not mentioned in one case +but of the remaining five three were entirely in the right lobe, one had +the major lesion on the right side and smaller separate abscesses spread +over the organ, and one with about equal distribution in all lobes. All +three confined to the right side were solitary. + +Abscesses of considerable size are not met with in the bird as in the +mammal perhaps because the former does not form real pus, necroses +developing instead. + +Congestion of the liver is a matter of small importance from the +standpoint of pathology unless it be of sufficient duration to cause +cyanotic atrophy and induration. However the facts that congestion of +this organ occurs three times as often in the mammal as in the bird and +that vascular cirrhosis has not been seen in the latter class, are +interesting and noteworthy. In addition ascites of hepatic origin has +not been seen in the birds. The explanation for this lies in the rich +anastomosis between the intestinal area and the caudal vena cava so that +the blood does not have to pass through the liver to reach the heart. +This arrangement would reduce the back pressure in passive congestion +and relieve the liver in the congestion due to toxic or inflammatory +distention of small vessels. + + +CIRRHOSIS. + +The chronic inflammations or so-called cirrhoses of the liver have been +subjected to a great deal of study and many theories have been expounded +as to their cause and classification. Here is not the place to discuss +the academic question of nomenclature but rather to adopt an acceptable +working classification and to analyze our material thereon. A cirrhosis +is a chronic inflammation of the liver indicated by increased connective +tissue with evidences of degeneration and attempts at regeneration on +the part of the hepatic cells. Certain cases of increased connective +framework fail to show the last two features and, since they must be +grouped near the cirrhoses because of the prominence of connective +tissue, they are called _fibroses_, _perilobular in type_. Among the +instances carrying out the full stipulations are livers with evidence of +a perivascular fibrosis and obstruction, to which are added degeneration +and regeneration of the lobular margins; such are PORTAL CIRRHOSES in +human medicine associated with passive congestion in the intestinal +area, and ascites. In a second variety, fibrosis seems to succeed upon +obstruction to the biliary lumina or upon peribiliary inflammation, +BILIARY CIRRHOSES. The effects of this are to dam back bile with the +production of varying degrees of jaundice and for the inflammation to +spread into the lobules, thus distorting their internal architecture; +this form is therefore unlike portal cirrhosis which alters the size and +shape of lobules as a whole. Fatty change is very prominent in certain +cases and it has been a custom, perhaps without warrant, to put such +livers into a separate group. It may be that they represent a different +chemical process. When there exists for a long time a venous stasis in +the liver, necrosis is apt to occur in the cells subjected to pressure +and the absence of fresh blood. This gives rise to a “nutmeg” liver upon +which may succeed a definite perivenous fibrosis. + +This then is a working classification of the hepatic cirrhoses. Perhaps +many slightly differing varieties might be constructed but this grouping +will permit comparison and contrast with human cases, and with instances +in the various orders. Because of the relatively small total, thirty- +two, it is perhaps unwise to attempt any conclusions as to distribution +but it is certainly noteworthy that twenty-six occurred in mammals. This +means 1.6 per cent. in mammalian autopsies against .2 per cent. in +avian. Among the former class the carnivores stand at the head of the +list, followed in order by the marsupials, ungulates, primates, and +rodents. + +Carnivora have shown a few typical portal cirrhoses from a pathological +standpoint but only one, in a badger (_Taxidea taxus_), was combined +with the classical picture of intestinal hyperemia and ascites. Two of +the cases were combined with chronic enteritis which may, of course, +have been secondary but there was also a hyperplasia of the spleen which +bespoke some grade of infection. None of the four showed involvement of +the biliary tract. One animal, a skunk (_Mephitis mesomelas_), was +jaundiced; it had anemia, nephritis and enlarged spleen but no +intestinal inflammation; perhaps the associated anemia may have been +responsible for the pigmentation. Biliary cirrhosis occurred in two +Carnivora, in both associated with enlarged spleen and nephritis. One +showed jaundice and the other, with a huge liver from congestion and +interstitial infiltration, had a small ascites. Fatty cirrhosis was +diagnosed in a raccoon but this is viewed with some reservation because +this animal easily stores fat and in this case it may not have been a +part of the process. In none of the foregoing cases did parasitism enter +into the causation of the change and I shall always specify when such a +factor was probable. The only vascular cirrhosis in our records occurred +in a Gray Wolf incident to a longstanding myocarditis (Gray Wolf, _Canis +lupus mexicanus_, Myocarditis, Adenomatoid goitre, Chronic +gastroenteritis, Vascular cirrhosis of liver, Subacute diffuse +nephritis, Edema of lungs, pericardium, and peritoneum). Two examples of +perilobular fibrosis appeared in this order, a raccoon (_Procyon lotor_) +and a paradoxure (_Trichosurus vulpecular vulpecular_). The only +noteworthy feature was, in the former, a very marked biliary stasis on +the lobular margins and in the connective tissue; this animal was not +jaundiced. + +Ungulata are normally well supplied with definite interlobular strands +which, in a few varieties, completely encircle the lobule but always +show as clear fibrous septa going out from the portal areas. This +richness of connective tissue renders more difficult a decision of +increase so that unequivocal degenerations and regenerations with +inflammatory changes have been demanded as criteria for cirrhosis. It +has been recognized that cattle get a definite increase in their +interstitial tissue without serious reaction in the parenchyma. With the +knowledge of these facts in mind it has been possible to detect two +distinct portal cirrhoses, two biliary cirrhoses and three perilobular +fibroses. It is however evident by examining the rest of the autopsy +notes that the chronic inflammations have had with one exception, little +influence on the animal’s life and death and the associated pathology is +not instructive in etiology. One old deer with the definite portal type +had ascites and intestinal hyperemia which hastened his end. + +The type of cirrhosis in the marsupial is progressively inflammatory and +of the biliary variety. In two of the three cases there was active +infection somewhere in the body, one a long continued streptothricosis, +the other and more important a choledochitis with involvement of the +pancreatic head. The third case showed a nephritis and a +pericholedochitis and pericholecystitis. In all three there was definite +evidence of biliary obstruction within the liver and in the occurrence +of general jaundice. + +Monkeys have presented one portal, two biliary, and one perilobular +cirrhoses. The London Garden reports a cirrhosis with gall stones in a +Chimpanzee. The case of the Barbary Ape is so good that it is quoted in +brief. + + + Barbary Ape ♀ (_Macacus innuus_). Found dead. Never known to be sick. + On exhibition nine years. Acute dilatation of stomach. Acute + gastritis. Portal cirrhosis of liver. Acute parenchymatous nephritis. + Chronic passive congestion of lungs. Chronic splenitis and + perisplenitis. Ascites. Mild passive congestion of abdominal + circulation. On opening the abdomen a dilated stomach occupies most of + the anterior part, displacing the intestines downward and backward. + The upper lobes of both lungs are uniformly deep red, soft, collapsed, + subcrepitant. Subclavian vessels—veins distended with red clot, + arteries with small amount of chicken fat clot. The heart is dilated + on the right side, filled with currant jelly clot. The liver is small, + surface hobnailed, edges rough, consistency tough, color brown. + Section surface glistening, moist, granular and opaque, mottled by + irregular brown areas separated by paler brown intercommunicating + bands. Gall-bladder is small, contains viscid yellow bile and duct is + patulous. Areolar tissue about the bile ducts is thick and opaque, the + duct wall itself is thick and yellow. Gall-bladder tightly attached to + capsule of liver. Spleen is slightly enlarged, soft and tough. Capsule + is smooth, opaque and thickened on gastric surface. The trabeculæ are + prominent, pulp mottled gray-red, few recent hemorrhages. Capsule of + the kidneys is smooth, strips easily leaving a smooth brown surface + with dilated vessels. Organ is soft. Section surface is glistening, + striæ wide and indistinct, glomeruli faintly visible. Microscopic + section of liver shows high grade of fibrosis almost entirely confined + to portal areas with a marked increase in bile ducts although no place + is found where these bile ducts are running into lobules suggesting + attempt at regeneration. Liver cells show high grade of fatty + degeneration in some places, whole lobules being necrotic. There is no + pigmentation and connective tissue is fairly rich in cells. Fibrosis + quite well advanced. Cells about equally fibroblasts, round cells and + polynuclears. Bile ducts very well preserved and cellular infiltrate + rather less directly around them than at other parts of connective + tissue. The section of kidney shows moderate congestion, granular and + vacuolar degeneration of epithelium generally distributed except in + proximal tubules where there is swelling and desquamation. Detritus + present in tubules and capsular spaces. Tufts swollen. + + +The biliary forms of Primates were associated in one case with an +undetermined parasite in the bile channels, in the other with +tuberculosis and chronic enteritis. In all the cases the relative +inconspicuousness of bile in ducts or in cells is worthy of mention. The +perilobular fibrosis in a small cebus was trifling in extent but was +associated with considerable round cell infiltration in isolated areas; +there was also nephritis, splenitis, and enteritis. + +The only representative of the rodents is a capybara (_Hydrochœrus +hydrochœrus_), their largest variety. This case was originally described +as a typical Lænnec or Pictou cirrhosis but I now class it as a portal +form. The distinct insular arrangement of the lobules, the failure of +involvement of the bile channels and the ascites are reasons for the +present decision. The animal suffered also from tuberculosis (not in +liver) and myocarditis. + +The Indian Elephant, “Bolivar” (_Elephas indicus_), an old specimen, is +the only member of his order to show cirrhosis. It may be considered as +a senile process in part but the extreme distortion and compression of +the lobules press the conclusion that it was a progressive inflammation. + +[Illustration: + + FIG. 18.—PORTAL CIRRHOSIS OF LIVER IN ATROPHIC STAGE. BARBARY APE + (MACACUS INNUUS). THE DILATATION OF THE STOMACH ALSO SHOWS IN + PHOTOGRAPH. +] + +[Illustration: + + FIG. 19.—ATROPHIC PORTAL CIRRHOSIS OF LIVER. INDIAN ELEPHANT (ELEPHAS + INDICUS). +] + +Aves fail to show lesions which could be called portal cirrhosis, five +of their six cases being biliary and one fatty with signs of continued +infection. The macroscopic anatomy of the avian liver with chronic +fibrosing hepatitis is fairly uniform and suggestive. In the first place +it is grossly nodular, lumpy, not finely granular or “hobnailed.” The +sensation to the finger is resilient rather than tough. The color is +variable but green and dull purple are the usual shades. On section no +peculiarities present themselves unless it be that one can find pale +spots on a dark background, which may correspond to the mammalian +connective tissue strands. Microscopically the increase of cellular +groups at portal spaces and the extensive growth of connective tissue +between the liver columns are the noteworthy features. There is nothing +in mammalian cirrhoses to compare with the intralobular growth of fibres +in birds. There is of course no regularity so that the degree of +replacement or necrosis of parenchyma is hard to estimate. Bile ducts do +not proliferate but seem, once obstructed and surrounded, to succumb to +the inflammation. The six cases in birds are: Psittaci, 3, Galli, +Anseres, Struthiones each one. The cases in the last two orders were +associated with parasites, to which bacteria or toxin may have been +added. It is interesting to note that the two frankly progressive +obstructive biliary cases in the parrots showed general jaundice. + +It was formerly customary in many quarters to speak of atrophic and +hypertrophic cirrhosis. Now it is generally thought that any form will +be large or small as growth and regeneration on the one hand, or +contraction, atrophy and degeneration on the other, may be predominant +at the time the organ is seen. It is perhaps misleading to judge by our +notes of what happens, but it is curious that in the thirty-two cases, +the pathologist could state only in seventeen instances that the liver +was larger or smaller than normal. This means therefore that the liver +of cirrhosis need not deviate greatly from its customary size. Nine of +the seventeen times the organ was considered smaller than normal, eight +times it was greater. These variations did not strictly correspond to +type, but the portal form, frequently called atrophic, was more often +small than was the biliary form. + +Gastrointestinal disease accompanied cirrhosis in fourteen instances. +Nephritis was present nineteen times. The spleen was enlarged six times, +in all of which definite evidence of infection existed in the body. +Choledochitis existed four times, twice with biliary cirrhosis, twice +with perilobular fibrosis; cholecystitis existed twice, once in a +monkey, and once in a bird with parasites. Pancreatitis was seen in +three biliary cirrhoses and once in a perilobular fibrosis. + +The relation of the existence of cirrhosis to the presence of a gall- +bladder is interesting. Among the thirty-two animals twenty-one have +gall-bladders, eleven have not. The exact number of animals in our whole +list with and without this structure, unfortunately cannot be given with +exactness. As nearly as I can figure it out, sixteen per cent. of our +animal posts have been on varieties without a gall-bladder, eighty-four +per cent. with it. This would make the absence of this reservoir a +factor favoring the development of cirrhosis since one-third of the +cirrhoses are in groups devoid of this bag, yet these same groups +supplied only one-sixth of the total postmortems. + + +GALL STONES. + +Our experience with concrements in the biliary system is limited to six +cases which can be detailed in brief. + + + American Beaver ♀ (_Castor canadensis_) showed a soft purplish liver + with groups of tortuous yellow lines; these prove to be groups of + hepaticola with fatty degeneration around them, but successful + regeneration is going on; bile ducts are not seriously involved over + any great part of the organ; the bladder is distended greatly with + thin, yellow-green fluid; duct is not patulous; common duct narrowed + at middle and above this constriction lies a small concrement; bladder + contains two large and several small pale yellow-green friable stones; + mucosa injected and covered with mucopus; the pancreas is not + affected. + + American Beaver ♂ (_Castor canadensis_) shows a slight bile + obstruction and pigmentation through the liver but no pus or + cirrhosis; bladder is collapsed containing only a little limpid brown + fluid; wall is slightly roughened but not opaque; there is a blue- + black stone 1.5 × 1 cm. free in the cavity; duct patulous; pancreas + and intestine not affected. + + Brant Goose ♂ (_Branta bernicla glaucogastra_) liver shows slight + fatty change; bladder much distended, contains twenty-six small, quite + hard, greenish stones; one is impacted in the cystic duct which is not + patulous. + + Pigtailed Macaque ♂ (_Macacus nemestrinus_) shows a normal liver; + bladder contains a small black concrement, very hard, no cystitis. + + Polar Bear ♀ (_Ursus maritimus_) showed a chronic cholecystitis and + cholangitis, the stone (?) in this case consisting of a solitary, + black, friable mass, six mm. in diameter. + + Mongoose Lemur ♂ (_Lemur mongoz_) showed a normal liver; bladder of + about normal size but the duct can be forced only by considerable + pressure; there is a small stone and a granule in the tortuous cystic + duct; no cholecystitis. + + +The specimens that are preserved show these to be chiefly inspissated +bile, those from the first beaver and the goose being the only ones to +rise to the dignity of gall stones; it would seem that there was plenty +of opportunity for calculi to form in the bladder of this beaver. In no +case is there a cholangitis or cirrhosis dependent upon cholelithiasis. + +While stones have been shown as infrequent there is a condition of the +bile which may be quite important. In Passeres, Accipitres, and Striges +one frequently sees a very dense inspissation of the bile both in the +cystic area and in the lesser independent bile duct. This need not be, +indeed usually is not, associated with hepatitis or cholecystitis. There +is no one thing more common than another in relation with it but the +diagnoses most often made are enteritis, distention of the proventricle +and gizzard, and constipation. + + +INFLAMMATION OF THE BILIARY SYSTEM. + +The biliary tract from its origin in fine intrahepatic radicles to the +bladder and to the end of the common or intestinal ducts is the seat of +many inflammations both acute and chronic, but since they are supposed +to lead to damage to the liver and pancreas and to the production of +gall stones, it is well to consider the system as a whole. As a matter +of fact separate analyses of cholangitis, choledochitis and +cholecystitis do not reveal different figures for each or for different +orders. The vulnerability of this tract is found to be directly as the +percentage of cirrhosis, to wit, the carnivores stand first, then the +marsupials, ungulates, Primates and rodents; among the birds the order +is Accipitres, Anseres, Struthiones, Psittaci, and Galli. It is +difficult in most instances to evaluate the various possible etiological +factors, but, due caution being exercised, gastrointestinal inflammation +could be held responsible in seventeen of the total of fifty cases. In +twelve of the seventeen this process was wholly or largely in the +duodenum. The next factor was general infection, at the head of which +pneumonia and “distemper” occupied about equal places. In marsupials, +the streptococcal and streptothrical infections to which these animals +are susceptible, was the prime factor. This group almost always has +definite signs of stasis both in the liver and, as indicated by +jaundice, in the general tissues. Pancreatitis was present in seven of +the fifty cases and in five of the seven, enteritis was also found. +Common duct stones were not observed. I shall have something to say +about pericholangitis and pericystitis under the head of pancreatitis. + + +TUMORS. + +The liver presents a good share of the tumors appearing in solid viscera +but, with the exception of a few points, they offer little of interest. +In the first place three angiomata have been seen and while they may not +be tumors in the accepted sense of the word, may be considered briefly. +A single cavernous angioma was seen in a goose. It occupied a large part +of the right lobe but did not seem to affect mechanically the function +of the organ since conditions wholly foreign to the liver were the cause +of death. A leopard presented several small groups of telangiectatic +angiomata lying mostly at portal spaces, a few also under the capsule. +The liver of a thrush was likewise scatteringly beset with small +angiomata. The original notes and recent examination do not reveal +parasites or perivascular sarcomatous change. + +Simple adenomata were observed in a woodchuck (_Arctomys monax_). This +diagnosis is made with the appreciation that nodular regeneration of the +liver after damage and in cirrhosis sometimes suggests tumor, but with +adenomata an increase of supporting framework may occur. The liver of +this animal presented numerous .3 to 10. cm. irregularly spherical, +encapsulated, firm or slightly resilient, brown masses which under the +microscope consisted of large pale vacuolated cells in columns or +strands not connected with bile ducts. The last feature speaks in favor +of the diagnosis of adenoma. The damage to the organ was probably +considerable and the portal circulation must have been impeded since +passive congestion and ascites were present. Enteritis and nephritis +seemed the causes of death. + +Adenomata or fibroadenomata of bile duct origin were seen in four +animals, a Red Fox (_Canis vulpes pennsylvanicus_), a Gray Fox (_Canis +cinereo argenteus_), a Jaguar (_Felis onca_) and a Common Deer (_Mazama +virginiana_). The first two present similar pictures, pinpoint to 8. +mm., gray, well outlined areas some of which are clearly cystic, others +opaque and more solid. In the first fox a larger mass was found near the +hilum. Careful study and consultation has failed to discover parasites +in these cases, although their presence was strongly suspected, so that +we were forced to conclude, in view of the rather typical microscopic +picture, that they are adenomata of bile duct origin. Their scattered +distribution, but with a tendency to be more numerous beneath the +capsule, corresponds with a human case just brought to my notice. The +mass in the liver of the deer was single and resembled an infarct, with +cysts exposed by cross section. This tumor was found on the +diaphragmatic surface of the right lobe. + +Tumors of an atypical, therefore malignant, epithelial variety were +found four times, in an Alpaca (_Lama pacos_) and three parrakeets; +these birds are very prone to have all kinds of tumors. The records of +the first animal could not be as satisfactory as might be desired +because of an advanced state of decomposition but there was a carcinoma- +like growth of the gall-bladder area and a large hard alveolated tumor +occupying one-half of the liver. The colon had been involved by the +former, with perforation. Two of the parrakeets showed a simple +carcinoma with well developed fibrous tissue bands running in all +directions through the large mass. The whole growth was comparable to +the usual picture of these massive tumors when they are primary in the +liver. All these three cancers seem to take their origin in the liver +cells but the third had such an interesting involvement of the +connective tissue that its minute anatomy will be given; it was +denominated adenocarcinoma sarcomatodes. + + + Undulated Grass Parrakeet ♂ (_Melopsittacus undulatus_). Section of + liver shows organic capsule normal. Nothing remains of the original + structure by which it might be recognized, suggestion in places of + granular cells resembling liver cells being only occasional + occurrences and in small numbers. Where liver cells do occur they are + highly granular in various degrees of atrophy and show various grades + of nuclear retrogression. Greatest part of section consists of dense, + white fibrous tissue in which lymphocytes are rather diffusely placed + together with large numbers of epithelium-lined spaces. These spaces + are often elongated after manner of imperfect ducts but are of + irregular form, have single layer of low cuboidal epithelium and + richly staining nuclei. Upon search certain acini are found to have + especially hyperchromatic nuclei and penetration of basement membrane. + In such localities collections of epithelial cells are to be seen in + plug form in lymphatics and acini of imperfect development of lumen + are found. In addition to these epithelial lesions connective tissue + ones are seen, occurring generally in restricted localities. The + interstitial framework is seen to consist of closely placed spindle + cells, some of which are especially elongated after manner of + imperfect ducts but are of irregular form, directed in a definite, + purposeful manner, but interlace in the whorling manner noted in + fibromas. Nuclei are, however, entirely too chromatic for a connective + tissue tumor. Whenever a vessel occurs in these regions its lining + endothelium is always swollen and nuclei in its wall will be + proliferated and of embryonic type. This latter condition is apt to + occur in patchy manner, part of wall appearing normal and other parts + containing these peripherated elongated nuclei. + + +Secondary tumors were observed in the liver seven times as follows: Red +Kangaroo (_Macropus rufus_) from malignant papilloma of the stomach; +Spotted tailed Dasyure (_Dasyurus maculatus_) from cancer in the small +intestine; Dorcas Goat (_Capra hircus_) from sarcoma in lymph nodes in +mediastinum; Raccoon-like Dog (_Canis procyonoides_) from mixed tumor of +thyroid; Undulated Grass Parrakeet (_Melopsittacus undulatus_) from a +brain tumor probably glioma; another of same species from a sarcoma of +pectoral muscle; European Robin (_Erithacus rubeculus_) adenoma of +adrenal (_hypernephroma_). + + + + + SECTION VII + THE ALIMENTARY TRACT, PART 3. + THE PANCREAS + + +The pancreas, an organ functionating as a gland with an internal +secretion and by pouring a digestive juice into the duodenum, remains a +structure of constant anatomy throughout the zoological classes under +discussion in that it is composed of compound racemose lobules whose +outlets join to form large discharging ducts, and of interstitial +bodies, the islands of Langerhans, without connection with the secreting +acini but having some relation with the blood and lymph vessels. The +organ originates embryologically by sprouts from the side of the +primitive gut just below the part destined to be stomach, and from an +outbudding of the common biliary duct. These two sprouts or pouches +combine to form one organ, but this does not necessarily effect a union +between their lumina. In some birds and mammals (Accipitres and some +Ungulata) the lobes of the pancreas remain distinct during life, and the +discharging tubules seem to empty only their respective lobes. However, +there is no uniformity in the matter, and indeed the anatomy of the +ducts is subject to very great variation despite the rather similar +beginnings of the organ. Those who are interested in this point may +consult Beddard,[25] Letulle and Nathan-Larrier,[26] and Opie[27]; there +will be given in the following pages the average findings of anatomy of +the gland body and of its ducts. + +The region of the pancreas in lower animals, especially those which +travel constantly on four feet, is one of great activity, and the organs +are more freely movable than in the human being. The only exception to +the latter part of this statement may possibly be found in the cats and +dogs, in which there are firmer attachments of the duodenum and pancreas +to the vertebral column and the liver; this is brought about by the +short gastrohepatic omentum and the abrupt curvature of the duodenum +toward the back, under the mesenteric stalk. In the Ungulata and +Marsupialia and in some Rodentia, the pyloric, duodenal, and pancreatic +attachments are relatively loose, and torsion of the pylorus seems to be +allowed for, since in these animals great distention of the stomach is +the rule. Among the Aves the anatomy is wholly different. The birds have +no attachment of the duodenum and pancreas to the posterior abdominal +wall, except indirectly through a narrow strip comparable to the +gastrohepatic omentum, one division of which passes to the beginning of +the duodenum, the other to its end, and by a thin tail of pancreas which +goes toward the spleen. The bulk of the pancreas lies in the U made by +the long free duodenal loop, the two organs being covered by the serous +membranes forming the middle abdominal sac. It will be seen from the +foregoing that the movability of the pancreas is considerable—a highly +necessary provision, because the stomach and duodenum are also movable +and subject to distention by food and alteration of position during +flight. + +In the class Mammalia there are usually two ducts, one entering the +duodenum in combination with the bile duct, the other variously above or +below this common opening. As will be seen in Table 14, however, there +are several exceptions to this statement, there being but one duct +opening independently of the bile duct. The general anatomy is closely +similar throughout this class, so I shall confine my notes to the +exceptions from the general rule, especially where they seem to be of +importance in the etiology of pancreatic lesions. + +In the class Aves the pancreas consists usually of two or three distinct +lobes lying one in front and two behind the cleft between the limbs of +the duodenal loop, and it discharges its secretion into the duodenum by +two or three ducts separately, and almost invariably above the bile duct +openings. One duct always opens near the top of the distal end of the +duodenal loop, near the bile duct. In the gallinaceous birds that have a +bile duct opening into the duodenum near the pylorus, there is usually a +pancreatic duct opening there also. In some birds a third duct passes +from the body of the pancreas to the duodenum at different places along +the loop. It does not seem probable that dislocation of the duodenal +loop would seriously interfere with the passage of the pancreatic +secretions, since the gland is so intimately related with the duodenal +serosa, but obstruction to the biliary flow due to changes in position +of the intestine is easier because the bile duct is separate and loose +and arises from the end of the gall-bladder. The ducts of both these +structures pass very obliquely through the duodenal wall a matter of +importance, as will be seen when discussing the infiltrative forms of +enteritis. The gall-bladder is not present in all birds, but this is +probably of no importance, as the hepatic ducts are wide and run +directly from the liver to the duodenum. The pancreatic ducts are short +and are closely bound around by glandular tissue up to a place quite +close to their entrance into the intestine. + +The musculature of the gall-bladder and the ducts seems comparable in +mammals and birds, and a constrictor or sphincter usually called the +muscle of Oddi, is present in all but pigeons (Oddi). There may be found +also muscular fibres in the major ducts of the pancreas, but they are +not so heavy nor distributed so definitely as similar tissue in the bile +duct walls. The mucosa of the pancreatic duct is much more folded in +birds than in mammals, seemingly, therefore, more adapted to obstruction +by swelling from any cause. + +Passerine birds have two pancreatic ducts usually on the ascending loop +of the duodenum, or there may be one ahead of the pyloric biliary duct. +The picarian varieties possess three ducts as a rule, one near the +beginning of the pylorus, one near its end and a third of inconstant +location. Owls have a system like Passeres, but the relation between the +organ and the intestinal loop is looser and the ducts are wider. Columbæ +have two pancreatic ducts in the ascending limb of the duodenum. +Gallinaceous varieties have a double biliopancreatic system, a duct of +each kind entering the descending and the ascending duodenal reaches, +with the biliary placed after the pancreatic in each instance. +Accipitres have always two and oftentimes three ducts as do Anseres, +both orders frequently having the third duct opening at the bottom of +the duodenal loop where stagnation can and does occur. Fulicariæ have +usually three ducts. + +The foregoing are the orders presenting pancreatitis and therefore those +whose anatomy concerns this study directly. The irregularity in number +and arrangement of ducts continues through all the avian orders which +show a greater aberration from standards than do the mammals. +Theoretically the birds should cast some light upon the unsettled +question of the causes of pancreatitis, and as a matter of fact such a +result seems to have been realized. In 1915 I published an article upon +a study of this subject which indicated that acute inflammations of this +organ may arise _via_ the lumen of the duodenum and pancreatic ducts, +while chronic processes were the result of periductal passage of +pathogenic agents. Further study would seem to indicate that disease of +the biliary tract is of importance in lesions of the pancreas since a +decidedly large number of cases is found in mammals, where the relation +of ducts is definitely more intimate than in birds. The work of +Archibald,[28] Deaver and Sweet,[29] and Judd[30] seem to agree with the +findings upon our material. This need not be, however, in discord with +the idea that acute inflammation is superficial in origin, chronic +lesions deep or lymphogenic. The discussion will be resumed in a +subsequent paragraph. + +The amount of pancreas to be found in birds is greater than that in +mammals. According to our figures the organ represents ¹⁄₄₀₀th of the +body weight in the former and ¹⁄₆₀₀th in the latter. These figures are +averages of a small number of instances and are not final. It is, +however, obvious to casual daily observation that birds as a class have +a large pancreas. + +The minute structure of the organ is governed by the same general rules +throughout the two classes under consideration. Birds do not have as +many interstitial islands as do mammals, but they are more compact and +seem more definitely constructed of coiled tubules. In so far as the +internal structure of the organ is concerned there has not developed in +our study pathology peculiar to any animal. The importance of the ducts +and position of the organ will be discussed later. + +Recognition of pancreatic disease during life is practically impossible. +In human medicine the signs and symptoms are vague and inconstant,[31] +diagnosis often being a matter of exclusion. Veterinarians, except under +the best hospital conditions make no attempt to diagnose pancreatic +lesions but, since the improvement of surgical practice, at times +operate upon cases of evident pain and distention which prove to be +pancreatitis. These things were evident in a deer that I saw and that +died on the following day from acute hemorrhagic pancreatitis; I made no +attempt at this diagnosis, believing it to be acute tympanites. The +feces were normal, according to the judgment of persons qualified to +give an opinion. + +The condition of the pancreas at autopsy on animals not dying with +lesions of this organ deserves some attention since it may confuse the +uninitiated. If the organ be seen in its normal resting stage shortly +after death, it is not difficult to recognize the condition as normal +for the species. Activity is indicated by a darker or redder color and +an increase of consistency. In carnivorous or omnivorous animals and +birds the pancreas in this state is a body with a distinct bulky +character, whereas in strictly herbivorous varieties, especially +ungulates, the structure is diffusely pink and doughy. This is important +since the early stages of self-digestion and decomposition assume this +same character in all varieties, while later stages present a deep red, +swollen, wet organ. These appearances must be differentiated from acute +hemorrhages or inflammations, a distinction based upon actual local +blood collections or extravasations and areas of degeneration in true +disease. Oftentimes differentiation must be made under the microscope +and in advanced decomposition, determination is impossible. When there +is torsion of the stomach, notably in ungulates, the pancreas is often +found decidedly congested. This, it seems, is due to a twist of the +duodenum and passive congestion of it and the pancreas—the only simple +explanation despite the apparent provision for a high degree of +mobility, as already explained. The organ is nearly always mildly +congested in severe grades of acute duodenitis, although it need not be +pathologically involved. It is, however, noteworthy that the pancreas is +an organ with a low morbidity index, especially when one considers its +proximity to a structure showing the highest disease index in the body, +the intestine. The succeeding paragraphs will reveal in comparison to +other organs only a small number of cases of degeneration, inflammation +and tumors. This has been ascribed to the freedom of blood supply and +the power of tryptic digestion. + +An expression of this relative immunity to pathologic change is met in +analyzing the data upon the simplest lesions, degenerations, to be +expected in many states of disease. Only a small number of cases present +themselves, and they are under expected conditions, namely in +association with acute general infection, sometimes definitely +septicemic in nature. About half of them were discovered +microscopically, affecting the islands of Langerhans in vacuolization or +granular disintegration. Focal necroses of the organ were met four +times, three turkeys and a cockatoo. It is noteworthy that all these +birds had some involvement of the liver, twice a complete acute +hepatitis and twice a cholangitis. This is the more interesting since we +shall learn that the liver is less often involved in avian than in +mammalian pancreatitis. Hemorrhages occur occasionally in the pancreas +in acute general infections and are seen in acute inflammations of the +intestines; the percentage incidence with the latter is, however, very +small. Pancreatic apoplexy proper has not occurred, for all the +instances of large hemorrhage into the organ have been combined with +changes forcing a classification of acute pancreatitis. + + +PANCREATITIS. + +Pancreatitis in the acute form is divided by many writers into +exudative, hemorrhagic and necrotizing, while for the chronic variety an +inter- and intra-acinus form has been described. It is questionable +whether it is fair in acute cases to focus attention by special +nomenclature on different macroscopic pictures, unless it be for +descriptive purposes solely, since there is nothing at hand to indicate +that differing agents cause one kind every time. The physical findings +seem to depend rather upon the speed of operation of the causation than +upon its essence. Sudden obstruction of the pancreatic duct is believed +to produce necrotizing processes to which hemorrhage may be added by +digesting of blood vessels. Exudative cases seem due to extension of +ulcerative inflammation, from a perforated gastric ulcer for example, to +which digestive pancreatitis may be added. The interacinus chronic +inflammations are usually considered as due to obstruction or infection +through the biliary or pancreatic ducts whereas vascular disease +produces intra-acinus connective tissue overgrowth. Analysis of the +records of this laboratory would seem to indicate that necrotizing and +hemorrhagic processes belong together, exudative in a class by +themselves, and that chronic disease may be either interlobular or +intra-acinar without regard to associated pathology. I have therefore +studied our cases from this standpoint. + +Pancreatitis has occurred in thirty-eight mammals and birds among the +5365 autopsies, an incidence of 0.7 per cent.; class incidence in +mammals twenty-seven or 1.5 per cent.; birds eleven or .3 per cent. +(Table 14.) Among the higher class all the important orders are +represented, but by no means in equal degree, whereas in the birds, less +than half of the orders are listed, with the important Psittaci missing, +despite a high death rate. + +It is perhaps well to be guarded in stating the relative vulnerability +of the pancreas in various orders, but one cannot avoid the observation +that Carnivora stand well in advance of the others (3. per cent. of +autopsies), to be followed by Ungulata (1.9 per cent.) and Rodentia (1.7 +per cent.). Nor can one fail to see that mammals have inflammations of +this organ five times as often as do birds. + + TABLE 14. + _Showing Cases of Pancreatitis, their Pathological Nature, the Character + of Ducts of the Particular Animal, the Associated + Pathology, All of Which Data are Collected at the Bottom into Totals for + Zoological Classes and Orders._ + + ════════════╤════════════╤════════════╤══════╤═════╤═════════════ + Order │ Acute │ Chronic │Number│Open │Cholecystitis + │Hemorrhagic │Pancreatitis│ of │with │ + │ or │ │Ducts │Bile │ + │Necrotizing │ │ │Ducts│ + │Pancreatitis│ │ │ │ + ────────────┼────────────┼────────────┼──────┼─────┼───────────── + Primates: │ │ │ │ │ + Marmoset │ │Chr. Dif. │ 2 │ 1 │ 0 + │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + Carnivora: │ │ │ │ │ + Wolf │Ac. Hem. │ │ 1 │ 1 │ ? + Fox │Ac. Hem. │ │ 1? │ 1 │ 0 + Bear │ │Chr. │ 1 │ 1 │ 0 + │ │ │ │ │ + │ │ │ │ │ + Raccoon │ │Chr. sl. │ 1? │ 1 │ 0 + Bear │Ac. Nec. │ │ 1 │ 1 │ 0 + Coati │Ac. Hem. │ │ 2 │ 1 │ 0 + Badger │Hem. and │Chr. │ 2? │ 1 │ ? + Ocelot │Ac. Hem. │ │ 2 │ 1 │ +? + Bear │Ac. Hem. │ │ 1 │ 1 │ 0 + Wild Cat │ │Chr. │ 2? │ 1 │ 0 + Lion │Ac. Hem. │ │ 2? │ 1 │ 0 + Skunk │Ac. Nec. │ │ 2? │ 1 │ ? + Raccoon │Ac. Nec. │ │ 1? │ 1 │ 0 + │ │ │ │ │ + Rodentia: │ │ │ │ │ + Beaver │Ac. Hem. │ │ │ 1 │ 0 + Porcupine │Ac. Hem. │ │ │ 1 │ 0 + Ungulata: │ │ │ │ │ + Antelope │Ac. Hem. │ │ 1 │ 0 │ 0 + Deer │Ac. Hem. │ │ 1 │ 0 │ + Deer │Hem. │ │ 1 │ 0 │ + Deer │Hem. │ │ 1 │ 0 │ + Elk │Ac. Nec. │ │ 1 │ 0 │ + Nylghaie │Ac. Hem. │ │ 1 │ 0 │ 0 + Peccary │Ac. Hem. │ │ 2 │ 1 │ 0 + Marsupialia:│ │ │ │ │ + Phalanger │Ac. Nec. │ │ 1 │ 1 │ 0 + Opossum │Ac. Nec. │ │ 1 │ 0 │ 0 + Opossum │Ac. Nec. │ │ 1 │ 1 │ 0 + Devil │ │Chr. │ 2? │ 1 │ + + Passeres: │ │ │ │ │ + Finch │ │Chr. │ 3 │ 0 │ 0 + Thrush │Nec. and │ │ 3 │ 0 │ 0 + │Hem. │ │ │ │ + Chaffinch │ │Chr. │ 3 │ 0 │ 0 + Picariæ: │ │ │ │ │ + Hornbill │Acute │ │ 3 │ 0 │ 0 + Striges: │ │ │ │ │ + Owl │ │Chr. │ 3? │ 0 │ 0 + Accipitres: │ │ │ │ │ + Kestrel │ │Chr. │ 3? │ 0? │ 0 + Columbæ: │ │ │ │ │ + Dove │ │Chr. │ 2 │ 0 │ 0 + Galli: │ │ │ │ │ + Pheasant │ │Chr. │ 2 │ 0 │ 0 + Fulicariæ: │ │ │ │ │ + Gallinule │Ac. Hem. │ │ 3? │ 0 │ 0 + Anseres: │ │ │ │ │ + Gadwall │Ac. Hem. │ │ 3? │ 0? │ 0 + Struthines: │ │ │ │ │ + Ostrich │Ac. Hem. │ │ 3? │ 0? │ 0 + ════════════╪════════════╪════════════╪══════╪═════╪═════════════ + _Totals_ │ │ │ │ │ + Primates │ 0 │ 1 │ │ │ + Carnivora │ 10 │ 4 │ │ │ 4? + Rodentia │ 2 │ │ │ │ 1 + Ungulata │ 7 │ │ │ │ + Marsupialia │ 3 │ 1 │ │ │ 1 + ────────────┼────────────┼────────────┼──────┼─────┼───────────── + _Mammalia_ │ 22 or 1.1% │ 6 or .32% │ │ │ 6 + Passeres │ 1 │ 2 │ │ │ + Picariæ │ 1 │ │ │ │ + Striges │ │ 1 │ │ │ + Accipitres │ │ 1 │ │ │ + Columbæ │ │ 1 │ │ │ + Galli │ │ 1 │ │ │ + Fulicariæ │ 1 │ │ │ │ + Anseres │ 1 │ │ │ │ + Struthiones │ 1 │ │ │ │ + ────────────┼────────────┼────────────┼──────┼─────┼───────────── + _Aves_ │ 5 or .14% │ 6 or .17% │ │ │ + Grand Total │ 27 or .5% │ 12 or .22% │ │ │ 6 + ────────────┴────────────┴────────────┴──────┴─────┴───────────── + + ════════════╤═════════════╤═════════╤═════════════╤═════════╤═════════ + Order │ Cholangitis │ Hepatic │Inflammation │ Acute │ Chronic + │ or │Cirrhosis│ outside │Enteritis│Enteritis + │Choledochitis│ │ Pancreas │ │ + │ │ │ │ │ + │ │ │ │ │ + ────────────┼─────────────┼─────────┼─────────────┼─────────┼───────── + Primates: │ │ │ │ │ + Marmoset │ 0 │ 0 │Lymphadenitis│ 0 │ 0 + │ │ │ adjacent │ │ + │ │ │ glands │ │ + │ │ │ │ │ + Carnivora: │ │ │ │ │ + Wolf │ + │ 0 │ 0 │ + │ 0 + Fox │ 0 │ 0 │ 0 │ ? │ 0 + Bear │ 0 │ 0 │ Areolar │ + │ + │ │ │ tissue and │ │ + │ │ │ glands │ │ + Raccoon │ 0 │ 0 │ 0 │ 0 │ 0 + Bear │ 0 │ 0 │ Slight │ + │ 0 + Coati │ + │ 0 │ 0 │ 0 │ 0 + Badger │ + │ Atr. │ 0 │ 0 │ + Ocelot │ +? │ 0 │ 0 │ + │ 0 + Bear │ +? │ 0 │ 0 │ + │ 0 + Wild Cat │ 0 │ 0 │ 0 │ + │ +? + Lion │ 0 │ 0 │ 0 │ + │ + + Skunk │ + │Infective│+ Lymphnodes │ 0 │ 0 + Raccoon │ 0 │ 0 │ 0 │ 0 │ 0 + │ │ │ │ │ + Rodentia: │ │ │ │ │ + Beaver │ + │ 0 │ 0 │ 0 │ + + Porcupine │ 0 │ 0 │ Lymphnodes │ + │ 0 + Ungulata: │ │ │ │ │ + Antelope │ 0 │ 0 │ 0 │ 0 │ 0 + Deer │ ? │ 0 │ + │ + │ 0 + Deer │ 0 │ 0 │ + │ 0 │ 0 + Deer │ 0 │ + │ 0? │ 0 │ 0 + Elk │ 0 │ 0 │ Lymphnodes │ + │ 0 + Nylghaie │ 0 │ 0 │ 0 │ + │ 0 + Peccary │ 0 │ 0 │ 0 │ + │ 0 + Marsupialia:│ │ │ │ │ + Phalanger │ 0 │ 0 │ 0 │ + │ 0 + Opossum │ 0 │ 0 │ 0 │ + │ + + Opossum │ 0 │ 0 │ 0 │ + │ 0 + Devil │ + │ 0 │ + │ 0 │ + + Passeres: │ │ │ │ │ + Finch │ 0 │ 0 │ 0 │ ? │ ? + Thrush │ 0 │ + │ 0 │ 0 │ 0 + │ │ │ │ │ + Chaffinch │ + │ 0 │ 0 │ 0 │ 0 + Picariæ: │ │ │ │ │ + Hornbill │ + │ 0 │ + │ + │ + Striges: │ │ │ │ │ + Owl │ +? │ 0 │ 0 │ 0 │ + + Accipitres: │ │ │ │ │ + Kestrel │ 0 │ 0 │ + │ 0 │ + + Columbæ: │ │ │ │ │ + Dove │ 0 │ 0 │ 0 │ 0 │ + + Galli: │ │ │ │ │ + Pheasant │ + │ 0 │ 0 │ 0 │ + + Fulicariæ: │ │ │ │ │ + Gallinule │ + │ 0 │ 0 │ + │ 0 + Anseres: │ │ │ │ │ + Gadwall │ 0 │ 0 │ 0 │ + │ 0 + Struthines: │ │ │ │ │ + Ostrich │ 0 │ 0 │ 0 │ + │ 0 + ════════════╪═════════════╪═════════╪═════════════╪═════════╪═════════ + _Totals_ │ │ │ │ │ + Primates │ │ │ 1 │ │ + Carnivora │ 4 │ 2 │ 3 │ 7 │ 2 + Rodentia │ │ │ │ 1 │ 2 + Ungulata │ 1 │ 1 │ 3 │ 5 │ + Marsupialia │ 1 │ │ 1 │ 3 │ 2 + ────────────┼─────────────┼─────────┼─────────────┼─────────┼───────── + _Mammalia_ │ 6 │ 3 │ 8 │ 16 │ 6 + Passeres │ 1 │ 1 │ │ │ + Picariæ │ 1 │ │ 1 │ 1 │ + Striges │ 1? │ │ │ │ 1 + Accipitres │ │ │ 1 │ │ 1 + Columbæ │ │ │ │ │ 1 + Galli │ 1 │ │ │ │ 1 + Fulicariæ │ 1 │ │ │ 1 │ + Anseres │ │ │ │ 1 │ + Struthiones │ │ │ │ 1 │ + ────────────┼─────────────┼─────────┼─────────────┼─────────┼───────── + _Aves_ │ 4 │ 1 │ 2 │ 4 │ 4 + Grand Total │ 10 │ 4 │ 10 │ 20 │ 10 + ────────────┴─────────────┴─────────┴─────────────┴─────────┴───────── + + ════════════╤════════ + Order │ Fat + │Necrosis + │ + │ + │ + ────────────┼──────── + Primates: │ + Marmoset │ 0 + │ + │ + │ + Carnivora: │ + Wolf │ 0 + Fox │ 0 + Bear │ + + │ + │ + Raccoon │ 0 + Bear │ 0 + Coati │ + + Badger │ 0 + Ocelot │ + + Bear │ 0 + Wild Cat │ 0 + Lion │ + + Skunk │ 0 + Raccoon │ small + │ + Rodentia: │ + Beaver │ 0 0 + Porcupine │ 0 + Ungulata: │ + Antelope │ ? + Deer │ 0? + Deer │ 0 + Deer │ 0 + Elk │ 0 + Nylghaie │ 0 + Peccary │ + + Marsupialia:│ + Phalanger │ + + Opossum │ + + Opossum │ + + Devil │ + + Passeres: │ + Finch │ 0 + Thrush │ 0 + │ + Chaffinch │ 0 + Picariæ: │ + Hornbill │ + Striges: │ + Owl │ + + Accipitres: │ + Kestrel │ 0 + Columbæ: │ + Dove │ 0 + Galli: │ + Pheasant │ 0 + Fulicariæ: │ + Gallinule │ 0 + Anseres: │ + Gadwall │ 0 + Struthines: │ + Ostrich │ 0 + ════════════╪════════ + _Totals_ │ + Primates │ + Carnivora │ 5 + Rodentia │ + Ungulata │ 2 + Marsupialia │ 4 + ────────────┼──────── + _Mammalia_ │ 11 + Passeres │ + Picariæ │ + Striges │ 1 + Accipitres │ + Columbæ │ + Galli │ + Fulicariæ │ + Anseres │ + Struthiones │ + ────────────┼──────── + _Aves_ │ 1 + Grand Total │ 12 + ────────────┴──────── + +Further analysis of the data leads into a consideration of the anatomy +of the viscus in terms of the acceptable theories of the origin of the +lesion. It is commonly believed that infection of the gland occurs by +passage of organisms through the duct opening in the intestines, +especially when there is swelling of the mucosa of both. For the human +being the idea is current that infection or obstruction of the common +bile duct may spread to the pancreatic duct, and that mechanical or +inflammatory obstruction of the papilla of Vater may permit the bile to +pass up the pancreatic duct. This theory is based upon certain +observations, notably those of Opie, in cases, where a gall stone +obstructed the ampulla, bile entered the pancreas and acute pancreatitis +arose, partly by the activating action of the bile upon the pancreatic +juice and partly by bacteria introduced at the same time. This method of +origin is perhaps accepted in most quarters, but there are some who +believe that infection of the gland may occur by the infiltration of +lymphatics around the pancreas by disease of adjacent parts—gall- +bladder, stomach or lymph nodes. Quotation has already been given to +reference literature, and I shall not go further into theory except in +pointing out how our material may help to answer the question. + +In the first place it seems perfectly obvious that infection might in +any animal travel from the intestine to the pancreas _via_ its ducts, +the main question to be settled being the relative importance of the +infection _via_ the bile duct. Let us now see if the variations in +anatomy will cast any light upon the matter. + +Among the 1860 mammals, there are as far as I can determine 1275 which +have one pancreatic duct opening in conjunction with the bile duct, 585 +in which the former has an intestinal opening independent of the latter. +Among this 1275 there are nineteen cases of pancreatitis, while among +the 585 there are eight cases, or as 14.9 to 13.6. All Aves have +separate biliary and pancreatic ducts and relatively little +pancreatitis, although frequently suffering with its most common +accompaniment, namely duodenitis. There is therefore some evidence that +more pancreatitis occurs when there is a physical proximity or +combination of bile and pancreatic ducts. + +Active infections of the biliary system in relation to pancreatitis are, +however, not as conspicuous as might be expected. In the mammals twelve +of the twenty-seven cases showed cholecystitis or cholangitis; in every +instance the form of pancreatitis was acute. Among the eleven avian +cases four showed inflammation of the biliary channels, but not of the +bladder. Hepatic cirrhosis was observed four times. In a thrush and a +skunk obvious infectious cirrhosis existed, and in both a necrotizing +pancreatitis was found. A badger suffered with atrophic cirrhosis of the +liver and a chronic pancreatitis with acute exacerbation. A deer showed +marked perilobular fibrosis with a recent hemorrhagic pancreatitis +probably due to duodenal torsion. Nothing very distinctive is to be +found in these cases, but they merely make the total of involvements of +the liver and its adnexa up to twenty. It is to be emphasized that +pancreatitis was not associated with lithiasis in ducts or bladder as +described on page 240. Peripheral cholecystitis and plastic +inflammations about the pylorus and lesser omentum are exceedingly rare +in wild animals, while they are not common in human surgical practice. +They did not occur at all in mammals in this series, the only external +inflammations being in lymph nodes in cases of frank infectious +character. There were distinct adhesions between liver, duodenum and +pancreas in two birds, one with acute, the other with chronic +pancreatitis. + +In so far as the kind of pancreatitis is concerned mammals had twenty- +two acute and six chronic forms, one animal having the former implanted +on the latter, while birds had five acute and six chronic. The +preponderance of acute over chronic lesions in mammals again recalls the +association of the biliary and pancreatic ducts, but if one expect that +such a relation establishes acute inflammation, the relatively high +figures for Rodentia and Ungulata, with a single duct removed from the +bile duct conflict with the data for orders having two ducts such as the +Carnivora. Every case in the former orders was of acute nature; only two +had any hepatic disease, four had lymph gland hyperplasia in the +pancreatic region, and seven had acute enteritis. The preponderance of +acute over the chronic cases in mammals and the nearly equal number in +birds is, however, apparent. + +The collateral pathology with the most definite relationship to +pancreatitis is enteritis and one may say that the former occurs in +proportion to the incidence of the latter. Acute forms, twenty-seven, +were associated with acute enteritis nineteen times. Chronic enteritis +was found with chronic pancreatitis in six of eleven cases. + +There is a rough relationship between the type of pancreas and the +nature of the lesions. The organ may be divided for this purpose into +the compact organ firmly held in place by attachments to the lesser +omentum, spleen and duodenum, and the velamentous organ which spreads a +considerable distance along the duodenum and sends out digitations into +the mesentery and thin processes toward the spleen. The first type is +seen in primates and carnivores and birds, while the second is +characteristic of rodents, ungulates and marsupials. The compact variety +showed all but one of the chronic cases while the loose organ was +affected by the acute pancreatitis in twelve of thirteen cases. + +The microanatomy of the cases may throw a little light upon our subject. +I was able to see the duct in one case of acute pancreatitis (bear). It +showed a simple catarrhal inflammation with a very moderate +circumferential round cell increase. The destruction of glandular areas +by edema, hemorrhage and necrosis offers nothing of importance except in +a few birds. In these the necrosis is more definite about cross sections +of ducts, and the islands of Langerhans are frequently spared until +necrosis is locally complete. In a case of chronic pancreatitis in a +bird, a cross section of pancreatic duct was found in the intestinal +wall; a chronic catarrhal and infiltrative enteritis existed in this +specimen. A very definite mantle of round cells was found about the duct +while the mucosa showed no change, although the lumen seemed large. +Interlobular fibrosis was the rule, only one case of intra-acinar +pancreatitis being encountered; this specimen, a bird, showed great +distortion of the acini and of the islets. + +The study of comparative pathology of pancreatitis does not settle its +etiology, but some very suggestive facts may be learned. The association +of hepatic and biliary disease and of enteritis in the causation of +pancreatitis seems amply confirmed, and the latter factor is in our +series numerically the greater. It is suggestively shown that +inflammations of the pancreas occur more frequently in the zoological +class in which the ducts of the organ and of the liver empty into the +duodenum together or in close association. Moreover, infections of the +liver and adnexa are very important in the mammals, more so than birds +in which enteritis, notably chronic in type, usually accompanied the +involvement of the pancreas. This is consistent with the incidence of +bile tract disease as already discussed under that subject, and it is +interesting to note that the mammals showing the greatest number of +cases of choledochitis and cholangitis also show the high case incidence +of pancreatitis. The birds that have bile tract disease have little +pancreatic disease. These facts when considered in connection with the +free biliary supply of the avian duodenum, the disassociation of the +ducts of the two glands and the close apposition of the pancreas to the +duodenal wall, suggest strongly that direct infection of the pancreas +can occur from the intestinal wall along the walls of the ducts perhaps +via the lymphatics. This is supported by the observation of at least one +case in which there was a definite inflammation under the adventitia of +the pancreatic duct, its mucosa being normal. The study also suggests +that acute pancreatitis is more often associated with acute lesions in +the intestines and with hepatic or gall-bladder disease, and that +chronic pancreatitis seems more often the result of chronic or repeated +intestinal inflammation. Peripheral inflammation such as occurs in +gastric or duodenal ulcers, has not been encountered in a distinct +character so that its value cannot be estimated. + +[Illustration: + + FIG. 20.—ADENOMA OF PANCREATIC DUCTS. CORSAC FOX (CANIS CORSAC). +] + +Cystic change in the pancreas has been observed a few times, but never a +large visceral collection or the so-called extra-pancreatic cysts of the +omentum. One acinus cyst was seen in a drake, one congenital cyst in a +lark, and multiple ductal cysts were seen in a baboon and a duck. The +parenchyma in all cases seemed entirely capable of functionating. + + +TUMORS. + +Tumors of the pancreas have been three in number, two being of academic +interest only. One of these concerned an apparent adenoma of the ducts +within the organ, discovered microscopically in the sections from a +Corsac Fox (_Canis corsac_). This is the only specimen we have had, and +I can find no description of the normal microanatomy of this species, so +that with a knowledge that certain carnivores have convoluted ducts, the +determination is made tentatively; it corresponds microscopically to a +ductal adenoma. The pancreas of a raccoon (_Procyon lotor_) showed a +true adenoma of glandular acini as two separate but closely applied firm +nodules surrounded by a capsule, and with distorted acini as seen under +magnification. The most important tumor was found in an Indian +Paradoxure (_Paradoxurus niger_), an adenocarcinoma involving the head +of the organ, enlarging it to twice its normal size; there were no +metastases. The animal suffered also with an infective hepatic cirrhosis +of recent origin, chronic nephritis of the arteriosclerotic type, +chronic fibroid splenitis. No obstruction to the biliary channels +existed. + + + + + SECTION VII + THE ALIMENTARY TRACT, PART 4. + THE PERITONEUM + + +This visceral envelope is principally important because of the fatal +character of its acute inflammations. In man peritonitis of acute origin +and type is commonly secondary to a focus of progressive inflammation in +some abdominal organ and usually speaks for the virulence of the primary +disease and for the low resistance of the serous membrane. Because of +this vulnerability, greater foresight is attempted to prevent the +extension of acute intra-abdominal inflammations and under operative +conditions punctilious care is used to avoid contamination of the +general peritoneal cavity. Involvement of the peritoneum in septicemic +states is relatively uncommon in man, but seemingly more frequent in the +lower mammal. This surface seems more resistant to infection at +operation in the lower animals since post-operative peritonitis after +castration and experimental procedure is certainly infrequent; our data +will permit no percentage figures of vulnerability under such +conditions. Judging, however, from the number of times at which the +diagnosis of acute peritonitis has been made, the lower animal has a +decidedly low percentage resistance although its pathological states are +primary or secondary to conditions unusual in man. Among the 5365 +autopsies acute peritonitis appears in the diagnoses 137 times or 2.4 +per cent.; mammals, 57 or 3 per cent.; birds, 80 or 2.3 per cent. + +The exact causes are usually obvious, practically always so in human +medicine, but a number of cases escape adequate explanation. From a +practical standpoint two origins are important to zoological +collections, trauma and intestinal perforations by sharp objects. +Ungulata frequently suffer abdominal injuries in fighting, as do +rodents. Peritonitis sometimes supervenes even in the absence of +penetrating wounds, probably by reason of damage to the intestine +whereby its permeability is increased. Pointed objects are frequently +swallowed by animals and perforation occurs. The danger of feeding split +bone to carnivores is well known; some years ago we lost two tigers and +a lion in this manner. + +Ileus, in one of the several forms, has been an occasional cause of +peritonitis in primates and ungulates. The extension of purulent +inflammation, abscesses and the like is easy to understand, but we have +seen several cases of apparent extension from enteritis without +perforation. The reason for this is probably in the kind of enteritis. +Monkeys with amœbiasis and gallinaceous birds with enterohepatitis have +supplied most of the cases, these infestations of the gut wall being +deep and spreading so that a chance is afforded to penetrate the serosa +along blood and lymph vessels. One case in a deer seemed to originate +from a simple catarrhal colitis; trichocephalus in the colon may have +helped. Parasites are not very potent in causing an acute peritonitis, +but aggravate the action of other agents. Septicemic states are at the +bottom of 24 per cent. of our cases of peritonitis. This is particularly +true of birds, it being recognized that their acute general infections +frequently have such an effect, but the primates and carnivores also +have a vulnerable peritoneum when septicemia exists. The principal +outstanding visceral lesions in the mammalian cases is pneumonia; in +birds it is cholera and plague. The rupture of eggs in birds lays the +foundation of a peritonitis, while bacteria from the oviduct or cloaca +complete the process. Chronic peritonitis is not common. It is usually +due to parasites or to tuberculosis. There has been observed, however, +no complete general involvement of the peritoneal cavity including the +liver and spleen, sometimes called “sugar-icing,” and believed to be +tuberculous in origin. The only tumor found in very close association +with the peritoneum occurred in a Chapman’s Zebra (_Equus burchelli +chapmani_) in which animal a fibromyoma seemed to spring from a loop of +intestine and grow away from the gut wall. It was undergoing myxoid +change. + + + + + SECTION VIII + THE URINARY TRACT + + +THE KIDNEY. + +The kidneys, ureters, bladder and urethra remain comparable in all +mammals excepting the monotremes where there is no urinary passage +through genital openings, the urine being ejected through the vesicoanal +pouch, a sort of cloaca. In the bird the first two parts remain as in +mammals while the ureters terminate in a hernia-like pouch of the rear +wall of the cloaca. It would seem from this arrangement that ureteral +transmission of infection from the anal area to the kidneys would be +facilitated in the lowest mammals and in the Aves. Variations in size, +shape and position exist to a minor extent in the higher orders but in +all forms, the system remains a post-peritoneal structure. + +Differences in construction are to be seen for example, in the single +pyramidal kidneys of marsupials and certain rodents, in the lobulated +organ of bears, cattle and seals, in the twisted viscus of horses, but +these gross appearances do not destroy the uniform scheme upon which the +functionating unit is built. The single-lobed kidney discharges all its +collecting tubules into one calyx while the multiple pyramids of the +lobulated organ are fitted with individual calices which in turn empty +into the pelvis proper; this is true whether the lobulations are +retained, as in the bear, or are smoothed out in the course of +development as in man. The secretory tubule remains in essentially the +same form in all kidneys; the modern idea of its anatomy may be found in +the work of Huber[32]. + +The most decided example of the lobulated kidney is to be found in the +class Aves, wherein the organ consists of two or three large lobes lying +in concavities of the sacrum, each lobe being made up of tiny lobules. +The latter appear to the unaided eye as fairly distinct divisions +whether viewed on the exterior or by cross section. There is a cortex +and a medulla to each, the separation being clear in a large specimen, +vague in a small one. These lobulations are quite well observed when the +kidney is full of urates, a common finding in birds. Magnification of +the avian kidney reveals an apparently simpler tubular arrangement than +is found for mammals[33][34], yet the relation of vascular plexuses and +secreting tubules remains similar. + +From the standpoint of comparative pathology attention can be drawn to +the glomerulus, to the interstitial tissue, and to the character of the +epithelium. The tuft of intricately wound capillaries called the +glomerulus has always been viewed as the part of the secretory unit +chiefly concerned in urine production whether one accept the older idea +that it excretes only fluid or the modern belief of many observers that +all parts of the urine go out through it. In the mammal the tuft is +closely wound, is surrounded by a distinct space and a limiting membrane +of appreciable width called Bowman’s capsule; all this so-called +Malpighian body has a breadth varying from 120 to 300 micra. There is +however great variation in the size of this body when seen in the +peripheral and deeper zones of the same organ, amounting at times to +seventy per cent. of the diameter. The capillary congeries forming the +avian tuft is by no means so delicate and one can see individual +capillaries with more ease. It may be impossible to discover a space +between the tuft and its exceedingly delicate capsule, the latter being +usually applied closely to the vascular corpuscle. The whole breadth +varies from 70 to 140 micra with an average of 110. There is more +uniformity in size than in the mammalian organ. + +Supporting tissues between the tubules seem less definitely nuclear in +the bird than in the mammal, at least in so far as connective tissue is +concerned, there being in the former only a few groups of mononuclears +to be seen in the cortex. Perivascular tissues are reasonably rich. The +epithelium of proximal and distal tubules is not easily fixed by our +customary laboratory techniques, the best results being obtained by +Zenker’s fluid. As seen in a routine specimen of a normal organ it is +vacuolated or very palely stained. The individual cells stand out +clearly and many present a pointed end to the tubular lumen. + + +KIDNEY WEIGHTS. + +According to the work of Mangan[35] and of Alezais[36], the bird has an +average kidney-to-body weight of 6.9 grams per kilo while man has a +ratio of 4.3 grams, dog 5.9 grams and guinea-pig 8.5 grams. The first +author would show that the fish-eating birds have the heaviest and +vegetarian birds the lightest organ. Our own figures are limited to the +weights of apparently normal organs in thirty-one mammals and five +birds; they are as follows: + + │per kilo of body weight + Primates (5)│ 7.7 grams│ + Carnivora (6)│ 7.6 grams│ + Rodentia (2)│ 15. grams│ + Hyracoidea (1)│ 7.5 grams│ + Ungulata (9)│ 3.5 grams│ + Edentata (1)│ 5.6 grams│ + Marsupialia (7)│ 7.6 grams│ + Monotremata (1)│ 11.2 grams│ + │ │Average 7. + Steganopodes (1)│ 9.1 grams│ + Anseres (1)│ 3.9 grams│ + Struthiones (3)│ 7. grams│ + │ │Average 6.7 + ────────────────┴───────────┴─────────── + +This to be sure is not a very exhaustive list but is the result of our +routine observations and subject to all limitations of such work. +Grossly diseased organs are naturally excluded. More avian weights are +not available because of the difficulty of removing the organ from its +bed, in a manner assuring us of completeness. I am inclined to view our +mammalian records as fairly representative. Figures to be found in text- +books of human and veterinary anatomy correspond to those given by the +authors just quoted and in our own list. The values for rodents, +hyraces, edentates and monotremes may be modified by more figures. + +There is however one point which does not appear in the list. Small +animals have relatively larger kidneys than large animals. This is +perhaps most strikingly illustrated among the ungulates which have the +lowest value quoted. A small deer had a kidney-to-body index of 5.9 +grams per kilo while a camel had only 2.8. Judging by the work of Magnan +the avian kidney should be larger than the mammalian, a conclusion with +which I am inclined to coincide, even though the weights cited do not +bear this out. + +In so far as the function and chemistry of the kidney and its excretion +are concerned this study can supply little. The general metabolism is +known for most animals, it being dependent upon diet and +gastrointestinal discharge of excrement. What lessons can be learned +will be discussed by Dr. Corson-White in the section on diet. Our +observations upon the ability of the kidney to excrete normal urine are +limited to the examination of vesical contents at death or of the +occasional specimen obtained in cages in the quarantine room. Renal +disease was formerly considered of little or no importance in veterinary +medicine or at least was studied only as a specific separate and +occasional occurrence. Kitt[37] systematized the knowledge of the +subject at the time he wrote but it remained for Hutyra and Marek in +their text-book to emphasize its general importance and to clarify +diagnostic measures. Breindl[38] pointed out that nephritis occurs more +often in acute general diseases, notably the specific infections, than +was customarily thought, thus placing the subject for the lower animal +where it is in human medicine. + +Renal disease is quite common among wild animals albeit there are +certain orders in which the lesions are less conspicuous. Clinical +diagnoses of nephritis, and this is the only diagnosis attempted, have +been made on monkeys by examination of urine which shows the same +characters as in the human disease. In ungulates more attention is to be +placed upon the cellular contents of the urine since renal epithelium is +apparently shed more readily and casts less often formed. Signs and +symptoms of renal disease are limited to edema and uremia; cases of the +latter are rare enough to discuss separately at the proper place. + + +ABSENCE OF ABNORMALITIES. + +Abnormalities of size, shape and position of the kidney are frequently +reported in literature of veterinary medicine and aplasia has been +described. Our material has failed to present cases of horse-shoe kidney +well known to occur in horses, cows, sheep and dogs. Wandering kidneys +are also known but have not been seen in our wild animals. Shall these +abnormalities be considered as due to degenerative changes in cross bred +animals or as the result of the strain of domestication? To such a +speculative question our material affords no answer. + + +HYPERTROPHY. + +That the kidney has the power of hypertrophy in a compensatory manner is +illustrated by two cases. A Japanese Macaque (_Macacus fuscatus_) ♂ +apparently had suffered with a unilateral nephritis which had gone into +a contracted stage. At all events much functionating tissue was gone, +the organ irregular and small, being half or less of the size of the +other organ which was larger than is considered normal for the species. +Histologically the large organ was practically normal. A common opossum +(_Didelphys virginiana_) suffered with a complete suppurative nephritis +of the right side which completely destroyed the organ; the origin of +this is not clear as no ascending disease could be determined and no +certain acute infection had existed; decomposition precluded +satisfactory bacteriology. The left kidney was nearly twice its normal +size and involved in an early diffuse nephritis, with miliary abscesses, +in which the glomeruli did not participate. There were in these sections +evidences of regeneration, swollen reduplicated epithelial coverings +presenting a picture similar to those seen in so-called chronic +nephritis secondary to interstitial change. + + +INFILTRATIONS. + +Pathological infiltrations of the renal structures are exceedingly +uncommon. Early in our experience we were often perplexed at the +appearance of certain organs, notably in carnivores and marsupials to +which we were inclined to apply the term fat infiltration. However the +absence of reasons for considering this picture pathological seemed +sufficient cause to ignore the finding, and later Pfeiffer[39] called +attention to the apparent inability of these kidneys to emulsify fat or +at least to combine it in an invisible form, an ability possessed by the +herbivorous organ. A monkey and a passerine bird only showed sufficient +fat visible in the renal epithelium to warrant a denomination of fatty +infiltration; these were both obese specimens. Amyloid infiltration +occurred in four mammals and six birds, being a sequel of its usual +causes, tuberculosis, chronic suppuration and osseous system disease. It +is perhaps well to emphasize the fact that every organ the seat of +amyloid deposit need not be enlarged. This teaching is common but I have +seen human cases without enlargement and only two of the ten cases in +these animals are noted as bulkier than normal. + + +DEGENERATIONS. + +Degenerations represent the reaction of the kidney to toxic or +infectious agents and might be considered as indicating the +vulnerability of the organ. Their incidence does not coincide with that +of nephritis as we shall see later. Any discussion of degenerative +phenomena, and especially in the kidney, should be limited by a +definition of what they are believed to be and their separation from +inflammations. Degenerations are swellings, granularities, +vacuolizations or infiltrations of tubular epithelium, changes which +destroy the outline and internal structure, perhaps including the +nucleus. No changes of the glomerular tuft or interstitial tissue are +necessary for this conception since when these occur the picture becomes +that of nephritis. In border-line cases it is safer to include the case +under the latter heading since then the physiology is apt to be +disturbed, albumen and casts appearing in the urine. Degenerations +appear in various pathological states—toxemia, infection, prolonged +congestion and others. The first named cause seems to be the most +important in our records and the seat of the toxine production seems to +be the intestine. Enteritis stands very high in the list of accompanying +factors, especially in Carnivora, Primates and in Aves. Perhaps the most +instructive cases are to be found in the Ungulata with toxic duodenitis. +The kidney in these animals is deep red or purple, with a spanned +capsule. The section surface bulges slightly, is of an opaque, dull +purple color and shows a congested zone between cortex and medulla. +Tubular epithelium may be found, under the microscope, sufficiently +swollen to fill the lumina, in places being like ground glass, in others +distinctly vacuolated. It cannot be stated absolutely which part of the +tubule is usually affected; it seems more often the distal convoluted +portions than other subdivisions. Glomeruli may be full of blood but +there is no increase in cells nor any material in the capsular space. +The urine is dark and may or may not show albumen. The kidney of +kangaroos with streptothricosis is similar to the picture just given. + +Mammals have shown a percentage incidence of renal degenerations of 4.8 +per cent. while Aves show only 3. per cent. In order of incidence the +carnivores head the list followed by Lemures, Accipitres, Rodentia, +Primates and Marsupialia; the remaining groups show but a few cases. A +form of degeneration is sometimes seen in the avian kidney the seat of +excess urate collections, especially when these are arranged as so- +called uratic infarcts. This last term has been applied to the streaking +and mottling of human kidneys by the accumulations of these salts in a +manner believed by some to be related to the formation of uratic +calculi. The epithelium of such a kidney may show granularity and +collections of acids and salts have been found in the lumina. In the +bird on the other hand one frequently sees masses of urates in one +lobule, or a part thereof, arranged to simulate closely the common +infarct shape. Secretory cells in the affected area are hydropic, with +absent or dislocated nucleus, or again they present a densely basic +staining protoplasm. This form of kidney is well seen in what has been +called here an uratic serositis, a coating of all somatic free membranes +with a thin, white, granular film. We have tried with many techniques to +preserve one of these cases but the deposit either dissolves or the +whole specimen becomes opaque. Although the term infarct is applied to +these lesions, they are of course not infarcts in the customary use of +the term. True infarcts are exceedingly uncommon and, with the exception +of one case which became infected and suppurated, have been negligible +in our material. + + +HEMORRHAGES. + +Hemorrhages into the kidney are found in acute infections and certain +diseases like leucemia; they are of little moment. Perirenal hemorrhage +is a somewhat striking and unusual affair. Recently I saw at a human +autopsy of a young subject a subcapsular hemorrhage from the renal +substance probably due to vascular rupture in an acute nephritis; there +was no history of injury. There have been three cases of subcapsular +hemorrhage in our records and as two of them represented the immediate +cause of death, are interesting enough to record. An armadillo suffered +an acute diffuse nephritis with much congestion but not enough to call +it hemorrhagic. There was a large hemorrhage around the left organ, +probably from a vessel near the hilum, sufficient to compress the kidney +and cause it to atrophy. A lion presented an acute vegetative +endocarditis with all its usual complications. The right renal capsule +was distended with recent clot to a size which reached to the pelvic +brim. Presumably an embolism caused thrombosis, ulceration and rupture +of some middle size vessel. A dormouse suffering with an acute general +infection probably emanating from the intestine, had several small +recent clots separating the kidney from its capsule. + + +NEPHRITIS. + +Nephritis, whether one begin its conception with the clinicopathological +picture originally given by Bright, with the purely pathological +classification of Weigert and Virchow or the modern tendency to +subordinate all physical changes to clinical phenomena, is nevertheless +a process of degeneration and inflammation affecting the secreting and +supporting structures of the kidney and leading to some degree of +impaired function. The disease is bilateral in so nearly every case that +for practical purposes unilateral cases may be ignored. This implies +that for some reason the renal tissues are generally susceptible to +etiological agents so that when one side is affected its fellow seems +always to participate or to follow. It seems desirable in studying +nephritis to evaluate fully the mutual relations of functionating and +supporting tissues and of the various sections of the first named. It is +taught in many places that inflammations of one or another of these +parts may occur independently, as for example a tubular nephritis, a +glomerulonephritis and an interstitial nephritis. If however one reflect +upon the dependence of the tubular function upon the glomerulus and +_vice versa_ or upon the effect of inflammatory exudates in the +supporting tissues upon the blood supply of the tubule, it becomes +evident that only the most trivial or evanescent pathological changes in +one can be without effect upon the others. It is difficult to see how, +for examples, a glomerulus could remain normal if its associated tubule +were destroyed or how if round cell infiltration or pus surround a +capsule for any length of time, this structure could fail to be doomed. +All this is by way of directing attention to the progress of physical +damage in a kidney which has received injury sufficient to cause +nephritis, but of course it does not explain the cause. + +In classification of nephritis different commentators have employed +different standards according as they viewed the acuteness or chronicity +of the process, or as the principal functionating structures, +glomerulus, tubular epithelium, blood vessels, or supporting connective +tissues, presented the most conspicuous changes. To these, clinicians +have added phenomena of constitutional complication or of direct renal +insufficiency. These latter being unavailable for us, we must fall back +upon a classification based upon physical changes and to this end we +have always used a slight modification of the Weigert method. This +classification offers little in the direction of etiology except that +toxins are believed to cause tubular changes, bacteria to produce +glomerular lesions and vascular deficiencies to lie at the root of +chronic interstitial nephritis. + +The origin of acute nephritis of chiefly degenerative character seems +best explained by reference to some form of toxemia, whereas exudative +processes, be they in glomerulus or supporting structures, seem to +depend upon the direct action of bacteria. The origin of a chronic +nephritis cannot be explained quite so readily. No one has answered with +complete satisfaction whether a chronic process always begins with and +proceeds from a single attack of acute disease, whether many acute +attacks succeed upon one another or whether many small crops of agents +successively attack the organ over a long time. Nor has an adequate +explanation of the rôle of damaged blood vessels been given. It is +reasonably easy in man to discover the existence of nephritis and of a +possible cause; this is only true of acute cases in wild animals. Focal +infections, those which might be the point of mobilization for bacteria +sent to the kidneys, are frequently found in man but with exception of +an occasional carious tooth, or a chronic osteitis are to be localized +with difficulty in lower animals. In so far as the rôle of a single +acute attack in the causation of chronic disease is concerned our +material offers nothing, but some collateral or presumptive evidence may +be mustered in regard to multiple infections. + +Wild animals do not give evidence of repeated attacks of acute disease +and indeed it would seem that they more often die of an acute infection +than live to have it repeated. Evidences of chronic infection, not +focal, are reasonably definite in forty-eight per cent. of the cases of +chronic nephritis encountered here. This suggests strongly that in this +material protracted infectious states offer opportunities for renal +damage of progressive character. Vascular disease has been found twenty- +eight times (see also section on arteries), in twenty-six of which the +nephritis seemed due to or advanced by the damage to the vessels. This +means further that only 14.3 per cent. of the chronic forms and 4 per +cent. of the total seem closely related to disease of blood vessels. + +Nephritis has been found in 12.2 per cent. of our total autopsies. +Mammals show an incidence of 20.6 per cent., birds 7.7 per cent. Only +the orders upon which more than one hundred autopsies have been held are +subjected to separate analysis. Some of the remaining orders give very +high figures which may indicate great renal vulnerability but it is +deemed unfair to make statements upon them. Carnivorous mammals and +birds lead their respective classes, the succeeding order of renal +vulnerability being marsupials, ungulates, rodents, Primates, Galli, +Striges, anserine birds, parrots, and doves. The leaders of this list, +Carnivora and Accipitres, occupy a definite position in the analysis of +acute and chronic lesions. Their kidneys show the smallest percentages +of acute lesions and the highest percentages of chronic lesions. This +would seem to indicate a resistance to acute injuries but susceptibility +to prolongated or repeated infections or intoxications. The relation of +chronic infection of some sort to chronic renal disease is not as clear +as the influence of acute infection to acute nephritis. Taking Carnivora +for example with 34.2 per cent. of chronic nephritis we find 22.4 per +cent. with evident chronic inflammation while in the 55 per cent. of +acute forms 40 per cent. are of acute infectious origin—the relation is +as 64 is to 74. + +While the relation of infection to nephritis is a consistent and +perfectly acceptable one, the frequency of this disease in the +carnivorous orders obliges one to think of high protein diet as a +favoring factor. Renal disease is common enough in other orders, some +strictly herbivorous, and it is fair only to emphasize which are the +leaders in incidence. In so far as anatomy or habits are concerned no +generalizations seem permissible. There is no relation of nephritis to +the size of the kidney as given on a previous page, to the length of the +alimentary tract, or to the expected longevity. + +Toxic nephritis is a term applied when the kidney is the seat of +epithelial degeneration, much congestion, perhaps leading to tiny +hemorrhages, and definite swelling of the tuft without exudation into +the capsular space. It is a severe grade of the degenerations already +mentioned and is exemplified by the organ in cases of acute duodenitis +of ungulates and in some monkeys dying after tuberculin injection. It +seems especially to follow gastrointestinal diseases believed to be due +to food intoxications. It seems important in monkeys and wild rodents. +No adequate explanation is at hand for the latter. + +As has already been stated vascular disease was present in twenty-six +cases in a manner suggesting some relation to the cardiorenal complex +but the only organ to which the term renal sclerosis of arteriosclerotic +origin could be applied is that of an eagle; the autopsy is cited. + + + Bald Eagle (_Haliæetus leucocephalus_). ♀ General obliterating + endoarteritis. Chronic interstitial nephritis. Passive congestion of + liver. Chronic localized myocarditis. Near the apex of the heart the + muscle shows a slight opacity. The kidney is enlarged, firm, section + surface glistening. Both section and surface show a mottled brown and + white appearance, following particularly on section the division into + cortices and medullæ. Digestive system apparently normal. Microscopic + section of heart muscle from the wall of the ventricle shows well + preserved muscle fibres with a slightly unusual degree of + pigmentation. Section from valve base shows a definite interfascicular + and intrafascicular fibrosis which is co-extensive with a similar + thickening of the endo- and pericardium. The new tissue under the + latter is edematous. The valve itself is thickened the fibres swollen + and hyaline. There is no reduplication of the endothelium. One artery + in the muscle is obliterated. This is not associated with any + degeneration of the muscle in the section. Section of kidney shows the + pale areas noted grossly to be made up of groups of arteries with + their extensive coalescing adventitiæ. The changes in the arteries are + precisely the same as those seen in the liver but are more extensive. + Connective tissue goes out from the arteries into the parenchyma + distorting the tubules and enclosing the glomeruli so that the capsule + of the latter is much thickened. Epithelium is granular, in some + places absent, nearly always low. Section of liver shows general + parenchyma practically normal with slight granularity in places and + moderate passive congestion. Veins are negative but arteries show a + general arteritis. The picture varies somewhat in different arteries + ranging from a simple thickening of the adventitia to a change + involving all three layers. There is hyaline change in the media in + many sections. Lumen is in all cases reduced and in some there is + active intimal proliferation in excess of what would be expected in + connection with the medial change. A few of the arteries have their + lumen completely obliterated. + + +This is meant to illustrate the picture of vascular disease in the +kidney in the absence of satisfactory evidence that nephritis _per se_ +antedated or accompanied changes in the vessels. In such cases vascular +disease dominates, renal parenchymatous damage being relatively +inconspicuous. Two old carnivores, a paradoxure and a skunk, presented +shrunken kidneys with prominent wide-walled vessels but in these some +definite evidence of old nephritis was at hand. + +In so far as the relation of senility to nephritis is concerned the data +at hand are not conclusive. In many old animals some degree of fibrosis +is present without the existence of truly destructive changes in the +parenchyma. Plimmer of London writes that there is increased nephritis +in old age but from our material I would be inclined to put in that in +many cases the nephritis was the reason for old age rather than that old +age brought on a nephritis. However the exact length of life and of +captivity is known in too few specimens to make a conclusion justified. + + +ASCENDING NEPHRITIS. + +There is some difference of opinion as to the definition of the term +ascending nephritis, a confusion arising partly from the intended +meaning of the participial adjective, partly from the frequency with +which infections or obstructions of the urinary outlets antedate or +accompany suppurative nephritis. Perhaps our records may help to +straighten out this matter. + +Ascending nephritis means for our study an infection which passes from +the pelvic surfaces of the pyramids outward toward the renal capsule. +Thus it is immaterial whether there be or be not an obstruction lower +down. Such forms of nephritis are infiltrative, frequently purulent and +are dependent upon pyelitis or the settling of bacteria in the deepest +parts of the medulla. + +Three explanations are given in human medicine for the origin of this +lesion. Some observers assume a direct transmission of bacteria up the +ureter from an infected bladder or urethra, in a direction contrary to +the urinary current. This, it is believed by some can occur only in the +presence of physical obstruction, stone, kink, or pressure of adjacent +masses upon the ureter, whereby its blood supply is damaged and +infection facilitated. Others would explain the path of infection as the +lymphatics of the ureteral wall which are infected at the opening in the +bladder by a deep seated cystitis or by infection from a periproctitis +or from the female genitalia. Still another explanation is offered by +those who do not credit ascending infections. They would have it that +pyelitis arises from bacteria in the blood stream and only in the +presence of injury (_calculus_), ureteral dilation (slowly progressive +stenosis, or kinks, floating kidney, pressure by pregnant uterus) and +similarly operative factors. There should be excluded from this category +cases of chronic nephrolithiasis, and of stone only in the pelvis. Under +such conditions it is inevitable that a low grade of fibrosis with +damage to the secretory structures should exist, even in the absence of +active bacterial invasion. The cases are only important for our present +subject when active bacterial infection is implanted upon them. + +Among our autopsies there have been found fourteen cases of ascending +nephritis and seven cases of pyelitis; the most instructive examples are +mentioned briefly as follows: Five of this twenty-one were associated +with general infectious diseases (three septicemias) and presented no +evidence of ascending obstruction. Two of this five were a bear and a +fox, the former suffering with streptothricosis septicemia, the latter +with distemper; one was a fox whose pelvic and renal lesion seemed +entirely primary for no apparent focus was detected; two were birds with +acute general infection. These cases seem therefore to be instances of +primary pyelitis. The following group includes cases with inflammation +low in the urinary tract. A fox had a cystitis, urethritis and colitis, +a distinct edema and congestion being found in the pelvis around the +rectum. Two opossums had cystitis, one due to a traumatic urethritis, +the other secondary to a prostatitis of undetermined causation. A +raccoon had a chronic cystitis with swelling and edema of the first +parts of ureter. A parrakeet showed ureteritis, pyelitis and nephritis +from simple cloacitis. + +Where obstruction was more definite the following cases were observed. +Suppurative nephritis succeeded upon gangrenous cystitis after uterine +prolapse in a deer. The following cases of pyelitis and nephritis were +associated with calculus, only in the renal pelvis—an armadillo, +Tasmanian devil, a deer and a goose. A cockatoo had a stone in the +cloaca which seemed to cause a definite obstruction to both ureters and +a catarrhal inflammation of the wall. Pyelitis and interstitial +nephritis can also follow excessive urate collections in birds. At a +later time this will be discussed more fully, but at this place two +cases of distinct abscess formation in a renal lobule based upon urate +collections may be mentioned since in a measure the lesions were +dependent upon obstruction. + +It is therefore evident that all the theories of the causation of +pyelitis with resultant nephritis seem acceptable. It has been claimed +that bacteria may be found in the blood stream before evidences of +pyelitis present themselves. Concerning this our records offer no +information, but it is worthy of note that five of twenty-one instances +gave a picture of septicemia. It is, however, fair to state that, while +mild cases of pyelitis occurred where there was, judging from the +protocol and histological sections, obvious opportunity for its ascent, +in ten other cases of cystitis and urethritis no pelvic or renal disease +is recorded; two of these were acute exudative cystitis and one was a +tumor. It seems that wild animals seldom live long enough to have +obstructions exert back pressure of urine to the extent which one is +accustomed to see in human medicine. Hydroureter and hydronephrosis have +not been seen. + +Abscess of the kidney has occurred occasionally in the metastatic form +and only twice as the large destructive process such as is seen in the +human being (surgical kidney). One massive abscess was seen involving +about one-third of the organ, and this seems to have had a tuberculous +basis. Another destructive purulent nephritis was quoted on page 268 +when illustrating compensatory hypertrophy. + +Examination of records and preserved specimens of nephritis reveals few +striking differences which might be considered characteristic for the +various orders. This is possibly due to the fact that the lesions have +been classified under the same system, a method which has proven +convenient and consistent. In support of this one might refer to that +form of nephritis which gives the most definite clinical and +pathological picture of renal disease, namely the chronic +parenchymatous. This is fairly well represented in Primates, Carnivora +and Ungulata. In one-fourth of the cases one finds distinct edema, +especially in the body cavities, cervical and mediastinal tissues, and +in one-fifth an appreciable grade of anemia; uremia was the terminal +picture in one animal of each order. + + +HISTOLOGY OF NEPHRITIS. + +An attempt to discover minute lesions peculiar to the various groups +gives results that are far from satisfactory. With reserve it may be +said that carnivorous animals show a tendency to greater interstitial +and glomerular lesions than do herbivorous ones, and that casts are more +often found, in all kinds of nephritis, in the former varieties. Rodents +are conspicuous exceptions to this statement, since they frequently have +glomerular lesions and casts in abundance; this exception exemplifies +the unwisdom of drawing definite conclusions in this respect. + +Birds as contrasted with mammals show very prominent tubular and +inconspicuous glomerular lesions. The principal alterations seen in the +avian kidney are round cell infiltrations of the deep cortical and outer +medullary zones, and cloudy or hydropic swelling of the convoluted +tubules. In chronic cases intertubular fibrosis is clear but not so +definite as the perivascular, while the glomerular tufts are +occasionally wholly normal. When these are destroyed it seems to have +occurred by compression rather than by inflammation. A form of nephritis +peculiar to birds might be termed local necrotizing. It seems to be due +to local urate deposits and to have its origin like that form already +mentioned under acute interstitial nephritis. It has been seen in avian +gout, a condition in which the kidneys may or may not have visible +masses of hardened urates in them. The gross picture is of a spotty pale +organ of a gray-brown color. Minutely studied the medulla, adjacent +cortical tubules and perhaps the pelvic tissues will present an opaque +condition taking a diffuse basic dye. Crystals have not been seen. This +form is especially common in Columbæ, Psittaci and Herodiones. + + +GENERAL EFFECTS OF NEPHRITIS. + +The results of nephritis generally speaking are edema, anemia, cardiac +hypertrophy, inflammations of the serous surfaces and uremia. Aside from +the cases of chronic parenchymatous nephritis cited above, edema has +been decidedly inconspicuous. It may be found in avian cases of acute +and subacute nephritis, about the flanks and in the thoracic areolar +tissues, but is only exceptionally perceptible before the body is +opened. Anemia is almost never extreme. The bone marrow although +mentioned in but few histories, seems unchanged. Cardiac hypertrophy was +observed ten times in 652 cases of nephritis, twice in 460 acute and +subacute cases, eight in 192 chronic cases. In the former no myocarditis +was found, in six of the latter it was found. Clinical and pathological +experience teaches that serous surfaces are frequently inflamed during a +nephritis. Observations on our material coincide with this statement, +but do not offer an explanation of it. The figures should be examined +for mammals and for birds separately, since the serous cavities of the +former are closed, separated, and protected, whereas a close apposition +exists between the serous membranes and the lungs in birds, an +arrangement facilitating infection from without. Nevertheless the bird +has definitely less serositis accompanying nephritis than does the +mammal—4.4 per cent., _versus_ 8.6 per cent. In the former class 70 per +cent. of these accompany acute nephritis associated with acute general +disease while only 45 per cent. of the 8.6 per cent. of mammals had +serositis, acute nephritis and general infection. This indicates clearly +that mammalian renal disease has some effect upon serous membranes other +than the simple participating coincidence of the two types of changes +during an acute general infectious disease. No one kind of nephritis was +especially characterized by this complication. + +Uremia, except under the best clinical conditions, is a term to use with +caution. I have seen several monkeys, a few marsupials and carnivores +and an occasional bird in a dazed ataxic condition, sometimes exhibiting +an atypical clonic or tonic convulsion, with fixed, rather small pupils. +To this picture I have applied the name uremia, and upon several +occasions have found a severe grade of nephritis. I must admit having +failed to find renal change, however, with this clinical picture, +especially in the carnivores and parrots, animals which “throw fits” at +times without apparent good reason. In so far as the monkey is +concerned, I am satisfied that the picture is similar to that seen in +the human being. The London Garden reports in 1917 the occurrence of +uremia in a Mandrill (_Papio maimon_). + + +CALCULI. + +Calculi are well known in the renal system of the domesticated animals +so that it is not surprising to find them well represented all through +the lower orders. Their structure, composition and effects do not +differ, however, and it remains only to point out their distribution. +One of the frequent results of renal and pelvic lithiasis is, however, +missing in our records, namely hydronephrosis, and indeed a pressure +dilatation of the ureter and pelvis has not been observed in all our +experience. This would seem to be explained first upon the infrequency +of stone, of obstructive new growths and inflammatory strictures and +second by the fact that lower animals do not long survive conditions +which would occasion back pressure upon the kidneys. + +Definite renal and pelvic calculi have occurred in five Ungulata, one +each in Edentata and Steganopodes. To these might be added cases of +uratic sand in one Carnivora, one Marsupialia, and uratic stones of +large size in the cloaca of two Passeres and one Accipitres. Uratic +collections within the avian kidney have been mentioned and will be +discussed later. + +According to written descriptions and three preserved examples the +calculi in four of the ungulates are mixed urates and carbonates, +although one in a deer was said to be “mulberry” in surface. The +specimens at hand are moderately hard with rough irregularly +crystallized outer shells like carbonate deposits. Incomplete moulding +to the calyx is found. The pelvic cavity while seeming to be enlarged is +not distended nor do the stones assume the “antler” character and +distort the pyramid. All the animals showing these stones have but a +single pyramid in the kidney. The fifth example in the ungulate had +early stones forming in the apex of the pyramid and not yet discharged +into the pelvis. Four of these cases showed stones on both sides, one +only in the left kidney. + +The case among the Edentata concerned an Armadillo (_Tatu +novemcinctus_), in the kidney of which there were definite smooth, +round, hard pebbles in the right pyramid and several fine grains in the +pelvis. There was a recent hemorrhage in the pelvis which, from local +appearances and autopsy survey, was due to the lithiasis. + +A Gannet (_Sula bassana_) represents the only avian true calculus. In +this case many small, hard, yellow stones occupied the right pelves, +which contained also loose urates. The lobules were much distorted and +showed a mild interstitial change. This accumulation was confined to the +left side. These well developed cases having been mentioned the next +most important may be quoted: + + + Tasmanian Devil (_Sarcophilus ursinus_). Inactive and rather on the + decline for several months. Chronic diffuse nephritis with acute + interstitial exacerbation. Calculi in kidney pelvis. The kidney size + is normal, shape irregular, capsule smooth, strips easily leaving a + rough mottled green-brown surface. Consistency is soft, tough, + resilient. Cortex slightly wide, medulla normal. On removal of capsule + the surface is found very irregular and elevations from the surface + are pale red gray-green color. These elevations do not correspond with + any change in cortex on section. Section is smooth, solid, markings + not clear but glomeruli are distincter than striæ. Line between cortex + and medulla obscure. The left kidney contains sand-like calculi, + possibly uratic, as there are some pale areas near point of pyramid + which are firmer than rest of tissue and rather gritty. Microscopic + section of kidney shows the architecture much disturbed by connective + tissue overgrowth in outer layers of medulla and inner layers of + cortex and following the medullary rays to the capsule. Tubules are + compressed and distorted in the vicinity mentioned. Epithelium is + elsewhere low, opaque and granular. The connective tissue about the + glomeruli is thickened and hyaline as it is in most other places. + Tufts are not yet compressed. Following medullary rays there is a + recent round and polynuclear infiltrate both around and in tubules. + + +A Golden Cat (_Felis temminicki_) presented sand in the urethra, which +had caused a traumatic urethritis and distention of the bladder. There +was no evidence of renal urate collections, but a low grade prostatitis +existed so that the bladder might have been distended before the urethra +became inflamed, thereby giving opportunity for sand to form or to have +arisen in the prostatic ducts. + +Three birds, a Bunting (_Passerina ciris_), a Bulbul (_Chloropsis +aurifrons_), and a Buzzard (_Buteo albicaudatus_), had large cloacal +urate calculi which could obstruct the ureter but had failed to do so; +one had an acute ascending pyelonephritis, however. + +Excessive urate collections in ureters and kidneys occur all through the +avian orders and in about the same percentages; meat and fish-eating +birds have practically no cases, however. The condition seems at times +the only finding at autopsy, or it may be associated with uratic +serositis. Gout of birds is commonly accompanied by it, but need not be +since two of the best examples of this disease had practically normal +kidneys. + +From these records it would seem that renal and pelvic calculi occur +almost exclusively in herbivorous animals. At least true stones forming +in the renal pyramid and pelvis are found most characteristically +developed in the Ungulata, the typically herbivorous mammal. Judging by +the bilateral distribution of stones and uratic collections, local +processes, inflammation especially, have less to do with their +production than the availability of precipitable inorganic salts in the +urine. + + +TUMORS. + +Tumors of the kidney have been observed sixteen times, fourteen of which +were primary and two secondary. The latter two concerned an +epitheliomatous metastasis from a malignant papilloma in the stomach of +a Kangaroo (_Macropus rufus_) and a sarcoma growing like an infarct +secondary to a mediastinal tumor in a Dorcas Goat (_Capra hircus_). The +only important primary tumor of the kidney in a mammal was found in a +Gray Squirrel (_Sciurus carolinensis pennsylvanicus_), a solid gray +nodule composed histologically of large and small deeply staining cells, +many containing large vacuoles and fitted with a small dark nucleus. The +arrangement of the elements was in irregular acini or bundles and +thereby suggested the tumor known as hypernephroma. A small nodular +adenoma was found at the upper end of the right kidney in a common +opossum (_Didelphys virginiana_) and seemed to be purely of renal +construction in that an attempt to retain tubular arrangement was +evident. + +[Illustration: + + FIG. 21.—CALCULI FROM RENAL PELVIS TO END OF URETHRA. COMMON RACCOON + (PROCYON LOTOR). THESE STONES WERE PALE YELLOW-GRAY. THEY CONSISTED + OF A URATIC BASE, BUT SOME PHOSPHATES AND CARBONATES WERE FOUND. THE + RIGHT KIDNEY WAS NOT AFFECTED. THERE WAS ONE IRREGULAR CALCULUS AND + THIRTY-SEVEN SMOOTH MASSES FROM BLADDER TO END OF PENIS. THIS CASE + IS NOT INCLUDED IN STATISTICS. OCCURRING AFTER THEIR COLLECTION HAD + CEASED. +] + +Twelve primary tumors occurred in birds, and of these five were found +among parrakeets, they being curiously enough all of the same type. +These cases were all discovered in the undulated grass variety +(_Melopsittacus undulatus_ ♂ ♂ ♂ ♂ ♂ ) and, because of this fact and +their histological similarity, have excited interest. Grossly they are +irregularly nodular or lobulated tumors usually springing distinctly +from one lobe, but sometimes destroying the whole organ; they are soft, +resilient and hold their place well during manipulation. Sometimes one +may detect the topography of the renal lobes on cross section while at +other times the mass is homogeneous. Microscopically one finds the +structure of papillary adenoma with cystic formations or the production +of atypical solid nests of epithelia which would have to be called +cancerous, for they certainly make no attempts to retain acinus or duct +groupings. Carcinomatous areas have been discovered in two of these +cases, not in the other three, which have been called papillary adenoma. +One of the tumors was subjected to many sectionings and different +stainings techniques to discover, if possible, animal and vegetable +parasites; this search failed. One of these tumors produced hemorrhage +by rupture of a pyramid but extension to adjacent tissue and metastases +have not been seen. Pathologically these must be classified with the +tumors but because of the number of closely similar growths in the same +avian species housed in the same enclosure, the possibility of a +parasitic cause will not be forgotten. + +The remaining seven renal neoplasms are made up of two adenomata in a +Jungle Babbler, (_Crateropus canorus_) and a red headed duck (_Fulligula +ferina americana_), two adenocarcinomata in a saffron finch ♀ (_Sycalis +flaveola_), and a chestnut-eared finch, ♂ (_Amadina castanotis_), two +hypernephromata in an American robin, ♀ (_Planesticus migratorius_) and +a European blackbird, ♀ (_Merula merula_), and a spindle celled sarcoma +on a scaly ground dove ♀ (_Scardapella squamosa_). One adenocarcinoma +sent out metastases to the lung, one hypernephroma had secondary growths +in the lungs, the other in the liver. The sarcoma case presented a +metastasis in the tibia. + +Diseases of the lower parts of the urinary tract are not numerous and of +incidental interest only; many are associated with or due to lesions in +the genital organs, and will be referred to later. Cystitis is uncommon, +only being observed some four times unrelated to prostatitis and +vesiculitis. Two of these cases were secondary to a traumatic +urethritis. No stones have been seen. A mixed cell sarcoma was found +springing from the bladder wall in a Richardson’s Kangaroo Rat +(_Perodipus richardsoni_). The written record has unfortunately been +lost, but the preserved slide confirms the original diagnosis. Rupture +of the bladder occurred in a Gray Fox with stenosis of the end of the +penile urethra causing retention and secondary cystitis. Another +stricture of the urethra in an Ocelot (_Felis chibigonazon_) caused +great dilatation of the bladder. This animal is thought to have chewed +off all the external genitalia because of lice, with the result that the +stump of the urethra became involved in a contracting cicatrix. +Opossums, raccoons and wild dogs have shown light cases of urethritis +seemingly traumatic in origin, and two dogs had cystitis and urethritis +associated with what was believed to be distemper. + + + + + SECTION IX + THE FEMALE REPRODUCTIVE ORGANS + + +The mechanism and organs of reproduction differ so widely in the classes +under discussion that it will be necessary to describe separately the +alterations in mammals and in birds. Examples of abnormality and disease +are not very numerous and I shall cite cases for many of the conditions +rather than prepare comparative lists as has been possible in many +foregoing sections. Some years ago Dr. Edward A. Schumann[40] studied +the comparative anatomy and physiology of the mammalian female +generative organs, and I shall condense and paraphrase his work. (The +complete articles may be found as in the references below.) This +gentleman, because of his gynecological experience and broad interest in +comparative biology, has been consulted whenever unusual material from +this tract has presented itself so that many of the descriptions that I +shall employ are due to him. I take this opportunity to acknowledge with +thanks his interest and helpfulness. + + +COMPARATIVE ANATOMY IN EXPLANATION OF HUMAN UTERINE ANOMALIES. + +The development of the genital tract seems to be essentially the same +through all orders in that the genital ridge forms the ovary and its +attachments while the Mullerian ducts supply the tubes, uterus and +vagina. Early in fetal life these two longitudinal ducts begin to +approach one another, and by the end of the third month should be in the +position which they are to retain for the full development of their end +result. In the human being this position is complete union and fusion, +with the production of a single tube from the uterine fundus to the +exterior, while in the lowest mammals, edentates and marsupials, the two +Mullerian ducts retain their lateral position, and upon completion of +embryonal life a double tube from the ovaries to the exterior is found. +If the normal fusion of the ducts does not take place, and if for any +reason their proper relation is not reached, an abnormality will result +varying according to the stage of development that has been reached. +Thus in man instead of a single uterus of triangular shape and a single +cervix, a double set of tubes may be found. It can be shown that the +abnormalities of the human uterus are of definite and fixed types +corresponding to an arrest of fusion or completion of the developmental +cycle as given for the Mullerian ducts and further that these very +deformities are comparable to normal organs of lower orders. In other +words abnormalities in arrest of development in the human uterus +represent normal types of lower uteri at various evolutionary stages. In +monotremes there are two ovaries, tubes, uteri, cervices, a urogenital +passage and a clitoris. This corresponds with Uterus didelphys with a +single vagina. This abnormality while occurring in the lowest mammal, +does not represent the most marked deformity known for the human being— +that in which the double tube remains to the vaginal outlet, a condition +found in the marsupials. In this order the uteri are entirely separate, +and each is fitted with its own vagina. The next higher order, Edentata, +seems somewhat out of place if it be judged by its female genitalia +since it is possessed of a triangular uterus and single vagina but +without distinct cervical segment; the tract is very similar to that of +the Primates. + +Rodents, in the various families, present no uniform uterine +construction, there being four kinds corresponding to as many degrees of +Mullerian duct fusion and differentiation. The lowest forms simulate the +marsupials, another group is like the monotremes, a third shows a +complete fusion with a single cordiform uterine body, while the last +resembles somewhat the first, but the uterine divisions are bound +together and the vagina is divided only half way down. The Insectivora +occupy a transitional position resembling higher and lower groups in +having a long uterovaginal canal, without distinct cervix, extending +upward into long curved cornua. Cetacea (whales) have a highly rugous +single vagina, a distinct, short uterine segment divided into two +separate horns. The genitalia of Sirenia resemble those of the last +group, but the cervix is better developed. In the last three orders the +clitoris begins to be well developed and to present externally. +Proboscidea have a single vagina separated from the short uterine body +by three transverse folds corresponding to the cervix; the two cornua +are long and wide. + +“The foregoing orders present in their uteri all the essential +characteristics of uterus bicornis unicollis with single vagina and are +therefore the homologues of this anomaly in man.” + +In the Perissodactyla, the bicornate uterus has a body of a little less +than half the whole length; there is a sphincter at the lower end of the +body but no projecting cervix. The cornua are longer still in the +Artiodactyla and are coiled in a manner suggesting spiral sheep’s horns; +there is a differentiated projecting cervix. In cats the length of the +uterine body and of the cornua are almost equal and both are flat tubes; +the cervix is prominent and the vagina long and rather smooth. The dog’s +uterus is similar but the two cornua are bound together or fused before +the point at which their termini enter that of the uterine body; the +cervix is not very prominent, but well formed and the vagina is rugous. +These types correspond to the uterus cordiformis. Lemurs have a common +uterovaginal cavity like the Edentata. The lower monkeys possess a long +slender uterus with definite superior lateral angles, the last vestiges +of the cornua, a prominent cervix and a short rugous vagina. The higher +apes have a uterine construction almost identical with that of man at +the stage of infantile development. + +“From the foregoing study it is clearly shown that every anomaly of the +female genitalia in Man is in reality the result of atavism and hence, a +degenerative change, and inasmuch as every special form of anomaly finds +its counterpart in the normal anatomical arrangement of the analogous +structures in one or another of the great mammalian groups, one +additional item of proof is offered in support of that greatest of +biological doctrines, the descent of Man from the lower forms of life.” + + +ANATOMY OF LABOR. + +In a second article Schumann reviews the comparative anatomy of labor, +demonstrating that the basic principles are essentially the same, +alterations only being in the direction of accommodation to the pelvic +construction. In order to make the analysis comparable with human +conditions the pelvis is studied as if the animal were standing erect +upon the hind limbs. + +The salient points of difference between the quadruped pelvis and the +biped, human type may be epitomized as follows: (a) The entire pelvis +lies (with the animal in its normal station) in a generally horizontal +position with a slight slope downward anteriorly. (b) The false pelvis +is almost entirely wanting, there being practically no bony structures +above the brim with the exception of the small upper portions of the +ilia. (c) The pelvis in quadrupeds is never basin-shaped, the lateral +walls from the iliac crests to the tuberosities of the ischia lying +roughly parallel to each other and enclosing a pelvic cavity rectangular +in outline. Only in the highest apes does the basin-shaped pelvis +appear. (d) The angle of the axis from the promontory of the sacrum to +the symphysis is always greater in the quadrupeds than in man, averaging +in the former from 70 to 80 degrees, in the latter about 55 degrees, (e) +The symphysis pubis is an extremely long joint, being frequently greater +than half the length of the entire pelvis, (f) The sacroiliac joint is +more or less movable in all quadrupeds, especially in young animals. The +rotation of the sacrum on the ilia increases the anteroposterior +(dorsoventral) diameter of the outlet and at the same time wedges apart +the ilia, thus increasing the lateral diameter. + +In regard to the forces of labor it is to be pointed out that in the +lower mammals the pregnant uterus hangs below the pubic arch so that the +fetus must rise at an angle of about 45 degrees to pass over the pelvic +brim. In so doing it meets the narrowest part of the triangular bony +pelvic inlet, the anterior pubic angle. Since the sacrum is above and +out of the way, the lateral diameter is the one which must be suitable +to the passage of the presenting part. This is the head in homo, the +largest part of the fetus, but in lower animals either head or breech +often accompanied by one or more extremities, may present; the head is +not the largest part in lower mammalian fetuses. The uterine contraction +proceeds as in man, the fundus and cornua acting alone until the cervix +contains the fetus, at which time all parts contract. In the bicornate +organ both sides must contract or the fetus might be forced from the +gravid to the empty side. In multiparous animals with both uterine horns +occupied, the fetuses lie head to head, breech to breech and are +expelled alternately from each side. + +In uniparous animals rotation is in the nature of an accommodation of +the greatest diameter of the fetal body in cross section to greater axis +of the mother—the dorsoventral. Uterine contractions cause the fetus to +unfold from its elliptical form and to assume an extended position, +permitting head or breech to enter the lower pelvis. The pubic angle +having been passed and the extension of the presenting part being +successfully accomplished, there is no striking difference in the manner +of external expulsion of the fetus. + + +DYSTOCIA. + +Dystocia in domesticated animals is a well studied subject, and its +general clinical phases are fairly well known. Several cases have been +observed, details of which are worthy of note since some of them are +entirely complete. + +Inertia uteri as a single non-obstructive condition seems not to have +been observed here, although well enough known to veterinarians. Nor has +a case of dystocia been seen as the result of excessive expulsive force. +Obstruction to natural passage by bony deformities or malformations is a +common occurrence in man but not so in lower animals. There may also be +dystocia by reason of a normally formed but too small pelvis when the +female has been impregnated by a much larger male, or if the female +conceived before the pelvis has achieved its full growth. + +Deformities may be due to irregularities of bony development, exostoses, +fracture or diseases of the osseous system. A most interesting case of +this type occurred in a Barbary ape (_Macacus innuus_) which had been in +the collection for two years and was apparently in good health when +discovered in labor. + + + No progress being made and the animal becoming shocked, an ineffectual + attempt was made to deliver by version, the monkey dying during the + operation. Upon autopsy the uterus contained a fetus apparently at + term. The head was extended so that the face presented, but the head + was not engaged. The cervix was fully dilated but the uterine muscle + was relaxed and flaccid. The fetus was dead when the animal was first + examined. The uterus contained two placentæ as is normal for these + apes, the left placenta being the place of attachment of the fetus + while the right one was somewhat smaller and presented no umbilical + cord. The fetus was normal in size and form, the face was extended and + its lower portion far advanced in a caput succedaneum. The + measurements of the fetal were as follows: bitemporal 5.5 cm., + biparietal 6 cm., occipitomental 8.5 cm., occipitofrontal 7.5 cm. The + pelvis (dried specimen) presents a most interesting condition. The + sacrum is bent sharply forward, carrying with it the border of the + ilia, which are bent upon themselves forward and downward. The lateral + walls of the pelvis are greatly narrowed, the ischia drawn inward. The + pubes and the symphysis are fairly normal. The pelvic measurements + are: diagonal conjugate 6 cm., true conjugate 4 cm., greatest + transverse 4 cm. + + +It is apparent at a glance that here was an impossible labor, since the +head of the fetus could not possibly enter the pelvis, the size of +which, _intra vitam_, must have been less than the above measurements by +reason of the soft parts. “This is in the experience of the writer a +unique case of a complete obstetric history, plus the specimens, of +labor with an osteomalacic pelvis in a wild animal.” + +Another case may be added to those already reported by Dr. Schumann, as +follows: + + + Hairy rumped Agouti (_Dasyprocta prymnolopha_). Dystocia. An + apparently normal fetus occupies the left uterine horn. The nose was + engaged in the pelvis and has been moulded in a curve pointing to the + right. The fetus measures—bitemporal 30 mm., cervical-coronal 31 mm., + length of fetus 17 cm. Pelvic inlet in the fresh state measures 18 mm. + transversely and about 17 mm. anteroposteriorly. The umbilical cord is + 10 cm. long and appears normal as do the membranes. Placenta presents + as a spherical mass of hard dense consistency, 35 mm. in diameter and + with apparently normal placental tissue occupying the lower border of + this spherical mass. On section the mass shows areas of alternating + soft red tissue separated by communicating trabeculæ of dense white + fibroid tissue. This mass is distinctly encapsulated, but the nature + of the enclosing membrane is indeterminate. The pelvis in dry state + shows evidences of malformation due to trauma. The right ileum is + pushed forward and inward carrying the acetabulum a short distance + inward and backward. There is a marked thickening about the right + acetabulum. At the upper portion of the symphysis there is marked + bending backward toward the sacrum with thickening of the bone. The + last sacral vertebra is sharply bent and anchylosed, forming an angle + of sixty degrees. The pelvic measurements in the dry state—at superior + strait-transverse 24 mm., right oblique 23 mm., left oblique 26 mm., + true conjugate 22 mm., outlet 17 mm., between the ischiatic spines. + + +This is obviously a traumatic malformation and forms a relatively +contracted pelvis. The delivery of an adult fetus is impossible. + + + Cape Hyrax (_Hyrax capensis_). Impossible labor due to malformation of + the pelvis. This animal died as the result of shock and exhaustion of + labor. She was pregnant of two fetuses, one of which was extracted + manually by the keeper but was dead at birth. Twenty-four hours later + the animal was found dead. On autopsy there was present a fully + developed fetus in the right cornu, the head just above the pelvic + inlet. The left cornu was large and boggy. The myometrium of the right + side was so thin as to be almost transparent. On examining the bony + pelvis the reason for the dystocia is at once apparent. The sacrum is + tilted to the right, and the body of the left ileum is bent sharply to + the right, the pelvic inlet being obliquely contracted, the right + oblique diameter being 16 mm. while the left is 23 mm. + + +The pelvic obliquity made the birth of a full sized fetus impossible, +the one delivered being under developed. The myometrium was evidently +stretched almost to the point of rupture when death occurred. + +Obstruction to the birth canal by abnormalities in the soft parts, such +as muscular rigidity, edema, or inflammation, tumors, atresia or +developmental defects are occasionally seen by veterinarians but have +not been encountered here. + +Dystocia from uterine displacements are uncommon except such as may +depend upon the failure of support by the abdominal wall, since this is +the principal support of the organ especially when gravid. Hernia or +hysterocele is known and anteflexion has been seen. Torsion, a rare +human condition, is not uncommon in lower animals probably due to the +loose dependent position of the pregnant cornua, attached only to the +pelvic walls by slender inactive suspensory ligaments. A case may be +reported, not originally described. + + + Canada Porcupine (_Erethizon dorsatus dorsatus_). Obstructed labor. + This animal died from exhaustion due to an impossible labor. On + autopsy the abdomen contained a moderate amount of clear serous fluid + with one small blood clot. The right uterine cornu was distended with + a fetus to about the same diameter as the uterine body. This cornu was + congested and edematous and its walls very thin. The cornu was twisted + one-half full turn from right to left, so that the pregnant portion + overlaid the uterine body anteriorly. The torsion produced a + compression of the vessels on the right side to the point of violent + congestion of the cornu. There was no apparent rupture of the uterine + walls, death having occurred from exhaustion. The fetus and its + membranes were normal. + + +Many forms of abnormalities in position are recognized for domesticated +animals, but since we know so little of the early stage in the wild +specimens no data can be given. + +Complicated labor in lower varieties of animals will follow lines +similar to those for man and domesticated animals. Hemorrhage from +trauma is not common at term, but several cases of abortion following +injury have been seen. Postpartum hemorrhage might be expected in the +higher apes which have a large discoid placenta similar to the human +form, but when the placenta is more loosely attached and is subdivided +as in lower forms, such bleeding is of no danger; when a cotyledon is +torn from the ungulate uterine wall, a free hemorrhage sometimes occurs. + + + Geoffroy’s Marmoset (_Leontocebus geoffroyi_). Puerperal relaxation of + the uterus with fatal hemorrhage. The uterus is 4 cm. long, 15 mm. + wide at intertubal line. Uterine wall averages 2 mm. in thickness. + Peritoneal surface is smooth, glistening and intact. Uterine + musculature is soft and relaxed. Entire organ is intensely congested + and on section uterine cavity contains a large firm blood clot + completely filling it. Mucosa is of deep purple color, shows many + fragments of decidua and is the seat of profuse hemorrhage. + + +Placenta previa is very rare. A row of cotyledons may form near the +internal os, therefore like a placenta previa, but it appears to be of +no consequence. Premature separation of the placenta is known to +veterinarians, and is exemplified by the following case in our records: + + + Black Lemur (_Lemur macaco_) was found dead in its cage. Upon autopsy + the uterus contained a small fetus with one leg and the tail + protruding from the vulva. The fetus was normal in size. There was a + large amount of free blood in the uterine cavity and extensive + extravasation into the myometrium. The placenta was completely + detached. + + +Rupture of the uterus and cervix have not been seen, but a traumatism of +the vagina gave occasion for the following death: + + + Bactrian Camel (_Camelus bactrianus_) died of shock in labor. Upon + autopsy the animal was found to have hydatid disease of the liver, + lungs, and spleen, cirrhosis of the liver, and nephrolithiasis. + Protruding from the vulva was a portion of the fetal membranes, the + whole vaginal wall and several coils of intestine which had escaped + through a large rent in the posterior vaginal wall. The anterior wall + was swollen and edematous, the whole region surrounded by clotted + blood. The cervix was obliterated, the membranes unruptured, the fetus + in the normal extended head presentation. The veil-like placenta was + somewhat injected but otherwise normal. There was some hemorrhage + about the rectum but none in the free peritoneum. + + +This animal had broken her hind leg just above the fetlock three weeks +before falling into labor, and was unable to stand. It is evident that +the difficulty of delivery associated with an unnatural and forced +posture due to the fractured leg was sufficient cause for the rupture of +the vagina where the tissues were degenerated as a result of the +coincident general disease. + +Inversion of the uterus is one of the common accidents of labor among +all animals, most frequently seen in ruminants. It is a condition more +to be expected in lower animals than in man because of the long slender +relaxed suspensory ligaments, the length of the uterus and the rigor of +the contractions. The immediate causes are those operative for human +beings. Three cases are recorded—one in an axis deer, one in an opossum, +one in a mouse, the last being detailed in the following notes: + + + A Japanese Waltzing Mouse (_Mus wagnerii rotans_) died a few hours + after an uneventful labor. On autopsy the entire uterus was found + inverted and prolapsed, the organ the seat of a violent congestion, + the animal having died of shock. + + +[Illustration: + + FIG. 22.—INVERTED AND PROLAPSED UTERUS. JAPANESE WALTZING MOUSE (MUS + WAGNERII ROTANS). UTERUS SHOWN LYING ON CARD. +] + + +THE PELVIS. + +A study of the dynamics of the female pelvis from an evolutionary +standpoint may explain some of the difficulties attending parturition. +Starting from the biological law that morphology follows function and +that the anatomy of a part alters to suit a changed physiology with such +modifications as are necessary to fit each part properly to interact +with other structures comprising the entire animal, it is evident that +two great changes have occurred in the evolution of homo—the assumption +of the upright posture and an increase of intellectual power +necessitating a larger cranium of modified form. To this end also the +pelvis would have to change both for support and to allow the passage of +the enlarged head. The functions of the pelvis are (1) to attach the +legs or hinder limbs to the trunk; (2) to furnish points of attachment +and fulcra for the great muscles which move the limbs, and in the case +of man, hold the trunk erect; (3) to provide egress and support for the +terminal canals of the intestinal and urinary systems; (4) to provide +for a birth passage; (5) to act as a shelf and support for the abdominal +viscera. In quadrupeds the first four functions being perfectly served, +there are fewer abnormalities of reproduction (and in the positions of +viscera as well—ED.). In man natural selection weeded out narrow pelves, +but the present product is as yet an imperfect structure for one of its +main uses, parturition. It should be a funnel-shaped basin of the shape +of the fetal head and of the same height at all points—that is not +oblique, there should be no promontory, the pelvic symphysis should be +short and the sacrum of the same height. This would obviate internal +rotation now necessitated by the oblique pelvis; this does not occur in +quadrupeds. + +Tracing the evolution of the pelvis, it is to be found first in fishes +where it is a loose disjointed, variable structure not attached to the +spine; in some it consists merely of ischia. In reptiles the box assumes +a form suggesting higher types. Passing from the toads to turtles and to +the crocodiles, the elements which go to make up the pelvis assume a +more and more osseous character and become more and more definitely +articulated with the spine or with the differentiated sacrum. Its +purpose in these low forms is mostly as a support for the muscles of the +legs and back. Birds present an advance in pelvic construction but with +a great preponderance of the vertebral column since thirteen to +seventeen bones may fuse to form a sacral “roof.” The ilia, ischia and +pubis are firmly combined. The box is long and narrow with a heavy part +for the acetabulum and broad surfaces for muscular insertions. The +pelvis of birds differs from that of cold-blooded vertebrates in the +greater number of vertebral segments entering into its composition, and +in their bony confluence. It differs from that of mammals by being +unclosed by an anterior symphysis and by a widely perforate acetabulum. +The ossification of the pelvic bones is to afford a support for the +legs, and the open pelvis allows passage of the large brittle egg. The +shape of the pelvis is of little importance in parturition in the +foregoing animals, except for birds which bear large eggs when the pubis +anteriorly is open for that purpose. + +In monotremes one finds the reptilian type of pelvis with the three +divisions of the innominate bone remaining separate. The pelvis is +short, heavy and flat and is fitted with marsupial bones. The marsupial +pelvis, possessing parallel walls made by the ilia and ischia and a long +symphysis, resembles roughly a triangular prism. The sacrum is wedge- +shaped, without a promontory and has a considerable movability. The +marsupial bones are quite long. The triangular outlet is many times the +size necessary for the passage of the fetus. + +The rodent pelvis is difficult to summarize morphologically by reason of +the great diversity of form occurring in the many genera of the order, +but it may be said that here the pelvis is usually of a type rather +higher in the scale than the other structural characteristics of the +order would indicate. The outlet is more commonly ovate than +rectangular, the ischia and ilia lie at a more marked angle to each +other, and the true conjugate forms a lesser angle than is common in +quadrupeds. The sacroiliac joint is, in general, freely movable. + +The female insectivorous pelvis is relatively large, the sacroiliac +junction usually being long and well knit while the pubes are slender, +wide of angle as to their descending rami and there may be no symphysis, +as in bats. Edentates have distinct bony unions of the elements of the +innominate bone and of this to the sacrum which increases in width +downward permitting a long synostosis with ischia and pubes; these +joints are not movable. The pubes are slender and the symphysis short. +The sacrosymphyseal angle is 80 degrees in the armadillo. The inlet is +roughly triangular to almost round. Cetacea have no clearly developed +pelvis, its place being represented by two long bones, larger in males, +which seem to be the insertion of the genital erector muscles. There is +no junction to form a pelvis nor is there an acetabulum. A pelvic box is +absent in the Sirenia, but lateral processes from the lumbar vertebræ +form a sort of ileum between which an ischium is located. + +Proboscidea have a massive pelvis lying vertical to the spine. The iliac +alæ are wide and deeply concave; the ischia are short, heavy and +parallel to the ilia; the pubes are short and combined in a heavy +symphysis; the sacroiliac joint is short, heavy and slightly movable; +the outlet is ovate. In one specimen examined the length was 4 feet, +symphysis 18 inches, true conjugate 19 inches, transverse diameter 17.5 +inches; crests of iliac were 28 inches long. + +Perissodactylic animals throughout this suborder have similar pelves +except in so far as the obliquity is concerned. In the rhinoceros it is +90° with the spinal column, in the horse 135°; the angle of the true +conjugate is 10° in the former, 50° in the latter. The lateral halves of +the box are heavy and parallel; the symphysis is short in the +rhinoceros, large in the horse; the outlet is ovoid. Artiodactyla, +including pachyderms and ruminants, show a variety of shapes and +constructions. Hippopotami have a short massive box tilted at about 150° +from the spine, with widely flaring ilia and ischia; the pubes are +slender but not combined in a strong symphysis. In ruminants the sacrum +consists of four fused units; the sacroiliac joint is fairly movable; +the obliquity is about 145°; ilia are long and slender and flaring; the +ischia are broad and parallel with the ilia; pubes are slender but form +a symphysis about two-fifths the total pelvic length; the infrapelvic +angle is wide; the outlet of the pelvis is almost rectangular. + +The general characteristics of the carnivorous pelvis may be summarized +as consisting of a long strong symphysis, parallel lateral pelvic walls, +a great sacrosymphyseal angle, and a marked separation of the bodies of +the ischia. The sacroiliac joint is in general moderately movable. + +The pelvis of lemurs is narrow, attached lightly to the slender sacrum, +tilted at an angle of 140° and is possessed of a short weak symphysis; +it resembles the structure in bats. In macaques the box is long, the +sacrum wide, with a short iliac synostosis, the ilia long, narrow and +curved out sharply, the ischia are continuous with the ilia and widely +separated; the symphysis is short, about one-sixth the pelvic length; +the angle of the superior strait is about 60°; the outlet is oval, the +transverse diameter being short. The chimpanzee pelvis is made up of a +wedge-shaped sacrum composed of three vertebræ, wide, flaring, concave +ilia, stout well separated ischia with flattened tuberosities and a +short symphysis parallel to the sacrum; the outlet is ovoid; true +conjugate angle is 65°; the sacroiliac junction has little motility. In +the gorillas the following points differ from the last described +structure. Five vertebræ comprise the sacrum and the anterior surface is +distinctly concave; the pelvic contour while still ovoid, has the two +diameters more nearly equal; the pelvic angle is obtuse; the true +conjugate is at an angle of 70°. + +In man the salient features of the pelvis are—a broad, wedge-shaped +sacrum, concave anteriorly, with wide articular surfaces and a limited +motility; widely flaring ilia including the concave curvature of the +body of the bone whereby the lateral diameter of the pelvic inlet +becomes wider than in lower orders; short stout pubes with a narrowed +angle beneath them; heavy blunt ischia with large tuberosities; true +conjugate is at an angle of 55°. The human fetal pelvis resembles that +of quadrupeds. + +Study of these data indicates that the quadruped pelvis retains many +things in common through all the orders especially in being a roughly +rectangular structure lying chiefly horizontally, with a poorly +developed false pelvis, straight ischia and a long symphysis pubis; the +angle of the true conjugate is greater than in man and may be up to 80°. +The long pubic synostosis changes the relation of the true and diagonal +conjugate, but the former is no indicator of pelvic capacity, since in +lower mammals the promontory of the sacrum lies anterior to the +symphysis; the vertical diameter is a better measure of pelvic size and +form. Sacral movement seems greater in lower animals especially in +youth. The shape of the pelvic inlet is triangular in the lowest forms, +the posterior base of this becoming wide as one ascends in a zoological +line; the concavity of the ilia also increases so that the higher the +animal the more curved are the lateral borders. In quadrupeds the +anteroposterior diameter is greater than the lateral; the reverse is +true in man. The long straight-sided quadruped pelvis is retained +because of the direction of the forces from the legs, which is as much +or more upon the anterior or pubic arch as upon the sacroiliac junction. +In the semiupright position of the monkey the force is directed backward +and downward upon the sacrum, this aiming to widen the pelvis by forcing +the ilia apart. The effect of the upward force from the femora is to +throw the pelvis upward and anteriorly by directing the line of action +through the acetabula more toward the ventral surface. The sacroiliac +ligaments hold the ilia firmly, their alæ being spread outward by the +force from above. Elevation of the pubes shortens their symphysis and +the true conjugate. By these changes the birth canal is shorter, +entirely bony, with the upper inlet on the same plane, and promontory +and symphysis are near enough the same level to be met at the same time +by the engaging head. In these pelves the anteroposterior diameter is +still long and superior rotation is not necessary. + +In Man the force exerted on the pelvis from above is greatest among all +animals and is greater when he is in active motion. The force is +directed from above to the sacroiliac joint, the iliac bodies and the +acetabular region while from below the pressure is directly exerted upon +the last named. The force from above rotates the sacrum downward at its +upper end, the attached sacroiliac ligaments at the same time pulling +the alæ inward and throwing outward the lower end, the acetabular part. +This tends to widen the pelvic box and to reduce its anteroposterior +diameter. But the force acting from the legs and the adductors of the +thigh push the lower parts of the ilia and the ischia and pubes apart, +thus counterbalancing the effort of the force from above. The combined +forces tend to bend the iliac bodies, thereby producing the curved +lateral margins of the superior strait and making the lateral axis long. +As between these two forces that from above is certainly the greater. + +The effect of these forces can be followed by comparing a quadruped +pelvis, a human fetal pelvis and an adult human one. The first two are +similar chiefly in the shape of the inlet and the flat character of the +ilia. This is strongly corroborative of the evolutionary development of +the pelvis to meet the demand of the upright position. The effects of +this evolution are as follows: First, to develop a forward inclination +of the sacrum and a concavity in its surface anteriorly, second to +increase greatly the iliopubic and ilioischiatic angles, third to cause +the acetabula to move forward of the lumbosacral axis, fourth to shorten +the bodies of the ilia and to develop in them a regularly curved +surface, the concavity of which faces forward and inward, fifth to +decrease the interpubic angle and accordingly to remove the triangular +quality of the pelvic contour, sixth to increase the transverse diameter +at the expense of the anteroposterior, and seventh to decrease greatly +the sacrosymphyseal angle with the result that the entire pelvic cavity +lies in one plane. + +The effect of forces in alterations of the pelvic architecture may be +seen in their several stages by the observation of the mammalian pelvis +in the course of its evolution and development. The transitions in form +are very gradual, but their gradations are well shown in the +characteristic forms which have been described; the quadruped, monkey, +anthropoid ape, human fetal and adult human type. + +By an examination of the adult pelvis and fetal skulls it will be seen +that the shape of the quadruped birth canal accommodates the fetal head +nicely when in extension since there is no large posterior cranial +development, the head and neck being of nearly the same thickness. In +the monkey, where the facial angle increases, the head does not advance +as a pointed presentation but as an irregular surface—the chin, forehead +or occiput. It is only when the head has assumed a high facial angle and +a well developed occipital lobe and the pelvic inlet has become +transversely wide, that internal rotation is necessary. + +Resuming a discussion of our records I shall at this place introduce +additional cases of pathology in the parturient genital organ and then +discuss the general system. Beside the cases of dystocia discussed in +preceding pages there occurred in a deer a complete eversion of the +uterus, which was incompletely involuted, accompanying prolapse of the +rectum and bladder due to straining after severe injuries, probably +inflicted by a male. The animal lived long enough to develop a purulent +cystitis which spread to the vagina, uterus and pelvic soft parts. The +left uterine cornu of an American bison was found to contain a +decomposing fetus at about half term; general sepsis had supervened +which led to the animal’s death in about a week, according to the +keeper’s observations. The history of a monkey, followed through two +pregnancies and finally dying of tuberculosis and sepsis is interesting. + + + Pigtailed Macaque (_Macacus nemestrinus_). Received March 5, 1903, + died October 29, 1904. This animal gave birth on December 28, 1903 to + a young one which appeared feet first; the arms appeared to have + penetrated the septum between the vagina and rectum and protruded + through the anus. Had to be cut off before delivery. She had a second + young one October 21, 1904, which was properly delivered but was weak + and lived two days, having received little attention from the mother. + The mother since has been weak in the hind legs, eaten almost nothing + and several times has passed a little blood in the stool. Lungs are + partially collapsed; contain scattered small pinhead tubercles; right + lower lobe contains a caseous nodule about the size of a cherry. Both + pleuræ contain clear fluid. Abdomen contains a half pint of cloudy + fluid. Omentum adherent along lower border and region of spleen and + contains pinhead tubercles. Surface of the liver is studded with + numerous pinpoint, pinhead and (old) pea sized tubercles. Some places + in the liver seem to be the result of two invasions. Spleen presents + small cherry sized tubercles thickly grouped together leaving small + amount of splenic tissue to be seen. Kidneys contain pinhead to barley + grain tubercles. Uterus is somewhat enlarged. External surface smooth. + Section shows wall to be about one-quarter inch thick. Uterine cavity + enlarged. Considerable bloody pus in uterine cavity. No communication + can be found between the bladder and the vaginal wall or between the + vaginal wall and the rectum. The intestines are negative. Mesenteric + glands enlarged and caseous. + + +Abortion and miscarriage are occasionally seen in the monkeys, rodents +and ungulates. The underlying reason for this can seldom be determined. +A few cases seem to depend upon annoyance or abuse by cage-mates, a few +to immaturity of the mother and some others seem the result of bone +diseases such as osteomalacia. It does not occur regularly in any group +or enclosure and appears to have no comparative pathological value. + +Injuries of the external genitalia of the nature of lacerated wounds are +occasionally seen in ungulates and carnivores, but never in monkeys. +Acute vaginitis, sometimes localized into an abscess of the wall has +been known to follow these traumata. Chronic changes have been met but +once, which example will be detailed under another heading. + + +INFLAMMATIONS. + +Endometritis has been observed sixteen times, as follows: Carnivora 10, +Rodentia 3, Ungulata 2, Edentata 1. In searching for causes it was found +that the association with a recent delivery of young, an abortion or the +retention of a fetus, was responsible five times. Association with +tumors of the uterus was noted four times. Injury preceded the condition +on two occasions, while one instance seemed to be hematogenic, being +secondary to a septic pneumonia. On four occasions the actual cause +could not be established with satisfaction. Pathologically the traumatic +and parturient cases were purulent while tumors seemed to produce a more +exfoliative or hypertrophic inflammation. + +Inflammation of the Fallopian tube has been observed but five times, and +only in one of these did the uterine wall fail to participate in the +disease. The animals affected were three carnivores, one rodent and one +marsupial. + +No particularly important association of this salpingitis and other +pathology was noted, and indeed the only noteworthy lesion of the organ +under discussion is now to be cited. + + + Nylghaie (_Boselaphus tragocamelus_). Chronic vaginitis, fibroma + uteri, chronic tuberculous salpingitis. The vulva and lower half of + the vagina are covered by a thin coating of yellowish mucus. Mucosa is + mottled purple, irregular, in some places smooth and flat, and in + others showing clear cysts with yellowish fluid contents. The upper + part of the vagina shows a pedunculated fibroid extending from the + cervix. This tumor measures 32 × 20 mm., and is attached to the + posterior cervical wall by a broad pedicle and is of smooth surface. + The right uterine wall shows a large fibroid which twists the uterine + lumen to the left. The tumor in the right uterine cornu is nodular, + measures 11 × 9 × 7 cm., shows many dilated veins coursing over the + surface and one section shows a soft central necrotic area. The left + uterine cornu shows a small fibroid at the lower end. There is a + chronic endometritis present. The outer half of the right tube is the + seat of firm nodular swellings, one of which proves to be a purulent + salpingitis (tuberculous), the others calcareocaseous salpingitis. + Both ovaries are fibroid and cystic. Microscopic section shows some + exfoliation of the epithelium of the vagina. The uterine cornu is + thickened and the fibrous tissue is greatly increased. The tube is the + seat of a purulent salpingitis with an occasional broken down tubercle + present. The ovaries show a mild degree of oöphoritis (Fig. 23). + + +OBSTRUCTIONS TO CONTINUITY OF BIRTH CANAL. + +Obstruction to the lumen of the genital canal was observed in three +mammals. + + + An American Bison (_Bison bison_), five years old and known to have + been in captivity three years died of a chronic gastroenteritis and + pulmonary parasites after many weeks of failing health. At autopsy a + double hydrosalpinx, and probably unilateral hydrometra, with low + grade cystic oöphoritis were found. A picture is reproduced. The notes + are not perfectly clear as to the anatomy but from the gross specimen + in preservative it would seem that the left uterine cornu was involved + in the dilatation (Fig. 24). + +[Illustration: + + FIG. 23.—PEDUNCULATED FIBROMA OF CERVIX; INTRAMURAL FIBROMA OF UTERINE + BODY; FIBROMA OF LEFT UTERINE CORNU; TUBERCULOUS SALPINGITIS AND + MURAL METRITIS RIGHT SIDE. NYLGHAIE (BOSELAPHUS TRAGOCAMELUS). +] + +[Illustration: + + FIG. 24.—DOUBLE HYDROSALPINX AND UNILATERAL HYDROMETRA. BISON (BISON + BISON). +] + + Lion cub (_Felis leo_) had congenital cystic uterus. The only + abnormality found is in connection with the internal genitalia. The + vagina is 50 mm. long, uterus 23 mm. long, horns of uterus each 90 mm. + long. The diameter of the uterus measures 10 mm. in both body and + cornua, the latter being distended by clear watery fluid. They are + symmetrically curved downward. They show no adhesions or obliteration + of the os uteri to account for fluid retention. The probe is readily + passed from the vagina to the end of the uterine horns. Vagina is + patulous through its whole course. Ovary and tube normal. + + An Axis Deer (_Cervus axis_) showed congenital hydrometra. This + specimen is from a day old animal, consists of the genitalia in which + the entire body of the uterus and both uterine cornua have been + transformed into a thin-walled translucent cystic cavity containing + clear fluid. The body of the uterus measures 15 mm. diameter, each + cornu reaching the diameter of 5 mm. The cornua are curled not unlike + ram’s horns, and are united by a line of adhesions above the body in + the midline. From the ends of the convoluted and cystic uterus and + cornua spring the normal tubes each with its ovary. + + +CYSTS. + +Cysts have not been noticed in the lower genital canal, but it is true +that this region is not exhaustively studied in routine autopsies; +however, no large cysts have occurred there. Cysts of the ovary have +been limited to the so-called cystic disease of this organ; one +parovarian cyst has been found. These animals, two ungulates, two +carnivores and a rodent, are noted as being young adults, only one of +which was known to have borne young. In only one, the rodent, was there +evidence of chronic peritoneal disease. The notes of the parovarian cyst +case are as follows: + + + An Aoudad (_Ovis tragelaphus_) showed a ruptured parovarian cyst with + normal right side pregnancy. The fetus, its placenta and membranes + show no change. The right broad ligament and ovary are negative, the + latter containing a red and gray corpus luteum. The left ovary is + fibrotic and the left ligament is the seat of a large hematoma, which + on section is found to contain thin sheets of gray translucent + membrane, like walls of a cyst. The vessels are all distended. + Arteries have stiff walls and are empty. Veins have well formed clot. + The whole uterus and adnexa were slightly turned to the right, but the + twist does not seem to have been sufficient to cause rupture of a + broad ligament vessel. Microscopic section of the broad ligament shows + a parovarian cyst into which there has been hemorrhage. The cyst is + separated from the ovary proper by a short band of tissue which + apparently consists of thinnedout ovarian cortex. + + +TUMORS. + +Tumors of this tract in the mammals have been confined to the uterus +proper, none having been found in the vagina, tubes or ovaries; in birds +one oviductal growth and two ovarian tumors are recorded. These tumors +are reported briefly according to their histological structures, a brief +summary being added at the end. + + + A Black Lemur (_Lemur macaco_) showed a local leiomyofibromatous + nodule on the lateral aspect of the uterine body near the cornu. + + A nine banded Armadillo (_Tatu novemcinctus_) gave an interesting + specimen which can be described as follows: The uterus is enlarged so + that it measures 90 mm. from external os to fundus. Tubes and ovaries + apparently normal. There is considerable grumous blood in the vagina + and cervix; the former is normal. The cervix is pale and opaque in its + lower half; upper half is slightly congested and mucosa decidedly + rugous. The uterus itself shows an attenuated muscular wall with a + thickened irregular mucosa which is the seat of pseudomembranous tabs + of a dull red color, while the mucous membrane itself is irregularly + red and yellow; also some grumous blood in the cavity. The size of the + uterus is due to a large fibroma attached to the left lateral wall + near the cornu. The mucous membrane of this is irregularly disturbed + in some places, the tumor being partly bare. Here and there the mucous + membrane shows the same degenerating hypertrophic character as seen on + uterine wall. The tumor is attached to the wall by a narrow peduncle + (Fig. 25). + + A nylghaie with multiple fibromata has already been described. + + A Jaguar (_Felis onca_) presented in the middle of the right uterine + cornu a cystic resilient tumor 3 × 4 cm., which proved to be a + fibroadenoma. + + A lioness (_Felis leo_) presented a penetrating malignant adenoma of + the uterine cervix upon which an active endometritis was implanted. + The tumor penetrated the uterine wall, which gave way, an acute fatal + peritonitis resulting. Metastases had occurred to the lung. + + A Wild Boar (_Sus scrofa_) had a generalized ulcerating carcinoma of + the uterine body. + + An instance of chorionepithelioma in a Canada porcupine is worthy of + separate description. + +[Illustration: + + FIG. 25.—PEDUNCULATED FIBROMA UTERI. NINE BANDED ARMADILLO (TATU + NOVEMCINCTUS). +] + +[Illustration: + + FIG. 26.—FIBROMYOMA OF UTERUS. CORNUA AND TUBES. INDIAN ELEPHANT + (ELEPHAS INDICUS). WHOLE MASS AS MOUNTED ON BOARD. IT MEASURED WHEN + FRESH ABOUT SIX FEET ACROSS. + + FIG. 27.—CROSS SECTION OF CORNU OF Fig. 26 AT HIGHER POWER. A PIECE + CUT OFF WHERE THE PALE AREA SHOWS ON THE RIGHT CORNU OF THE OTHER + FIGURE. +] + + Canada Porcupine (_Erethizon dorsatus dorsatus_). Acute suppurative + catarrhal endometritis, hemorrhage in myometrium, chorionepithelioma. + In anterior abdominal wall a short quill was found imbedded. A very + small quill was imbedded in the retrocervical muscles. A quill about 2 + cm. long lies free in the peritoneal cavity attached by recent plastic + adhesions to peritoneum over left pubic ramus. A fourth quill was + adherent by recent fibrous lesions to anterior wall of cecum. + Peritoneum contains a moderate excess of thin watery fluid. Liver and + spleen are negative. Kidney is large, greenish yellow, firm, smooth + and glistening. The right uterine cornu is subinvoluted (the animal + was delivered of a fetus before arrival at the Garden, which was + sixteen days before death). Its walls are thick and distinctly + congested, the congestion being of inflammatory type. Microscopic + section of uterus shows a regular, not ulcerated serosa. Subjacent + fibrous tissue is loose and contains a granular precipitate together + with a few red blood cells. Muscular bundles under this are widely + separated evidently partly by trauma, but certainly also by edematous + interstitial tissue in which fibrillæ are widely separated and between + which free red blood cells and plasma cells are seen. Capillaries + ramifying through muscular bundles are greatly distended and + congested. Numerous large arteries are present in addition. Some of + these contain pink granular material within their walls together with + diffuse collection of red blood cells. Fibroblasts extend into this + necrotic mass from other sections of the walls. Lumen of such arteries + is diminished and in places quite obliterated by recent organization + tissue. At many places in muscularis are large cells of irregular + rounded form and some cytoplasms incline toward the basic tint with + one or several large hyperchromatic nuclei. They are especially likely + to occur close to a capillary. There is an especially large + accumulation of these cells at that point of section farthest from + fundus. Here these cells occur in chord-like masses which infiltrate + the muscularis both internally and externally. This particular mass + lies in the muscularis internal to great arteries and well removed + from mucosa. In this mass are giant cells with multiple nuclei + scattered through the whole cytoplasm together with smaller cells with + exceptionally large hyperchromatic nuclei. Subepithelial tissue is + especially congested and contains numerous fibroblasts together with a + few well formed glandular acini. Lining epithelium is discontinuous, + of simple tall columnar type, in places becoming flattened or even + lost. Lumen of organ is practically completely occupied by pus. + + The Indian Elephant “Empress” (_Elephas indicus_) showed calcified + fibroids of the fimbriæ; gross and microscopic notes and a photograph + are given. The uterus is bicornate in type. In its body there are + numerous fibrous nodules 1 to 4 cm. diameter. They can be traced from + the cervix to the ends of both horns and tubes. At the end of each + tube there is a great mass of calcified partly conglomerate tumors + some of which are partly, others quite, pedunculated. One specimen + measuring 2 × 1 × 1½ cm. has a peduncle 15 cm. long. The mass on the + right side weighs 3,926 grams, that on the left side about the same. + Section of tumor from uterine cornu shows the classical appearance of + a leiomyoma with usual whorling and interlacing bundles of involuntary + muscle fibres. Degenerative and vascular changes not seen nor is there + any notable addition of fibrous tissue. This latter tissue is shown + only in small amounts at one end of section. + + +The preceding data record the discovery of three fibromata of the uterus +and one of the fimbriæ; one fibroadenomata of the cystic type, one +malignant adenoma, one adenocarcinoma, and one chorionepithelioma. They +were found in Lemures 1, Carnivora 2, Ungulata 2, Proboscidea 1, +Rodentia 1, and Edentata 1. Metastases occurred but once, to the lung. +No secondary tumors were found in the uterus. + +While upon the subject of neoplasms of the female genitalia, it may be +well to describe the three instances found in the avian organs. A very +definite case of adenocarcinoma occurred in the oviduct of an Undulated +Grass Parrakeet (_Melopsittacus undulatus_), a variety of bird very +susceptible to neoplasms. The notes in an abbreviated form are given: + + + Immediately under the ovary is an irregular mass measuring 2 cm. long, + 1 cm. wide, 1 cm. deep. The lower part of the tumor thus comes to + press against the cloaca. It is adherent anteriorly to the peritoneum. + It apparently consists of two parts, an upper rounded larger, and a + lower spherical smaller. Both parts are well encapsulated and + separated from each other by a well defined constriction. The upper + part has a pale opalescent appearance. It cut easily with moderate + resistance. The lower portion externally has an egg-yellow color + streaked with red. Upon section it has the same general appearance but + contains in addition numerous small, irregular, yellow areas which + mask the general opalescent appearance. The centre of this node + contains an empty space (cyst) 1 × 2 mm. Microscopic section consists + of an oval or elliptical mass showing over one convexity a depression + simulating a constriction. A thin fibrous capsule extends over most of + the section which is extra thick at the point of constriction. + Constriction roughly divides the section into two. The upper portion + consists of one or two coarse septa of fibrous tissue. From these + central areas a delicate connective tissue framework extends + peripherally. In this framework are great numbers of irregular gland + spaces. These gland spaces are so closely placed in most cases that + room is afforded for but one nucleus of the bundle. The gland spaces + vary in size, some large, some small, and show grotesque shapes. The + larger gland spaces here contain granular debris and pyknotic nuclei. + Compound granule cells suggesting colostrum corpuscles may be seen in + this debris. The epithelium of the gland spaces consists of a single + layer of columnar epithelium of low cuboidal type. In places it is + heaped up so as to present several layers. In places too it is not + applied in a regular manner to the basement membrane but breaks + through and then the cells extend in most disorderly fashion into the + lymphatics of the stroma. At these points the nuclei are + hyperchromatic. The lower portion follows closely the description + given above save that the glandular spaces are much larger. They + contain pink glandular material with admixture of compound granule + cells. At the convexity of the tumor the acini are especially large. + Here they contain a pink granular material which stains more intensely + than the other granular contents and, too, inside of this intense pink + material are sharply circumscribed areas of yet more intensely pink + staining material. This latter substance has a streaming appearance + under the high power. This streaming appearance is due to elongated + areas of less dense material which are placed with their long axes + parallel. This lower portion shows, furthermore, even with the naked + eye, two large cysts which are lined by epithelium and contain a very + small number of compound granule cells. The capsule at the lower pole + is worthy of note from the extreme dilatation of its capillaries. + + +[Illustration: + + FIG. 28.—PAPILLARY ADENOMA OF OVARY. WILD TURKEY (MELLEAGRIS + GALLOPAVO). +] + +A papillary adenoma was found in a wild turkey (Fig. 26) and a mixed +cell sarcoma in a King parrakeet (_Apromictus cyanopygius_). None of +these tumors sent out metastases. + +Interest in the avian reproductive tract from a pathological standpoint +centres around the tumors as already given, and abnormalities in egg- +bearing. Among our specimens there have been many cases of soft shelled +eggs apparently blocked in the oviduct, of “egg-binding” and of the +inspissated-egg-remains in the abdominal cavity. These conditions are +well known to veterinarians and are explained on the basis of improper +food, immaturity of the bearing fowl, injury and inflammations of the +cloaca and oviduct. I made an attempt to associate these conditions with +infectious disease incidence and with the normal egg size. The results +are not harmonious. No relation existed between general or local +infection and any of these conditions. Gallinaceous birds with their +large eggs show the highest percentage (2.3 per cent.), but Anseres with +a somewhat larger relative egg size show 1.6 per cent. Passeres, with +eggs of very variable size but relatively large pelves, have an +incidence of .6 per cent. Struthiones’ eggs are relatively small; their +incidence is 1.5 per cent. + +Salpingitis occurred in seven cases, but there have been no evidences of +an acute infectious disease such as is responsible for gleet. + + +THE MAMMARY GLAND. + +This structure has been the seat of three inflammatory conditions and +four tumors. The former occurred twice in nursing animals, one of which +seemed to be suffering with distemper, another from puerperal sepsis, +while the third case was probably traumatic. The animals were in order, +a raccoon, a coati and a skunk. Four cancers of the breast have been +observed, all richly cellular or glandular in type; none of the +scirrhous variety has been encountered. Two of them were ulcerating and +one was about to become so. One gave extension to the axilla and lung, +one had penetrated the abdominal wall and grown around the kidney; the +remainder had not yet extended. The animals were Black Bear (_Ursus +americanus_) (thoracic mamma with extension), Common Opossum (_Didelphys +virginiana_) (two sections of breast in pouch), two White footed Mice +(_Peromyscus leucopus_) (posterior abdominal right gland and whole +side). These animals were all adult but not old. + +[Illustration: + + FIG. 29.—ADENOCARCINOMA OF MAMMARY GLAND (TWO SECTIONS WITHIN POUCH). + COMMON OPOSSUM (DIDELPHYS VIRGINIANA). +] + + + + + SECTION X + THE MALE GENITALIA + + +Affections of the penis are limited to phimosis and occasional +inflammations on a traumatic basis. The latter is best seen in +carnivorous animals like raccoons and coatis, but has little +pathological interest. Two cases of phimosis have been seen at the +autopsy table and one in an animal (hyena) still living. The last was +operated upon some years ago and has given no trouble since. The prepuce +of this beast is seldom retracted, but no swelling or retention of urine +has occurred. A Red River Hog (_Potamochœrus porous_) dying of a variety +of lesions, was found to have contracted preputial opening, the edges of +which were tight and adherent to the glans penis at various spots. The +prepuce had been dilated with urine to a large size from which +collection the fluid could be pressed dropwise only by considerable +pressure. Opening the sac revealed forty to fifty gray white sand +granules about the size of millet seeds. A gray fox (_Canis cinereo +argenteus_) had a mild grade of phimosis; in this case probably +traumatism had some etiological relation, for it is the one referred to +before in which a terminal urethral stricture was followed by rupture of +the bladder. + +The testes have been peculiarly free of disease, only a small number of +lesions having been found. A raccoon had an acute inflammation, +traumatic in origin, and a few passerine birds were noted as showing +involvement of this organ in the presence of some general infectious +diseases. Two tumors were found in birds, none in mammals. The avian +cases both occurred in Red shouldered Parrakeets (_Palæornis eupatrius_) +and were round cell sarcomata, without metastases. + +Acute inflammations of the prostate and Cowper’s glands occurred only +once as secondary to pelvic infection. Chronic change was observed in +these bodies on two occasions, and prostatic hyperplasia, commonly +called hypertrophy, was seen thrice. The mammalian prostatic area is +known to become overfilled with secretion and to be affected by +inflammation when it is not discharged. This occurred in a wood rat +(_Neotoma pennsylvanica_) and a wild boar (_Sus scrofa_), the former +having the condition so marked that prostate and seminal vesicles were +swollen backward into the pelvis like a tumor. Histologically one finds +in these conditions an engorgement of the glandular and ductal spaces +with a mucoid substance and a mild round and plasma cell infiltrate in +the connective tissue; there are no marked evidences of active +inflammation. The testes were not abnormal in these cases. + +The three cases of “hypertrophy” of the prostate are worthy of separate +record. + + + Indian Paradoxure (_Paradoxurus niger_) the prostate is greatly + enlarged, of pale orange color, soft and does not exude pus on section + or pressure. + + Common Opossum (_Didelphys virginiana_) The prostate is enlarged, + soft, gray-yellow. Urethra contains a little gray mucus but seems + patulous. Seminal vesicles negative. + + Rhesus Macaque (_Macacus rhesus_). Glandular hyperplasia of prostate. + The bladder is collapsed. The opening of the urethra is occupied by a + firm, friable yellow-white cast of matter apparently inspissated + semen. Urethral mucous membrane normal. Prostate is 7 × 4.5 × 3 cm. + firm, resilient, dull purple-gray, capsule negative. Section shows + normal lobulations containing apparently normal secretion. Vasa + negative. Testes negative. Microscopic section of prostate shows acini + of various sizes lined by a single layer of tall vacuolated cells with + nucleus at the bottom. Cells probably nowhere reduplicated. Acini + nowhere grossly atypical but everywhere hyperplastic and dilated + irregularly. Mass is adenomatous in general increase but no part is + truly neoplastic. Interstitial tissue rather less than normal + proportionately. No “amyloid” bodies. + + +[Illustration: + + FIG. 30.—PAPILLARY ADENOMATOUS HYPERPLASIA OF THE PROSTATE GLAND. RING + TAILED LEMUR (LEMUR CATTA). +] + +Still another case of accessory sex gland enlargement was found in a +Ring tailed Lemur (_Lemur catta_), this time, however, with more +suggestion of a neoplastic change. The prostate of the lemur is normally +large, pale gray-pink and rather firm. Histologically it is about +equally glandular and fibrous. In this case the cellular activity is +undoubted, and one must consider it adenomatous. The cause of death was +enteritis, being perhaps more serious in the presence of the urethral +obstruction. + + + The seminal vesicles are distended to 7 × 2 cm. with a thick boiled- + starch-like material. Wall and mucosa are negative. Prostate large, + tense and injected. Its cut surface is pale purple, homogeneous; + character of fluid is normal although excessive. Urethra is occupied + by a cast of rather tenacious starch-like matter which begins at neck + of bladder and runs almost to meatus. Openings of excretory ducts are + prominent. Mucosa and submucosa of urethra are deep purple and the + former seems to be slightly opaque as if covered with desquamated + epithelium. Testes and epididymes seem normal. Vasa deferentia are + slightly distended with excess of normally turbid fluid. Microscopical + section shows hyperplastic epithelial condition with accumulation of + droplets of hyaline matter but there is no amyloid deposit. In places + it is possible to see a hyperplastic and loosened epithelium with + nuclei becoming vacuolated, and the whole being cast off. Less + granular free globules suggest that this is the method of origin of + the hyaline globules free in the acini. The picture is one of + papillary adenoma. In some places there is surely reduplication of the + lining cells. Connective tissue is deeply staining, compact and with + adult nuclei. Growth is not very vascular. There are no corpora + amylacea. + + +A case of tuberculous prostatitis and seminal vesiculitis was seen in a +Japanese Macaque (_Macacus fuscatus_). Judging by the advanced stage of +these lesions and their more recent character in other viscera, the +disease was suspected as pelvic in origin, possibly due to infection by +a thermometer. Whether or not such be the case cannot be established, +but at all events, separate thermometers kept in carbolated vaseline +were employed after this death. The females caged with this animal did +not develop tuberculosis of the pelvic organs. + + + + + SECTION XI + THE DUCTLESS GLANDS + + +THE THYROID BODIES. + +The ductless glands occupying the anterior cervical regions, known as +the thyroids and parathyroids are structures to be found in some form in +all vertebrates, but increase in distinctness of outline and +construction upward in the zoological scale. In the bird they present +themselves as discrete rounded bodies lying well to the side of the +midline resting usually upon the carotid artery or jugular vein or both. +As one removes the skin reddish brown globular masses will be exposed to +view, sometimes showing an irregular lobular outline, a variation due to +separate but attached masses of parathyroid glandules; the latter may be +yellowish or even white. For the most part, however, distinct thyroid +and parathyroid bodies are separated with difficulty, and one must +discover the latter by microscopical section. In the mammal these organs +are by no means so readily found when removing the cervical integument, +for they are usually buried beside the trachea and covered by +sternohyoid and sternothyroid muscles. Their position, relative to the +larynx and upper end of the sternum, varies considerably but this seems +to have little importance in the enlargements to which the gland is +liable. It is, however, lower, that is more posterior, than in the human +being, rarely rising as high as the lateral thyroid cartilages. The +principal lobes are elliptical or roughly triangular masses with their +long axis corresponding to that of the animal’s body and apposed +mesially to the trachea. When enlargement occurs it develops in the +anterior or ventral direction, pushing through the cleft between the +muscles and the trachea to present under the cervical skin. In +quadrupeds it may become dependent and the swelling is nearer the +sternum than is the case in man. The isthmus is a very variable +structure, and its presence or absence cannot be said to be a constant +character in any order, or indeed in any family. I have seen in old +animals a fibrous band extending over the face of the trachea connecting +the capsule of the lateral lobes, which might have been an isthmus at +one time. From these few observations the idea of atrophic fibrosis +occurred to me. Such may be the reason for the absence of this +transverse link in some adult specimens. + +The amount of thyroid tissue possessed by an animal might be judged by +measurement or weight. The former is misleading since the density might +vary, as it certainly does in the two classes and between certain orders +in mammals. Actual weights would afford little comparison, whereas the +weight in terms of total body weight may supply a guide to the amount of +gland normal to an animal. There are given in Table 15 the grams-per- +kilogram-body-weights of the thyroid bodies (thyroid and parathyroids +both sides combined) of twenty animals whose gland seemed entirely +normal at autopsy. They are all adult specimens, free of cretinoid +characters and of bone or heart diseases, conditions which might reflect +abnormalities to these glands. The list is too small to warrant any +conclusions, but in one respect confirms Murray’s[41] observation and +certain experimental work, notably of Vincent and Jolly[42] and Carlson, +Rooks and McKie[43]. The carnivores have more thyroid than ungulates +(averages .55 gm. _vs._ .18 gm.), but the marsupials on our list have +nearly as high an average as the former, namely .44 gm. To these figures +might be added others which I have worked out from the list given by +Murray; it is only possible to compute the gram-perkilogram value for a +few of his examples since the body weights are not given in all. Using +2.2 pounds as equal to one kilogram, the seal of 432 kilos had .03 gm. +of thyroid, lion had .18 gm., leopard had .46 gm., a serval .36 gm., a +skunk 2.35 gm., (was this normal?) while a single herbivore with the +weight given was a porcupine having .25 gm. per kilo. The average of +Murray’s carnivores is therefore .67 gm. per kilo of body weight, +whereas our figure is .55 gm. That the incidence of thyroid +abnormalities stands in direct relation to carnivorous character has +been recognized before, and is abundantly borne out by our statistics, +as will appear at a later place. + + TABLE 15 + _Showing Weights of Animals, of Their Thyroid Bodies and the Relation + of These Weights Per Kilogram._ + ═════════════════════════════╤═════════════╤═════════════╤═════════════ + │Grams of Body│ Grams of │ Grams of + │ │ Thyroid │ Thyroid per + │ │ │Kilo of Body + ─────────────────────────────┼─────────────┼─────────────┼───────────── + Primates: │ │ │ + Woolly Monkey │ 2,370│ 2.│ .84 + Lagothrix lagotricha │ │ │ + Carnivora: │ │ │ + Wild Cat │ 8,180│ 2.│ .24 + Felis ruffus │ │ │ + Silver Fox │ 3,325│ 4.│ 1.2 + Canis chama │ │ │ + Kamchatkan Bear │ 31,800│ 22.│ .63 + Ursus beringiana │ │ │ + Lynx │ 9,500│ 1.│ .1 + Felis canadensis │ │ │ + Jaguar │ 29,500│ 16.│ .54 + Felis onca │ │ │ + Rodentia: │ │ │ + Ground Squirrel │ 550│ 2.│ 3.6 + Xerus capensis │ │ │ + Ungulata: │ │ │ + Zebra │ 340,000│ 64.│ .19 + Equus burchelli │ │ │ + Giraffe │ 384,000│ 45.│ .12 + Giraffa camelopardalis │ │ │ + Barasingha Deer │ 56,800│ 8.│ .14 + Cervus duvanceli │ │ │ + Kashmir Deer │ 56,800│ 20.│ .35 + Cervus cashmirianus │ │ │ + Urial │ 22,700│ 2.5│ .11 + Ovis vignei │ │ │ + Marsupialia: │ │ │ + Kangaroo │ 18,000│ 10.│ .55 + Macropus robustus (?) │ │ │ + Tasmanian Devil │ 3,120│ 4.│ .13 + Sarcophilus ursinus │ │ │ + Wombat │ 26,000│ 7.│ .27 + Phascolomys mitchelli │ │ │ + Wallaby │ 3,360│ 3.│ .9 + Genus and species (?) │ │ │ + Edentata: │ │ │ + Anteater │ 3,300│ 2.│ .6 + Myrmecophaga tetradactyla│ │ │ + Accipitres: │ │ │ + Wedgetailed Eagle │ 2,300│ 1.│ .43 + Aquila audax │ │ │ + Struthiones: │ │ │ + Rhea │ 18,000│ 5.│ .27 + Rhea americana │ │ │ + Emu │ 36,300│ 23.│ .63 + Dromæus novæ-hollandiæ │ │ │ + ─────────────────────────────┴─────────────┴─────────────┴───────────── + + +ANATOMY. + +The minute anatomy of the normal thyroid is fully given in text-books, +and is doubtless pictured in the minds of all but students of the +subject as a fixed and definite affair. Such is not the case. There is +certainly a variation in gross size under conditions of seasonal and +sexual activity, and it would seem acceptably demonstrated that changes +in diet, especially where meat is concerned, are associated with +swellings or shrinkage of the glands. These gross changes must be due to +alterations in histology. In youth also the bulk is larger, a condition +due to cellular activity, while as middle age advances the thyroid +becomes smaller and more balanced in its colloid and cellular +proportions. I need not detail the ultimate constituents of the gland, +but it is well to emphasize a few points which must be taken into +consideration in microscopical diagnosis. In the first place, the +lobules or acini are not all of the same size in normal organs. This is +especially true in the normal adult gland but may be so in youth. The +cells which form the inner lining of the acinus are low cuboidal in +shape but the elements which lie under them are oval and do not change +with hyperplasia of the former. The colloid which fills the glandular +spaces is very susceptible to mechanical and chemical agencies. In +material preserved in alcohol it may be shrunken away from the cells or +heavily vacuolated, while in tissue preserved a long while in any liquid +it may be found contracted or broken. Large vacuolated or vesicular +cells are characteristic of the human parathyroid; this type is by no +means so prominent in the lower animals, and in the few examples studied +closely the arrangement is less definitely glandular than in man. + +The avian thyroid is distinct from the mammalian in the delicacy of its +fibrous framework and the flatter character of its epithelia. Acini are +usually of more uniform size. Capsular vessels are prominent but +internal vascularity is less in birds than in mammals and their goitres +are not solid. + + +PHYSIOLOGY. + +The physiological value of the thyroid-parathyroid complex has been the +subject of extensive study and voluminous literature without exhaustion +of the possibilities, but with the result that we are possessed of +knowledge explaining certain phases of abnormality, even if the normal +functions be not unexceptionally demonstrated. The accepted alterations +of functions are hypothyroidism—inadequate physiology, and +hyperthyroidism—excessive activity. Absence or atrophy of the thyroid +bodies is usual in hypothyroidism, while enlargements, collectively +called goitre, commonly accompany excessive function. Exemplifying the +former, cretinism is the result of failure of normal function and +development during fetal life while myxedema is the expression of the +disappearance of thyroid secretion after it has once been operative; the +latter may occur in infancy after nursing has ceased, or at any time +that the thyroid may atrophy, during some of the forms of goitre for +example. Hyperthyroidism may express itself, with or without visible +enlargement of the thyroid body, in nervousness, gastrointestinal +disturbances, tachycardia, loss of weight and exophthalmos. The first +group, which might be called athyroidism, is often associated with +alterations in the bony skeleton in the form of chondrodystrophy or of +rickets, while some degree of osseous change is observed with myxedema. +Goitre, be it simple or exophthalmic, may be followed by cardiac +enlargement or by myocarditis. + +The character of the thyroid secretion is not known except that it is +influenced by the availability of iodine in the diet, but there are some +other as yet unexplained features. The normal thyroid fed to cretins or +persons suffering with myxedema, has the power to improve the condition +apparently by supplying iodine and the other essential elements. Iodine +is an important constituent of the gland, being present in combination +with protein. Its quality varies indirectly with the amount of colloid +and of hyperplasia (Marine). The administration of this element is +beneficial in colloid goitre but is harmful in the toxic variety. Even +though the administration of thyroid extract may relieve athyroidism, +this procedure in normal animals fails to produce typical pictures of +hyperthyroidism. Carnivora fed thyroid gland do not show toxic symptoms +until excessive amounts are given, whereas herbivorous varieties are +much more sensitive to this feeding.[44] Tachycardia, nervousness and +exophthalmos are not produced by these experiments, an interesting +observation since these signs are not recorded in wild animals, and only +vaguely reported by veterinarians. Man is apparently very sensitive to +thyroid dysfunction. + +On the other hand, meat-eating animals are more sensitive to excision of +the thyroid body than are grain eaters.[45] Chemical studies have shown +that the thyroid is concerned in basal metabolism since this is +increased in hyperthyroidism and decreased in myxedema; nitrogen output +is much elevated. + +Thyroid physiology stands probably in some relation to the cardiac +mechanism since in simple colloid or simple hyperplastic goitre if of +long duration, cardiac enlargement and disease may be greater than the +excess work occasioned by the mere physical bulk of the enlarged gland +in the neck would seem to warrant. A detoxicating function has been +ascribed to the gland, but Murray discredits this on the ground that +congestion occurs in infectious disease of warm blooded animals but not +in snakes. He thinks the gland more likely stands in some connection +with the thermoregulatory mechanism. + +It is evident from the foregoing that the thyroid is closely related to +protein metabolism, and that this is in some way connected with the +ability the body possesses to use iodine in the food if it can get it. +Feeding of meat to fish was found by Marine to increase the size of the +thyroid. With all this in mind it is not astonishing that two-thirds of +our cases of thyroid abnormalities were found in the order Carnivora. + +The anatomical changes of the human thyroid that precede or accompany +the various clinical pictures cannot be said to be uniform to a degree +that one can even approximately predict in every case what will be found +at operation, at autopsy or by the microscope. Furthermore, much +discussion has existed upon the importance of the several changes, the +association with clinical phenomena and the nomenclature. I shall not +enter the academic discussion with our material because so much has +depended, in human medicine, upon symptoms, signs and chemistry—data +that we cannot adduce. Upon many occasions I have seen animals with very +evident goitres, but have not been able to detect bulging of the eyes or +especial nervousness. One striped hyena carried his mass for several +years. It swelled up occasionally and seemed to cause dyspnœa. At one +examination of the beast, to see if anything could be done for him, a +large cyst broke under the examining hand, whereupon a deep inspiration +was heard and relief was apparent. This handling was repeated twice, +these times with the purpose of breaking cysts and when this was +successful disappearance of the dyspnœa was observed. However, a similar +attempt upon another hyena and a wolf failed possibly because no large +thin-walled cyst was present. These and the case of the lion cub (page +170) are the only instances in which the enlarged thyroid seemed to have +given serious difficulty, and the symptoms were probably due to +pressure. Many, indeed most, enlarged thyroids have been found at +autopsy, when the Garden personnel was unaware of their existence. +Interesting notes of familial cretinism will be found under the +appropriate heading. + + +PATHOLOGICAL ANATOMY. CLASSIFICATION. + +And now to return to the question of morbid anatomy of the thyroid +gland, I shall begin by outlining briefly the classification to be used +in analyzing our cases, a system which combines those of many +pathologists, yet which I believe contains the essentials of all. The +changes in the gland being hyperplastic and recessive, at times to a +stage of atrophy, no clear cut definite line of demarcation separates +all these pictures; instead they must be thought of as merging into one +another. When the thyroid enlarges more or less continuously with a +maintenance of considerable colloid, the picture is that of COLLOID +GOITRE. The gland is pale, gelatinous, tense but resilient and may show +large cystic areas with fluid contents. Microscopically studied the +acini are overfilled with colloid yet the lining cells are retained but +flattened. The cysts may show the ruptured septa of the original acini. +Enlarged soft reddish glands are found at times to contain much colloid, +nearly every acinus being distended with it, but in such organs the +epithelia are high or even reduplicated; the amount of contents is the +striking feature. These are termed HYPERPLASIA WITH COLLOID. Hyperplasia +may go on with the absorption of colloid, HYPERPLASIA WITHOUT COLLOID. +The gland is then a darker body of more solid character, red, dull +purple or uniformly pale pink, somewhat dependent upon the blood +content. By magnification one sees smaller acini with prominent high +cuboidal or cylindrical epithelia and little or no colloid. The increase +of cells seems to be due both to an increase in their size and number. +As the proliferation increases the lining layer must be accommodated so +that it bulges out into the lumen as a bud or papilla which, if it be +extensive or universal in the thyroid, gives rise to the ADENOMATOID +GOITRE OF PAPILLOMATOUS type. This growth is accompanied by much +congestion and small or large hemorrhages may occur, forming cysts +containing a blood stained fluid. Grossly such a gland has solid and +cystic areas, is mottled red and gray or brown from old pigmentation and +is usually of very irregular shape. These forms are more or less uniform +and general, but in certain instances the hyperplasia tends to remain in +isolated areas or nodules, and in these develop solid masses of thyroid +epithelium, sometimes with a small lumen usually devoid of colloid, and +a rather rich but loose fibrous supporting tissue, the whole picture +resembling the microanatomy of the fetal gland; to these the name fetal +adenoma has been given, but since they are not fetal in origin and do +not behave like tumors I have called them NODULAR ADENOMATOID +HYPERPLASIAS. The next step in hyperplasia would remove it from benign +to malignant in pathological character, and the term NEOPLASTIC +HYPERPLASIA is used; this must of course be limited to the epithelial +growths, since sarcomata, while they occur in the gland, come from other +cells. + +The changes in atrophy consist in irregular distortion of the gland by +fibrous tissue to which may be added large colloid or fluid cysts. There +is no uniform finding in the thyroid for the diseases believed to be due +to its atrophy, functionally at least, namely cretinism and myxedema. In +the former there may be no thyroid, or it may rather closely resemble +the normal organ while in the latter definite scarring and distortion is +the rule. The gland acini are compressed, the cells vacuolated or +crushed out of existence or there may be colloid cysts. + +Inflammations occur as swellings of the interstitial tissues and of the +acinus cells during many acute infections. Repetitions of this may leave +a definite increase of connective tissue with large cells in the acini, +a lesion which many observers have looked upon as underlying certain +goitres and myxedema. + + +HYPERPLASIAS. + +The cause of progressive hyperplasias has been ascribed to infection, to +chemical substances in water and food, endogenous toxins, heredity and +many other factors. While we can add nothing definite in this matter it +is worthy of notice that all our animals are exposed to the same general +climatic conditions, receive the same water, are fed from the same +stocks and many varieties may be in charge of the same keeper. The +influence of preëxisting infections cannot of course be measured. +Inbreeding or captive breeding seems to have a very definite effect upon +thyroid insufficiency as is well known and so sharply emphasized by +McCarrison in his reference to intermarriage among certain Moslems; I +shall cite the history of a wolf bitch which gave birth to three cretin +litters while apparently well but mated to a goitrous male. These facts +concerning the etiology are given merely to emphasize the high degree of +probability that the distribution of the lesions of the thyroid gland +among our specimens indicates the susceptibility of the various orders. +This perhaps needs no emphasis for the carnivores, but it does for the +marsupials. The literature contains many references to goitre in +domesticated ungulates; this would give the impression that they are +common among them, and so they may be, but this is not the case for wild +ungulates. There being no doubt that the Carnivora have the highest +incidence of thyroid enlargement, man being especially prone to it, and +since goitre may be induced in fish by feeding meat, the inference is +direct that high protein diet stands in some relation to this condition. +Thirty-nine of our sixty thyroid lesions occurred in the order +Carnivora; all the families of land varieties are represented; 8.1 per +cent. of the specimens coming to autopsy showed definite thyroid +alterations. However, marsupials have also a decided thyroid +vulnerability as indicated by 4 per cent. of the specimens presenting +abnormalities at death. Four of the seven cases were among the +carnivorous opossums and “devils,” the remaining three being in +herbivorous kangaroos. The influence of high protein diet is not evident +in birds. + +A discussion of the essential pathology can be based upon the +accompanying table. In making a diagnosis care was used to exclude mild +swelling of the gland seen in acute infectious disease and under +conditions of sexual activity. The gross diagnosis was checked by +microscopical section, and all but a very few have been reëxamined for +the purpose of making the table. + + TABLE 16. + _Showing Distribution of Lesions in the Thyroid Body by Giving the + Number of Cases Met in the Autopsies upon + the Various Orders, According to the Classification Given in the Text._ + + ═══════════╤═══════╤═══════╤═══════════╤═══════════╤═══════════ + Order │ Cases │Colloid│Hyperplasia│Hyperplasia│ Papillary + │ of │Goitre │ with │ without │Adenomatoid + │Thyroid│ │ Colloid │ Colloid │Hyperplasia + │Disease│ │ │ │ + ───────────┼───────┼───────┼───────────┼───────────┼─────────── + Carnivora │ 39│ 7│ 6│ 5│ 4 + Rodentia │ 1│ │ │ │ + Ungulata │ 2│ 1│ │ │ + Marsupialia│ 7│ 1│ 1│ 1│ 1 + Passeres │ 2│ 2│ │ │ + Psittaci │ 2│ │ │ │ 1 + Accipitres │ 1│ │ 1│ │ + Galli │ 2│ 1│ │ 1│ + Alectorides│ 1│ │ 1│ │ + Anseres │ 3│ │ 2│ │ + ───────────┼───────┼───────┼───────────┼───────────┼─────────── + Total │ 60│ 12│ 11│ 7│ 6 + ───────────┴───────┴───────┴───────────┴───────────┴─────────── + + ═══════════╤═══════════╤═══════════╤══════╤═══════╤═══════ + Order │ Nodular │ Malignant │Mixed │Sarcoma│Atrophy + │Adenomatoid│Hyperplasia│Tumors│ │ + │Hyperplasia│ │ │ │ + │ │ │ │ │ + ───────────┼───────────┼───────────┼──────┼───────┼─────── + Carnivora │ 9│ 1│ 1│ 1│ 7 + Rodentia │ │ │ │ 1│ + Ungulata │ │ │ │ │ 1 + Marsupialia│ 3│ │ │ │ + Passeres │ │ │ │ │ + Psittaci │ │ 1│ │ │ + Accipitres │ │ │ │ │ + Galli │ │ │ │ │ + Alectorides│ │ │ │ │ + Anseres │ │ │ │ │ + ───────────┼───────────┼───────────┼──────┼───────┼─────── + Total │ 12│ 2│ 1│ 2│ 8 + ───────────┴───────────┴───────────┴──────┴───────┴─────── + +[Illustration: + + FIG. 31.—HYPERPLASIA WITH COLLOID. AMERICAN BADGER (TAXIDEA TAXUS). + MEASUREMENTS; 3 × 1.5 CM.; 3 × 1.5 × 1½ CM. +] + +[Illustration: + + FIG. 32.—ADENOMATOID GOITRE. RACCOON-LIKE DOG (CANIS PROCYONOIDES). +] + +This rather diversified group of pathological lesions would warrant one +to expect a notable number of instances of disease observed during life, +suggesting that the thyroid was at fault; such, however, is not the +case. In the first place, no case of exophthalmic goitre, as the symptom +complex is known in man, has been observed, yet the anatomical +alterations, hyperplasia without colloid, and with papillary or solid +adenomatoid character, are abundantly represented. For the pathologist +to accept a case as toxic goitre I would ask evidence of enlargement of +the heart and perhaps in addition degeneration of the myocardium. The +animal showing the closest resemblance to the disease in man was a +Raccoon-like Dog (_Canis procyonoides_) whose history and notes are +given in brief. + + + Raccoon-like dog (_Canis procyonoides_) ♀ . Acute hemorrhagic + splenitis. Acute fermentative gastritis. Subacute catarrhal enteritis. + Acute general infection. Hypertrophic cirrhosis of liver. Chronic + interstitial nephritis. Hypertrophy of heart with acute myocarditis- + infiltrative and parenchymatous. Chronic lymphadenitis with acute + exacerbation. Epigastritic and gastric venous stasis. Nodular + adenomatous goitre. The right thyroid is lower, both measure 4 × 3 × 2 + cm., are soft, resilient with dense gray capsule. Section shows cysts + filled with blood separated by pale septa of soft tissue of varying + thickness. One similar mass under angle of jaw seemed like a lymph + node but on section is like thyroid. Parathyroids not found. Pleuræ + negative. Lungs are gray, collapsed except lower half of lower lobes + which are slightly emphysematous and edematous. No consolidations. + Pericardium contains about 3 cc. clear, colorless fluid. Epicardium is + glistening, transparent and pale. Heart muscle is soft flaccid, pale + mottled gray-brown. All chambers are distended with mixed clot. The + coronary muscles and columnæ are mottled brown and gray. The tips at + insertion of chordæ are pale. Streaks of gray run through muscles. One + area 1 × 2 cm. of softening found in middle of left auricular muscle. + Aorta negative. The liver is enlarged, surface rough and irregular, + edges rounded and uneven, consistency firm and tough, color mottled + deep red-brown. Section surface glistening, moist, granular, opaque. + Lobular markings not lost but obscured. Connective tissue lines not + clear but surely diffuse in lobules. Scars on surface leading to + definite connective tissue strands about vessels and irregularly + placed. Gall-duct patulous with limpid bile. Spleen is well forward in + front and below stomach. It is much enlarged, soft, tough, has a + smooth, tense capsule. Section surface shows homogeneous purple pulp + with faint, narrow but tough trabeculæ. Follicles distinctly outlined, + slightly large but merely of a slightly paler purple than pulp. On + surface are many round 2–5 mm. sharply outlined gray thickenings of + the capsule and immediately subjacent pulp. The right kidney’s lower + half has been replaced by a thin-walled clear cyst 3 × 2.5 × 2 cm. The + left kidney is small, capsule strips with difficulty tearing surface + slightly. Surface and section are mottled pink and gray, glistening + and opaque. It is firm, dense and tough, cortex narrow, medulla wide. + Cortex has obscure, irregular markings with few small cysts, striæ and + glomeruli, faintly visible, margin between layers irregular. Veins are + distended over surfaces of stomach, under surface of diaphragm, in + peritoneum over liver but not in abdominal wall. Stomach contains sour + gas and water. Mucosa especially near cardia is deep purple. Rugæ are + large and permanent but mucosa and submucosa are soft and on section + congestion does not extend deep. The tips of the rugæ near pylorus are + infiltrated and the infiltration is surrounded by a zone of + congestion. Mucosa seems about to slough but has not separated. At + pylorus mucosa becomes deep brown-red, dense, swollen, opaque and + covered with a slimy, soft brown mucus. Folds are prominent but + temporary. In jejunum and ileum mucosa is still swollen and opaque and + rugæ are still larger than normal and temporary with a dense sensation + on compressing them. The color is not brown but deep pink and yellow + with areas of submucous injection. Follicles not visible. Colon is + negative except for slight thickening of mucosa unaccompanied by + congestion or opacity. Lymph glands of small omentum are small, firm, + yellow, homogeneous; those of the mesentery are large, edematous, + yellow brown and tense with lymph which escapes on section. Lymph + channels up to mesenteric stalk can be traced. + + HISTOLOGICAL NOTES.—Liver architecture much altered by passively + dilated hepatic capillaries chiefly toward the centre of the distorted + lobules. This distortion is in the form of irregular liver columns + separated by irregular vessels and interlobular connective tissue. + This latter is increased everywhere but is abnormal in distribution + within the lobules. The connective tissue at the portal spaces is not + so much increased but it shows most around arteries. Bile ducts seem + not increased in numbers. Much bile pigment in large, coarse, dark + brown masses chiefly settled within portal spaces. The cells show + slight fatty infiltration. No multinucleation. Organ is not seriously + robbed of functionating tissue. Alterations are not equally + distributed over section. Spleen shows enormous congestion with edema + of the few chords and perifollicular tissue left unengorged with + blood. Follicles are negative. No connective tissue increase. Blood + destruction not now active but there are many hemosiderotic masses + irregularly scattered. The subcapsular areas are loose edematous + follicles. Heart muscle fibres have lost all transverse striations, + some are hyaline while others are fibrillar. The nuclei are decreased + in number but there is no increase of connective tissue nuclei. No + pigmentation. There are several areas of round and polynuclear cell + infiltration and one distinct abscess in section. The perivascular + tissues are edematous. Muscle fibres are large and wide. Thyroid made + up largely of slightly enlarged acini in most of which a slightly + eosin-stained hyaline collection is found. There are a few cysts + containing a thrombus and hemorrhage. There are no typical colloid + cysts. Some scars from old hemorrhages may be seen. There is much free + blood in and between acini. Blood pigment free and in granule cells is + abundant. Some acinus cells show fat droplets. Lung shows old + interstitial tissue increase especially about vessels and a few scars, + some of which are forming cartilage. These are deeply encapsulated. + Mesenteric lymph nodes show trabecular thickening with active + connective tissue formation which is also present about follicles and + along edges of chords. Follicles lack germ centres, solidly lymphatic. + About them and in and along chords are many tissue cells some of + Maximov type and a few eosinophiles. Many of these and endothelial + cells are phagocytic of red blood cells. (Fig. 32.) + + +Just at the time of completing this book another case strongly +resembling exophthalmic goitre in man was encountered in a Gray wolf +(_Canis lupus_). This animal had a history of enlarged neck and +enlarging abdomen for about six months. His appetite and discharges +remained about normal but weight was lost and activity reduced to a +minimum. Attempts at removing the fluid believed to be in the +peritoneum, by the use of diuretics, failing and the beast being in such +poor shape, he was killed. An enormous adenomatoid goitre, concentric +hypertrophy of the heart, passive dilatation of all cervical and +thoracic veins, passive congestion of the liver and congestion of the +portal area were autopsy diagnoses. It will be noted that no +exophthalmos and nervousness were observed during life. + +Bone disease and atheroma are at times associated with thyroid +insufficiency in man. The former, aside from osteogenesis imperfecta of +cretinism, occurred only once in a carnivore and once in a marsupial. +There is but one case of atheroma among the sixty cases of thyroid +disease. + +The reaction of the avian thyroid in its hyperplasias is somewhat +different from that of the mammalian. The delicacy of the septa and the +relative paucity of vessels is perhaps the reason that the gross and +microscopic pictures differ from those found in mammals. It should be +emphasized, however, that while one can perceive a hyperplasia of the +gland of both classes when the testes or ovaries are active, there +appears less participation of the thyroid in birds in infectious +diseases than is the case for mammals. In simple functional hyperplasia +the capsular vessels are prominent, but the cross section need show no +change. In the continued hyperplasias the organ remains more solid, +being less apt to develop cysts; large cysts are occasionally seen, +however, and in one case the entire gland was composed of them. +Microscopically the differences are largely of degree in that the +process is less frank in development, but the essential changes of +swollen epithelia and condensed colloid remain the same. + + +ATROPHIES. + +The thyroid gland in its functional capacity, may be considered to +undergo hyperplasia and then atrophy of the parenchyma cells. Normally +this would leave the colloid, the epithelia and the supporting tissue in +proper balance, but in the presence of low grade inflammation or where +an abnormally hyperplastic process retrogresses, the connective tissues +may exceed their norm, the epithelia may be shed or remain high and the +colloid be irregular in distribution. Such a state of atrophy may exist +in fetal life, arise from unknown cause during a course of toxic goitre, +or perhaps insidiously in chronic toxic conditions. When this occurs in +fetal life cretinism or myxedema arises, when in later life, only the +latter appears. Judged entirely by microscopic findings, eight instances +of atrophic changes in the thyroid have been found. Three of these were +in Carnivora and were secondary to definite goitres, but were not +followed by myxedema; one of these three was a cretin. A brother of this +cretin but not himself a cretin, died at the age of five months from +acute dilatation of the heart, and with a decidedly atrophic thyroid +gland. A lion showed a distorted gland, the result of chronic +inflammation, a condition also present in a leopard, in the latter +possibly in association with a general infection of the heart, vessels +and kidneys of long standing. A case in a bear can only be explained on +the basis of chronic intestinal toxemia. A camel is the only other +variety of animal to show this regressive change. The beast suffered +with a marked anemia with marrow atrophy and hydatid disease; +calcification was found in the thyroid. + +[Illustration: + + FIG. 33.—COLLOID GOITRE WITH HEMORRHAGE FROM LEFT GLAND WHICH KILLED + THE BIRD. BLACK AREA IS CLOTTED BLOOD. MUTE SWAN (CYGNUS OLOR ♂ ). +] + +[Illustration: + + FIG. 34.—AT THE LEFT, THE INSIDE OF THE CALVARIUM SHOWING HEMORRHAGIC + PACHYMENINGITIS. AT THE RIGHT IS A FEMUR, SHORT AND HEAVY BUT WITH + THIN CORTEX; CONSTRUCTION IS ORDERLY. CRETIN GRAY WOLF PUP (CANIS + MEXICANUS). +] + +As has been repeatedly stated, myxedema has not been seen, but +hypothyroidism has expressed itself in these animals as cretinism. The +most interesting pathological fact concerning the relation of the +thyroid to this maldevelopment is that there is absolutely no uniform +gross or microscopical change constantly present in the typical cases. +This will become more evident as the following records of our cases are +perused. In 1914 an apparently normal Gray Wolf bitch threw two normal +young ones which died of lack of maternal care; they were not posted. +The father of this litter died shortly and was found to have a +sarcomatous hyperplasia of the thyroid. A year after the first lot a +second litter was born of an apparently perfect father which still +lives. This animal was purchased in the same lot with the mother, and +the two could be related. The first father was not related to the +female. This litter consisted of seven, two dying almost at once and +burned, the other five not being especially good specimens. They died at +ages ranging from two to five months and were all cretins or cretinoid. +Two showed hemorrhagic pachymeningitis, one external, one internal, and +the usual bulky skeleton of cretinism (Fig. 34). The bones were +constructed in a rather orderly and somewhat graceful manner, the +uncalcified epiphyses being only occasionally distorted. The same two +animals, mated again in 1916, had as offspring seven pups. One evident +cretin was killed while another runt was sacrificed and found to have +fractures of both femora around which no trace of callus was +discoverable (Fig. 35). Two other cubs were apparently normal, while the +remaining three did not develop and soon showed the cretin characters. +When this group was about three months old they were fed chopped horse +thyroid; one improved decidedly, one slightly, the third not at all, but +it might have been too weak to get its share. These animals lived from +eight months to three years; the two good ones remain alive. In 1919 the +mother was killed by her cubs, probably because she was weakened by long +sickness. A papillary adenomatoid goitre, endocarditis, nephritis and +chronic enteritis were found. The pathological changes in the thyroids +of the cretins were as follows: In the second litter two cubs had +hyperplasia with colloid, one had nodular adenomatoid change and the +fourth showed distinct atrophy secondary to colloid increase. In the +third group two had distinct colloid changes, once pure and once as a +secondary process with some evidence of atrophy to alter the fibrous +tissue and shape of the acini. The remaining four seem to be all colloid +in character, but I am not satisfied with the description or sections so +that I shall not offer an unqualified diagnosis. The adrenals of these +animals all showed some medullary congestion but no change in the +chromaffin or lipoidal content. + +The deformative lesions of bones are frequently associated with lesions +in the pituitary body. Several of our thyroid cases have been studied +for such changes without their discovery. Indeed no gross alterations +have been noted among many hundreds of hypophyses seen in removing the +brain nor in a small number studied histologically. Those examined under +the microscope have seemed to correspond to the descriptions given by +Stendell in Oppel’s _Handbook of Comparative Microscopic Anatomy_. + +[Illustration: + + FIG. 35.—PATHOLOGICAL FRACTURE OF FEMUR. CRETIN GRAY WOLF PUP. +] + +[Illustration: + + FIG. 36.—ADENOCARCINOMA SARCOMATODES. ADENOMATOUS PORTION ATTACKING + CAPSULE. RACCOON-LIKE DOG (CANIS PROCYONOIDES). +] + + +TUMORS. + +True malignant hyperplasias of the thyroid epithelium in man are being +more thoroughly studied in recent times so that similar lesions in the +lower animals gain interest. The notes given below are of value as +individual observations only, but since three were in carnivores, +another indication is at hand of the vulnerability of this order. One of +the cases is admitted upon diagnosis alone, the slides and records +having been lost, but since the determination was made by Dr. C. Y. +White, I am satisfied to accept it. The four of which notes are at hand +are as follows: + + + Raccoon-like Dog (_Canis procyonoides_) ♂ . Adenocarcinoma + sarcomatodes. Metastases to liver and lungs. Fatty degeneration of + liver and kidney. Acute diffuse splenitis. Submucous hemorrhages in + stomach. At level of thyroid cartilage on each side and removed 1 cm. + from same is a rounded encapsulated nodule measuring 2.5 × 2 × 1 cm. + Portions are hard, others fluctuate suggesting cystic degeneration. + Below these nodules are two bodies also bilateral, evidently lobes of + thyroid, each measuring 5 × 2.5 × 2.5 cm. They are firm with some foci + of cystic softening. From a ruptured cyst of the right lobe grumous, + red, malodorous material exudes. Peripheries of such cyst show + greenish discoloration. Bodies as a whole are greenish black in color. + They are well encapsulated, do not meet in midline but are joined at + lower pole by firm, apparently colloid, material. All through lung + especially under pleura there are dark red, rounded, firm, well + circumscribed foci measuring 2–8 mm. diameter. They project markedly + on pleural surface. No capsule can be made out. Upon incising they + have lighter red centres and deeper peripheries. They cut with + resistance and have no inclination toward a wedge shape. Surface is + for most part smooth except where tumors are present. Organ is soft + and distinctly yellow. All portions of liver contain rounded and + irregular nodules, some deep, others superficial. They vary in size + from 2 mm. to 3.5 cm. diameter. No capsule can be made out, yet they + are circumscribed. The central portions of larger nodules are dirty + gray and friable. Peripheral parts dark red. Smaller lesions are solid + red and of fleshy consistency. Spleen is deep dark red, homogeneous. + Histological section of thyroid shows firm, old, dense capsule very + irregular in thickness seemingly on account of the penetration of the + enclosed tumor cells. Such infiltration gives the inner outline of + capsule a very irregular, bizarre appearance, and at times thins the + capsule until it is reduced to nil. In one place the tumor elements + appear outside the capsule at a point where a large vessel is apposed + to outside capsule. The appearances within this capsule vary; in + places the picture is that of a carcinoma. Small, round, interspersed + with larger irregularly shaped acini are seen lined by a single layer + of low cuboidal epithelium. Very frequently indeed the lining cells + contain fine granules of golden brown pigment even where their lumina + contain no blood. Some of the larger acini contain altered blood cells + and a smooth, pink material, knife streaked and vacuolated + peripherally. In some parts of section these acini are regular and + well formed, in others they are very irregular and appear to be + eroding the capsule. A second appearance concerns the connective + tissue. Appearing in almost any part of the section and bearing no + regular relation to the epithelial elements or the section in general + are areas of closely packed large spindle cells with hyperchromatic + nuclei. In another place such spindle cells are arranged purposefully + to form irregular capillaries containing blood. A third appearance + results from a combination of the first two. Here there are acini, + between which run blood capillaries with remarkably rich and numerous + embryonic lining cells. A section stained by Van Gieson stain proves + that part of the pink intra-alveolar material is colloid. Every + gradation can be made out in tint of this material from pink to salmon + to orange. It is often very difficult or impossible to state whether a + given blood-filled space is a blood vessel or an acinus with + hemorrhage. In both structures the lining consists of flattened cells. + In one there is the possibility of colloid, in the other of + hematogeneous hyaline, both with peripheral vacuolization. Lung shows + walls of alveoli thickened by young type of cells. Nuclei of cells + lining bronchi are prominent, in good condition. Much coal pigment + through whole section. Air sacs empty. There are several rounded nodes + through section consisting of closely packed spindle and round cells. + Blood is abundant in such nodules both in small lined spaces like + capillaries and in larger necrotic foci where there is abundant blood + pigment. In one place an irregular, large acinus is seen containing a + smooth pink material. A large part of the interstitial tissue is + diffusely infiltrated by the large, round cells with hyperchromatic + nuclei (Figs. 36 and 37). + + Prairie Wolf (_Canis latrans_) ♂ . Mixed tumor of thyroid. Metastases + to lungs. The neck of the animal is enormously enlarged, the diameter + exceeding that of the body. Thyroid is enormously enlarged to about + the size of a child’s head, rather firm before incision. When incised + about 300 cc. blood stained fluid drained. It is rather soft and quite + friable looking as if made up of fatty and hemorrhagic matter. The + lung is of mottled deep red color with here and there on surface small + hemispherical areas about the color of the surrounding tissue but of + slightly increased resistance. They are raised above the surface and + measure 2–7 mm. in diameter. Histological section of thyroid shows a + mixed tumor. It is not possible to say that it is a pure thyroid gland + tumor. It is largely sarcomatous, the round cell alveolar arrangement + dominant at one place, at another the short spindle cell but not + typical, so-called spindle celled type. There are many areas of small + and a few of large hemorrhage. Cartilaginous deposit is occurring at + some places in the field showing the latter type of sarcoma. Section + of lung contains a large sarcoma nodule. The cells consist of round + cells without the large cartilage-like cells found in the original + tumor mass. + +[Illustration: + + FIG. 37.—ADENOCARCINOMA SARCOMATODES. SARCOMATOUS PORTION. RACCOON- + LIKE DOG (CANIS PROCYONOIDES). +] + +[Illustration: + + FIG. 38.—ADENOPAPILLOMATOUS HYPERPLASTIC PORTION OF THYROID. UNDULATED + GRASS PARRAKEET (MELOPSITTACUS UNDULATUS). +] + + Coypu (_Myocastor coypus_) ♂ . Sarcoma of right thyroid. The thyroids + occupy a position deep in the neck upon the anterior vertebral + muscles, the left higher than right, being up to level of top of + thyroid cartilage. Only a half-inch of lower pole of right remains and + it is like the left which is soft, deep brown-red, delicately + lobulated, closely bound to trachea but movable in fascia. It is + 30 × 10 × 3 mm. The upper part of the right organ is occupied by, or + at least within the same capsule as a 25 × 15 × 10 mm. encapsulated, + pink mass with many small vessels on its exterior. It is soft and on + section the surface is mushy, of gray-pink-yellow, and seems to have + an exceedingly delicate trabecular network. Posterior and superior to + this, lying near the salivary glands but back of them is a similar + mass 15 × 12 × 5 mm. Still another lies anterior to what remains of + the right thyroid and is about 8 × 5 × 4 mm. The adrenals are + 30 × 13 × 8 mm. slightly hard and not unlike a long kidney in + arrangement. The cortex is wide, regular, brown or tawny, the medulla + rich in vessels and deep brown. Histological section of thyroid is an + almost completely cellular mass with here and there delicate and + incomplete trabeculations. Small blood vessels are numerous and + consist of a delicate line with a cell nucleus here and there, that is + no true wall. It seems as if the blood channels were simply regular + spaces through the cell mass. The cell type is mononuclear with + definitely acidophilic “granuloid” somewhat vacuolated protoplasm. The + nucleus is almost without exception eccentric, rather poor in + chromatin but in places diffusely staining. Mostly, however, the + nuclear skein is in spots or threads and fairly dense around margins, + therefore not unlike a thyroid cell and a plasma cell. Here and there + one finds compressed remains of thyroid acini. There is decided + irregularity of size and shape in these cells. Its origin is not clear + but this seems like a sarcoma of the thyroid. + + Undulated Grass Parrakeet (_Melopsittacus undulatus_) ♂ . Medullary + carcinoma of thyroid. On opening the body a mass 10 × 6 × 4 mm. is + found in the upper thoracic region on the right side. A similar mass + measuring 5 × 3 × 2 mm. lies in similar position on the left side. + They are identified as thyroid glands only from their position and + from the numerous large vessels which radiate from them. An especially + large vessel leads directly to the heart. Long axes extend + anteroposteriorly. The masses are of a firm gelatinous consistency, + the color of carpenters glue in lower portions, shading off to a dirty + canary yellow above. They have a translucent appearance in lower + portions. The surface is fairly smooth, adherent latterly and + posteriorly. They are well circumscribed. At one end of the + histological section thyroid tissue is easily identified. It varies + from normal in that its spaces are often very large, contain villus + projections or may be completely filled by large compound granule + cells with no colloid. Other acini are atypical and contain typical + colloid. Continuous to such thyroid tissue is a very large, rounded + tumor. It consists of round cells with round nuclei in which many + mitotic figures may be seen. An arrangement into acini cannot be made + out nor is colloid material abundant. In one or two places an + irregular collection of such material may be seen with peripheral + vacuolization but its confines are always indefinite. As far as + section goes the mass is well encapsulated but the lymphatics are + infiltrated by the tumor cells. The tumor, too, is sharply separated + from the relatively normal thyroid. Irregularly scattered through + section are remarkable cells with nuclei three or four times the size + of other nuclei. They may be hyperchromatic or normally staining. + (Figs. 38 and 39.) + + +The THYMUS BODY is a structure encountered in our specimens with greater +regularity than is the case in human autopsy experience. However, no +great size of the gland is observed, and there is no record or +recollection of anything which could resemble an enlargement suggesting +status thymicolymphaticus nor has a tumor with this organ as its origin +been observed. In one case only did the thymus present what was believed +to be an unusual size. An adult Gray Lagothrix (_Lagothrix lagotricha_) +died with an acute intestinal infection. Its thymus was a large, soft, +deep pink body lying in the anterior mediastinum, running up to the +clavicular joints and down along the sternum. The death had ample +explanation without any state of this organ. The thymus body has not +been found enlarged in association with thyroid disease. + +[Illustration: + + FIG. 39.—MEDULLARY CARCINOMATOUS PORTION OF THYROID. UNDULATED GRASS + PARRAKEET (MELOPSITTACUS UNDULATUS). +] + +The SUPRARENAL or ADRENAL BODY is an organ of essentially the same +general construction in the two classes here studied except that in +birds the cortical portion may be imperfectly developed and in some of +the lower groups is decidedly narrow. This outer zone may indeed be +entirely missing since tissue comparable to it is distributed elsewhere +in the body, notably with ganglia along the vertebral column. The organ +is infrequently the seat of alterations, detectable either grossly or +microscopically. Congestion and small hemorrhages are rather common in +acute infectious disease especially when the respiratory system is +involved, but these rarely destroy tissue or materially reduce the +chromophilic cells. These circulatory disturbances have, however, been +predominatingly among the mammals although birds have suffered with +infections to a high percentage. The medulla is much more often the seat +of congestion while, when hemorrhage has occurred, the cortex is +apparently always involved. Lipoidal reduction has been seen in a few +mammals, Primates and Carnivora, once to a state of complete exhaustion. +More serious lesions have occurred eleven times, and since the cause and +meaning of disease in this body are so vague it seems well to recite +briefly each one. + +A Weeper Cebus (_Cebus capucinus_) suffered for several months with +constantly but slowly increasing skeletal deformity of the osteomalacic +variety. He died after moving him to a new cage, his end being hurried +by a scalp wound. At autopsy the skeletal condition was determined to be +of the above named kind. The organs were in good condition. The adrenals +were decidedly enlarged for a monkey of this size, measuring 1.8 cm. in +length. The medulla was a solid, brownish, homogeneous portion covered +with a very narrow, barely discernible cortical zone. This was +apparently due to a uniform hypertrophy of the cells of the medulla. The +testes were slightly atrophied and fibrotic. A Black Spider Monkey +(_Ateles ater_) had a history of stiffness of legs for six months. This +was probably a sign of osteomalacia since at autopsy this condition was +found together with a secondary anemia, chronic gastritis, acute +enteritis and brown atrophy of heart. The adrenal was knob-shaped, the +cortex was wide, brown, regular, the medulla small gray-purple. +“Histologically the capsule of the adrenal is thicker than is commonly +seen in Primates and connective tissue bands between the units of the +zona glomerulosa are somewhat stouter than common. The cells of this +layer take the stain a little more deeply than usual, but are otherwise +negative. The layer separating cortex and medulla is occupied by a band +of well formed connective tissue which is not proceeding inward but +outward and so encroaching upon the zona reticularis as to remove it +completely in places, in others to make isolated islands of its cell +groups. Fine lines of connective tissue are penetrating from this into +the middle layer but not disturbing it as yet. The connective tissue +septa penetrating the medulla are somewhat wider than one would expect +but show no activity in their growth. The medulla is somewhat broken up, +vacuolated and the chromophilic cells are not especially prominent, +indeed some of them seeming to have undergone necrosis.” A puma (_Felis +concolor_) died after a sickness of two weeks from acute gastroenteritis +with its usual visceral associations, including acute nephritis, and +with calcifications in the adrenals. These structures were quite firm +and nodular, on section tough and resilient. “The cortex is irregular, +brown, with paler brown medulla. Areas of calcifications appear as small +dots, as linear formations and in some places seemingly around blood +vessels. Histological section shows marked vacuolization of cells, +particularly of cortex. There is a diffuse overgrowth of connective +tissue which has become hyaline. Here and there small calcareous +deposits may be seen but no massive areas as mentioned above.” + +A Himalayan Thar (_Hemitragus jemlaicus_) came to his end, after a +history of convulsions, from nephritis, which had resulted in general +edema including the serous sacs, and an associated cardiac dilatation. +His adrenal was egg-shape, of normal size, with a wide, irregular dull +brown cortex and a homogeneous opaque, darker brown medulla. +“Histologically the cellular structure of the cortex is partly +destroyed, partly dropped out and partly disturbed by overgrowth of +connective tissue. This connective tissue is quite prominent in the +medulla where it is surely increased although it is made more prominent +by absence of cells, some of which have been degenerated and some +dislodged.” A Japanese Macaque (_Macacus fuscatus_) after drooping three +weeks presented at autopsy the following numerous lesions: anemia, +chronic atrophic gastritis, atrophy of heart muscle with regeneration, +hemosiderin pigmentation of liver, perilobular fibrosis of liver, +chronic diffuse nephritis (subcapsular type), congestion of spleen, +fibrillar fibrosis of spleen, hemosiderin pigmentation of spleen, local +amyloid infiltration of spleen, calcareous infiltration in medulla of +adrenal. Grossly the adrenal showed a thick, orange yellow cortex and +small solid, brown medulla. “Histologically the organ appears normal in +all respects save for the presence of a few small irregular areas of +calcification in the medulla. These occur apart from any recognizable +necrotic or fibrous areas. In one place one appears to lie within the +lumen of a blood vessel. No fibroses or special congestions found +anywhere in the organ and cells show normal details and normal numbers +of vacuoles.” + +A California hair seal (_Zalophus californianus_) which had been +refusing food and having loose stools for about ten days presented after +death the following diagnosis: Hypernephroma of adrenal, chronic +hypertrophic enteritis with acute exacerbation, hemorrhagic splenitis, +passive congestion of liver, congestion and edema of lungs with +catarrhal pneumonia, acute fibrinous pericarditis, chronic +lymphadenitis, chronic interstitial nephritis. His right adrenal seemed +about normal, being 5 × 2 × 1 cm. with a narrow, dull yellow cortex and +a large mottled gray-brown medulla. The left one was 5 × 3 × 1 cm. The +upper pole is swollen and contains in its centre a spherical tumefaction +which is red, mottled, sharply outlined, with a suggestion of a capsule +and slightly firmer than surrounding organ. “Histological section shows +a capsule of very noticeable thickness but possibly not much in excess +of normal. The cortex particularly in its deeper layers is much injected +and in some places there has been hemorrhagic diffusion. In many places +in the zona fasciculata, more especially near the periphery, there is +breaking up of the cell tubes with an infiltration of large round cells +and some chromatophilic cells. In other places this seems to have gone +on to fibrous tissue increase and necrosis of the cortical fibrous cell +types. The connective tissue layer below the cortex is wide and the +spaces filled with blood. This connective tissue also surrounds islets +of medullary cells which are not specially chromatophilic. The mass in +the medulla is made up of varying sized alveoli surrounded by rather +rare, highly vascularized connective tissue and enclosing islets of +medullary cells. These alveoli may be subdivided by septa. Hemorrhage +has occurred into many of them. The individual cell masses are made up +of groups of rather large cells with illy defined margin, a granular, +opaque but not vacuolated protoplasm. They have a bladder-like nucleus +in which the centrosome is large and prominent. Definite mitotic figures +could not be found, but mitosis is probably present. A few cells with +double nuclei were seen and one with four. In many of these large +islands the centre has gone to pieces from hemorrhage or necrosis. Some +of the vessels are thrombotic and one shows a very pronounced +periarteritis.” A brown cebus (_Cebus fatuellus_) was killed because of +a poor tuberculin test chart. His organs were negative except the right +adrenal body which was 3 × 1.5 cm., or four times the size of its +fellow. It was a tense body with a smooth, mottled, deep yellow surface. +On section there were deep yellow islands separated by pale brownish +septa; the structure did not resemble adrenal. Histological section +showed a hypernephroma of vacuolated cell type, roughly alveolar. Two +other cases, which because of their microanatomy are to be called +hypernephroma can be added to those just cited. One occurred in an +undulated grass parrakeet (_Melopsittacus undulatus_), the other in a +black duck (_Anas obscura_). As illustrative of this tumor the former +will be cited in brief. “Hypernephroma of adrenal with hemorrhage into +body cavity. A tumor approximating in size the head of the host extends +from the region of the internal genitalia and adrenals lying more on the +right than on the left side extending fully to cloaca and shoving all +abdominal viscera forward. It has a pedicle springing from between the +two upper lobes of the kidney where adrenals and internal genitalia are +not distinguishable. Tumor is coarsely lobulated, well encapsulated, +nowhere adherent. It has a pale, dirty yellow color, richly marked by +red lines of congested vessels. It is fairly soft, _i.e._, about +consistency of normal liver. Upon incising, the cut surface bulges +markedly, is a dirty gray-yellow, blotched with darker gray areas, shows +no internal hemorrhages or markings of special import. No metastases +noted to any other organ. Microscopic section shows a light capsule +surrounding the tissue of the tumor. The latter has a very scanty +fibrous reticular framework showing no orderly or purposeful +arrangement. Upon and between the reticulum, irregular and for the most +part elongated collections of cells are placed. At times these present +an elongated fascicular form, but this is not by any means a prominent +feature. The cells themselves are large, rounded or polygonal, have +coarsely granular cytoplasm which only in rare cases contains vacuoles. +Nuclei of these cells stain very poorly, but it can be made out that +they are of large epithelial type and of vacuolar appearance.” + +A somewhat unusual tumor was encountered in a Polar bear (_Ursus +maritimus_), an adenocarcinoma of the adrenal, when judged purely by its +histology but a secondary tumor in the lung displayed the more familiar +picture of large vacuolated cells as seen in hypernephroma. The +diagnosis follows: “Scirrhous adenocarcinoma of adrenals, secondary +carcinoma of lymph glands, secondary hypernephroma of lung, secondary +carcinoma of diaphragm, acute mucopurulent bronchitis, acute catarrhal +enteritis, chronic diffuse fibrous cholecystitis, cholelithiasis, slight +acute interstitial pancreatitis, follicular hyperplasia of spleen with +fibrosis, hydrothorax, hydropericardium, chronic hypertrophic +osteoperiostitis, encysted trichina in diaphragm, fatty infiltration of +diaphragm, chronic diffuse nephritis, chronic productive lymphadenitis, +pigmentation of lymph gland. Both adrenals are smaller than normal, of +woodeny consistency, the pale cortex and medulla are poorly separated +from each other. The cut surface shows gray white and tawny mottling and +occasional calcareous points. Histological section shows an extra +capsule of fibrous tissue containing highly distended veins; the lining +contains masses of tumor cells, many of which are necrotic. It is +distinctly denser in type than normal and more abundant in places +showing a proceeding fibrosis. Parenchyma shows but few irregular +islands containing non-neoplastic cells, some of which are highly +vacuolated, others are not. Interstitial tissues in peripheral parts are +often grown together with the deeper portion where are intermixed tumor +areas. The latter consist of small round acini of variable size lined by +cells of active type. Nuclei are large and hyperchromatic, cytoplasm +broad and disintegrating. Parts show necrosis and hemorrhage. Upon +search transitionals from non-neoplastic to neoplastic cells can be +discovered in same fasciculus.” + + + + + SECTION XII + THE SKELETON AND ITS JOINTS + + +The bones with their articulations have been the subject of extensive +study and research by zoologists in the direction of classification and +evolution. Adaptation of the osseous construction to the needs of the +animal is well appreciated biological knowledge. For example, the keel +of the sternum in birds affords broad origins for the flying muscles, +the pectorals, which also insert on the alæ of this bone and on the +clavicle, and in addition use these latter formations as fulcra. So too +the extremities of quadrupeds are angular in their upper two segments +for the purpose of supplying a direct action of the flexors employed in +running and leaping. The thick masseter muscle of carnivores is +accommodated in the deep zygomatic fossa. Many other examples might be +cited, but these serve to direct attention to the adaptation of function +and construction. Pathological changes in our materials are however too +few to permit conclusions as to possible relation of zoological position +and development except such as may refer to deformity incident to the +degenerative processes—rickets, osteomalacia and osteogenesis +imperfecta, and in these conditions the alterations are merely passive +accommodations to weakened support in order to obtain comfort. To put +the matter in other words, it would seem that, aside from the diseases +just named, there is no outstanding change in the skeletal tissues +peculiar to zoological orders that might indicate vulnerability of the +system or the methods of response to injury or disease. + + +EFFECTS OF TRAUMA. + +There must be considerable reserve or reconstructive power in the bones +of animals since it is a common thing at autopsy to see unmistakable +evidences of repair of fractures, dislocations and inflammations. Some +illustrations are introduced to exemplify this healing ability, one of +which was found in an animal shot by a hunter, the other an incidental +autopsy discovery. Even though there be no definite relationship between +the zoological order and osseous disease, it is interesting to record a +very simple observation. Animals with long extremities, especially when +the bones are quite near the skin, have a rather high incidence of +fractures and inflammations. Thus the ungulates have of all orders the +highest percentage of these traumatic and infective lesions; herons and +gallinaceous birds follow the ungulates. Marsupials, primates and +carnivores, in this order, are susceptible to inflammations but not to +fractures. Bones are often broken, among the Cervidæ, Bovidæ and +Camelidæ, when as they are chased by mates, they fall upon the slippery +floor of the cages; or again the mounting of a small animal by a large +buck may crush the former to the earth. Two cases of fractured pelvis +have been seen in antelopes from a fall with extended hind legs. + +It would seem that repair is usually satisfactory if the animal has a +quiet retreat where callus may form and union occur. A heron is known to +have broken both bones of the leg; at autopsy a very insignificant +circumferential callus remained, the member being as straight and strong +as normal. Figure 40 shows the femur of a deer shot by a hunter; the +shortening was considerable, but function was doubtless good because the +hunter could perceive no limping as the animal ran. The most interesting +fracture among our records was an intracapsular fracture of the hip in a +Huanaco (_Lama huanacos_) shown in Figure 41. This animal slipped on the +ice in December and was thought to have broken something near the hip, +but it limped around without any great show of pain until the following +May, when it died of meningitis secondary to an _otitis media et +interna_. At autopsy an unhealed, complete fracture of the neck of the +right femur was found, apparently separating the head from the neck, the +former being dislocated to the upper angle of the obturator foramen. +Everywhere about the joint callus had been thrown out, but not in a +manner to effect a junction of the broken ends nor to seal the edge of +the acetabulum to the femoral neck. This was probably due in part to the +irregularity of the line of fracture and to the interposition of the +upper part of the dislocated head between the lower rim of the +acetabulum and the surgical neck of the bone. When the specimen was +fresh traces of capsule were found over the upper half of the +acetabulum. While it is usually difficult to decide the manner in which +these injuries effect their damage and deformity, it might be ventured +to explain this case as due to extreme posterolateral extension of the +leg driving the head of the femur downward and inward, rupturing the +capsule and the ligament bridging the acetabular notch, to rest on the +pubis at the upper edge of the obturator foramen where it could find a +sort of joint cavity made by the pubic and ischial segments of the old +acetabulum, but about an inch and a half below its normal location. + +[Illustration: + + FIG. 40.—HEALED FRACTURE OF FEMUR. FROM A DEER SHOT BY A HUNTER. +] + +[Illustration: + + FIG. 41.—PARTIALLY HEALED INTRACAPSULAR FRACTURE OF HEAD OF RIGHT + FEMUR. HUANACO (LAMA HUANACOS). +] + +Another injury to the hip joint was noted in a Livingstone’s eland +(_Taurotragus oryx livingstonii_). This beast was not positively known +to have fallen, although it was suspected that such an accident had +occurred by reason of sudden inability to rise. At autopsy, death having +succeeded on signs of shock, a complete upward and backward dislocation +of the right femoral head was found; there was also an intracapsular +rupture of the left round ligament, but on this side the femoral head +had not left the acetabular cavity. + +Many other fractures have been observed but generally without +interesting features. The conclusions which may be drawn from our +experience are that animals with long bones, and liable to chase have +the greatest liability to fractures, and that the healthy beast, given +seclusion and quietude, possesses great ability to heal its broken +bones. Pathological fractures are occasionally seen. (Consult notes on +cretin wolves.) + +Before entering upon a discussion of the most important of osseous +lesions, rickets and osteomalacia, certain inflammatory states may be +appropriately described. + + +INFLAMMATIONS. + +Hypertrophic osteoperiosteitis: A male lion (_Felis leo_) at the Garden +three years died, after being out of condition for a long time, from +chronic ulcerative pulmonary tuberculosis with terminal pneumonia, +nephritis and enteritis. Both hind feet had been observed as enlarged +and apparently painful for some weeks before death. Upon dissection the +bones of both hind feet are the seat of extensive hypertrophy, and the +periosseous fibrous tissues are thickened. A large mass about the size +of a small orange lies attached to the outer side of each ankle. The +hypertrophic periosteitis extends up the tibia a distance of about three +inches and the fibula for about the same distance. These two bones are +adherent to each other for about 1½ inches. The joint between them and +the tarsal bones is apparently perfectly free. The calcaneum is the bone +most severely involved; on this is a large rounded mass which extends on +the bone for a distance of about 2½ inches. The small bones of the foot +are more or less severely involved but are not bound together, the +joints being practically free. The terminal and next phalanges are +entirely free from disease while the metatarsals are severely involved +and grown together into one large mass. On section this appears as a +mass of spongy bone lying on top of the cortex. In the dried specimen +this looks very like old pumice stone. Histological section shows the +periosteum raised from the bone by mononuclear infiltration. The bone +marrow spaces are filled by a very delicate gelatinous material. The +lamellæ are thickened. A photograph of the foot with a normal example is +given. (Fig. 42.) (See also Tuberculosis section—Carnivora.) + +[Illustration: + + FIG. 42.—HYPERTROPHIC PERIOSTEITIS. RIGHT HIND FOOT WITH A NORMAL + LEFT. LION (FELIS LEO). THIS CONDITION WAS ASSOCIATED WITH CHRONIC + PULMONARY TUBERCULOSIS. +] + +[Illustration: + + FIG. 43.—MARKED SCOLIOSIS IN A COCKATOO. +] + +A cockatoo died from acute miliary tuberculosis; the upper thoracic and +lower cervical vertebræ are involved in an S-shaped scoliosis which +reduces the height of the thorax by perhaps a centimetre. Thorough +dissection was not made, the trunk being kept as a museum specimen and +for study in event another avian scoliosis occurred; but from palpation, +separation of the muscles and stretching of the spinal column it does +not appear that a tuberculous osteitis of the vertebra existed. It seems +that this may be due to congenital deformity or old injury. + +A white-nosed coati (_Nasua narica_) suffered with generalized +tuberculosis which also affected the wrist joint with a caseous and +ulcerative arthritis. + +Gouty arthritis has been recorded but three times, although on several +occasions small uratic deposits in tendon sheaths have been observed in +birds; gout has not been seen in mammals. An illustrative case in a +Boat-billed Heron (_Cancroma cochlearia_) will be given in the section +on gout. + +Arthritis as an acute infectious disease such as rheumatism of the human +being, has not been observed, but copious examples of acute, subacute or +chronic monoarticular inflammation are recorded. Nearly all of these +have a definite explanation—traumatism or acute general disease, and +there are a few cases of polyarthritis with chronic disease. Notable +among the last are two instances of chronic dry ossifying arthritis and +synovitis, one with tuberculosis, the other with actinomycosis, both +occurring in ungulates. A third case similar in character deserves +special mention. The Indian elephant “Bolivar” (_Elephas indicus_) died +from pulmonary tuberculosis, myocarditis, nephritis and hepatic +cirrhosis. The joints of all extremities showed atrophic arthritis with +fluid, the synovial membranes being ulcerated or retracted and fibrotic. +The articulating surfaces where not roughened by erosion, were +flattened. It is perhaps worthy of mention that this old and familiar +animal was the occupant of the same enclosure, floored with cement, for +over thirty years, conditions which might be partly instrumental in the +arthritic changes as well as in the flattening of articular surfaces. + +The Ungulata frequently suffer with wounds, ulcers and abscesses about +the lips, nose, and soft tissues of the jaws which may at times be +confusingly like actinomycosis. This disease we have seen in gazelles +and tapirs but have had to exclude it in several other members of this +order. A number have come to autopsy with osteitis of the lower +mandible, some evidently traumatic in origin, others probably due to +infection _via_ the teeth. Figure 44 represents the jaw bone of an +Isabelline gazelle (_Gazella isabella_) suffering with a rarefying +osteitis from a root abscess, and illustrates well the possibility of +focal infection from this source. + + +DEGENERATIVE SKELETAL DISEASES. + +While the foregoing instances of disease in the osseous system are +interesting examples of individual pathological lesions, they are +insignificant in comparison with the forms of bony change known under +the names of rickets, osteomalacia, osteogenesis imperfecta and the +like—systemic conditions which are chiefly degenerative but have certain +evidences of inflammation in addition. The modern knowledge of the first +two named is so far from complete that it cannot be said that there is +any certainty of their identity. Indeed there seem to be some reasons to +think that there is more than one variety of rickets, that all cases are +not dependent upon the same cause, and that in essence it is the same +process as osteomalacia, the latter, however, occurring at a later age. +We shall show that in the same order, Primates, both diseases may occur +in animals fed upon the same diet, and that one family tends to have one +disease, another family the other. + +[Illustration: + + FIG. 44.—DENTAL ROOT ABSCESS AND OSTEITIS OF JAW BONE. ISABELLINE + GAZELLE (GAZELLA ISABELLA). +] + + +RICKETS. + +Since the two conditions are diagnosed separately in veterinary practice +and each seems to have a distinct place in medical ideas, it may be well +to outline upon what criteria the two diagnoses have been made in this +Garden. Rickets is essentially a disease of early life. The animal is +noted as having a large head, squatty station, heavy extremities and a +prominent belly. Death occurs as the result of enteritis or pneumonia. +Occasionally such a young specimen seems to recover from the disease but +retains the distortion of his skeleton; this is important, for we +believe that osteomalacia, except the variety confined to periods of +pregnancy, rarely ends in recovery when once thoroughly established. At +autopsy the cranial bones are the seat of osteotabes, the face is broad, +the epiphyseal junctions are swollen by irregular osteogenesis and +granulation tissue, the periosteum shows an irregular fibrous tissue +overgrowth—the last two processes producing bones of irregular contour +and thickness. Section through the osteogenetic ends of the long bones +shows actively congested marrow up to the articular cartilages with very +tortuous strands of spongy bone or cartilage, and when considered +transversely, there is a bone-forming layer of many times the normal +thickness but bloody red instead of pink. + + +OSTEOMALACIA. + +Osteomalacia appears in mature animals or at least those well able to +care for their own nourishment. The earliest observations are not +referable to the skeleton but to the change in the activity of the +beast. He will be noted as less active in running, jumping or searching +for his food. The customary position is a sitting or lying one. No +change is noted in the head or face. As the disease progresses, the +animal becomes quite inactive, seeks solitude but will eat well if the +food be conveniently available and he does not have to fight for it. The +movements are stiff and seem painful. About this time definite +alteration in the shape of the chest is perceptible, and in some cases +there is anterior curvature of the legs. Movement becomes so difficult, +probably from weakness and pain, that it seems as if paraplegia actually +existed. The inability of affected monkeys to climb has given rise to +the term “cage paralysis,” but this term should not be restricted to +weakness, the result of osteomalacia since it is used by dealers and +keepers to imply the cramped station and gait of an animal long housed +in quarters too small for it, an appropriate application because it +suggests cause and effect. However, the appellation is widely and +loosely used insuring its employment in diagnosis for entirely different +conditions such as degenerative bone disease and hind-quarter laming +from enteric intoxications; for these affections one might use the term +in an adjectival or descriptive sense. + +Our Primate collection has suffered considerably with osteomalacia, and +we have devoted much time to the study of its cause and treatment. +However, the Garden is not alone in this experience, for wherever +certain species are kept the disease appears. The description of cases +in the New York Garden by Blair and Brooks[46] is excellent, and with +the exception of data concerning the nervous system, almost exactly +parallels our own observations. They lay much stress upon the changes in +the brain, cord and ganglia as constant in well developed cases but as +probably secondary to the osseous, hemic and metabolic disturbances. We +have been unable to find any pathological lesions in four thoroughly +studied brains and cords from well developed cases. As will appear +later, our most satisfactory findings were in the dietary and metabolic +chemistry and in the osseous pathology. The cases recorded by Campbell +and Cleland[47] would seem to be undoubted instances of myelitis, but +the osseous changes are not sufficiently discussed. In many cases it +would seem, therefore, that there is some change in the nervous system, +but there may be some examples without this and with predominant osseous +lesions. We are inclined to think that these two groups differ +qualitatively, and we look upon the confusion as demanding for its +ultimate solution the use of exact nomenclature, especially the +exclusion of “cage paralysis” as a diagnostic term. The only division we +can understand at the present time depends upon the gross changes in the +bones, those with and those without definite irregularities in contour +due to periosteal overgrowth. Certain of the former may show no +unevennesses at all, the deformity being due to softness of the +skeleton. The other group has shafts of irregular thickness, swellings +around the joints and much beading of the middle of the ribs. + +Whether or not there be true paralysis is difficult to settle, but in +our cases we have decided always in the negative because of the ability +of the monkeys to grasp firmly with the hind digits. The animals tend to +lie in one position, determined probably by comfort, the result being +that they develop sores at the points of contact with their cage floor, +and deformities of the skeleton (see Fig. 45). These deformities are +especially well exhibited by the chest, the vertebræ and the pelvis and +are referable to the almost constant squatting of the animal; the long +bones may be bowed but not as much as in rickets, nor is the epiphyseal +junction so knobby as in that disease. + +The foregoing description is based chiefly upon observations on monkeys +but may be closely paralleled in carnivores and rodents. These latter, +however, lie rather than sit during the development of the disease, so +that thoracic and pelvic deformity is relatively less than in monkeys. +Death is due to enteritis, anemia, shock from fractures and respiratory +inflammation. + +In so far as the deformities of the skeleton may serve to distinguish +between rickets and osteomalacia, I can only point to the preponderance +of changes in the skull and extremities in the former and of the trunk +bones in the latter. Deformity of the chest, barrel-shape shortening and +pigeon breast, is due more to posture than to the essentially osseous +changes. “Rachitic rosary” may occur in both, but it is always better +exhibited in rickets; in this disease the swellings occur at the +costochondral junction, while in osteomalacia rosary-like nodules may +develop anywhere along the ribs. + +Examination of the anatomical lesions is, however, somewhat more +helpful, and the following description for osteomalacia may be +contrasted with that already given for rickets. The peculiar change is a +thinning of the shaft of long bones and reduction of the subperiosteal +plates of flat bones. + +In mammals the long bones are more affected than in birds whose sternum, +ribs and beak show the severest changes. The skull is frequently not +affected to a serious degree, but may, however, show advanced lesions, +the cranial plates being thinned in places so that they may be bent in, +or occasionally a periosteal thickening may be found; the head as a +whole is not misshapen. The ribs are softened and may be of paper +thickness although there may be found a periosteal overgrowth, perhaps a +kind of splinting, which makes the diameter variable. At costochondral +junctions, beading may be found, but without the active congestion seen +in rickets. Similar alterations may be found in the long bones, here in +characteristic degree in that the shaft walls are thin, by removal of +the endosteal and periosteal layers sometimes with definite retraction +of the marrow. Occasionally subperiosteal thickenings, made of +osteofibrous tissue are encountered. At the epiphyses there are strands +of gelatinous tissue, fibrous and cartilaginous, separating pink or +blood-red areas of marrow. These strands may contain calcareous matter +and are probably the remains of the cancellated tissue. Despite all this +activity at the ends of the long bones there is not the extreme +prominence of articulations so characteristic of rickets. Gelatinous or +cartilaginous islands may be seen in the deep red shaft marrow. + +[Illustration: + + FIG. 45.—OSTEOMALACIA. MODERATELY ADVANCED CASE WITH HOWEVER WELL + ESTABLISHED DEFORMITY OF THORAX AND PELVIS. THIS POSITION WAS + CONSTANT FOR THREE MONTHS BEFORE DEATH. BLACK HANDED SPIDER MONKEY + (ATELES GEOFFROYI). +] + +Fractures may be found and around them may form a blood clot or loose +fibrous tissue entirely devoid of bone salts. If a break has existed for +some time a very pronounced fibrous overgrowth from the periosteum is +apt to occur, indeed an excessive fibrosis may exist, but this is +ineffective for healing of the fracture or splinting of the shaft. +Certain cases, notably in Carnivora, seem to have especial activity in +and around joints so that when the member is dissected one gets the +impression of osteoarthritis. In such cases the synovia may be fibrotic +and the articular surfaces dry. The pelvic deformities are similar to +those in the human being—lateral contraction with bending in of the +superior rami of the pubis with the production of a beak, to which the +name “duckbill” has been given. The anterior curvature of the lumbar +spine makes an acute angle at the upper end of the sacrum. + +Histological examination of a number of our cases of osteomalacia and +rickets have failed to show any lesion different from those known for +the human being and for domesticated animals. It is noteworthy that not +all bones of a given case will show the changes to the same degree even +though grossly they may seem comparably affected. So too there is no +certain relation between the degree of deformity as shown by the body as +a whole and the advancement of osteoporosis as seen under the +microscope. These observations are in accord with those of Brooks and +Blair. Just why this is cannot be stated, but as the cause of these two +bone diseases may not always be the same, variations in gross and minute +anatomy are not remarkable. + +Analysis of the bones shows a loss of calcium and an excess of sulphur +and magnesium. The loss of the first is chiefly _via_ the intestinal +discharges but also _via_ the urine. The metabolism of one monkey showed +a high calcium and phosphorus loss with moderate retention of sulphur +and magnesium. + +Because of the importance of osteomalacia and rickets in cebus monkeys +and certain other animals, Dr. E. P. Corson-White has been investigating +its etiology. I shall refer briefly to her results as they affect our +present subject but shall leave for discussion in the chapter on diet, +which she has written, the broader question of food and systemic +disease. + +It must be understood that the instances included in this general +discussion of degenerative osseous disease are cases of definite +character and development. There may have been, in addition to the +numbers cited in the list on page 357, many more animals at autopsy with +early or unrecognized constructive or destructive abnormalities, and we +are thoroughly familiar with the imperfect skeletal development of +specimens, inbred or reared in captivity or even those adult when caught +yet under Park conditions for many years. In these latter groups the +changes vary from incomplete construction (an example of atrophy was +quoted on page 24) to actual degeneration as in osteomalacia. Inbreeding +seems to be a potent factor in many cases, a well known fact in human +and veterinary medicine. The importance of inactivity in the causation +of degenerative bone disease, the unused muscles giving the bones +nothing to do, is certainly admitted but it is immeasurable. It is +probably not great in a cage of mixed varieties of monkeys. The effect +of the absence of sunlight in osseous degeneration is no factor in our +material. The exhibition house is well lighted and many animals are out +of doors all year around. + +The ductless glands have repeatedly been accused of responsibility for +these disorders. In our seventy-nine cases of osteomalacia and thirty- +four of rickets, no abnormality has been observed in ovary, testes or +adrenals except for moderate congestions. Two cases were associated with +pancreatic disease, once acute, once chronic. The thyroid body has been +found to have been definitely abnormal only once—secondary hyperplasia +with colloid in a carnivore. In the Primates this body was frequently +congested and has shown small colloid cysts but was not uniformly +enlarged or atrophic. As a therapeutic measure I have administered +adrenalin to two monkeys, one for a few weeks, one for nearly six +months; this treatment was without any perceptible effect upon the +process. + +Dr. Corson-White has, by the study of some cases during the life of the +monkey, confirmed the decreased alkalinity of the blood in connection +with the increased output of calcium in the feces and urine. + +Since the explanation of the disease by blaming the ductless glands has +failed, Dr. Corson-White has undertaken a study of the diet given our +monkeys to see if any fault in it were a part of the etiology. Analysis +of this diet (see list page 426) computed from Atwater’s table, and by +actual analysis of the amounts of food consumed by the animal in four +four-day periods, gave: + +1. Protein—low in quantity and poor in quality; especially low in +phosphorus content. + +2. Fat—very low. + +3. Carbohydrate—very high, almost eleven times the value of all other +ingredients. + +4. Ash—decidedly low and predominatingly acid. Further analysis of this +ash showed a trace only of calcium and phosphorus and iron and only a +small amount of sodium; potassium, sulphur and magnesium were slightly +higher. + +5. Vitamines A, B, C, were present in extremely small amounts—A was +exceptionally deficient, and in the rations of some days was entirely +lacking. + +There are in this monkey diet several factors of importance. 1. Low +vitamine contents—especially Vitamine A—factors which are essential for +life and growth. 2. A high carbohydrate diet—which in oxidation yields +an acid ash and which favors the growth of intestinal bacteria producing +acid and gas. The acid from these two sources must be neutralized either +by the alkali derived from food, or from the body storage. This diet, +however, is abnormally low in ash and especially in the alkaline salts +of the ash, therefore making it an ideal diet for the production of +osteomalacia. + +The following table shows the additions necessary for corrections of the +separate ingredients of the diet: + + Monkey diet Corrected by + Rice Casein, Salt mixture, Carrots, or Lettuce. + Bread Casein, Butter fat, Salt mixture, especially Phosphorus. + Potato Salt mixture, especially NaCl and CaCO_{3}. + Raw peanuts Salt mixture. + Bananas Casein, Yeast, or Carrots. + Corn Casein, Tryptophan, Lacto-albumin. + Apple Casein, Gelatin, Butter fat. + Onion Casein, Gelatin, Butter fat. + + + The complete diet may therefore be rendered adequate by the addition + of fresh, whole milk and leafy vegetables, or by butter fat, salt + mixtures and leafy vegetables. + + +It would seem from these data that in this inefficient diet we have, if +not the cause of osteomalacia, at least a very potent factor in its +production. The disturbance of the calcium and phosphorus metabolism may +be due primarily to the deprivation of the alkaline salts from the diet +(famine osteomalacia) or to a drain from the alkaline storage of the +body, associated with a deficient diet (as in the cases of osteomalacia +of pregnancy and lactation) or in the combined action of a diet faulty +in more than its salt content, which by the production of acid in its +oxidation and by favoring the development of acid-forming bacteria, +causes the drain of the body alkali for the neutralization of this acid, +or it is due to the combination of all these factors acting through +their influence on the ductless glands. + +It is important also that while this disease is very common among the +Cebidæ it has never been found among the macaques. This may be due to +the fact that, owing to the storage sacs in the mouth of the macaques, +more food proportional to body weight is consumed, or there may be an +essential difference in the basal metabolism of the families and +individuals. All the factors enumerated do tax the metabolic resources +of the body and depress the functions of the endocrine glands. Only +detailed and accurate quantitative studies of normal metabolism and the +effect of alterations of it on the ductless glands will give a more +definite answer to the problem. + +This work indicates clearly the alterations to be made in the diets to +meet the requirements of the Cebidæ and is to be followed by +investigations along similar lines for other families. + + TABLE 17. + _A List of the Orders Exhibiting Definite Lesions of Osteomalacia and + Rachitis._ + ═══════════════════════╤═══════════════════════╤═══════════════════════ + │ Osteomalacia │ Rachitis + ───────────────────────┼───────────────────────┼─────────────────────── + Primates │ 29 │ 10 + Lemures │ 4 │ 2 + Carnivora │ 3 │ 8 + Hyracoidea │ 2 │ 1 + Rodentia │ 5 │ 3 + Marsupialia │ 1 │ 10 + │ 44 │ 34 + Passeres │ 3 │ + Psittaci │ 9 │ + Accipitres │ 2 │ + Columbæ │ 12 │ + Galli │ 9 │ + │ 35 │ + ───────────────────────┼───────────────────────┼─────────────────────── + │ 79 │ 34 = 113 + ───────────────────────┴───────────────────────┴─────────────────────── + +Having discussed the nature of these diseases and some of the factors in +their causation, analysis of their distribution may be appropriately +added. The accompanying list (Table 17) illustrates the orders in which +the two diseases have been found. Veterinarians are familiar with +systemic osseous diseases in all the domesticated herbivores, but Hutyra +and Marek note them as uncommon in dogs and birds. Among the Primates, +osteomalacia occurs almost exclusively in New World monkeys, Cebidæ and +Hapalidæ, whereas rickets is much more common among macaques +(Cercopithecidæ). Eight of the ten cases of rickets in monkeys seem to +have arrived at the Garden with evidences of this disease. Half of the +cases were arrested, or at least not florid, when the beast came to +autopsy. All of the osteomalacic lemurs belonged to the ring tailed +species, born in the Garden and dying at ages from three to seven years. +The cases of rickets among the Carnivora were four Felidæ, three Canidæ +and one Procyonidæ while all the osteomalacia cases were in the last +family. Six of the eight cases among the rodents affected squirrels. The +large number of cases of rickets among the marsupials is due to a litter +of small opossums thrown by an apparently healthy mother and dying in +from six weeks to three months. + +The avian varieties which show the most definite osteomalacic changes +are the pigeons and pheasants, with the parrakeets presenting nearly as +characteristic lesions. Birds when affected with this disease, may come +to autopsy in fairly good plumage and without any very marked +emaciation. This is remarkable, for when the _cresta sterni_ is palpated +this ridge may sometimes be bent enough laterally to touch the _alæ +sterni_. How the bird can sit upon a perch when it is possible to bend +the femora almost double, is difficult to understand. Deformity is by no +means so frank as in mammals although periosteal overgrowth may be quite +marked at times. Anemia is undoubted in nearly every instance, the +pallor of the muscles seeming to be as great as if the specimen were +intentionally bled to death. + + +OSTEITIS DEFORMANS. + +Dr. Corson-White was fortunate enough, during the course of her work +upon osteomalacia of monkeys, to detect a specimen which did not show +the usual excessive excretion of calcium but on the other hand retained +this element and evinced alkali hunger. The general appearance of the +specimen was similar to that of monkeys having osteomalacia but at +autopsy a definite picture of Paget’s disease or osteitis deformans was +discovered. This led to a search for cases in the literature and to the +following study, which I paraphrase and condense from Doctor Corson- +White’s notes. + +Osteitis deformans is a chronic constitutional affection characterized +by the absorption of compact bone, chiefly in the cranium and long +bones, and the laying down of fibro-osteoid tissue in such an excess as +to enlarge the affected bones. This material, which is soft and cuts +with reasonable ease, has calcareous matter in it as shown by Röntgen- +ray examination. Paget described it in a classical article in 1876[48] +since which time the reported cases have mounted to three hundred and +fifty. Because it has only been recognized in its best developed stages, +it may be that early mild or arrested cases have been overlooked. +Judging by the instances claimed to have been found in museum +collections of bones, it is probably an affection dating to antiquity. +So far these remarks apply only to man but in lower animals the reports +are very few and those are not available in the original. The abstracts +and references show considerable confusion. The names osteitis +deformans, osteoporosis, osteitis fibrocystica, osteodystrophia +deformans and osteosarcoma, leontiasis ossei, etc., are used almost +interchangeably. In 1901 Barthelemy[49] described a condition (_Maladie +du Son_) in horses in which there was a marked enlargement of the head +and of the epiphyses of the long bones. His cases were more allied to +osteitis fibrosa cystica. Paget’s disease always attacks the diaphyses +of the bones and not the epiphyses. Goldman[50] described typical +examples of this condition in fowls. Jöst[51], in one communication, +described a case in a horse which he says was identical with that +condition described by Paget as osteitis deformans and by Virchow as +leontiasis ossei; he also refers to similar cases in goats and monkeys. +Rossweg[52] found it in goats. In wild animals the only suggestive +article found was by Jöst but the description was probably of an +osteoporosis and a craniosclerosis which occurred in a young lion and a +monkey. All the communications deal with either domesticated animals or +those in captivity. + +The etiology of this condition is as obscure to-day as it was at the +time of Paget’s first description. Prince thought it might be due to a +defect in some peripheral nerve or nerve centre or to a tract +degeneration. Cases have been reported in conjunction with a myelitis. +There has been however little on which to base these suppositions. Paget +felt that the process was at least upon an inflammatory basis and +deduced this from the enlargement and the excessive production of an +imperfectly developed structure with increased blood supply. Many felt +that rickets, osteomalacia and osteitis deformans were all +manifestations of the same disease. A bacterial cause was proposed by +Arcangelli who claimed the discovery of diplococci and improvement from +a vaccine. Lancereaux[53] and Richards felt that focal infection played +a profound rôle in the etiology. However all other observers fail to +isolate an organism from the bones or to get improvement from removal of +infectious foci. Heredity has been held responsible in seven per cent. +of the cases in human beings. + +That some inflammatory factor is partly responsible seems plausible when +one considers the active growth of fibrocellular tissue in the endo- and +periosteum. The more interesting theories go back to perversions of +internal secretions, pituitary, parathyroid etc., (Macallum & Vogtlein). +Higbee and Ellis[54] say in relation to the neurotrophic theory that if +the neurotrophic mechanism governs metabolism and is influenced by the +activity of the ductless glands, there is considerable likelihood that +its disturbance may possibly be found to be the cause. + +Da Costa[55] believed the disease to be a disorder of bone metabolism +probably dependent on the absence or perversion of some internal +secretion. There is much evidence on hand to indicate that disorders of +the ductless glands do influence bone metabolism, and changes in these +glands have been reported in cases of Paget’s disease, although the +findings and lesions have been far from uniform or distinctive or even +confined to one gland. Eight cases were reported as possibly due to a +hypothyroid condition; pituitary changes were found in three; adrenal +changes in one; parathyroid reported missing in two; three had sclerotic +thyroids. Many case reports make no mention whatever of the glands of +internal secretion. + +Da Costa interprets the retention of calcium, phosphorus and magnesium, +with the sulphur loss found in these cases, as indicating a stimulated +osseous or osseoid formation accompanying the resorption of a highly +sulphurized organic matrix. In the course of this calcification +procedure we suppose a certain quota of the sulphur of the matrix is +replaced by other elements, a process which must entail retention of +calcium, phosphorus and magnesium and increased elimination of sulphur. +He shows the close parallelism between the mineral metabolism of a +growing boy, a case after parathyroidectomy and a case of osteitis +deformans, and suggests that this depends in some way either on the +absence or perversion of some internal secretion, possibly of the +parathyroids, which controls calcium exchange in the body. Substances +from some cause arise which have the power to abstract calcium from the +body tissues, the abstraction of these salts being the first step in the +production of the disease. + +The example which is reported in full was the first to be encountered in +our 5,365 autopsies but shortly after this series was concluded two more +came to autopsy and Dr. Corson-White’s studies were made to embrace +these. + +A reddish woolly monkey (_Lagothrix infumatus_) received November 25, +1919, was a particularly active specimen and as far as we could +determine a perfectly healthy adult animal. He passed the tuberculin +test and was placed on exhibition. In April, 1920, he was first reported +as crippled and was removed to the laboratory in June, 1920. At that +time the long bones of the legs and arms were bowed anteriorly and +laterally, the degree of curvature making the hands and feet seem +disconnected. The monkey could stand but made no voluntary effort to do +so. There was evidently some pain although it could not have been at all +severe. He resented handling, especially of his arms and legs. The head +was rounded, resembling that of a baby, and the eyes were protuberant +suggesting an exophthalmos. The maxillary bones were so excessively +thick that the mouth could not close and the monkey drooled saliva. His +blood on admission to the infirmary in May was—Hg eighty-nine per cent., +R. B. C. 4,370,000, W. B. C. 5,800; one week before death it was Hg +fifty-four per cent., R. B. C. 2,860,000, W. B. C. 6,000. Routine urine +examination showed a constant trace of albumin, hyaline and granular +casts. There was at no time a Bence-Jones protein reaction, excess of +indican, indol, or diacetic acid. He had a constant slight diarrhœa with +some flatulence, the semifluid, constantly acid feces presenting a +preponderance of Gram-positive coccoid organisms. His appetite was fair +and he showed marked craving for lime, eating plaster from the walls +when he could get it. Because of this desire for lime he was given a +salt mixture to see if it would have any effect on the bone condition. +The mixture used was the following: + +[Illustration: + + FIG. 46.—OSTEITIS DEFORMANS. SKELETON SHOWING GENERAL THICKENING OF + ALL BONES, BUT ESPECIALLY OF THE SKULL, JAWS AND LONG BONES. NOTE + THICKNESS OF CALVARIUM, 10 mm.; NORMAL IS ABOUT 3–4 mm. THE HUMERUS + IS TWICE NORMAL SIZE. THE WIDTH OF THE ULNAR CORTEX IS SHOWN BY A + TRANSVERSE SECTION NEAR THE ELBOW JOINT. REDDISH WOOLLY MONKEY + (LAGOTHRIX INFUMATUS). +] + + NaCl 0.874 grams + KCl 0.548 grams + CaH(PO) H_{2}O 3.608 grams + Ca lactate 0.386 grams + Mg citrate 0.848 grams + K citrate 1.953 grams + +This mixture the animal ate with avidity and seemed more comfortable; +other than that no change was noted. + +An inorganic metabolism examination was attempted on the ordinary diet +and the diet plus the salt mixture. Under the circumstances at our +disposal this was not entirely accurate but showed such marked variation +from the control animals examined—normal and osteomalacic—and such +marked correspondence on the four separate four-day periods of each +intake that it seemed acceptable. The result of this investigation on +the first series of four four-day periods was: + + ═══════════╤═════════╤═══════════════════╤═════════════════════════════ + │ Intake │ Output │ Total + ───────────┼─────────┼─────────┬─────────┼───────────────────────────── + „ │ „ │ Feces │ Urine │ „ + ───────────┼─────────┼─────────┼─────────┼───────────────────────────── + Calcium │0.0280 │0.014 │0.0022 │0.0162 = 0.0118 retention + Magnesium │0.0640 │0.034 │0.0123 │0.0463 = 0.0177 retention + Phosphorus │0.1540 │0.027 │0.0430 │0.07 = 0.084 retention + Sulphur │0.1440 │0.002 │0.1680 │0.17 = 0.026 loss + ───────────┴─────────┴─────────┴─────────┴───────────────────────────── + +The result on the higher salt content was practically the same, the +retention being in proportion slightly less. The diet for these small +monkeys is two apples, two bananas, six small sweet potatoes, with a +lump of boiled rice about the size of an egg. The content of this diet +has been found very low in calcium, phosphorus, sodium, chlorine and +iron, while potassium, magnesium and sulphur were high. To this diet +lime water was added to increase its inorganic content. + +This Reddish Woolly Monkey died August 20, 1920, and was immediately +posted. There was marked thickening of the frontal, occipital and +parietal bones, upper and lower jaws. The increase in the size of the +alveolar margins prevented the closing of the mouth; only the last four +teeth could be brought into apposition. The enlargement of the mandibles +reduced the capacity of the mouth cavity. The skull while decidedly +thickened did not enlarge at the expense of the cranial cavity. There +was a cervical and dorsal kyphosis. The chest was increased +anteroposteriorly and contracted laterally. The long bones were thick, +bulky and deformed. (Fig. 46.) + +A Black Spider Monkey (_Ateles ater_) showed a general hyperplasia of +the whole shaft of the long bones. She was much deformed by curvatures +and swellings of the skeleton—head enlarged, face deformed by the +swelling of the upper and lower alveolar processes, jaws do not close +and the palatal bones were flattened, skull irregularly thickened, +elastic but not soft, slight subperiosteal growth. Thickening of the +long bones was largely due to subperiosteal growth; section of the ulna +showed a subperiosteal osseoid layer surrounding the old shaft. This +tissue seemed to be very poor in lime salts, cutting without any grit. +Marrow cavity was filled with a fairly firm, deep red marrow which did +not bleed on section. The third monkey, a Brown cebus (_Cebus +fatuellus_) showed exactly the same general picture but was less +severely affected than the other two. + +“The more minute study of the bones of these monkeys shows a variety of +pictures while preserving one general form. The skull was smooth, +mottled by irregularly placed areas of congestion; it was asymmetrically +thickened; differentiation between cortex and diploe, internal and +external tables was lost; calcareous matter was absorbed and the +resultant bone was soft, elastic and porous; lacunæ enlarged and lined +with bone corpuscles and giant cells. Other areas show more dense bone, +the reparative processes being more active in that the lamellæ are wide +and the vascular spaces narrower. As a rule the compact bone is +absorbed, the Haversian canals are more or less confluent and there is +generally a marked increase of newly formed osseoid tissue. The +ossifying periosteitis obliterates the depressions for the cranial +arteries and the sutures. The skull cap becomes finely porous, +cancellous and even cavernous. The spaces are filled with a soft, red +marrow-like material. The bones at the base of the skull are much less +involved; the pericranium, dura and brain are normal. + +“The long bones show interlacing narrow strands which are in some +regions wide, in others narrow or thin as in spongy bone. Large +irregular cavities are present and there is a disappearance of the +compact bone and an encroachment on the medullary canal of a relatively +dense new bone with small irregular trabeculæ surrounded by osteoblasts +and a fibrous connective tissue which fills the outer trabecular spaces. +The new bone is often both subperiosteal and subendosteal, the latter +often gaining on the former. It is always soft and irregularly +calcified. The general arrangement of the strands in the deep layers is +longitudinal but in the subperiosteal bone they are very irregular and +almost at right angles with the central strands. In this new osseoid +tissue cysts are frequent, varying in size from very small to rather +large cavities filled with a cloudy gelatinous material. The picture +here is very like osteitis fibrosa cystica. Endosteal cells proliferate +and may fill up the marrow spaces so that solid masses of fibrous tissue +result. Frequently the osteoid material shows fibrillæ. The compact bone +may be irregular with well marked Haversian systems. Toward the +periosteum the cells may become scanty, the bone dense in structure +while toward the interior the cells are more numerous and in the more +cancellous portions, the trabeculæ become slender and far apart; here +they may be covered by a single row of osteoblastic cells. The +intertrabecular spaces are large, irregular and filled with a delicate +alveolar tissue containing only a minimal number of normal bone marrow +cells, large capillaries and no giant cells. Periosteum may be of usual +thickness; the bone immediately beneath is spongy. The sclerosis of the +bone in its densest areas is entirely due to the ossification of spindle +cells which have remained in the place of the original marrow of the +bone. As a whole the bone is nowhere normal in amount or proportion but +the small Haversian systems are properly made, the abnormality being +chiefly due to cellular and fibrous growth around the large lamellæ +which at times is normal in amount but usually much in excess. In places +this consists wholly of fibroblasts, at others of giant and round cells +very suggestive of sarcoma. All histologists apparently agree that +Paget’s disease starts as a resorption of already calcified bone.” + +These data seem to supply ample evidence that the autopsy diagnosis of +Paget’s osteitis deformans was correct. While the anatomy and course and +chemical changes presented by these monkeys do not settle the causation +of the disease, they offer very definite suggestions which Dr. Corson- +White summarizes in the following cautious conclusions. + +“Many of the cases of Paget’s disease first came under the observation +for fractures, accidents common in osteomalacia but very rare in +developed cases of osteitis deformans. Early cases all presented +diarrhœa, which was present in all the early human cases seen, and in +all the cases reported in monkeys. This symptom was mentioned in +fourteen of the cases from the literature. It was also a constant +symptom in primate osteomalacia. The diet of these monkeys was +exceedingly low in those substances essential to bone development, and +Sherman has shown that the calcium balance is regulated to a certain +extent by the calcium ingested, and that when the diet was poor in this +element, the output materially exceeds the intake, a fact which is +immediately changed where the animal is put on a diet high in calcium. +So far as we could find there are no studies on the mineral metabolism +of beginning cases of Paget’s disease. It seems possible from the +osteomalacic animals previously studied, that the low mineral and +otherwise faulty content of the diet might so disturb the chemical +equilibrium directly, through the neurotrophic mechanism or through the +perversion of the ductless glands, that the mere addition of lime water +might entirely change the pathological picture. This is in accord with +the histology. The initial histological picture is always resorption of +bone, a general decalcification which later presents an irregular +proliferation. The disease then progresses along different lines ending +as osteitis fibrosa cystica, Paget’s or Von Recklinghausen’s diseases, +etc., dependent upon the strength of the reparative stimulus and the +organism upon which it acts. + +“These cases are of interest (1) because they are typical examples of +Paget’s disease as it has been described in man both clinically and +pathologically, (2) because the disease shows the same general type of +inorganic metabolism that was exhibited in man, (3) because of the +alkali hunger shown by one monkey, and by two human cases, a hunger +which was severe, which preceded the deformity and disappeared after the +deformity was established, (4) because the disease developed in animals +fed on a diet insufficient in its inorganic and vitamine content to +which an excess of calcium was added. + +“From this study it seems possible that Paget’s disease may be just one +stage in a deficiency disease, a reparative response through a +neurotrophic mechanism or through the perversion of the glands governing +calcium metabolism which has been perverted by an improperly balanced +diet.” + + +TUMORS. + +Neoplastic diseases of the bones have yet to be classified to everyone’s +satisfaction. All gradations of hyperplasia of osteogenetic cells and +fibres and of the marrow elements, from simple inflammation to true +sarcoma, are recognized. As one reviews a large series of lesions, +clearly defined types may be found, but there are transition stages to +which an exact name is difficult or impossible to apply. Nor does the +pathological diagnosis always fit with the clinical course. Thus, for +example, the giant cell tumor of bones looks malignant, and is not, and +its structure may be simulated in such diseases as fibrous osteitis and +Paget’s disease. As we have seen in the discussion of the latter of +these two, abnormalities of fibre and cell growth simulate neoplasms +very closely. In addition it might be mentioned here that actinomycosis +may produce bony growths resembling sarcoma. When osteitis deformans +affects the facial bones especially, it has been called leontiasis +ossium, and it is then a more nodular, tumor-forming process, the +enlargement consisting of fleshy masses occupying the whole bone, but +especially the marrow cavity. Histologically the lesion is +fibrocellular, frequently with numerous giant cells; accumulations of +small sarcoma-like alveoli may be found. We have encountered four cases +among common opossums (_Didelphys virginiana_) and one in an Isabelline +Gazelle (_Gazella isabella_) and, because of the localization and fleshy +consistency of the tumor, we have called them osteosarcomata for +descriptive purpose, but not for classification among neoplasms (where +they will not be found). Two of the opossums had osteoporosis and +gelatinous marrow in the ribs. All these animals had been in the +exhibition under a year, and as far as known are not related. Figure 47 +shows the gross character, while the following is the description from +one protocol. + +[Illustration: + + FIG. 47.—EXAMPLES OF LOCAL OSTEOMATA RESEMBLING OSTEOSARCOMA AND + FIBROUS OSTEITIS; THEY PROBABLY BELONG TO THE DISEASE KNOWN AS + LEONTIASIS OSSIUM. +] + +[Illustration: + + FIG. 47B. A AND B, OPOSSUMS (DIDELPHYS VIRGINIANA). +] + +[Illustration: + + FIG. 47C. C, ISABELLINE GAZELLE (GAZELLA ISABELLA). +] + +[Illustration: + + FIG. 48.—FIBRO-OSTEOMA, A LOCAL SINGLE TUMOR OF THE UPPER JAW. THIS + DID NOT RESEMBLE THE CHANGES IN ACTINOMYCOSIS, BUT THE INFECTION WAS + NEVERTHELESS EXCLUDED BY BACTERIOLOGICAL SEARCH. ISABELLINE GAZELLE + (GAZELLA ISABELLA). +] + + + Common Opossum (_Didelphys virginiana_) ♀ . Osteosarcoma of alveolus, + rarefying osteitis deformans of skull, hypertrophy of thyroid, acute + catarrhal enteritis, acute hyperplasia of spleen. About the middle of + both lower rami and involving the posterior half of each upper maxilla + is a uniform elliptical growth apparently emanating from alveolus. + Teeth not loose, but can be moved in tumor to be described. On section + a white glistening homogeneous growth is seen apparently originating + in the body of the alveolus and around the teeth. The shaft of bone is + soft and easily broken. What remains of marrow is irregularly + injected. In upper jaw there is a distinct porosis of facial bones; + they and the enclosed sinuses are deeply injected. Lower four ribs on + both sides show distinct nodulations of pale color along a bluish + bone. All ribs are very soft and section shows osteoporosis of shaft + with injected marrow and distinct cartilaginous periosteal bone + formation. The skull is everywhere soft and the bone is apparently + increased in thickness, rich in blood, but porotic. Rest of skeleton + seems well calcified. Microscopic section of tumor shows practically + the same picture. Bone is nowhere normal in amount and proportion but + the Haversian systems seem properly made, the abnormality consisting + chiefly of cellular and fibrous growth around larger lamellæ, which at + times is normal in amount but usually much in excess. In places this + consists wholly of fibroblasts, at others of giant and round cells + very suggestive of sarcoma; indeed all areas must be called giant cell + sarcoma. There is an attempt to lay down osteoid tissue at places + particularly beneath periosteum. The giant cells are in great numbers + and some seem osteoclastic. As the lamellæ disappear young connective + tissue seems to take their place but giant cells do not remain + numerous at such places. Despite its atypical nature it must probably + be looked upon as an osteosarcoma. The tooth socket is not much + involved save for hyalinization of root matrix immediately about + dentinal zone. + + +In another Isabelline Gazelle (_Gazella isabella_) there was a fibro- +osteoma localized to one side of the superior maxilla (Fig. 48); this +has been included among the tumors, while the above mentioned cases have +not been so grouped. + +True osteosarcoma seems not to have occurred. One tumor was seen upon +the wing of a Cuvier’s Toucan (_Rhamphastos cuvieri_) which was formerly +diagnosed as sarcoma, but later examination reveals some giant cells in +arrangement suggestive of tuberculous osteitis; since this is the only +case and not unequivocally a tumor its record is hardly warranted. +Osteomata of the hard variety have been seen on the ribs of a pigeon and +a pheasant as small rounded compact well outlined tumors. It is thought +that they represent products of healing after osteomalacia or rickets. +An osteochondroma growing from the nasal cartilage was found in a +caracal (_Felis caracal_), a fibro-osteoma was found on the vertebra and +clavicle of a Beechy’s spermophile (_Citellus grammurus beecheyi_) and a +fibroma occurred on the clavicle of a lesser snow goose (_Chen +hyperboreus hyperboreus_). The only other tumor from a bone was an +endothelioma from the periosteum of the clavicle in a moorhen +(_Gallinula chloropus_). It corresponds to the usual idea of this tumor. +It probably caused death by cachexia, and by its size, interference with +respiration. The only secondary tumor was a metastasis in the tibia from +a spindle cell sarcoma of the kidney in a scaly ground dove +(_Scardapella squamosa_). + + +THE MUSCLES. + +The skeletal muscles of the wild animals of our collection have been +quite free of pathological lesions such as atrophies and dystrophies and +indeed seem relatively seldom affected by disease. Occasionally +hyalinization will accompany infectious disease or local suppurations +will spread into the muscles. Much more often filaria, sarcocystis, +flukes and larval insects will be found resident within or between +muscle bundles; this will be discussed at a later time. Six tumors have +been found, three of which certainly developed in a muscle, while for a +fourth case no primary growth was discovered. This last one, to dispose +of it at once because of its peculiarity, was an adenocarcinoma found as +a firm, conglomerate, encapsulated mass in the sheath of the gluteal +muscles of a waltzing mouse (_Mus wagneri rotans_). No other growth was +discovered although it must be admitted the body was not exhaustively +searched for some tiny nodule to which primary focus this muscle mass +could have been secondary. That metastases may be larger than original +growths is well known. The gross diagnosis was sarcoma. If this be an +original tumor it might be explained as arising from ectopic mammary +tissue. + +The five other tumors were sarcomata, one of large cells almost +syncytial in size, shape and number of nuclei, two definite spindle cell +growths and two of fibrosarcoma type. The first occurred in an all green +parrakeet (_Brotogerys tirica_), the second in an undulated grass +parrakeet (_Melopsittacus undulatus_), the third in a larger Egyptian +gerbille (_Gerbillus pyramidum_), the fourth in a white-footed mouse +(_Peromyscus leucopus_), and the last in a bean goose (_Anser fabalis_). + + + + + SECTION XIII + THE CENTRAL NERVOUS SYSTEM AND THE SPECIAL SENSES + + +Diseases of this system and its specialized end organs of sense in the +eye, ear and nose are recognized by veterinarians as occurring among +domesticated animals, in which however they are by no means so common as +in human beings. Because of the natural reserve of wild beasts and +because their habits and manners are not so familiar to the observer, it +would seem that clinical evidences of disease of the nervous system are +rarest among them. The brain, cord and nerves of our specimens have not +been studied with the minuteness accorded to the examination of other +viscera since we have not had the personnel to devote the time to this +really colossal undertaking, our work with these tissues being directed +toward the accumulation and preservation of apparently normal brains +from every species; there are now some nine hundred brains on the +shelves. However, whenever the history of the animal before death has +suggested that disturbance in the nerve organs might exist, they have +been dissected grossly and examined microscopically. Had we subjected +all our material to microscopic study it is quite possible that we might +have discovered more lesions. This is still possible by reason of our +gross material and autopsy protocols. + +We have been fortunate in having Dr. W. B. Cadwalader, Secretary of the +Society, and Dr. J. H. W. Rhein with their broad experience in +neurology, take interest in this phase of the subject and study our +material. The number of cases in which definite lesions have been found +is surprisingly small, so that no generalizations can be attempted +except perhaps in a negative sense. After the study of thirty-nine +brains and cords from animals in whose history some suggestion of +nervous system disease existed, Doctor Cadwalader could find +abnormalities in only twenty-two cases, mostly however of a very +indefinite character. This observer further points out that in his +experience with our material, his observations of our animals and a +review of the literature, he is unable to find satisfactory instances of +the so-called system or tract diseases such as tabes and lateral +sclerosis. This he suggests is due to the absence of arterial sclerosis +in the lower types of brain, intimating further that perhaps the +relation of syphilis to human arteriosclerosis and degenerative nervous +system disease is thereby strengthened. These facts being true it is not +astonishing that massive cerebral apoplexy and cerebral softening do not +occur[56]. The lesions that have been found were either definitely +infectious, as encephalitis or acute septicemia, tuberculosis, +poliomyelitis, meningitis, or the minute hemorrhages and vague +granularities or vacuolizations of nerve cells in toxemic conditions. +The material being limited and broad statements being impossible, the +important cases will be cited individually or in small groups. + + +CONVULSIONS. + +Before entering upon the special subjects, a word might be added +concerning the clinical evidences of neurologic conditions as seen in +the Garden. Perhaps the most common and certainly the most definite +clinical sign of nervous disturbance is the convulsion. General spasms +or fits are fairly common among the carnivores and monkeys, in the +former most often associated with intestinal parasitism, in the latter +with no especial relationship unless it be renal disease. The +convulsions have been general, with and without the preservation of +consciousness. No cases of focal or Jacksonian spasms are recorded +although we shall cite two instances of tuberculoma reasonably near the +motor area in the cerebrum. The exact cause of many cases cannot be set +down since intracranial disease does not often exist. + +Intoxication from chemical products of disturbed digestion or from worms +themselves is the usual explanation of spasms associated with intestinal +parasitism; if this be true, intoxication in the absence of demonstrable +parasites may also be the cause in certain cases of enteritis. However +we have seen fits when enteritis, parasites and renal disease were not +found. If these were true epilepsy, they are instances of perhaps the +rarest disease of animals, which I do not presume to diagnose. + +Convulsive seizures in herbivorous animals are exceedingly rare although +I have seen clonic movements of a spasmodic character in antelopes and +deer shortly before death from gastroenteritis. Ataxia and +incoördination are much more common. Birds, notably parrots and soft- +billed insectivorous varieties, are not uncommonly afflicted with fits +but as they are rarely observed except by the keeper the exact nature is +difficult to describe. Those seen by the writer have been of two kinds. + +The first and more common consists of falling from the perch in a dazed +and stiff condition, with dilated fixed eyes, stiffened and spread-out +legs and wings. Recovery follows shortly and the bird resumes its perch +either in excitement, or slowly and uncertainly, perhaps to have another +attack in a few minutes. These cases, in the few instances in which they +could be followed, were due to faulty feeding and enteritis and showed +either nothing or a mild congestion of the brain. The other variety of +fit is epileptiform, a rapidly developing clonic spasm of all parts of +the body with a tendency to opisthotonos. In one case of this character, +a parrot, no lesions were found in the brain, an enteritis existing +however. Another case concerned a pet Indian Shama I had at my home. He +had been doing well and singing loudly, until one evening he was allowed +to remain in a tobacco-smoke-filled room whereupon next morning he +stopped eating and singing. Later that day the clonic form of +convulsions appeared, growing worse for thirty-six hours or until death. +At autopsy no food was found in the alimentary tract. The brain and cord +were congested grossly, while minutely, perivascular hemorrhages and +marked vacuolization and diffuseness of staining were found in ganglion +cells of the bulb, pons, anterior spinal horns and in the pyramidal +cells of the cerebellum. Happening so promptly after exposure to tobacco +smoke, when the bird was doing well, I venture to associate the two. + + +ATAXIA. + +Incoördination and ataxia are so often observed and under so many +conditions that it is well nigh impossible in any individual case to +give an adequate explanation before death. They are in all probability +the expression of sickness and nothing more in the vast majority of +instances. When they are observed in such cases as the tyromata of the +cerebrum or in certain of the ungulates, they may mean something +definite. In this latter order and to a less extent in carnivores, one +frequently sees weakness and uncertainty of gait in the hind quarters, +the legs being usually coördinate but tending to give way under the +weight of the body. + +From a study of veterinary literature and our own material it would seem +that this may have many explanations. In the first place, it may simply +indicate weakness expressing itself in the heaviest part of the body, +the animal inclining its femora forward to assist in supporting the +heavy abdomen. It may be an expression of abdominal pain, the recti +becoming rigid and the quadriceps of the thigh participating in the +protection of the belly. Almost any of the intra-abdominal conditions, +gastroenteritis, mesenteric thrombosis, peritonitis, or diseases of the +psoas muscle and lumbar vertebra, might occasion this attempt at +support. Disease of gluteal muscles, as hemoglobinuric fever, may +produce a palsy of the whole pelvic girdle with weakness of the hind +legs. There may be associated with the weakness of the hind legs a +humped-up condition of the lumbar spine and retraction of the abdomen, +sometimes called “tucked in;” in two definite cases of this last sort we +have found renal pelvic stones and once intestinal sand. Some instances +are undoubtedly due to meningomyelitis or to poliomyelitis and at the +place for this subject a few cases will be discussed. Meningitis has not +been found in the ungulates showing this weakness. There have been +however cases of ataxia in the hind legs of deer and antelopes, which +did not have a ready explanation fitting in with the foregoing. Two of +these we thought might be due to certain grasses in the enclosures and +have changed the exhibition spaces. No conclusion can be drawn from this +as yet. No enterocolic disease could be found nor any lesion of the +sciatic nerve and lumbar enlargement of the cord. We have however +discovered sciatic neuritis in a case like hemoglobinuric fever in a +Burchell’s zebra. The history of the animal is similar to that of this +disease in domestic animals in so far as symptomatology is concerned; in +so far as confinement in a stall is concerned no data is at hand but +death occurred on December 26th in the zebra house whereas he had been +accustomed to go out into the yard all summer and autumn. + + +MENINGITIS. + +The coverings of the brain and cord have not been the seat of the well +known acute inflammations seen in domestic horses and cattle. Eleven +instances of disease in the meninges are recorded but, with very few +exceptions, have been accompanied by other lesions offering a ready +etiological explanation. These cases are however not very instructive +except perhaps three in monkeys where the meningitis seemed to be +secondary to gastroenterocolitis. In one case a colon bacillus was +apparently responsible, in a second no bacteriology was undertaken and a +third was too rotten for the results to be dependable. A focus of +infection aside from the intestinal area could not be found. The only +noteworthy finding was the scantiness of the cerebrospinal fluid and the +almost exclusive subpial exudate; these facts would seem to strengthen +the thought that the virus came through the blood stream. Another case +was due to extension, through the temporal bone to the lateral sinus, of +a necrotizing process beginning in the buccal muscles or parotid gland; +the necrosis bacillus and a host of Gram-positive cocci were found. A +Canadian porcupine suffered with a mucopurulent nasopharyngitis which +involved the deep sinuses, the middle ear and the temporal bone; smears +from the pus over the corresponding cerebral hemisphere and from the +nasal pus showed pneumococcus forms; the lungs were not affected. The +llama which showed the intracapsular fracture of the femur (page 344) +had also hemorrhage into a fibrinous exudate in the mastoid cells with +deep opaque congestion and edema of the pia above the petrous portion of +the temporal bone. Decomposition precluded satisfactory bacteriology but +it is suggested that probably injury in falling started a hemorrhage in +the ear upon which a secondary infection was implanted. What seems a +true meningitis secondary to otitis media and mastoid suppuration was +seen in a marmoset. + +A case of the well known but obscure condition known as chronic +productive pachymeningitis was observed in a badger. Although it cannot +be explained it is cited as a matter of record and interest. + + + American Badger (_Taxidea taxus_). Pachymeningitis externa. The dura + is fast to the skull and cannot be removed. Scattered irregularly over + the entire inner surface of the skull are pale pinhead sized hard + nodules. It is impossible to tell if they are in the dura or the bone. + The brain shows engorged vessels but is otherwise negative. + + +Two instances of hemorrhagic pachymeningitis associated with cretinism +were seen in wolf cubs. The following notes illustrate both cases. + + + American Gray Wolf (_Canis mexicanus_). Cretinism. Hemorrhagic + external pachymeningitis with craniotabes. Upon removing the calvarium + a marked craniotabes of the under surface is found and with it a deep + red and purple staining of outside of dura and inner table of skull. + These changes are most marked along the longitudinal sinus at internal + occipital protuberance and along left parietal region. Dura on left + side is distinctly congested. This is also true of pia. The brain and + its base seem normal. + + +Cyst of the brain. A sooty mangabey (_Cercocebus fuliginosus_) had been +in the Garden for about four months and was apparently an adult normal +animal. It died rather suddenly after a distinct convulsion with +semiconsciousness. At autopsy in addition to a nephritis, a large cyst +was found to occupy the posterior third of the left hemisphere. Its +walls were composed of a thin (one-sixteenth inch) rim of cerebral +substance and the meninges; its contents were clear. The notes do not +record any examination for parasites. This monkey showed no localizing +signs. + + +TUBERCULOSIS. + +Gross tuberculous lesions have been found in the brain in several +specimens with generalized disease but only two cases are of special +interest. A Rhesus macaque (_Macacus rhesus_) suffering with generalized +but chiefly lymphatic tuberculosis, showed a large plaque on the +external surface of the dura over the vertex where it was adherent to a +yellow, fairly firm nodule about ten mm. across. This nodule was deeply +imbedded in the brain substance, barely projecting above the surface, +generally spherical and not encapsulated. There was no peripheral +reactive zone. The meninges were not altered anywhere except as above. +The blood vessels were not especially congested. The pia arachnoid +contained no excess of fluid but the summits of the convolutions were +flattened. The mass was located in the posterior frontal convolution, +near the longitudinal fissure, occupying nearly its whole breadth and +penetrating about one centimetre. It did not enter the fornicate gyrus. +There was a completely degenerated core about two mm. across. The +adjacent bone was beginning to erode. No localizing signs were reported. + +The other case, that of a young Drill baboon (_Papio leucophæus_), was +studied with Dr. J. H. W. Rhein and can be reported in the following +condensed notes. + + + The baboon appeared to be perfectly well until October 18, 1906, when + some lameness in the anterior and posterior extremities on the right + side was observed. This gradually increased, and was associated with + general convulsions. On November 30th, I made an examination and found + the following condition: The right upper and lower extremities were + weaker than on the left side. On the left side the power seemed to be + fair. He was able to hold on to an iron bar with the fingers of the + upper and lower extremities on the right side but in withdrawing the + bar it was not difficult to overcome his grasp and the power on this + side was distinctly less than on the left. The movements of the right + arm were somewhat ataxic, as observed when he made efforts to grasp + the bar. The knee jerks were increased on both sides and appeared to + be equally so. There was no evidence of facial palsy. He moved both + sides of the face equally well at times when he expressed anger or + fear in the facial expression. The tongue seemed to be retracted + equally well on both sides. Tests for hemianopsia were, of course, + unsatisfactory, but he seemed to recognize readily the approach of the + iron bar from both sides. There was no disturbance of the rectal or + bladder functions, although at autopsy the bladder was full. Death + occurred on December 2, 1906. At the autopsy the brain and spinal + cord, with the other organs were examined. The dura was adherent to + the left side of the brain, in the prefrontal region, in the upper + third and when the brain was removed it was observed that an area of + softening lay beneath this point. A small caseous mass was also + observed at the base of the right lung, and beneath the diaphragm on + the right side was a large abscess, partly involving the liver. The + tubercle bacillus was found in the pus removed from the area of + softening beneath the left cortex. A study of the brain revealed the + presence of three foci of softening. The largest one was situated in + the left hemisphere in the prefrontal region, and extended from just + beneath the cortex in the upper third of the region, downward almost + to the base of the brain. This area was cylindrical in shape and + measured 2.5 cm. in its greatest diameter. The area of softening + consisted of caseated material and pus, in which the tubercle bacillus + was found present. The second area of softening was found on the right + side of the brain, much smaller in extent and measuring 1.5 cm. + diameter. There was no pus present in this area, but it consisted of a + circumscribed mass of caseous material. The apex of this area of + softening was just beneath the cortex in the prefrontal region on the + right side, and in the removal of the brain the cortex was torn just + above this area of caseation. This point was .5 cm. in front of the + central fissure and about 1 cm. below the superior surface of the + brain. A third area of softening was observed posteriorly, in the + white substance, in the parieto-occipital region, and measured about 6 + mm. in diameter. A study of the sections of the brain shows + beautifully the extent of the destruction of the brain tissue. The + optic thalamus and the lenticular nucleus, and the posterior limb of + the internal capsule, on the left side, are destroyed in part. The + anterior limb of the internal capsule in one section, is preserved, + notwithstanding the fact that the optic thalamus on the same side has + been in large part destroyed. In spite of the fact that the posterior + limb of the internal capsule has been destroyed at some levels, it is + interesting to note that the degeneration of the pyramidal tracts of + the pons and medulla on the opposite side and the lateral columns of + the spinal cord are not intensely—although distinctly—degenerated. It + is very interesting to note that in view of the severe damage to the + posterior limb of the internal capsule on the left side, there was not + more paralysis, for it will be remembered that there was considerable + power of prehension in the right upper and lower extremities. + + +ENCEPHALOMYELITIS, POLIOMYELITIS. + +While, as has been stated, no well defined cases of the recognized +meningocephalic infectious diseases have been observed in the Garden, +there have been several animals in whose cord and brain changes were +found comparable to the infections disease known in man as +poliomyelitis. On several occasions since this disease was recognized as +occurring in epidemic form it has been observed that domestic mammals +and fowls suffered from a similar condition. The general vicinity of +Philadelphia had a low grade epidemic among children during the years +from 1907 to 1912 and it is during this time that most of the cases of a +comparable character were observed among our animals. It is to be +emphasized that attacks were entirely sporadic and the cases did not +appear to bear a relation to one another. This character is quite in +accord with certain of the outbreaks in man. However we cannot state +that the disease is exactly the same as seen in the human being for, as +will be noted in the cited examples, all the pathological features were +not fulfilled. + +It is not always possible to differentiate between myelitic disease and +polyneuritis of man or animals. Studied symptomatically the cases in our +records which proved to have degenerative and infiltrative lesions +comparable to poliomyelitis showed gradual but progressive paralysis +expressed by inability to move rather than disinclination—in other words +loss of power rather than restriction because of pain. None of the +animals in which poliomyelitis was demonstrated have exhibited the +ataxia of the hind legs discussed on a previous page nor have we found +myelitic lesions in the few cords from animals suffering with this +weakness. The nearest approach to a cerebrospinal explanation for +weakness and palsy was in a zebra which died with constipation, acute +nephritis, and hepatic perilobular fibrosis. In this animal a pronounced +subpial mononuclear infiltrate was observed, in places involving the +superficial parts of the cerebral gray matter, especially about the +congested vessels of this area. This condition was present to a slight +degree in the cord. There was then a low grade meningoencephalitis but +no nerve cell changes. So far as is known to me no animal showing a +definite local paresis or paraplegia recovered from the attack; had this +occurred we might have observed residual palsies. + +In so far as lesions are concerned they are perhaps best illustrated by +the appended cases, but since even in them there is a lack of +uniformity, it may be well to discuss the basic changes of all. The +outstanding abnormality in the microscopic anatomy is the richness of +small mononuclear cells beneath the pia, both spinal and cerebral, +around the smaller blood vessels and to a lesser extent around the +multipolar cells of the gray matter. These do not present the dense +colonization often seen in the acute cases of infantile paralysis in man +but are prominent in comparison to normal nervous tissue. Hemorrhages or +at least small groups of erythrocytes outside of blood vessels are seen +here and there. Vacuolization of ganglion cells is variable, being +prominent in some, trifling or absent in others. Glial proliferation is +often quite marked, and in one case to be cited seems the prominent +lesion. + +The animals in which meningopoliomyelitis has been found were three +monkeys, two Canadian lynx, a bear and a raccoon; about a score of cords +from other animals with some kind of palsy have been studied +microscopically without discovering it. The following cases illustrate +our material. The only instance of two cases in close relation concerns +the lynx (_Felis canadensis_). They occupied the same cage and died +twelve days apart. No symptoms were recorded until a few days before +death when a general paralysis appeared, deepening to completeness on +the day of death. No case occurred in neighboring cages. Doctor Rhein +studied all these cases, and his notes are used for these records. +Portions of the lumbar and cervical enlargements and of the thoracic +regions of the cord were stained with hemalum and acid fuchsin and with +thionin. The pia was slightly infiltrated. There was some cellular +infiltration of the anterior septum, and the vessels here showed an +increase in the nuclei of the walls and a slight perivascular +infiltration. The pial infiltration seemed to be equally distributed in +the entire circumference of the cord, although perhaps a little more +marked over the anterior and posterior septa. The vessels of the gray +matter were congested and the walls of the vessels in most part showed a +proliferation of the nuclei. There were a few small hemorrhages into the +gray matter, probably agonal. As compared with the human cord and the +cords of monkeys, antelopes and dogs, there was an unusually large +number of glia nuclei, which, if found in the human cord, would be +looked upon as a proliferation process. In some cases these nuclei were +heaped together in masses, and were evidently pathological. There was +also, about the ganglion cells, some pericellular round cell +infiltration, and this was more marked around a few cells which were +almost entirely destroyed. The ganglion cells themselves were swollen. +Some showed eccentric nuclei, and many of them stained poorly, while one +or two showed distinct vacuolization. In one field a ganglion cell was +partly destroyed by a recent hemorrhage. There were, however, a number +of cells which appeared normal. This process seemed to be fairly +distinct in the lumbar and cervical enlargements, but was not clearly +demonstrated in the sections from the dorsal region. The cellular +infiltration of the horns was evidently not leucocytic, but presented +the appearance of a connective tissue proliferation. Although these are +not the exact lesions found in poliomyelitis in the human animal, they +are at least suggestive of the same process since the infiltrating cells +are of the lymphatic or connective tissue types. There is no acute +inflammatory leucocytic infiltrate. + +A weeper cebus (_Cebus capucinus_) ever since he was received acted in +such a peculiar manner, seeming to have only partial control of his +movements, that he was known as the “Crazy Monkey.” There was no history +of illness before death. Pathological diagnosis: Chronic enterocolitis, +chronic adhesive pericarditis, early interstitial change in kidney, +edema of lungs, meningitis and poliomyelitis. The pia of the paracentral +cortex was thickened and was the seat of a round cell infiltration of +moderate degree, the cells being of the mononuclear type. The blood +vessels of the cortex were congested and the nuclei of the walls were +increased. The round cell infiltration of the pia had in some places +extended into the cortical layers. The pia surrounding the medulla +oblongata was also the seat of a slight round cell infiltration. The pia +of the spinal cord, however, did not show any cellular infiltration. The +cells of the anterior horns of the spinal gray matter were extensively +diseased, being swollen in places, some surrounded by a glia +proliferation and many with marked vacuolization. + +A common raccoon (_Procyon lotor_) was observed in the laboratory to +have complete paralysis of the anterior and partial paralysis of the +posterior extremities. This latter was almost complete in muscles +controlling the feet, while the thigh and hip muscles showed some +irregular incoördinate movements. Respiration shallow but regular. +History shows that the power of the extremities began to fail about a +month before death and was absolutely lost in the fore extremities three +days before the animal was killed. Diagnosis: Poliomyelitis. Examination +of the central nervous system showed the presence of marked round cell +infiltration of pia of cortex and of spinal cord, more particularly in +the lower thoracic and lumbar regions. Ganglion cells in the lumbar +region were markedly diseased. There were numerous old and fresh +hemorrhages and a moderate degree of round cell infiltration in the +anterior horns. Two young of this animal, born three months before its +death, showed weakness and gradual increasing paralysis of their +extremities beginning when three months old (that is at the time of the +death of their mother), and lasting until their death, one in the +seventh and one in the eighth month of life. These were found not to +have changes in the central nervous system, but there was sufficient +rachitis to account for this paralysis. + +The only tumor of the central nervous system found among these animals +occurred in an Undulated Grass Parrakeet (_Melopsittacus undulatus_). +The gross notes are very vague but the microscopy is suggestive of a +glioma. The growth in the brain consists of large irregular masses of +large cells with vesicular nuclei and pale homogeneous protoplasm. +“Scattered between these accumulations are irregular strands of spindle +cells, with spindle-shaped nuclei, taking the hematoxylin very deeply. +The supporting tissue is almost without cells, taking the eosin faintly, +and is quite loosely arranged. No fibrils are seen among the cells. The +blood vessels are congested, and at one place there is a small +hemorrhage. The vessel walls are the same as the rest of the connective +tissue. There is a slightly atypical metastasis in the liver.” + +A case, the identity of which is still undecided, was observed in a +Green Monkey (_Cercopithecus callitrichus_); it may belong among the +gliomata or glioses. There was in the middle of this monkey’s cerebrum a +gray area about 3 × 2 × 1 cm. with a softened centre, the more solid +parts being found under the microscope to consist of glia tissue, blood +vessels and degenerated cells. No true gliomatous formations could be +discovered. Because of the indefiniteness of the lesion, it is not +included in the tumors or inflammations. Clinically the effect of the +change was to cause blindness and ataxia but motor power was not greatly +impaired. + +A very small number of tumors of the brain in wild animals is on record +in the English and German literature, perhaps the most interesting being +what resembles in description a subdural neurocytoma reported by Wilson +in the _Proceedings of the London Zoological Society_, 1908. The mass +was separate from the cerebellum, but had hollowed out a place for +itself in this part of the hind-brain. + + +BRAIN WEIGHTS. + +The policy of preserving the brain of all species enables us to record +in the accompanying list the weights of a large number of specimens. In +order that the figures may have a representative and comparative value +only those are given where the total body weight of the animal is also +known. The specimens were removed by the laboratory staff, most of them +by one person, and by the same technique. All brains were weighed +immediately upon removal from the body, no preservative being near the +organ. The brains were themselves externally normal. Our technician is +skillful in removing the organ, practically always getting the pituitary +body, and cutting off the brain stem at the foramen magnum, the pia +remaining but the dura removed. Because the specimens were taken, in +practically all cases, from animals that died in the Park, and because +of the shortness of the list (196), it seems wise not to attempt +conclusions referable to comparative weights of the different orders and +families. However, the data seem worthy of record because it is doubtful +if anywhere one can find so many weights taken under comparable +conditions by the same personnel. One can find a considerable list of +brain weights and values in many publications throughout the literature, +notably in an article by Ziehen in Bardeleben’s _Handbuch der Anatomie_ +(Vol. IV, Abt. III 363), but from no single source are there so many +varieties or so long a list. Ziehen’s tables are compiled from the +literature and therefore represent data collected under different +conditions, many of which were probably pathological. The appended +figures are to be considered as raw material collected under uniform +conditions. + +Examination of the figures bears out in a measure some of the remarks +made by Ziehen, notably those which indicate that between large and +small varieties of the same general group, the smaller has the greater +brain weight value and that the youthful animal has more brain than the +adult. + +The brains at the museum are fixed in saline-formaldehyde—sufficient +strength of the former to suspend the organ in the container and four +percentage of the latter. When fixation is complete, as indicated by +density, preservation is done in one per cent. formaldehyde, the organ, +usually bound in gauze, being laid in cotton. A list of important +references is added to the weight tables—some antedating Ziehen’s +articles, but principally those that have appeared since the publication +of his monograph. + + +PRINCIPAL REFERENCES TO THE RELATIVE WEIGHT OF THE BRAIN + + ZIEHEN: In _Bardeleben’s Handbuch der Anatomie des Menschen_, Vol. 4, + pt. 3. + ZIEHEN: _Handbuch der Anatomie des Nervensystems_, Jena, 1903. + GIRARD: _Bulletin de l’Institut Gen. Psychologie_, Vol. 7, p. 53. + VON BUSCHAU: _Real Encyclopedie der Gesamten Heilkunde 3. Aufl._ + VON BUSCHAU: _Neurologisches Zentralbl._, 1897, March. + BRANDT: _Bull. de la Soc. Imperial des Naturalistes de Moscow_, 1867, + 40, pt. 2, 525. + MIES: _Verhandl. der Gesellsch. deutscher Naturforsch und Arzte_, 1898, + 353. + DHERE ET LAPICQUE: _Archives de la Physiologie_, October, 1898. + LAPICQUE ET GIRARD: _C. R. des Sceances de l’Academie de Science_, + Paris, 1905, 140, 1057. + LAPICQUE: _Bulletin de Museum d’Histoire Naturelle_, 1909, No. 7, 408. + LAPICQUE: _Revue du Mois_, Paris, April, 1908, 445. + LAPICQUE: _Bulletin et Memoires de la Société d’Anthropologie de Paris_, + 1907, 5, Vol. 8, No. 3, 261. + LAPICQUE: _Biologica_, Vol. 2, 1912, p. 257. + FUNK: _Inaug. Dissert. Wurzburg_, 1911. + POYNTER: _Cerebral Anthropology_, Lincoln, 1913. + MOLLISON: _Arch. für Anthropologie_, 1914, XIII, 388. + HULTGREN: _Das Hirngewicht des Menschen_, Upsala, 1912. + WEBER: _Festschrift für Karl Gegenbauer_, 1898. + DUBOIS: _Bulletin de la Soc. Anthropologie_, Paris, 1897, 337. + DUBOIS: _Archiv. für Anthropologie_, Vol. 25, 1898. + DUBOIS: _Proc. Sci. K. Acad. Wet., Amsterdam_, 1914, 16, 647. + DUBOIS: _Zeitschrift für Morph. und Anthropologie_, 1914, Vol. 18, 323. + MARCHAND: _Hirngewicht des Menschen_, Leipsig, 1902. + RUDOLPH: _Beiträge zur Path. Anatomie_, Jena, 58, 1914, 48. + KRAEMER: _Mitt. der Deutsch. Landwehrgesell_, 29, 1914, 55. + + TABLE 18.—_Giving the Actual Weight of the Brain and the Relation of this to that + of the Body in 196 Animals._ + ════════════════════╤═══╤══════╤═══════════╤══════╤═════════╤════════╤══════╤══════ + Order Family │Sex│Known │Development│ Time │Condition│ Body │Brain │Grams + │ │Age at│ │ in │ │ Weight │Weight│Brain + │ │Death │ │Garden│ │in Grams│ in │ Per + │ │ │ │ │ │ │Grams │ Kilo + │ │ │ │ │ │ │ │ of + │ │ │ │ │ │ │ │ Body + │ │ │ │ │ │ │ │Weight + Genus Species │ „ │ „ │ „ │ „ │ „ │ „ │ „ │ „ + Common Name │ „ │ „ │ „ │ „ │ „ │ „ │ „ │ „ + ────────────────────┼───┼──────┼───────────┼──────┼─────────┼────────┼──────┼────── + PRIMATESA: │ │ │ │ │ │ │ │ + SIMIADÆ: │ │ │ │ │ │ │ │ + Simia satyrus, │ │ │ │ │ │ │ │ + Orang utan │ ♂ │ │Immature │4 yrs.│Good │ 15,500.│ 405.│ 26.1 + │ │ │ │6 mo. │ │ │ │ + Orang utan │ ♀ │ │Immature │4 yrs.│Thin │ 22,178.│ 300.│ 13.4 + │ │ │ │2 mo. │ │ │ │ + Hylobates │ │ │ │ │ │ │ │ + hainanus, │ │ │ │ │ │ │ │ + Hainan Gibbon │ ♂ │ │Mature │4 yrs.│Good │ 5,900.│ 115.│ 19.4 + │ │ │ │3 mo. │ │ │ │ + Hylobates │ │ │ │ │ │ │ │ + leuciscus, │ │ │ │ │ │ │ │ + Silver Gibbon │ ♀ │ │Mature │14 │Very thin│ 3,030.│ 75.│ 24.7 + │ │ │ │days │ │ │ │ + │ │ │ │ │ │ │ │ + CERCOPITHECIDÆ: │ │ │ │ │ │ │ │ + Presbytis │ │ │ │ │ │ │ │ + cephalopterus, │ │ │ │ │ │ │ │ + Ceylon Entellus │ ♂ │ │Mature │1 mo. │Good │ 4,080.│ 58.│ 14.2 + Cercopithecus │ │ │ │ │ │ │ │ + sabæus, │ │ │ │ │ │ │ │ + Grivet Monkey │ ♀ │ │Mature │14 │Good │ 3,530.│ 65.│ 18.4 + │ │ │ │yrs. │ │ │ │ + Cercopithecus │ │ │ │ │ │ │ │ + patas, │ │ │ │ │ │ │ │ + Red Monkey │ ♂ │ │Mature │2 yrs.│Good │ 5,060.│ 105.│ 20.7 + │ │ │ │9 mo. │ │ │ │ + Cercocebus │ │ │ │ │ │ │ │ + fuliginosus, │ │ │ │ │ │ │ │ + Sooty Mangabey │ ♀ │ │ │3 mo. │Good │ 3,342.│ 105.│ 31.4 + Macacus arctoides,│ │ │ │ │ │ │ │ + Brown Macaque │ ♂ │ │ │3 yrs.│Good │ 3,161.│ 100.│ 31.7 + │ │ │ │6 mo. │ │ │ │ + Macacus │ │ │ │ │ │ │ │ + nemestrinus, │ │ │ │ │ │ │ │ + Pigtailed │ ♀ │ │ │4 yrs │Very Thin│ 4,560.│ 100.│ 21.9 + Macaque │ │ │ │3 mo. │ │ │ │ + Pigtailed │ ♀ │10 mo.│Baby │10 mo.│Good │ 1,390.│ 67.│ 48.2 + Macaque │ │ │ │ │ │ │ │ + Macacus rhesus, │ │ │ │ │ │ │ │ + Rhesus Macaque │ ♂ │6 mo. │Baby │6 mo. │Good │ 462.│ 67.│ 145. + Papio porcarius, │ │ │ │ │ │ │ │ + Chacma Baboon │ ♂ │ │Mature │1 wk. │Thin │ 12,300.│ 180.│ 14.6 + Papio │ │ │ │ │ │ │ │ + cynocephalus, │ │ │ │ │ │ │ │ + Yellow Baboon │ ♂ │ │Mature │4 yrs.│ │ 8,942.│ 140.│ 15.6 + │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + CEBIDÆ: │ │ │ │ │ │ │ │ + Ateles ater, │ │ │ │ │ │ │ │ + Black Spider │ ♀ │ │ │1 mo. │Good │ 1,790.│ 125.│ 70. + Monkey │ │ │ │ │ │ │ │ + Black Spider │ ♀ │ │ │2 mo. │Good │ 2,475.│ 105.│ 42.5 + Monkey │ │ │ │ │ │ │ │ + Black Spider │ ♂ │ │ │2 mo. │Good │ 3,630.│ 125.│ 34.4 + Monkey │ │ │ │ │ │ │ │ + Lagothrix │ │ │ │ │ │ │ │ + lagotricha, │ │ │ │ │ │ │ │ + Woolly Monkey │ ♀ │ │ │9 mo. │Thin │ 1,634.│ 82.│ 50.3 + Cebus fatuellus, │ │ │ │ │ │ │ │ + Brown Cebus │ ♀ │ │ │2 yrs.│Thin │ 1,500.│ 60.│ 40. + Cebus albifrons, │ │ │ │ │ │ │ │ + White fronted │ ♂ │ │ │ │ │ 1,750.│ 61.│ 34.8 + Cebus │ │ │ │ │ │ │ │ + Aotes vociferans, │ │ │ │ │ │ │ │ + Noisy │ ♂ │ │ │2 wks.│Good │ 480.│ 20.│ 41.7 + Douroucouli │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + CALLITRICHIDÆ: │ │ │ │ │ │ │ │ + Callithrix │ │ │ │ │ │ │ │ + pencillata, │ │ │ │ │ │ │ │ + Black eared │ ♂ │ │ │1 yr. │Good │ 135.│ 10.│ 73. + Marmoset │ │ │ │ │ │ │ │ + Black eared │ ♂ │ │ │6 mo. │Good │ 250.│ 15.│ 60. + Marmoset │ │ │ │ │ │ │ │ + Leontocebus │ │ │ │ │ │ │ │ + œdipus, │ │ │ │ │ │ │ │ + Pinche Marmoset │ ♂ │ │ │1 wk. │Good │ 167.│ 14.│ 84. + │ │ │ │ │ │ │ │ + LEMURES: │ │ │ │ │ │ │ │ + LEMURIDÆ: │ │ │ │ │ │ │ │ + Lemur catta, │ │ │ │ │ │ │ │ + Ring tailed │ ♀ │Mature│ │7 yrs.│Good │ 1,470.│ 30.│ 20.4 + Lemur │ │ │ │ │ │ │ │ + Ring tailed │ ♀ │ │ │1 yr. │Good │ 1,240.│ 20.│ 16. + Lemur │ │ │ │3 mo. │ │ │ │ + Lemur mongoz, │ │ │ │ │ │ │ │ + Mongoose Lemur │ ♀ │ │ │2 yrs.│Good │ 1,457.│ 20.│ 13.8 + Galago maholi, │ │ │ │ │ │ │ │ + Maholi Galago │ ♂ │5 yrs.│Mature │5 yrs.│Good │ 100.│ 4.│ 40. + │ │3 mo. │ │3 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + CARNIVORA: │ │ │ │ │ │ │ │ + FELIDÆ: │ │ │ │ │ │ │ │ + Felis viverrina, │ │ │ │ │ │ │ │ + Fishing Cat │ ♂ │ │ │10 mo.│Good │ 7,000.│ 60.│ 8.5 + Felis chaus, │ │ │ │ │ │ │ │ + Jungle Cat │ ♀ │ │Mature │5 yrs.│Good │ 3,640.│ 45.│ 12.2 + │ │ │ │3 mo. │ │ │ │ + Felis ruffus, │ │ │ │ │ │ │ │ + American Wild │ ♀ │ │ │4 yrs.│Thin │ 4,402.│ 50.│ 11.1 + Cat │ │ │ │ │ │ │ │ + Felis onca, │ │ │ │ │ │ │ │ + Jaguar │ ♀ │20 │Mature │15 │Very thin│ 29,500.│ 170.│ 5.7 + │ │yrs. │ │yrs. │ │ │ │ + Felis eyra, │ │ │ │ │ │ │ │ + Eyra │ ♂ │ │ │3 mo. │Good │ 5,000.│ 44.│ 8.8 + Felis canadensis, │ │ │ │ │ │ │ │ + Canada Lynx │ ♀ │ │Mature │4 yrs.│Very thin│ 7,270.│ 80.│ 11. + │ │ │ │6 mo. │ │ │ │ + Felis │ │ │ │ │ │ │ │ + chibigonazon, │ │ │ │ │ │ │ │ + Brazilian Ocelot│ ♀ │ │Young │1 mo. │Thin │ 1,350.│ 35.│ 26. + Felis pardalis, │ │ │ │ │ │ │ │ + Common Ocelot │ ♀ │ │ │10 mo.│Good │ 5,800.│ 50.│ 8.6 + Common Ocelot │ ♂ │ │Young │2 mo. │Thin │ 2,700.│ 45.│ 16.6 + Felis concolor, │ │ │ │ │ │ │ │ + Puma │ ♂ │ │ │ │Good │ 52,700.│ 150.│ 2.8 + Puma │ ♀ │ │Mature │8 yrs.│Very thin│ 29,500.│ 50.│ 1.69 + │ │ │ │6 mo. │ │ │ │ + Puma │ ♂ │ │Baby │ │Good │ 1,067.│ 55.│ 51.5 + Puma │ ♀ │ │Baby │ │Good │ 998.│ 55.│ 55. + Felis tigris, │ │ │ │ │ │ │ │ + Bengal Tiger │ ♀ │ │Mature │12 │Fair │ 66,000.│ 250.│ 3.8 + │ │ │ │yrs. │ │ │ │ + Bengal Tiger │ ♂ │ │Mature │12 │Very thin│ 91,000.│ 240.│ 2.6 + │ │ │ │yrs. │ │ │ │ + Felis uncia, │ │ │ │ │ │ │ │ + Snow Leopard │ ♀ │ │Mature │8 yrs.│Good │ 22,700.│ 120.│ 5.3 + │ │ │ │ │ │ │ │ + HYÆNIDÆ: │ │ │ │ │ │ │ │ + Hyæna hyæna, │ │ │ │ │ │ │ │ + Striped Hyæna │ ♂ │ │Mature │4 yrs.│Poor │ 27,200.│ 92.│ 3.3 + │ │ │ │ 3 mo.│ │ │ │ + Striped Hyæna │ ♂ │ │Mature │8 yrs.│Good │ 36,300.│ 90.│ 2.4 + │ │ │ │10 mo.│ │ │ │ + │ │ │ │ │ │ │ │ + CANIDÆ: │ │ │ │ │ │ │ │ + Canis │ │ │ │ │ │ │ │ + procyonoides, │ │ │ │ │ │ │ │ + Raccoon-like Dog│ ♀ │ │Mature │3 yrs.│Good │ 4,770.│ 25.│ 5.2 + Raccoon-like Dog│ ♀ │ │ │ │Good │ 4,900.│ 35.│ 7.1 + Canis familiaris, │ │ │ │ │ │ │ │ + Eskimo Dog │ ♂ │ │Mature │ │Very thin│ 36,300.│ 100.│ 2.7 + Canis cinereo │ │ │ │ │ │ │ │ + argenteus, │ │ │ │ │ │ │ │ + Gray Fox │ ♀ │ │Mature │3 yrs.│Good │ 2,652.│ 40.│ 15. + Canis cinereus │ │ │ │ │ │ │ │ + argenteus scotti, │ │ │ │ │ │ │ │ + Scott’s Gray Fox│ ♀ │ │Mature │2 yrs.│Good │ 2,200.│ 53.│ 25. + │ │ │ │6 mo. │ │ │ │ + Canis chama, │ │ │ │ │ │ │ │ + Silver Fox │ ♂ │ │ │7 mo. │Good │ 3,325.│ 40.│ 12. + Canis mesomelas, │ │ │ │ │ │ │ │ + Blackbacked │ ♂ │ │ │2 yrs.│Good │ 6,000.│ 60.│ 10. + Jackal. │ │ │ │6 mo. │ │ │ │ + Blackbacked │ ♀ │ │ │ │ │ 3,500.│ 70.│ 20. + Jackal │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + MUSTELIDÆ: │ │ │ │ │ │ │ │ + Mustela foina, │ │ │ │ │ │ │ │ + Beech Marten │ ♀ │ │Mature │3 yrs.│Good │ 810.│ 15.│ 18.3 + Mustela americana,│ │ │ │ │ │ │ │ + Pine Marten │ ♂ │ │Mature │4 yrs.│Good │ 680.│ 13.│ 19. + Gulo gulo, │ │ │ │ │ │ │ │ + Wolverine │ ♀ │ │ │3 yrs.│Good │ 5,700.│ 75.│ 13.1 + │ │ │ │3 mo. │ │ │ │ + Galictis barbara, │ │ │ │ │ │ │ │ + Tayra. │ ♂ │ │ │7 mo. │Good │ 1,480.│ 55.│ 37. + Mephitis │ │ │ │ │ │ │ │ + mephitica, │ │ │ │ │ │ │ │ + Common Skunk │ ♀ │ │ │6 mo. │Good │ 1,755.│ 6.│ 3.4 + Common Skunk │ ♀ │ │ │2 wks.│Good │ 1,700.│ 7.│ 4.1 + Meles meles, │ │ │ │ │ │ │ │ + European Badger │ ♂ │ │ │3 yrs.│Good │ 7,473.│ 46.│ 6. + │ │ │ │ │ │ │ │ + PROCYONIDÆ: │ │ │ │ │ │ │ │ + Procyon lotor, │ │ │ │ │ │ │ │ + Common Raccoon │ ♂ │ │Mature │7 yrs.│Good │ 9,000.│ 42.│ 4.6 + │ │ │ │3 mo. │ │ │ │ + Common Raccoon │ ♀ │ │Mature │9 yrs.│Good │ 5,450.│ 37.│ 6.9 + │ │ │ │2 mo. │ │ │ │ + Procyon lotor │ │ │ │ │ │ │ │ + hernandezi, │ │ │ │ │ │ │ │ + Mexican Raccoon │ ♀ │ │ │2 yrs.│Good │ 6,130.│ 40.│ 6.5 + Nasua nasua, │ │ │ │ │ │ │ │ + Ring tailed │ ♂ │ │ │1 yr. │Good │ 1,600.│ 40.│ 25. + Coati │ │ │ │4 mo. │ │ │ │ + Ring tailed │ ♂ │ │ │10 mo.│Good │ 1,600.│ 35.│ 24.3 + Coati │ │ │ │ │ │ │ │ + Nasua narica, │ │ │ │ │ │ │ │ + White nosed │ ♂ │Mature│ │8 yrs.│Very thin│ 5,000.│ 44.│ 8.8 + Coati │ │ │ │ │ │ │ │ + Potos │ │ │ │ │ │ │ │ + caudivolvulus, │ │ │ │ │ │ │ │ + Kinkajou │ │Mature│ │3 yrs.│Good │ 1,440.│ 35.│ 24.2 + │ │ │ │2 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + URSIDÆ: │ │ │ │ │ │ │ │ + Ursus malayanus, │ │ │ │ │ │ │ │ + Sun Bear │ │ │ │1 yr. │Good │ 41,000.│ 125.│ 3.5 + │ │ │ │9 mo. │ │ │ │ + Ursus beringiana, │ │ │ │ │ │ │ │ + Kamchatkan Bear │ ♀ │ │ │ │Very thin│ 31,800.│ 315.│ 9.9 + │ │ │ │ │ │ │ │ + PINNIPEDIA: │ │ │ │ │ │ │ │ + OTARIIDÆ: │ │ │ │ │ │ │ │ + Eumetopias │ │ │ │ │ │ │ │ + stelleri, │ │ │ │ │ │ │ │ + Steller’s Sea │ ♂ │ │ │4 yrs.│Very thin│120,400.│ 515.│ 4.27 + Lion │ │ │ │ │ │ │ │ + Zalophus │ │ │ │ │ │ │ │ + californianus, │ │ │ │ │ │ │ │ + California Hair │ ♂ │ │Mature │6 yrs.│Very good│ 94,000.│ 420.│ 4.46 + Seal │ │ │ │9 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + RODENTIA: │ │ │ │ │ │ │ │ + MURIDÆ: │ │ │ │ │ │ │ │ + Peromyscus │ │ │ │ │ │ │ │ + leucopus, │ │ │ │ │ │ │ │ + White footed Mouse│ ♀ │5 yrs.│Mature │5 yrs.│Good │ 39.│ 1.│ 25.6 + │ │ │ │ │ │ │ │ + CASTORIDÆ: │ │ │ │ │ │ │ │ + Castor canadensis,│ │ │ │ │ │ │ │ + American Beaver │ ♀ │ │ │8 yrs.│Good │ 10,000.│ 40.│ 4. + │ │ │ │2 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + OCTODONTIDÆ: │ │ │ │ │ │ │ │ + Myocastor coypus, │ │ │ │ │ │ │ │ + Coypu │ ♀ │ │ │ │Good │ 2,000.│ 20.│ 10. + │ │ │ │ │ │ │ │ + HYSTRICIDÆ: │ │ │ │ │ │ │ │ + Hystrix │ │ │ │ │ │ │ │ + longicauda, │ │ │ │ │ │ │ │ + Malaccan │ ♀ │ │Mature │18 │Thin │ 6,000.│ 26.│ 4.3 + Porcupine │ │ │ │yrs. │ │ │ │ + Erethizon dorsatus│ │ │ │ │ │ │ │ + dorsatus, │ │ │ │ │ │ │ │ + Canada Porcupine│ ♀ │ │ │2 mo. │Good │ 4,065.│ 20.│ 4.9 + Coendon │ │ │ │ │ │ │ │ + prehensilis, │ │ │ │ │ │ │ │ + Brazilian Tree │ ♀ │ │ │1 wk. │Good │ 480.│ 14.│ 29.1 + Porcupine │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + CAVIIDÆ: │ │ │ │ │ │ │ │ + Cavia porcella, │ │ │ │ │ │ │ │ + Wild Guinea-Pig │ ♂ │ │Mature │6 yrs.│Good │ 320.│ 4.│ 12.5 + │ │ │ │2 mo. │ │ │ │ + Hydrochœrus │ │ │ │ │ │ │ │ + hydrochœrus, │ │ │ │ │ │ │ │ + Capybara │ ♂ │ │ │1 mo. │Good │ 19,000.│ 50.│ 2.63 + │ │ │ │ │ │ │ │ + PROBOSCIDEA: │ │ │ │ │ │ │ │ + Elephas maximus, │ │ │ │ │ │ │ │ + Asiatic Elephant│ ♂ │3 yrs.│Young │1 mo. │Good │241,000.│3,432.│ 14.1 + │ │ │ │ │ │ │ │ + HYRACOIDEA: │ │ │ │ │ │ │ │ + HYRACIDÆ: │ │ │ │ │ │ │ │ + Procaria capensis,│ │ │ │ │ │ │ │ + Cape Hyrax │ ♂ │ │ │8 mo. │Good │ 1,800.│ 15.│ 8.3 + Cape Hyrax │ ♀ │ │ │1 yr. │Good │ 2,170.│ 20.│ 9.2 + │ │ │ │9 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + UNGULATA: │ │ │ │ │ │ │ │ + TAPIRIDÆ: │ │ │ │ │ │ │ │ + Tapirus indicus, │ │ │ │ │ │ │ │ + Malayan Tapir │ ♀ │ │Mature │7 yrs.│Thin │250,000.│ 300.│ 1.2 + │ │ │ │4 mo. │ │ │ │ + Malayan Tapir │ ♂ │ │Young │3 mo. │Good │ 80,000.│ 225.│ 2.8 + │ │ │ │ │ │ │ │ + EQUIDÆ: │ │ │ │ │ │ │ │ + Equus prjivalskii,│ │ │ │ │ │ │ │ + Wild Horse │ ♀ │1 wk. │Baby │1 wk. │Good │ 22,700.│ 330.│ 14. + Equus burchelli, │ │ │ │ │ │ │ │ + Burchell’s Zebra│ ♂ │ │Mature │6 yrs.│Good │341,000.│ 645.│ 1.9 + │ │ │ │ │ │ │ │ + BOVIDÆ: │ │ │ │ │ │ │ │ + Strepsiceros │ │ │ │ │ │ │ │ + capensis, │ │ │ │ │ │ │ │ + Greater Kudu │ ♂ │ │ │4 mo. │Thin │285,000.│ 290.│ 2.2 + Cobus leche, │ │ │ │ │ │ │ │ + Leche Antelope │ ♀ │ │Mature │10 │Good │ 52,700.│ 200.│ 3.8 + │ │ │ │yrs. 6│ │ │ │ + │ │ │ │mo. │ │ │ │ + Damaliscus │ │ │ │ │ │ │ │ + albifrons, │ │ │ │ │ │ │ │ + Blessbok │ ♂ │ │Mature │11 │Good │ 58,100.│ 245.│ 4.2 + │ │ │ │yrs. │ │ │ │ + Boselaphus │ │ │ │ │ │ │ │ + tragocamelus, │ │ │ │ │ │ │ │ + Nylghaie │ ♀ │ │ │2 yrs.│Good │136,300.│ 310.│ 2.3 + │ │ │ │2 mo. │ │ │ │ + Poephagus │ │ │ │ │ │ │ │ + grunniens, │ │ │ │ │ │ │ │ + Yak │ ♂ │3 yrs.│Young runt │3 yrs.│Runt │114,000.│ 290.│ 2.5 + │ │6 mo. │ │6 mo. │ │ │ │ + Yak │ ♀ │ │Mature │5 yrs.│Thin │177,000.│ 385.│ 2.2 + Taurotragus oryx │ │ │ │ │ │ │ │ + livingstonii, │ │ │ │ │ │ │ │ + Livingstone’s │ ♀ │ │Old │13 │Good │327,000.│ 415.│ 1.3 + Eland │ │ │ │yrs. │ │ │ │ + Hemitragus │ │ │ │ │ │ │ │ + jemlaicus, │ │ │ │ │ │ │ │ + Himalayan Thar │ ♂ │ │ │2 yrs.│Good │ 31,800.│ 165.│ 5.2 + │ │ │ │2 mo. │ │ │ │ + Himalayan Thar │ ♂ │9 mo. │Young │9 mo. │Good │ 9,100.│ 130.│ 16. + Ovis tragelaphus, │ │ │ │ │ │ │ │ + Aoudad │ ♂ │ │ │3 yrs.│Good │ 77,200.│ 233.│ 3. + │ │ │ │2 mo. │ │ │ │ + Aoudad │ ♀ │ │Old │3 yrs.│Good │ 41,000.│ 195.│ 4.8 + │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + GIRAFFIDÆ: │ │ │ │ │ │ │ │ + Giraffa │ │ │ │ │ │ │ │ + camelopardalis, │ │ │ │ │ │ │ │ + Giraffe │ ♀ │ │ │5 yrs.│Good │500,000.│ 630.│ 1.2 + │ │ │ │8 mo. │ │ │ │ + Giraffa capensis, │ │ │ │ │ │ │ │ + Giraffe │ ♂ │ │Old │7 mo. │ │383,000.│ 670.│ 1.7 + (Southern) │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + CERVIDÆ: │ │ │ │ │ │ │ │ + Cervus duvanceli, │ │ │ │ │ │ │ │ + Barasingha Deer │ ♀ │1 mo. │Baby │1 mo. │Good │ 9,500.│ 121.│ 13. + Cervus eldi, │ │ │ │ │ │ │ │ + Eld’s Deer │ ♂ │ │ │ │Good │ 59,000.│ 225.│ 3.8 + Cervus elaphus, │ │ │ │ │ │ │ │ + Red Deer │ ♀ │ │ │ │Good │ 72,700.│ 310.│ 4.4 + Cervus porcinus, │ │ │ │ │ │ │ │ + Hog Deer │ ♂ │11 mo.│Young │11 mo.│Good │ 25,000.│ 130.│ 5.2 + Hog Deer │ ♂ │ │ │3 yrs.│Good │ 41,000.│ 125.│ 3. + │ │ │ │4 mo. │ │ │ │ + Cervus sika │ │ │ │ │ │ │ │ + manchuricus, │ │ │ │ │ │ │ │ + Manchurian Sika │ ♂ │ │Mature │6 yrs.│Good │ 56,800.│ 265.│ 4.6 + Deer │ │ │ │3 mo. │ │ │ │ + Cervus │ │ │ │ │ │ │ │ + cashmirianus, │ │ │ │ │ │ │ │ + Kashmir Deer │ ♂ │ │ │3 yrs.│Fair │ 56,800.│ 275.│ 4.6 + │ │ │ │4 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + CAMELIDÆ: │ │ │ │ │ │ │ │ + Camelus │ │ │ │ │ │ │ │ + bactrianus, │ │ │ │ │ │ │ │ + Bactrian Camel │ ♂ │ │Mature │11 │Fair │430,000.│ 610.│ 1.4 + │ │ │ │yrs. │ │ │ │ + Camelus │ │ │ │ │ │ │ │ + dromidarius, │ │ │ │ │ │ │ │ + Common Camel │ ♀ │ │Mature │5 yrs.│Fair │472,700.│ 465.│ .98 + │ │ │ │ │ │ │ │ + HIPPOPOTAMIDÆ: │ │ │ │ │ │ │ │ + Hippopotamus │ │ │ │ │ │ │ │ + amphibius, │ │ │ │ │ │ │ │ + Hippopotamus │ ♂ │1 mo. │Baby │1 mo. │Good │ 40,000.│ 195.│ 4.87 + │ │ │ │ │ │ │ │ + SUIDÆ: │ │ │ │ │ │ │ │ + Macrocephalus │ │ │ │ │ │ │ │ + africanus, │ │ │ │ │ │ │ │ + Wart Hog │ ♀ │ │Mature │7 yrs.│Good │ 59,000.│ 151.│ 2.5 + │ │ │ │9 mo. │ │ │ │ + Wart Hog │ ♂ │ │ │2 yrs.│Good │ 82,700.│ 150.│ 1.8 + │ │ │ │9 mo. │ │ │ │ + Wart Hog. │ ♂ │ │ │ │Good │ 90,000.│ 158.│ 1.7 + │ │ │ │ │ │ │ │ + TAYASSUIDÆ: │ │ │ │ │ │ │ │ + Tayassu tajacu, │ │ │ │ │ │ │ │ + Peccary │ ♀ │ │Mature │6 yrs.│Good │ 19,650.│ 95.│ 4.8 + │ │ │ │6 mo. │ │ │ │ + Peccary │ ♂ │ │ │3 yrs.│Good │ 22,700.│ 75.│ 3.3 + │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + ENDENTATA: │ │ │ │ │ │ │ │ + DASYPODIDÆ: │ │ │ │ │ │ │ │ + Tatu novemcinctus,│ │ │ │ │ │ │ │ + Nine banded │ ♀ │ │ │2 yrs.│Good │ 1,840.│ 10.│ 5.4 + Armadillo │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + MYRMECOPHAGIDÆ: │ │ │ │ │ │ │ │ + Myrmecophaga │ │ │ │ │ │ │ │ + tetradactyla, │ │ │ │ │ │ │ │ + Tamandua Anteater │ ♀ │ │ │1 wk. │Good │ 3,300.│ 24.│ 7.3 + │ │ │ │ │ │ │ │ + MARSUPIALIA: │ │ │ │ │ │ │ │ + DIDELPHYIDÆ: │ │ │ │ │ │ │ │ + Didelphys │ │ │ │ │ │ │ │ + virginiana, │ │ │ │ │ │ │ │ + Common Opossum │ ♂ │ │ │2 wks.│Good │ 2,500.│ 6.5│ 2.6 + Common Opossum │ │ │Young │3 mo. │Good │ 351.│ 6.│ 17. + │ │ │ │ │ │ │ │ + DASYURIDÆ: │ │ │ │ │ │ │ │ + Sarcophilus │ │ │ │ │ │ │ │ + ursinus, │ │ │ │ │ │ │ │ + Tasmanian Devil │ ♂ │ │Mature │4 yrs.│Thin │ 2,950.│ 8.│ 2.7 + │ │ │ │6 mo. │ │ │ │ + Dasyurus │ │ │ │ │ │ │ │ + viverrinus, │ │ │ │ │ │ │ │ + Common Dasyure │ ♀ │ │ │2 yrs.│Good │ 680.│ 4.5│ 6.6 + │ │ │ │2 mo. │ │ │ │ + Common Dasyure │ ♂ │ │ │8 mo. │Good │ 1,130.│ 5.5│ 4.8 + Common Dasyure │ ♂ │ │ │1 yr. │Good │ 1,430.│ 7.│ 4.9 + │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + PHASCOLOMYIDÆ: │ │ │ │ │ │ │ │ + Phascolomys │ │ │ │ │ │ │ │ + mitchelli, │ │ │ │ │ │ │ │ + Wombat. │ ♂ │ │Mature │9 yrs.│Excellent│ 25,900.│ 70.│ 2.7 + │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + MACROPODIDÆ: │ │ │ │ │ │ │ │ + Macropus │ │ │ │ │ │ │ │ + giganteus, │ │ │ │ │ │ │ │ + Great Gray │ ♂ │ │Mature │3 yrs.│Good │ 34,000.│ 65.│ 1.9 + Kangaroo │ │ │ │2 mo. │ │ │ │ + Macropus rufus, │ │ │ │ │ │ │ │ + Red Kangaroo │ ♂ │ │Mature │5 yrs.│Good │ 63,600.│ 70.│ 1.1 + │ │ │ │8 mo. │ │ │ │ + Macropus unguifer,│ │ │ │ │ │ │ │ + Nailtailed │ ♂ │ │ │2 wks.│Good │ 4,600.│ 12.│ 2.6 + Wallaby │ │ │ │ │ │ │ │ + Macropus thetidis,│ │ │ │ │ │ │ │ + Thigh striped │ ♂ │ │ │2 wks.│Good │ 5,150.│ 25.│ 4.8 + Wallaby │ │ │ │ │ │ │ │ + Macropus │ │ │ │ │ │ │ │ + ualabatus, │ │ │ │ │ │ │ │ + Black Wallaby │ ♀ │ │ │1 yr. │Good │ 8,170.│ 35.│ 4.2 + │ │ │ │6 mo. │ │ │ │ + Aepyprymnus │ │ │ │ │ │ │ │ + rufescens, │ │ │ │ │ │ │ │ + Rufous Rat │ ♀ │3 yrs.│Mature │3 yrs.│Good │ 1,130.│ 15.│ 13.3 + Kangaroo │ │1 mo. │ │ │ │ │ │ + Rufous Rat │ ♀ │6 yrs.│Mature │6 yrs.│Good │ 1,485.│ 15.│ 10.+ + Kangaroo │ │9 mo. │ │9 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + PASSERES: │ │ │ │ │ │ │ │ + ICTERIDÆ: │ │ │ │ │ │ │ │ + Quisculus │ │ │ │ │ │ │ │ + quiscula, │ │ │ │ │ │ │ │ + Purple Grackle │ ♂ │ │ │2 yrs.│Good │ 115.│ 2.7│ 23.4 + │ │ │ │7 mo. │ │ │ │ + Icterus icterus, │ │ │ │ │ │ │ │ + Common Troupial │ ♂ │ │ │2 yrs.│Good │ 53.│ 2.│ 27.7 + │ │ │ │7 mo. │ │ │ │ + Common Troupial │ ♂ │ │ │4 yrs.│Thin │ 68.│ 2.│ 29.4 + │ │ │ │7 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + PLOCEIDÆ: │ │ │ │ │ │ │ │ + Amadina │ │ │ │ │ │ │ │ + erythrocephala, │ │ │ │ │ │ │ │ + Red headed Finch│ ♀ │ │ │4 yrs.│Good │ 25.│ 1.2│ 48. + Munia malacca, │ │ │ │ │ │ │ │ + Black headed │ ♂ │ │ │3 yrs.│Good │ 13.│ .7│ 52.6 + Finch │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + TANAGRIDÆ: │ │ │ │ │ │ │ │ + Euphonia violacea,│ │ │ │ │ │ │ │ + Violet Tanager │ ♀ │ │ │2 days│Good │ 15.│ 1.│ 66.6 + Violet Tanager │ ♂ │ │ │2 days│Good │ 16.│ 1.│ 62.5 + Tanagra cana, │ │ │ │ │ │ │ │ + Silver blue │ ♂ │ │ │6 mo. │Good │ 29.│ 1.│ 34.5 + Tanager │ │ │ │ │ │ │ │ + Silver blue │ ♀ │ │ │1 yr. │Good │ 30.│ 1.│ 33.3 + Tanager │ │ │ │2 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + FRINGILLIDÆ: │ │ │ │ │ │ │ │ + Zonotrichia │ │ │ │ │ │ │ │ + albicollis, │ │ │ │ │ │ │ │ + White throated │ ♂ │ │ │1 yr. │Good │ 35.│ 1.5│ 42.8 + Sparrow │ │ │ │6 mo. │ │ │ │ + White throated │ ♂ │ │ │6 mo. │Good │ 32.│ 1.5│ 46.9 + Sparrow │ │ │ │ │ │ │ │ + White throated │ ♂ │ │ │1 yr. │Good │ 23.│ 1.3│ 56.5 + Sparrow │ │ │ │8 mo. │ │ │ │ + Eophona melanura, │ │ │ │ │ │ │ │ + Black tailed │ ♂ │ │ │2 mo. │Good │ 31.│ 2.│ 64.5 + Hawfinch │ │ │ │ │ │ │ │ + Black tailed │ ♂ │ │ │1 mo. │Good │ 30.│ 1.7│ 56.6 + Hawfinch │ │ │ │ │ │ │ │ + Java Sparrow │ ♂ │ │ │ │Good │ 28.│ 1.2│ 42.8 + Passerina ciris, │ │ │ │ │ │ │ │ + Nonpareil │ ♂ │ │ │9 mo. │Good │ 15.│ .5│ 33.3 + Bunting │ │ │ │ │ │ │ │ + Pipilo │ │ │ │ │ │ │ │ + erythropthalmus, │ │ │ │ │ │ │ │ + Towhee │ ♀ │ │ │1 yr. │Good │ 16.│ 1.2│ 75. + │ │ │ │2 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + TURDIDÆ: │ │ │ │ │ │ │ │ + Turdus iliacus, │ │ │ │ │ │ │ │ + Red winged │ ♀ │ │ │5 yrs.│Good │ 55.│ 1.5│ 27.2 + Thrush │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + PITTIDÆ: │ │ │ │ │ │ │ │ + Pitta strepitans, │ │ │ │ │ │ │ │ + Noisy Pitta. │ │ │ │1 yr. │Good │ 92.│ 2.5│ 27. + │ │ │ │8 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + CRATEROPODIDÆ: │ │ │ │ │ │ │ │ + Garrulax │ │ │ │ │ │ │ │ + leucolophus, │ │ │ │ │ │ │ │ + White crested │ ♀ │ │ │2 yrs.│Good │ 105.│ 2.7│ 25.7 + Jay Thrush │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + PICARIÆ: │ │ │ │ │ │ │ │ + RHAMPHASTIDÆ: │ │ │ │ │ │ │ │ + Rhamphastos │ │ │ │ │ │ │ │ + cuvieri, │ │ │ │ │ │ │ │ + Cuvier’s Toucan │ ♀ │ │ │11 │Thin │ 356.│ 8.│ 22.4 + │ │ │ │yrs. 9│ │ │ │ + │ │ │ │mo. │ │ │ │ + │ │ │ │ │ │ │ │ + BUCEROTIDÆ: │ │ │ │ │ │ │ │ + Lephoceros │ │ │ │ │ │ │ │ + flavirostris, │ │ │ │ │ │ │ │ + Yellow billed │ ♀ │ │ │1 yr. │Good │ 177.│ 6.│ 33.8 + Hornbill │ │ │ │9 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + STRIGES: │ │ │ │ │ │ │ │ + ALUCONIDÆ: │ │ │ │ │ │ │ │ + Aluco pratincola, │ │ │ │ │ │ │ │ + Am. Barn Owl │ ♂ │ │ │1 mo. │Good │ 470.│ 11.│ 23.4 + │ │ │ │ │ │ │ │ + BUBONIDÆ: │ │ │ │ │ │ │ │ + Bubo virginianus, │ │ │ │ │ │ │ │ + Great Horned Owl│ ♀ │ │ │1 yr. │Good │ 1,415.│ 12.│ 8.4 + Otus asio asio, │ │ │ │ │ │ │ │ + Screech Owl │ ♂ │ │ │1 day │Good │ 122.│ 6.│ 49. + Strix varia varia,│ │ │ │ │ │ │ │ + Barred Owl │ ♀ │ │ │11 │Good │ 1,022.│ 12.│ 11.6 + │ │ │ │yrs. │ │ │ │ + │ │ │ │ │ │ │ │ + PSITTACI: │ │ │ │ │ │ │ │ + PSITTACIDÆ: │ │ │ │ │ │ │ │ + Conurus cactorum, │ │ │ │ │ │ │ │ + Cactus conure │ ♀ │ │ │1 yr. │Good │ 64.│ 4.│ 62.5 + │ │ │ │6 mo. │ │ │ │ + Chrysotis │ │ │ │ │ │ │ │ + leucocephala, │ │ │ │ │ │ │ │ + White fronted │ │ │ │1 yr. │Good │ 251.│ 8.5│ 33.8 + Amazon │ │ │ │ │ │ │ │ + Chrysotis │ │ │ │ │ │ │ │ + levaillanti, │ │ │ │ │ │ │ │ + Levaillant’s │ │ │ │1 yr. │Good │ 300.│ 12.│ 40. + Amazon │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + ACCIPITRES: │ │ │ │ │ │ │ │ + SERPENTARIIDÆ: │ │ │ │ │ │ │ │ + Serpentarius │ │ │ │ │ │ │ │ + serpentarius, │ │ │ │ │ │ │ │ + Secretary │ ♂ │ │ │2 wks.│Good │ 3,768.│ 15.│ 4. + Vulture │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + FALCONIDÆ: │ │ │ │ │ │ │ │ + Haliæetus │ │ │ │ │ │ │ │ + leucocephalus, │ │ │ │ │ │ │ │ + Bald Eagle │ ♀ │ │ │1 yr. │Good │ 2,860.│ 15.│ 5.2 + │ │ │ │3 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + COLUMBÆ: │ │ │ │ │ │ │ │ + COLUMBIDÆ: │ │ │ │ │ │ │ │ + Ocyphaps lophotes,│ │ │ │ │ │ │ │ + Crested Pigeon │ │ │ │3 mo. │Thin │ 142.│ 2.│ 14. + Lophophaps │ │ │ │ │ │ │ │ + leucogaster, │ │ │ │ │ │ │ │ + Plumed Pigeon │ ♂ │ │ │ │Good │ 52.│ 1.2│ 23. + Phaps chalcoptera,│ │ │ │ │ │ │ │ + Bronze winged │ ♀ │ │ │4 yrs.│Good │ 219.│ 1.5│ 6.8 + Pigeon │ │ │ │2 mo. │ │ │ │ + Columba phæonata, │ │ │ │ │ │ │ │ + Dark backed │ ♂ │ │ │2 yrs.│Good │ 360.│ 2.│ 5.05 + Pigeon │ │ │ │9 mo. │ │ │ │ + Scardapella │ │ │ │ │ │ │ │ + squamosa, │ │ │ │ │ │ │ │ + Ground Dove │ ♀ │ │ │2 yrs.│Good │ 23.│ 1.7│ 64. + │ │ │ │9 mo. │ │ │ │ + Zenaidura macroura│ │ │ │ │ │ │ │ + carolinensis, │ │ │ │ │ │ │ │ + Carolina Dove │ ♂ │ │ │2 yrs.│Thin │ 92.│ 1.│ 10.8 + │ │ │ │9 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + GALLI: │ │ │ │ │ │ │ │ + PHASIANIDÆ: │ │ │ │ │ │ │ │ + Coturnix │ │ │ │ │ │ │ │ + pectoralis, │ │ │ │ │ │ │ │ + Stubble Quail │ ♀ │ │ │2 yrs.│Good │ 70.│ .7│ 10. + Lophortyx │ │ │ │ │ │ │ │ + californica │ │ │ │ │ │ │ │ + californica, │ │ │ │ │ │ │ │ + California Quail│ ♀ │ │ │1 yr. │Good │ 180.│ 1.5│ 8.33 + │ │ │ │4 mo. │ │ │ │ + Arboricola │ │ │ │ │ │ │ │ + atrogularis, │ │ │ │ │ │ │ │ + Black throated │ ♀ │ │ │1 yr. │Good │ 151.│ 2.5│ 16. + Hill Partridge │ │ │ │2 mo. │ │ │ │ + Meleagris │ │ │ │ │ │ │ │ + gallopavo │ │ │ │ │ │ │ │ + silvestris, │ │ │ │ │ │ │ │ + Eastern Wild │ ♂ │ │ │ │Good │ 6,340.│ 12.│ 1.9 + Turkey │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + CRACIDÆ: │ │ │ │ │ │ │ │ + Ortalis vetula, │ │ │ │ │ │ │ │ + Mexican Guan │ ♀ │ │ │2 yrs.│Thin │ 442.│ 5.│ 11.3 + │ │ │ │2 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + MEGAPODIDÆ: │ │ │ │ │ │ │ │ + Catheturus │ │ │ │ │ │ │ │ + lathami, │ │ │ │ │ │ │ │ + Brush Turkey │ ♂ │ │ │3 mo. │Good │ 1,487.│ 5.│ 3.37 + │ │ │ │ │ │ │ │ + ALECTORIDES: │ │ │ │ │ │ │ │ + GRUIDÆ: │ │ │ │ │ │ │ │ + Grus lilfordi, │ │ │ │ │ │ │ │ + Lilford’s Crane │ ♂ │ │ │1 yr. │Good │ 3,790.│ 18.│ 4.7 + │ │ │ │4 mo. │ │ │ │ + Tetrapteryx │ │ │ │ │ │ │ │ + paradisea, │ │ │ │ │ │ │ │ + Stanley Crane │ ♂ │ │ │3 yrs.│Good │ 4,450.│ 13.│ 2.9 + │ │ │ │3 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + STEGANOPODES: │ │ │ │ │ │ │ │ + ANHINGIDÆ: │ │ │ │ │ │ │ │ + Anhinga anhinga, │ │ │ │ │ │ │ │ + Darter │ ♂ │ │ │3 yrs.│Good │ 251.│ 8.5│ 33.8 + Darter │ ♀ │ │ │7 yrs.│Good │ 998.│ 6.│ 6. + │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + HERODIONES: │ │ │ │ │ │ │ │ + ARDEIDÆ: │ │ │ │ │ │ │ │ + Nycticorax │ │ │ │ │ │ │ │ + nyctanassa, │ │ │ │ │ │ │ │ + Yellow crowned │ ♂ │ │ │1 yr. │Good │ 620.│ 7.│ 11.3 + Night Heron │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + CICONIIDÆ: │ │ │ │ │ │ │ │ + Leptoptilus │ │ │ │ │ │ │ │ + dubius, │ │ │ │ │ │ │ │ + Adjutant Stork │ │ │ │ │ │ 7,873.│ 36.│ 4.5 + Leptoptilus │ │ │ │ │ │ │ │ + crumeniferus, │ │ │ │ │ │ │ │ + Marabou Stork │ │ │ │ │ │ 4,580.│ 24.│ 5.2 + │ │ │ │ │ │ │ │ + PLATALEIDÆ: │ │ │ │ │ │ │ │ + Carphibis │ │ │ │ │ │ │ │ + spinicollis, │ │ │ │ │ │ │ │ + Straw necked │ │ │ │ │ │ 1,665.│ 89.│ 4.8 + Ibis │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + PALAMEDES: │ │ │ │ │ │ │ │ + Palmadea derbiana,│ │ │ │ │ │ │ │ + Derbian Screamer│ ♂ │ │ │3 yrs.│Good │ 2,730.│ 10.│ 3.6 + Derbian Screamer│ ♂ │ │ │1 wk. │Thin │ 1,700.│ 8.│ 4.7 + │ │ │ │ │ │ │ │ + ANSERES: │ │ │ │ │ │ │ │ + ANATIDÆ: │ │ │ │ │ │ │ │ + Cygnopsis │ │ │ │ │ │ │ │ + cygnoides, │ │ │ │ │ │ │ │ + Chinese Goose. │ ♂ │ │ │2 yrs.│Good │ 2,740.│ 15.│ 5.5 + │ │ │ │6 mo. │ │ │ │ + Plectropterus │ │ │ │ │ │ │ │ + niger, │ │ │ │ │ │ │ │ + Black Spurwinged│ ♂ │ │ │9 yrs.│Good │ 2,735.│ 13.│ 4.7 + Goose │ │ │ │ │ │ │ │ + Cereopsis novæ- │ │ │ │ │ │ │ │ + hollandiæ, │ │ │ │ │ │ │ │ + Cereopsis Goose │ ♀ │ │ │2 yrs.│Good │ 2,370.│ 9.│ 3.6 + │ │ │ │3 mo. │ │ │ │ + Cereopsis Goose │ ♂ │ │ │1 yr. │Good │ 2,748.│ 11.│ 4. + Anser domesticus, │ │ │ │ │ │ │ │ + Sebastopol Goose│ ♂ │ │ │3 yrs.│Good │ 3,106.│ 19.│ 6.1 + │ │ │ │2 mo. │ │ │ │ + Anser fabalis, │ │ │ │ │ │ │ │ + Bean Goose │ ♂ │ │ │12 │Good │ 2,640.│ 13.│ 4.9 + │ │ │ │yrs. 6│ │ │ │ + │ │ │ │mo. │ │ │ │ + Chloephaga │ │ │ │ │ │ │ │ + magellanica, │ │ │ │ │ │ │ │ + Upland Goose │ ♂ │ │ │2 wks.│Thin │ 1,822.│ 8.│ 4.4 + Coscoroba │ │ │ │ │ │ │ │ + coscoroba, │ │ │ │ │ │ │ │ + Coscoroba Swan │ ♂ │ │ │1 mo. │Good │ 1,915.│ 9.│ 4.7 + Anas │ │ │ │ │ │ │ │ + platyrhynchos, │ │ │ │ │ │ │ │ + Mallard Duck │ ♀ │ │ │3 yrs.│Good │ 1,471.│ 8.│ 5.4 + Mallard Duck. │ ♀ │ │ │3 yrs.│Good │ 525.│ 6.│ 11.4 + Dafila acuta, │ │ │ │ │ │ │ │ + Pintailed Duck. │ │ │ │3 yrs.│Good │ 489.│ 6.│ 12.2 + Fuligula ferina, │ │ │ │ │ │ │ │ + Pochard │ ♂ │ │ │4 yrs.│Good │ 600.│ 6.│ 10. + │ │ │ │6 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + STRUTHIONES: │ │ │ │ │ │ │ │ + STRUTHIONIDÆ: │ │ │ │ │ │ │ │ + Struthio │ │ │ │ │ │ │ │ + molybdophanes, │ │ │ │ │ │ │ │ + Samoli Ostrich │ ♀ │ │ │9 yrs.│Thin │ 60,000.│ 37.│ .65 + │ │ │ │3 mo. │ │ │ │ + │ │ │ │ │ │ │ │ + CASUARIIDÆ: │ │ │ │ │ │ │ │ + Casuarius │ │ │ │ │ │ │ │ + papuanus, │ │ │ │ │ │ │ │ + Papuan Cassowary│ ♂ │ │ │8 yrs.│Good │ 24,000.│ 30.│ 1.3 + ────────────────────┴───┴──────┴───────────┴──────┴─────────┴────────┴──────┴────── + + + + + SECTION XIII-PART II + THE EYE + + +INFLAMMATIONS. + +Conjunctivitis is rather rare but does occur in all varieties of +animals, seldom however, to the extent that the specimen has to be +sacrificed. So far as the daily reports can be relied upon we have had +no epidemic inflammations of the eye. The parrots and monkeys are the +only animals that can be handled enough for treatment, and in them the +applications have not seemed very efficacious. Two cases of +conjunctivitis and iritis have had a tuberculous basis and two other +specimens have had tuberculosis in the eye. Two parrots had, in +association with generalized tuberculosis, semisolid masses in the orbit +which dislocated the bulb, thickened the lids and presented as yellowish +granulating tumors under the conjunctiva; a Swainson’s long-tailed jay +(_Calocitta formosa_) had this lesion on both sides. The only case in a +mammal concerned an Anubis baboon (_Papio anubis_) in which one eye had +been enucleated, two weeks before death, for purulent ophthalmitis. The +other eye became affected shortly after the extraction and the animal +was killed; it was found to have caseous pneumonia. The tuberculous +process had probably begun in the region of the optic nerve and involved +the whole bulb. Secondary infection with pyogenic cocci had been +superimposed upon the original process. Keratomalacia, encountered on a +few occasions, will be discussed by Doctor White. + +Iridocyclitis was found in a white browed guan (_Penelope +superciliaris_) the notes of which are condensed as follows: + + + The internal organs show nothing of value pathologically. The right + eye shows moderate conjunctivitis and a marked thickening of the + cornea with complete opacity. The lens is destroyed and the retina + infiltrated by gelatinous material. Humors are watery, non- + suppurative, but the fundal portion of the retina shows several poorly + circumscribed, yellowish white, gelatinous collections. Microscopical + section of cornea shows replacement of normal bundles by wavy ones + intermixed with small numbers of nuclei. These are never of + inflammatory type, but always of connective tissue type. Conjunctival + mucosa defective in centre, puckered but shows no subjacent + inflammatory features. Ciliary body richly infiltrated by lymphocytes + and vessels distinctly congested. This condition extends over whole + anterior surface of iris and for a short distance over posterior. + Sclera shows much bone formation. Chronic interstitial keratitis, + subacute interstitial iritis and cyclitis. + + +CATARACT. + +Opacities of the cornea are quite common among our specimens, most often +due we believe, to local trauma; ungulates exhibit them more than other +varieties. Cataractous opacities of the lens are frequently observed in +senile animals but, while I have no figures for the statement, I believe +they are not as common among our specimens as can be observed in +domestic horses and dogs. No record has been made of streaky clouds or +spots in the lens but only of complete opacities. There are three only, +an aoudad (_Ovis tragelaphus_) a macaw (_Ara macao_) and a summer duck +(_Aix sponsa_) the last of which alone is interesting. This bird, a +fully developed adult female, was killed because of total blindness and +found to have a low grade chronic pancreatitis and a bilateral +Morgagnian cataract, the lens capsule containing a thin cloudy fluid +with the nucleus quite freely movable in it. + + +AMBLYOPIA. + +A very interesting case of amblyopia in a young monkey was studied and +reported by Dr. H. M. Langdon and Doctor Cadwalader in the _Journal of +Comparative Pathology and Therapeutics_, Vol. XXVIII, Part 4. Because of +its unusual character and careful investigation, the report is +reproduced here: + + + Pigtailed macaque (_Macacus nemestrinus_) was born June 9, 1913, in + the monkey house, a well developed baby. He thrived and was as good as + any for his age. He was never known to have anything wrong with him + until on the morning of June 3, 1914, when he was found on the bottom + of the cage in the monkey house. He had clenched hands and feet, jaws + tightly closed, lips drawn back, eyes staring and glassy, with + convulsive shaking of the extremities. At intervals he would become + limp, with fists still clenched, and with only occasional jerks in the + extremities. This would last about a minute, and then convulsive + movements would be resumed. The entire “fit” lasted about ten minutes. + He was immediately removed from the large cage in the monkey house to + a small one in the back room of the laboratory. When put in the small + cage he staggered as if dazed, and groped about apparently blind. He + never recovered his sight entirely, but at times seemed to see better + than at others. He was not seen in a “fit” in the laboratory. On June + 24th, a small piece of banana was offered by a person who stood + directly in the sunlight. The monkey came to the front of the cage, + reached out and grasped very firmly the thumb of the hand holding the + banana but did not take the banana although he very plainly wanted it. + The banana was thrown into the cage, hitting the monkey on the back. + He turned very quickly, then smelled over the floor of the cage until + he found the banana. On June 30th, he was examined by Doctor Langdon + and the following condition was noted: + + “Pupils react to the light of the ophthalmoscope. Optic discs are + normal. Arteries possibly a little small. No other fundus changes.” On + July 1, a cloudy day, he was laid facing a window. A coat sleeve was + laid over his eyes for a minute and then quickly removed. His pupils + were seen to react slowly but distinctly to the light. His gaze would + not follow a finger moved in front of his eyes. When put back in the + cage he climbed up on the wire at the back and then tried to climb the + plain sheet-iron side. He groped and felt for a support and then fell. + This he did several times. About August 1, when the eyes were + examined, there seemed to be more visual perception and very + distinctly prompter pupillary reflex, which condition remained about + the same when examined October 1. He died October 10, 1914, of a + compound fracture of the right femur inflicted by a monkey in the + adjoining cage. + + At autopsy the viscera appeared normal throughout. The animal was + fairly well nourished. There was about 5 cc. clear, pale yellow fluid + under the dura. It escaped upon removal of the brain. There were + adhesions of the dura over the temporal lobe (inferior surface), + posterior and external to the optic tract, so firm as to remove some + periosteum and superficial bone. Rest of dura seemed normal. + + Examination of the brain. Sections were made from different parts of + the cerebral cortex, all of which were more or less alike. There was + swelling of the endothelium of the pial lymph spaces, with some + separation of the fibres of the pia itself which extended into the + sulci. The perivascular lymph spaces of the larger arteries of the + cortex were dilated, and the adjacent cerebral tissue was edematous. A + well marked endothelial swelling and hyperplasia affected a number of + the arteries and capillaries producing marked general or nodular + thickening in some places. Accompanying these hyperplastic changes + there was a marked calcification of some of the arteries. This was not + confined to one tunic, but in some instances it extended almost + completely through the vessel wall, and here and there the lumen of a + vessel was nearly obliterated. The main features were endothelial + hyperplasia, edema of the pia and of the subpial cortex with some + calcification of the vessels. It was perhaps less well marked in the + occipital lobes than in other parts. The optic nerve and other + portions of the brain appeared to be normal. + + +MOON BLINDNESS. + +It seems also profitable to repeat here a report Dr. H. M. Langdon and I +made in 1911 upon a horse with periodic ophthalmia or “moon blindness,” +a widespread condition and one upon which there is even to-day little +known and much contradictory theorizing. It is worthy of record that Dr. +J. H. W. Eyre of Guy’s Hospital, had a case to study at the same time as +ours. He did not find the protozoön-like body discussed below, but laid +weight upon the isolation of St. aureus, an organism often mentioned in +the literature about this disease. I cite the whole report since our +publication in the 1911 Report of this Garden seems not to have been +quoted in any of the reference articles on “Moon blindness.” Those who +are interested in the clinical and pathological sides of the question +will find a good summary in _Veröff. aus der-Jahres. Vet. Berichten der +beamt. Tierärzte Preussens_, 1908, and the bacteriology of the equine +eye by Karsten, _Inaug. Disser._ Giessen, 1909. + +“During the latter part of 1909 and first part of 1910 we had a horse +referred to us suffering with recurrent ophthalmia or moon blindness. +This affection, suggested by its name, is supposed to have some relation +to the lunar periods. Some points in our work showed that such may be +the case. Attacks appear not infrequently at the time of the full moon, +and in our only experimental infection twenty-eight days elapsed between +inoculation and a general ocular inflammation. + +“This affection manifests itself as a conjunctivitis early in the +attack, but rapidly progresses to an iridocyclitis and lastly to a +panophthalmitis. After each attack the ball is smaller until it is so +shrunken as to be sightless from chronic thickening and opacities. The +causation is not known. The disease behaves not unlike an infectious +one, remaining in a stud for years at a time. Not every horse may be +affected. It has been connected with dampness, bad fodder, overwork and +the like. Again others have connected it with malaria or rheumatism. +Potapenke, Vigezzi, Koch and others have found various microörganisms, +no two of which seem to be the same. Even an animal organism like +malaria has been described. (Whether or not malaria has anything to do +with the disease, it must be said that our horse was favorably affected +in regard to temperature as well as to the eye condition by repeated +subcutaneous injections of Quinine Bisulphate, Grain xx daily.) The +attacks last five to nine days. One or both eyes may be attacked and not +uncommonly do they alternate. One eye may cease to have attacks while +the other continues. The experiments here recorded were made with the +idea of transmitting the disease to other horses. They were only +partially successful. During eight months the affected animal referred +to us had six attacks of ophthalmia. The attack was observed for study +on the first occasion, but during the second his anterior chamber was +entered by a needle attached to a syringe, the exudate aspirated and +injected into the eye of a horse with apparently healthy eyes. The +history of this second horse will be given later. The attacks of the +first horse ranged from six to twelve days. Five of the six affected the +left eye and one the right. In January, 1910, the left eye was used for +further inoculation, and following this traumatism complete recovery +never took place. The corneal scar left by the needle tract almost +disappeared, but an inferior anterior synechia formed and was followed +by a spreading opacity of the cornea, much wrinkling of the iris and +opacity of the depths. After the fourth attack in this eye it was +completely blind. Material was obtained from this eye during its last +attack, but it was merely serous fluid containing a few blood cells and +epithelium, but no bacteria. + +“In transferring the affection from this animal, the conjunctival sac +was washed with 1–5000 bichloride of mercury solution and well rinsed +with salt solution. The anterior chamber was then entered with an +aspirating needle and the exudate removed. This consisted of 0.4 cc. +slightly turbid straw colored fluid containing a few shreds of lymph. +Bacteriological cultures, moist and dry preparations were made from a +part of this, while the remainder was introduced into the anterior +chamber of the second horse. This animal’s eye showed the effects of the +traumatism for eight days, and then was normal save for a small opaque +spot in the cornea left from needle puncture. After twenty-three days a +small patch of lymph collected in the pupil. This increased slowly +accompanied by lacrymation until the twenty-seventh day, when a sudden +and violent conjunctivitis arose. The lymph in the anterior chamber +likewise suddenly increased and rapidly became pus, forming a hypopyon. +The conjunctivitis became purulent. The violent stage lasted five days +and slowly subsided, leaving an ectropion with a densely injected bulbar +conjunctiva, almost complete corneal opacity and an irregular +contraction of iris, apparently due to several small synechiæ. The +depths could not be seen because of the corneal condition. This stage of +affairs remained during the rest of the animal’s life, two months. He +was permitted to live to see if an exacerbation of this chronic process +or involvement of the other eye would appear. Such not occurring in two +months, he was killed and the eyes removed. Fluid removed from the left +eye of the first horse when killed during the last attack was injected +into the anterior chamber of a third horse. This animal’s eye received +the operation well and the trauma had entirely disappeared when the +animal died on the eighth day. + +“LABORATORY EXAMINATIONS.—From fluid removed from horse eye (No. 1) +anaerobic cultures made on milk and blood serum, blood agar, glycerine +agar; cultures were made directly from the fluid, while the coagula were +dried upon slides and stained as follows: Loeffler’s, Gram’s, Giemsa. In +all there are very few recognizable bodies. They are red blood cells, +polynuclears and a very few small mononuclear cells. In regard to +microörganisms three structures present themselves. A well staining +Gram-positive, rounded end rod of fairly uniform size but tending to +grow in pairs and stain rather irregularly with Loeffler and Giemsa. +These forms are sometimes called ‘dumbbell’ in that they are bipolar, or +even seem to have a constriction in their centre. Another form is +peculiar and cannot be said to be recognized as a bacterium. It is +circular, of fairly regular size and contour and in many places looks +like a very large coccus. In Loeffler’s stain it is colored deeply in +the centre with a paler marginal zone and an unstained halo about it, +which, however, is not like a capsule. In the Gram and Giemsa method it +is deeply blue or purple with a retractile centre and very sharply +outlined contour. These forms varied from 3 to 5 microns. The third form +is a wavy delicate short mycelium-like thread. Smears from the cultures +as made above showed chiefly a Gram-positive, rounded end rod but which +did not grow on planting out. It grew on aerobic media, but was not +found on anaerobic. The Gram-positive organism would not grow beyond the +fourth generation. It was not identified with any known species by the +characters manifested during the short time we were able to keep it +alive but could be placed in the Hog Cholera group. The mycelium was +found to be an aspergillus. In regard to the large coccus-like body, +little can be added to the above description. Further examination did +not reveal characters permitting us to place it among the protozoa. No +evidences of division were seen. The body is quite uniform in +appearance, varying only in size. Whatever this is it seems to be an +organized body.” + +“Cultures from pus in the anterior chamber of the second horse showed +the palely staining rod, an aspergillus and Micrococcus aquatilis. The +first was planted on horse serum bouillon, but did not grow after the +first generation. These cultures were made after death, but the cultures +made during the acute attack direct from conjunctival sac contained such +a host of organisms that no judgment could be formed of their relative +importance. The polar staining rod was found in smears. No large coccus- +like bodies were observed in the second horse. Fluid taken from the +first horse’s eye at death was sterile.” + +“These observations are at variance with those of others but such +results are not unique in this respect. It seems as if the polar +staining rod deserves some consideration, and we expect to devote some +attention to it if another horse suffering from recurrent ophthalmia +come to our notice. The large coccus-like bodies are very interesting +and may be protozoa. The finding of the amœba in the cases of Potapenke, +increases their importance. Before, during and after the fourth attack +of the first horse twenty grains of quinine bisulphate were given +hypodermically daily for twenty days. The attack was very mild. Before +the drug was given his temperature had ranged from 99° to 101° F. +Immediately after the first dose the temperature fell to below 99° F., +and remained at a very regular level during the entire twenty days. No +malarial organisms were found in the blood.” + +The ear is without special interest except as a place of localization of +sarcoptes, demodex and fly larvæ. A few cases of acute catarrhal otitis +media have been found in association with nasopharyngitis both of the +nonspecific variety and that which resembles distemper. One case which +led to meningitis has been mentioned. + + + + + SECTION XIV + CONSTITUTIONAL DISEASES + + +There is a long list of diseases including among others such conditions +as hyperthyroidism, osteodystrophies, diabetes and gout which are spoken +of as constitutional but which in reality are usually dependent upon +some lesion peculiar to a definite organ. Several have been discussed +under systemic diseases so that there remain for consideration in this +section only two, gout and diabetes. + +Constitutional diseases are recognized in wild animals either not at all +or by some happy chance which permits of examination direct enough to +elicit diagnostic criteria. Gout has been discovered for example in some +parrots and herons because of their swollen feet and their movements. In +veterinary practice fairly accurate diagnoses are possible but in wild +collections they are nearly always hit or miss. Therapeutics naturally +follow this rule. + + +GOUT. + +Gout in mammals has been observed in the London Zoological Garden but +has not been encountered here or we have overlooked it. Avian gout on +the other hand in one of its forms comes to our attention not +infrequently. It occurs most often in parrots, gallinaceous and anserine +birds and herons; occasionally accipitrine birds will suffer with it, an +observation more often recorded in European collections than with us. +The figures show no predominance of percentage for any order but the +records indicate that the most beautiful examples of internal uratic +deposits occur in the anserine birds and parrots, while the best +specimen of general gout, including the joints, was found in a boat- +billed heron (_Cancroma cochlearia_) quoted below. + +In so far as etiology of this disease is concerned in domestic stock, +too rich food, especially in protein, and restriction of activity seem +to be credited with the greatest influence. These factors, while +doubtless of importance for birds as they are believed to be for man, do +not seem to fill all the requirements since all our specimens are +confined and, because of their lack of exercise, possibly receive too +much food. Judging by our observations and by publications from other +gardens, carnivorous birds are not conspicuous for the incidence of gout +whereas grain- seed- and fish-eaters suffer more often. This suggests +that these varieties cannot dispose of dietary protein which might be +excessive for their metabolism while in captivity, whereas carnivorous +species have a digestive and chemical reserve to take care of excess +protein. Some such accommodative power must exist in human beings since +not every large meat-eater develops gout. Heredity, often blamed for the +human disease cannot help us with these birds. Examination of the diet +list at the Garden does not reveal a great percentage of concentrated +protein in the feed of the grain- and seed-eaters. The disease occurs +too seldom to disturb the accepted dietary for its possible elimination. +Studies now going on may indicate appropriate changes in the dietaries +that might be responsible. + +Arthritic gout appears usually in the pedal joints but may be found in +the wings. Irregular, sometimes very deforming swellings appear which +must be tender judging by the quietness of the bird and by its behavior +if the joints be touched. Most often the swelling seems greater upon the +flexor (palmar) surfaces of the toes or in the end of the tarsal +articulation. Aside from these few observations there is nothing +peculiar about the attack or the specimen during its sickness. +Chronicity seems to be the rule and little emaciation may be found. +Appetite is normal or excessive, provided the food can be reached. + +Internal or serous membrane gout cannot be recognized during life so far +as I know. The bird may seem in its usual condition of feather, +activity, appetite and elimination, when suddenly it will fade in a day +or so and die. At autopsy the serous surfaces of the heart and +peritoneum will be white with uric acid crystals and the kidneys a pale +yellow brown with markings indicating that the pelves and tubules are +choked with urates. + + + The boat-billed heron (_Cancroma cochlearia_) had had bad feet for + three months. The general condition is poor as to plumage and flesh. + The tarsal and metatarsal joint areas of both legs are surrounded by + firm tough swellings involving skin and periarticular tissue. That on + left foot has ulcerated and bled. On section the swelling is found to + consist of reddened fibrous tissue around tendons, the latter + apparently running through smooth sheaths. At both ankles are urate + deposits clearly seen in this inflammatory tissue but at the lower end + of the tarsus there are no distinct deposits. The joint surfaces do + not seem to be involved. Knee, hip, and wing joints seem uninvolved. + Internally all surfaces are opaque by sprinkling of whitish or + yellowish dots like urates; this is especially marked over heart. + Pleuræ aside from urates are negative. Lungs very slightly uniformly + congested throughout. Aorta and branches are stiff, intima smooth. The + liver is soft, deep brown color, architecture seems normal. The kidney + has a smooth capsule and a smooth pale yellow surface. Organ is firm. + Section surface is glistening and opaque, every lobule clear, pelves + filled with pale yellow material, cortical areas irregular. Alimentary + tract negative. Microscopical section of kidney shows general + topography retained, vessels very much injected, some showing + thrombosis. Cortex slightly irregular probably by swelling of medulla. + Tubular epithelium swollen and granular or desquamating and + degenerating. Glomeruli vary in size and shape, mostly fill out the + capsule. Capillary cells show some vacuoles. Some urate collections in + tubules; practically all pelvic tubules have some urates. Interstitial + tissue not increased. Blood vessel walls somewhat loose. Endothelium + prominent. No areas of degeneration seen. + + +DIABETES. + +Diabetes is an infrequent but well recognized disease among domestic +animals. Its detection depends on a rather vague chain of symptoms +confirmed by the discovery of sugar in the urine. For the suspicion that +a wild animal was suffering with diabetes one would have to rely upon +great thirst, loss of flesh, depression, excessive urination and +possibly cataractous opacity of the eye. Such a chain of symptoms has +not been detected. At every occasion at postmortem that the bladder is +full of urine, a routine examination is made. In this way we detected +one case which seems to have been diabetes, the diagnosis being based +upon the glucosuria and the lipemia. For some unknown reason a section +of the pancreas was not made, a regrettable matter since a definite +purulent gingivitis existed and may have lain at the basis of an +infective pancreatitis, well known to be the cause of certain cases of +diabetes. The case is recorded in full since it is unique, no other case +in a wild animal being fully reported. + + + The arctic fox (_Canis lagopus_) ate and appeared well the day before + it was found dead. Diagnosis—Diabetes mellitus. The animal was in good + condition. The left conjunctiva was reddened, congested, edematous, + with slight mucopurulent discharge in canthus. Muscles have a cloudy + appearance. Fat lacks rich yellow color. The general impression of + anemia is present. Lungs and pleura are normal throughout. Heart + muscle is pale, firm and tough. The tricuspid shows thickening of the + edge of posterior leaflet, the mitral shows slight sclerosis of edge + of mesial leaflet. The auricles are distended with clot. Left + ventricular wall is greatly thickened. Upon incising the heart the + surface of blood shows fine fat globules. Peritoneum is normal. Liver + is slightly increased, surface smooth, edges rounded, consistency + soft, color brownish red with yellow mottlings which are without + definite boundaries; the section surface is moist, granular and + opaque. The bile is fluid, green-yellow and the duct is patulous. The + spleen is slightly enlarged and soft. The kidney is slightly enlarged, + capsule strips easily leaving a smooth, purplish red surface; section + surface is glistening, moist and exudes blood; consistency is slightly + softened; cortical striæ very distinct. The bulging cut surface and + poor demarkation of cortex and medulla characteristic of acute + nephritis are present. The organ shows fat globules in the expressed + blood. The adrenals are very small, firm, brown, bean-shaped bodies + with a brownish medulla. The bladder is slightly distended with turbid + urine. Urine shows dark granular casts, compound granule cells, + spermatozoa and a positive Fehling’s test. Prostate is large and firm + and a turbid material exudes from external meatus. The mouth shows + several decayed teeth. In the neighborhood of last molars on left side + of upper jaw a bead of pus exudes; further pressure results in no + greater flow. The stomach is distended with a great quantity of + undigested food and gas; no worms. Serosa and wall normal but anemic. + Duodenum normal. Jejunum contains numerous worms about 1 to 1.5 cm. + long; it is distended with gas. The pancreas is large, soft, like fat, + white; it extends between the layers of mesentery along the course of + the duodenum; at first the pancreas was mistaken for fat. + + HISTOLOGICAL NOTES.—Spleen shows a distinct overgrowth of trabeculæ. + Beyond this there is nothing pathological. Liver shows distended + portal venules in which there are chains of bacilli. There is no + especial fibrous overgrowth of capsule of Glisson; capillaries are + choked with shadow corpuscles and here too, long chains of bacilli may + be seen; parenchyma cells show postmortem change. Adrenal is the seat + of postmortem degeneration, not congested, nor is there any evidence + of bacterial invasion. The kidney shows no interstitial changes, in + fact the section seems to be entirely normal save for moderate + congestion. Vessels show no bacteria. + + + + + SECTION XV + THE RELATION OF DIET TO DISEASE + + BY + + DR. E. P. CORSON-WHITE + + +Food in the widest acceptation of the term, means every thing ingested +that goes, directly or indirectly, to growth, repair of the body, or +production of energy, all of which phenomena must continue when food is +withheld or supplied in insufficient quantities. Under the latter +condition the processes go on at the expense of the body tissues as +these are protected only when the diet is adequate in every way. A +proper diet, therefore, must be one on which an animal will attain +maximum development, maintain a normal weight curve, show a minimum +susceptibility to disease, live out a full term of life, breed normally, +and rear healthy offspring, capable of normal independent life after +they are weaned. It must fulfill the caloric needs of the body, and in +young animals it must also supply the growth impulse. In its physical +properties it must fit the morphological demands of each type of +gastrointestinal tract. In its chemical content it must supply all the +elements found in the body in usable form, and in amounts sufficient to +cover the needs of the body for growth, repair and waste. To evaluate +fully the influence of food on the individual animal it is necessary to +study its relation: (1) to the type of alimentary tract, (2) to the type +of bacterial flora and their metabolic processes, (3) to the chemical +needs of the body, (4) to the changes arising in the catabolism and +anabolism of all types of food, (5) to exercise or its lack, keeping in +mind always the constant interdependence of all factors. Our knowledge +of nutrition has to a very large extent paralleled the advances in +chemistry, especially the researches into the structural makeup of +living cells, the intermediate stages in their upbuilding and +degradation and the products resulting from their physiological +activities. + +Incorrect feeding both qualitative and quantitative undoubtedly plays an +important rôle in producing disease. In the early works on nutrition, +the proportion of fats, carbohydrates and proteins was regarded as the +essential point of a normal diet. The researches on the composition of +foods marked the first real epoch in this history and Fischer’s[57] +studies on the variation in the composition of proteins from different +sources first introduced the idea of quality. Later Mendel and Osborne +investigated the biological values of purified proteins, while at the +same time McCollum and others were studying the value of the groups of +proteins occurring in a single natural food stuff, were calling +attention to the so-called vitamines, and were emphasizing the need of +balanced inorganic materials. These studies have practically +revolutionized our knowledge, particularly of the effects of badly +balanced foods. They have clearly demonstrated that dietary values can, +in all probability, be discovered only by careful biological study of +feeding experiments together with the finer analysis of the components +of the diet, especially of the protein and fat radicles. At the same +time a definite appreciation of the rôle of each element in metabolism +must be kept in mind. + +These varied studies on nutrition have shown that the chemical +requirements of a diet are in their ultimate analysis essentially the +same for all species of the higher animals—that is all require +approximately the same amount of protein, fat, carbohydrate, etc., per +kilo of body weight, while the morphology of the tract decides the +physical properties of the diet. + + +RELATION OF FOOD TO ALIMENTARY TRACT. + +Food derived from animal sources is high in protein, readily digested, +and highly putrefactive. This type of diet is suited to an alimentary +tract which permits rapid passage through its length, and is fitted with +sturdy walls. The gastric section is simple, the intestine short and +narrow with ill-defined separation of its parts into small gut, cecum +and colon. This type is found in all land Carnivora. The fish-eating +carnivores have a strong tubular stomach and an enormous length of +intestine, but no cecum. The omnivores occupy a middle place. In them +the alimentary tract consists of a simple stomach, a short wide +intestinal tube, and a more complex, although still comparatively +simple, cecum which is generally longer than that found in the +carnivores. This tract is too small to manipulate the bulky vegetable +masses necessary to provide their minimum protein requirement, and too +long and complicated to dispose quickly of the putrefactive animal +tissue. Among these animals colitis is common, due to the fact that the +shape and position of this part of the tract favors stasis, or at least +a sluggish movement of its contents at a point in the digestive scheme +where the food residue is rich in protein by-products, ready for +bacterial growth. + +The herbivores with food derived from plants which requires a long +period of time for its digestion, have, on the other hand, voluminous +stomachs, or large ceca or both; and very long small intestine. In this +tract the concentrated food of the carnivores would provide an +enormously excessive protein intake or if only the protein requirement +is supplied would leave the tract so empty that it would be unable to +functionate. + +All studies in comparative anatomy demonstrate the fact that while +neither a complex stomach nor a large cecum is essential to the +digestion of vegetable food, a capacious and complex alimentary canal, +as a whole, bears a relation to vegetable diet, particularly in the +mammals. Either a highly developed concentrated glandular apparatus is +added to the stomach, as in the wombats, beavers and dormice, or the +stomach is subdivided, sacculated, or otherwise amplified as in the +ruminants and herbivorous marsupials. Sometimes both complexities are +combined as in the case of the sloths. If the simple stomach is +retained, it is supplemented by a large sacculated colon or cecum, as in +the horse. In birds, the proventricle is larger in meat- and fish- +eaters, while the gizzard is more muscular in grain- and insect-feeders, +and the intestines are longer in those devouring coarse green grass and +leaves. The length of the ceca is related entirely to the diet, the long +ones corresponding to the diet which needs protracted periods of time to +exhaust its nutriment. + + +THE BACTERIAL FLORA. + +The bacterial flora harbored in the intestinal tract is closely related +to the type of food and to the character of the alimentary tract. +Levin[58] found sterile intestinal tracts in white bears, seals, +reindeer, eider ducks and penguins when in the Arctic regions; but these +same animals when they are brought to a temperate climate rapidly +acquire intestinal bacteria. The function of the normal inhabitants of +the tract is, probably, to protect the body against invasions of +obnoxious species. Herter found in man that a few species adapt +themselves to the digestive tract and control the growth of newcomers +capable of doing injury. These common varieties become a source of +danger only when present in large numbers. + +Bacteria which produce decomposition of food in the digestive tract are +of three types: (1) Pure putrefactive anaerobes, (2) organisms both +fermentative and putrefactive, but tending generally to antagonize the +putrefactive anaerobes, and (3) fermentative organisms. In the stomach, +fermentation of carbohydrates with the production of organic acids is a +frequent occurrence. Putrefactive types are very rare except with +pyloric stenosis, a condition which favors excessive fermentation by +diminishing the tone and motility of the stomach and the amount of +hydrochloric acid. This condition is further increased by excessive +carbohydrate food. In general the products of fermentation tend to +restrict putrefaction, yet both may be operative. In the small +intestines, bacteria are always present because of the protein richness +of secretions, the rapid digestion of food and the slight or ineffectual +antiseptic properties of intestinal juice, bile and pancreatic +secretions. The putrefactive bacteria rapidly increase and decompose any +protein that is unabsorbed—a process most marked in the colon because +its shape and position favor stasis or slow movement of its contents. In +general the greater the amount of unabsorbed and digestible protein and +the longer the material stays in the intestinal tract, the greater the +putrefaction. The meat-eating animals develop Gram-negative bacilli, +while the carbohydrate-eaters show a predominance of Gram-positive +types. + +Ingested food never contains the enormous amount of bacteria found in +the feces. The alimentary tract with its contents forms a most +efficiently combined incubator and culture medium, in which bacterial +growth exceeds that of any known location both in intensity and +complexity. The range of reaction and composition of nutritive +substances at different levels of the intestinal tract is such that a +great variety of bacteria capable of growth at body temperature develop. +The prominent types that appear in the flora of each order of mammals +are fairly constant in their occurrence. They depend primarily on food +ingested, and show well marked seasonal variations, dependent again on +changes in food. Faulty feeding may itself give rise to a toxic +condition of the gastrointestinal tube, and thus often prepares this +soil for the development of organisms. + +The intestinal flora also changes along rather definite lines as the +diet of the host changes from the monotony of the infant to the variety +of the adult. At birth the tract is sterile, but bacteria soon make +their entry through the mouth in food and water. The majority of these +organisms pass to the stomach where many are destroyed, but a number +travel to the intestines where they may gain a foothold. There is always +a mechanical transportation of intestinal bacteria from higher to lower +levels. A continued preponderance of protein in the diet of all animals +leads to a partial or complete suppression of the Gram-positive acid- +forming groups and an increase of the proteolytic Gram-negative types; +while on the other hand an excess of carbohydrate leads to diminution or +suppression of proteolytic activity and an increase in the fermentative +organisms. Therefore the most important normal factor in determining the +intestinal flora in health is the chemical composition of the ingested +foods. + +The nature of the dominant organisms which develop in diets rich in +carbohydrates varies with the carbohydrate itself. In all ordinary diets +there are (1) starches—forms not readily fermentable, and (2) sugars— +which are largely absorbed from the higher levels of the small +intestine, leaving residual starches and proteins in relatively great +concentration in the lower levels. Therefore the obligate fermentative +organisms are prominent only in the higher levels, the facultative +appear in the intermediate places, and the obligate proteolytic +organisms in the lower intestines. This accounts in a measure for the +great increase of lower intestinal disturbances in omnivores. Complete +proteins resist putrefaction, but the products of protein digestion and +of the intestinal secretions constitute the main substrata for +putrefactive bacteria. Animal protein develops more active proteolytic +bacteria than vegetable protein, which accounts for the greater +predominance of putrefactive infections in carnivores than in omnivores. + +There are two important factors to consider in discussing the influence +of diet on intestinal bacteria: (1) The substitution of types, which +frequently follows a monotonous diet, and (2) the change in metabolism +of existing types of bacteria when dietary conditions are such that the +intestinal medium at one or another level fluctuates in its content of +usable carbohydrate and other nutrient. The nature and extent of these +modifications and their effects upon the host vary greatly, not only +qualitatively but quantitatively. An invasion of the tract by exogenous +bacteria, as the dysentery bacillus, cholera, typhoid, etc., in food or +water may lead to a more or less pronounced replacement of some of the +normal intestinal types by these alien organisms, and to the production +of disease. + +The importance of all the foregoing facts concerning the changes in the +food, in the intestinal cultural substrata and in the advent of new +kinds of organisms was emphatically demonstrated in the marked fall in +gastrointestinal diseases in carnivores after proper screening of meats. +The simple protection of the food given to these animals eliminated the +air bacteria which, entering from dust and flies, alter the chemistry of +the meat before consumption or change the flora of the intestine after +consumption. Normal organisms, or types indistinguishable from them, may +multiply, through unusual conditions, extend their normal habitat, and +eventually lead to abnormal reactions detrimental to the host. These +facts throw considerable light on the site and character of +gastrointestinal lesions found in various orders, a subject to be +discussed more fully later. + +There are many intestinal disturbances of unknown causation, in some of +which bacteria presumably play a secondary part. The primary disturbance +is due to the products resulting from the action of bacteria upon food. +Many toxic bodies are produced either before or after ingestion by the +bacterial decomposition of carbohydrate, fat or protein, independent of +any actual infection. The symptoms arising from bacterial decomposition +of foods depend largely on the organism concerned and vary from a mild +intoxication to a severe toxemia. + + +RELATION OF DIETARY GROUPS TO AUTOPSY DIAGNOSES. + +Analysis of the autopsies on file from sole point of view of dietary +habits of the animals gives rather interesting groupings of disease +states, which apparently and, in some cases definitely, emphasize the +relationship between food, metabolism and disease. (Table 19.) + +From this table a few facts stand out prominently. It is definitely +shown that both birds and mammals on a diet of mixed animal and plant +tissue show a low percentage of disease in the gastrointestinal tube, +liver, pancreas and kidney. The mammals on this diet give the highest +figures for anemias and degenerative osseous conditions. Birds on this +diet show very little osteomalacia, but a fair amount of anemia. +Possibly this may be accounted for by the fact that all of them pick +gravel and may be able from this to supply some of the inorganic +deficiency. Carnivorous birds and mammals, on the other hand, show an +exceedingly large assortment of gastrointestinal disorders, diseases of +the accessory glands of digestion, and of the kidneys. Disorders of the +thyroid gland are almost entirely confined to carnivorous mammals—7.5 +per cent., compared to 0.25 per cent. in all other orders. Gout, while +common among birds, was not present in any mammalian autopsy, while +arthritis in mammals reached its highest record among grass- and grain- +eating herbivora. The percentage of rickets was highest in the young +carnivores (2.6 carnivores as against .4 per cent. in all other +mammals), and was very rare among all birds. + +The succulent vegetable diet was lowest in its relation to degenerative +visceral disorders and highest in acute gastritis; the latter fact was +probably due to the fermentation of soft moist food that requires rather +a long time for its primary digestion. This type of food has also a high +and easily available sugar content which makes it a very favorable +medium for many of the fermentative types of bacteria. Most of the +lesions in this group were around the pylorus and upper duodenum. + + TABLE 19. + _An Analysis of the Pathological Findings Described in the 5,365 Autopsies from + the Point of View only of the Dietary Habits of the Animals. The Percentage + Results Represent the Proportionate Number of Cases of Each Pathological Lesion + Found in the Entire Group of Animals on Each Special Diet without Reference to + Zoological Orders._ + ═════════════════╤═══════════════════════════════╤═══════════════════════════════ + Disease states │ Mammalia 1860 │ Aves 3505 + ─────────────────┼──────┬───────┬────────────────┼──────┬───────┬──────────────── + „ │Omniv-│Carniv-│ Herbivora │Omniv-│Carniv-│ Herbivora + │ ora │ ora │ │ ora │ ora │ + ─────────────────┼──────┼───────┼──────────┬─────┼──────┼───────┼─────┬────────── + „ │ „ │ „ │Succulent │Grain│ „ │ „ │Seeds│Succulent + │ │ │Vegetables│ │ │ │ │Vegetables + ─────────────────┼──────┼───────┼──────────┼─────┼──────┼───────┼─────┼────────── + Malnutrition │ .1│ 1.6│ .6│ 2.2│ .05│ .4│ .1│ + Food Poisoning │ .3│ │ │ 2.5│ .05│ .2│ .08│ + Acute Gastritis │ 3.2│ 6.3│ 9.3│ 3.1│ .9│ 2.│ 1.3│ 13.5 + Acute Duodenitis │ .5│ .3│ │ .5│ .1│ 1.4│ 1.2│ 5.4 + Acute Enteritis │ 2.5│ 3.4│ 3.│ 3.1│ 7.│ 1.│ 8.│ 5.4 + Acute │ 26.3│ 53.2│ 19.9│ 29.2│ 25.3│ 38.6│ 35.6│ 64.8 + Gastroenteritis│ │ │ │ │ │ │ │ + Chronic Gastritis│ 1.1│ 6.│ 2.│ .8│ .2│ 1.4│ .3│ 5.4 + Chronic Enteritis│ 2.│ 5.6│ 3.│ 2.2│ 1.1│ 3.3│ 1.3│ 13.5 + Colitis │ 1.9│ │ │ │ │ │ │ + Acute │ .1│ 2.2│ 1.│ 3.1│ .4│ .6│ .08│ + Pancreatitis │ │ │ │ │ │ │ │ + Chronic │ .5│ 1.7│ │ │ .2│ 1.2│ .5│ + Pancreatitis │ │ │ │ │ │ │ │ + Acute Liver │ .8│ 1.3│ .3│ 1.4│ 4.2│ 2.8│ 2.5│ 2.7 + Disease │ │ │ │ │ │ │ │ + Chronic Liver │ 3.│ 6.3│ 3.3│ 6.│ 1.1│ 2.5│ 1.6│ 13.5 + Disease │ │ │ │ │ │ │ │ + Acute Nephritis │ 9.1│ 12.2│ 12.7│ 12.4│ 5.1│ 6.7│ 4.1│ 8.1 + Chronic Nephritis│ 4.5│ 11.6│ 6.7│ 7.8│ 2.9│ 6.7│ 2.1│ 13.5 + Myocardial │ .1│ .34│ │ 1.1│ .3│ 2.│ .4│ 8.1 + Degeneration │ │ │ │ │ │ │ │ + Arterial Disease │ .1│ 3.1│ .3│ 2.2│ .3│ 3.1│ .66│ 1.8 + Anemia pernicious│ .3│ .32│ │ │ │ │ │ + Anemia secondary │ 4.2│ .32│ 1.2│ 1.5│ 1.1│ 2.5│ 1.5│ + Thyroid Disease │ │ 7.5│ .3│ .7│ .3│ .2│ .3│ + Adrenal Disease │ 1.6│ 1.3│ .3│ 1.5│ │ │ .08│ + Diabetes │ │ .2│ │ │ │ │ │ + Osteomalacia │ 5.2│ .4│ 2.3│ .2│ .1│ .6│ 2.8│ + Osteitis │ .6│ │ │ │ │ │ │ + deformans │ │ │ │ │ │ │ │ + Arthritis │ │ .3│ .3│ 2.2│ │ .2│ .08│ + Rickets │ .1│ 2.6│ .6│ .7│ │ │ .08│ + Gout │ │ │ │ │ │ .4│ .08│ + Sore Eyes │ │ .3│ │ .2│ .1│ │ .3│ + Malignancy │ .05│ .9│ .6│ │ .05│ │ .6│ + Tuberculosis │ 32.6│ 3.5│ 4.5│ 9.6│ 12.│ 1.7│ 17.2│ 5.7 + ─────────────────┴──────┴───────┴──────────┴─────┴──────┴───────┴─────┴────────── + +Overeating is a factor that must be borne in mind when considering the +hay- and grass-eating herbivora. Packing of the rumen is a not +infrequent discovery. This condition is also found in certain seed- +eating birds. As a supply of food is constantly at the disposal of these +animals and exercise is prevented by captivity, continuous eating +becomes their principal diversion. In this group also food poisoning was +highest, a condition which may be due to (1) spoiled food, (2) poisonous +substances in the foods, (3) fermentation of grass foods (spoiled hay or +musty fodder). Malnutrition also, is higher than with any other diet, +due probably to the somewhat meagre nutritious value of the food. This +group also shows a high percentage of acute pancreatitis, degeneration +of the liver, myocardium and arteries. Arthritis was present in this +group 2.2 per cent., against 0.2 per cent. in all other groups. + +A study of Table 19 demands a constant recollection of the morphology of +the tract involved and its main points of vulnerability, the bacteria +capable of living on the particular type of food or its constituents and +the by-products produced during the digestion and absorption of these +foods. Not one of these factors can be ignored in evaluating the +influence of diet, which to be correct must supply elements in +proportions that are chemically available for body needs (for instance, +Von Wendt[59] found that more iron was required if the diet was +deficient in calcium). These proportions must be worked out by carefully +combined chemical and biological experiments. + + +MALNUTRITION. + +There was one omnivorous beast, a Hamadryas Baboon, which represented +the only true case of starvation, probably induced by nostalgia, as it +never ate after coming into the Garden. Thirty cases of partial +starvation or malnutrition are listed in our records, the majority among +the rarer specimens, ten carnivorous, seven herbivorous and one +omnivorous mammals, ten carnivorous and two seed-eating birds, due +possibly to inappropriate diet or to some unknown factor that rendered +the diet inadequate. At the autopsy nothing was found to account for +death except the draining of all storage supplies. + + +STARVATION. + +The reports of studies conducted during long laboratory fasts have been +among the most valuable records for the understanding of the chemical +requirements of diet and of the close chemical interrelationship +existing between the different food factors. In absolute starvation life +is very short, primarily because water is necessary for respiration, for +dissolving products of metabolism and for preventing changes in +digestive intestinal secretions. The amount of water needed varies with +different species of animals. If the water is supplied, the organism is +enabled to maintain its energy for continued existence from the +destruction of its own tissues. The length of life depends upon the +amount of protein ingested before the fast commenced, and the amount of +stored fat and glycogen, especially that stored in the liver. The +mechanism of the results is similar. The animal body uses first its +available glucose, and when this is partially exhausted burns its stored +fat and protein. The fat combustion is usually defective, ketone bodies +appearing in the urine in large quantities. The change from fat to +protein metabolism accounts for the premortal rise in metabolism which +occurs usually a few days before death. The chemical composition and +corpuscular richness of the blood is tenaciously preserved; glucose and +protein concentration are practically normal up to the day of death. +There is at times a slight increase in globulins and always an increase +in fat due to its transportation from storage depots. The cause of death +is primarily due to loss of substance in organs necessary to life and to +an acid intoxication. + +Wasting occurs first in stored substances, fat, glycogen, etc., then in +the least used organs. The bones usually show some rarefication. The +animal, as a rule, dies from acid intoxication before atrophy of the +organs is marked. + +In the wild, when animals are forced to seek their food with the +expenditure of much energy and where feasts are often followed by fasts, +this using up of storage supplies cannot help being a factor in +preserving the integrity of the storage and eliminative organs. In +captivity this cannot occur. Food is supplied regularly, exercise is +lacking, consequently overloading and disease of storage and eliminative +organs is more or less constant—a situation very marked in the +Carnivora. + + TABLE 20. + _Detailed Analysis of the Various Diets Used at the Philadelphia Garden + on Basis of 100 Grams of Mixed Food._ + ═════════════╤══════════════╤═════════════╤══════════════╤═════════════ + │ Omnivora │ Carnivora │ Herbivora │ Herbivora + │ │ │ Succulent │ Coarse Food + │ │ │ Vegetables │ + ─────────────┼───────┬──────┼──────┬──────┼───────┬──────┼──────┬────── + „ │Mammals│Birds │ Meat │ Fish │Mammals│Birds │ Hay │ Seed + │ │ │ │ │ │ │ Food │ Food + ─────────────┼───────┼──────┼──────┼──────┼───────┼──────┼──────┼────── + Protein │ 14.3│ 11.5│ 15.6│ 17.2│ 6.1│ 3.2│ 6.4│ 7.1 + Fat │ 9.5│ 7.2│ 18.8│ .3│ 2.6│ .5│ 2.2│ 1.3 + Carbohydrate │ 26.7│ 41.2│ │ │ 18.5│ 25.7│ 35.9│ 51.2 + Calcium │ .034│ .068│ .058│ .109│ .067│ .025│ .071│ .044 + Magnesium │ .058│ .093│ .118│ .133│ .164│ .119│ .289│ .16 + Potassium │ .497│ .713│ 1.694│ 1.671│ .538│ .242│ .644│ .324 + Sodium │ .103│ .284│ .421│ .373│ .08│ .291│ .089│ .261 + Phosphorus │ .263│ .484│ 1.078│ 1.148│ .556│ .342│ .692│ .458 + Chlorine │ .117│ .377│ .378│ .528│ .038│ .044│ .073│ .063 + Sulphur │ .338│ .486│ 1.146│ 1.119│ .134│ .125│ .217│ .163 + Iron │ .0032│ .0063│ .015│ .0055│ .0018│ .0012│ .0022│ .0012 + ─────────────┴───────┴──────┴──────┴──────┴───────┴──────┴──────┴────── + +A further study of Table 19 in the light of the finer analysis of the +ingredients of the diets, shown in Table 20, explains, at least in part, +the high percentage of certain types of disease in relation to +particular diets. + +In the food of the first group, the omnivorous mammals, there is a +moderately increased carbohydrate content and an unevenly balanced +inorganic content, the last being the factor most at fault. The calcium +and phosphorus are both so low that at the best the animal could only be +in equilibrium, while any drain of the fixed bases would sooner or later +have to be replenished from the calcium and phosphorus storage depots, +the bones. Osteomalacia is most marked in the Cebidæ, monkeys whose diet +is even lower in these same elements: calcium .025, phosphorus .116, and +iron .0008 per 100 grams of food. The inorganic composition of all +animals is grossly similar; the typical digestion developed from the +habitual diet of the animal explains the more apparent changes and +variations in their reactions to certain deprivations. + + +IRREGULARITIES OF INORGANIC METABOLISM. + +Twelve essential elements are present in the body, namely: carbon, +nitrogen, hydrogen, oxygen, phosphorus, calcium, sulphur, sodium, +chlorine, potassium, iron, magnesium. Of these, five are furnished by +the protein molecule and three of the five are duplicated in the fats +and carbohydrates; the remaining seven must be present in the mineral +ash. These elements functionate in three ways, (1) as constituents of +bone, (2) as essential elements of organic compounds, (3) as soluble +salts in body fluids. Chlorine, sodium, sulphur are supplied in +sufficient quantity with most diets. In the case of chlorine, marked +differences exist between the herbivores and carnivores. The meat-eating +mammals easily acquire sufficient sodium chloride from the flesh and +blood of their victims, while the herbivores on the other hand, find in +their vegetable food large amounts of potassium and very little sodium +or chlorine which must therefore be acquired separately. Both omnivores +and herbivores crave salt, probably because this large potassium content +of vegetable food tends to increase the sodium elimination. A +deprivation of salt always leads to a distaste for foods rich in +potassium. So far as is known excessive sodium stimulates protein +catabolism, and through the overstimulation of the digestive tract, may +interfere with the absorption of food. + +Sulphur is largely taken into the body in organic combination with the +protein, (a very little inorganic sulphur appears in the drinking water) +therefore if the protein requirements are adequate the sulphur will +usually be adequate. + +Magnesium is abundant in meat and most plant tissues; so that except in +diets of highly refined foods, it is more often excessive than +deficient. + +The other elements, calcium, phosphorus and iron are frequently +insufficient, especially for animals on omnivorous diet (cf. Table 20). +Phosphorus enters into every living cell, and in cases of starvation is +excreted up to the last. It is involved in practically all the cell +functions. In the body it is present (1) as an inorganic compound in the +bone tissues and blood where it helps to maintain neutrality, (2) as +phosphorus-containing protein, phosphatids and phosphoric esters of a +carbohydrate, all closely associated with the cell and its nucleus. In +foods, phosphorus occurs in the same positions, that is, inorganically +or combined with protein, fat or carbohydrate. It is not entirely proved +but is very probable that the phosphorus in organic combination has the +greater metabolic value, inasmuch as there is greater storage of +nitrogen and stimulation of tissue growth on foods containing +phosphorized proteins, fats, etc. It has been shown, however, that the +animal body can satisfactorily supply its phosphorus requirements by +inorganic phosphates. The omnivorous diet, even the widely varied diet +of man, is very often deficient in phosphorus, a fact which becomes very +important when we consider that the omnivorous diet produces many acid +residues which must be neutralized, and that phosphorus is largely +responsible for the maintenance of tissue neutrality. Voit showed that +the phosphates excreted during starvation were withdrawn from the bones; +and there is much proof that during the daily metabolism a certain +slight movement of phosphorus takes place. The metabolized phosphorus is +excreted by carnivores practically from the kidney alone; by herbivores +almost entirely through the intestinal wall, while in the omnivores it +is excreted by kidney and intestinal tract. Whether these facts have any +real influence on the phosphorus need of different types is not +altogether determined. + +Calcium also enters into many of the essential functions of life, +coagulation of the blood, contractility of the heart, etc. Omnivorous +diet is usually deficient in this element, which is very irregularly +distributed both in animal bodies and plants. Insufficient amounts lead +to deprivation of body tissues and to the production of osteomalacia- +like conditions. Voit produced marked thinning of the skull bones and +sternum by a diet poor in calcium. Steenbok and his associates had the +same results in cattle by feeding “shorts” a diet rich in magnesium. +Etienne[60] showed that an excess of magnesium in an otherwise well +balanced food caused a continual loss of calcium. Adults stand a +deprivation of calcium much better than children or young animals. They +often show no symptoms and retain a normal blood content as the losses +from the blood and soft tissues are promptly replaced from the bones. +Sooner or later all these animals show weakness and flexibility of the +bones. Osteomalacia occurred in 5.2 per cent. of the animals on an +omnivorous diet, that is this number showed gross evidence of absorption +of bone salts. This condition occurring in man and the lower animals is +a generalized softening of adult bones that were at one time normally +calcified. Three clinical varieties are recognized in man: a mild form +seen in pregnant, puerperal and lactating women, a senile form in which +the lesions are usually limited to the pelvis, and a severe progressive +form encountered in both sexes and at any age. This last form ends in +marasmus. Its chemical characteristic is a loss of calcium and +phosphorus with retention of sulphur and magnesium. + +The progressive type has occurred very frequently among the Cebidæ whose +diet on careful examination, showed a protein content low in quantity, +poor in quality, and especially deficient in the phosphorus-containing +proteins and total fat. The carbohydrate was high. The ash was small in +amount and predominatingly acid. The daily ration often showed only an +unweighable trace of calcium, phosphorus or iron. Sodium, potassium, +sulphur and magnesium, on the contrary, were present in amounts +sufficient for equilibrium or in excess. The Vitamines A.B.C. were +present but were not always correctly proportioned. The fat soluble A +was low and in some daily rations was entirely lacking. + +Diet has at various times been proposed as at least one factor in the +production of this condition, a premise that has gained considerable +weight through the increase in the number of cases, both in man and in +the domesticated animals, reported from the war-famine district of +Central Europe where the dietary was restricted and unbalanced. It has +been shown that when calcium is low in the diet, the amount excreted +materially exceeds the intake. Benedict[61] has further shown that even +during absolute fasts calcium is excreted. The requirements of this +element for man have been fairly well worked out, but for animals we +have no standards. Still it seems certain from the foregoing +observations that storage supplies are called upon very early in cases +of deprivation, while in pregnancy and lactation when the calcium +requirements are greatly increased, a reason is found for a higher +incidence of osteomalacia, Steenbok and Hart[62] have shown that the +skeletons of cows and goats gave evidence of a drain of inorganic salts +during the production of milk unless the calcium and phosphorus of the +diet were liberally supplied. In osteomalacia it would seem that +inefficient diet, if not the cause, was at least a very potent factor in +pathogenesis. The disturbance of the calcium-phosphorus-metabolism may +be due to the deprivation of the alkaline salts as in the famine +osteomalacia, to a drain from the alkaline storage of the body +associated with an inefficient diet as in the osteomalacia of pregnancy +and lactation or to the combined action of a diet faulty in more than +its salt content, which by the production of acid in its oxidation and +by favoring the development of acid-forming bacteria, causes a drain of +the body alkali for neutralization of the acid; or it may possibly be +due to a combination of all these factors acting through their influence +on the ductless glands. + +Paget’s disease or Osteitis Deformans is a chronic constitutional +process which usually involves all the bones of the adult skeleton. +DaCosta[63] believed it to be a disorder of bone metabolism probably +dependent upon absence or perversion of some internal secretion. We have +had the unique opportunity of observing three cases of this disease in +Cebidæ, the family of monkeys which has presented the highest incidence +of osteomalacia. The experience is all the more interesting because of +the typical picture presented by the specimens, and of the absence of +references in the literature on the subject, to the occurrence of the +malady in wild animals. The interesting point about these cases lies in +the fact that the disease appeared in all three only after lime water +was added to the diet to supply the deficiency of calcium. + +Search for literary record of the disease brought to light a case in a +horse that Barthelemy[64] described, but this involved the epiphyses of +the bone while osteitis deformans is confined as a rule to the +diaphyses. This case was probably more closely allied to osteitis +fibrosa cystica. Goldman[65] described examples in fowls and Rossweg[66] +refers to specimens in domestic goats and monkeys. Many of these cases +first come under observation through fractures, an accident common to +osteomalacia, but very rare in well developed osteitis deformans. The +diet of our monkeys was exceeding low in those substances essential to +bone development. Sherman[67] has shown that the calcium balance is +regulated to a certain extent by the calcium ingested, and that when the +diet is poor in this element, the output materially exceeds the intake, +a condition which is definitely changed when the animal is put on a diet +high in calcium. + +So far as we could find there are no recorded studies of the mineral +metabolism of beginning cases of Paget’s disease. It seems possible from +the study of osteomalacia that the low mineral and otherwise faulty +diet, added to the symptoms produced by that diet might so disturb the +chemical equilibrium, directly through the neurotrophic mechanism or +through the perversion of the ductless glands, that the mere addition of +the lime water might entirely change the pathological picture. This is +in accord with the histology where the initial lesion is resorption of +bone followed by irregular proliferation. It is also in accord with the +probable chemistry of calcification. These animals all showed a lowered +carbon-dioxide-carrying-power of the blood, and therefore lowered +ability to carry calcium in solution. It is possible that Paget’s +disease is but a stage in a deficiency disease, a faulty reparative +response through a disordered neurotrophic mechanism, or through a +perversion of the glands governing calcium metabolism. Such perversion +could be caused by an improperly balanced diet, or by the addition of an +excess of calcium to the diet of an animal whose body fluids were unable +by reason of previous faulty diet or other disorder, to hold it in +solution. In young animals the calcium demands are much higher than in +adults, a need met in the high calcium content of breast milk, a content +in excess of almost every other food, but apparently just sufficient to +maintain calcium equilibrium. After it is weaned the young animal +frequently shows disorders of its inorganic metabolism. Herter estimated +that a child should store at least 0.1 gram of calcium daily and he +described many cases of arrested bone development occurring during +infancy and early childhood, because of an inefficient assimilation of +calcium. One case, probably of this character, was found in a Hamadryas +Baboon (_Papio hamadryas_) a typical example of infantilism. The animal +was an adult male about half the size of an adult female. His skin was +fine and more delicate than normal, the bones were small and slender, +contour of body was that of a young animal, genitalia were imperfectly +developed, thyroid gland apparently normal, gastrointestinal tract +atrophic, associated was a slight arthritis, portal cirrhosis of liver +and diffuse nephritis. + +First among the results of inorganic insufficiency in youth stands +Rickets. This disease occurs in children starting usually at about the +sixth month and continuing with irregular remissions for several years. +The bone changes, which are the most prominent, are always associated +with more or less severe anemia, a general lowered resistance and flabby +musculature. The excretion of calcium is very high in the feces and low +in the urine. There is a frequent negative calcium balance dependent +upon the great loss in the feces. Healing is preceded by a +hyperretention of calcium and a relative increase in the urinary +calcium. The excessive loss of calcium in the feces is not brought about +through the agency of fats because fat could only remove calcium as +insoluble soaps and these are not at all increased. This fact +contradicts the idea of fat starvation as a cause of rickets. Howland +and Kramer found that the blood in active rickets had a normal or +slightly lowered calcium content, but a regularly reduced phosphorus +content. The latter deficiency was extreme at times. They ascribe to +this deficiency the failure of the bones to calcify. It can be readily +understood that a decrease of phosphorus in the blood would render +difficult the precipitation of calcium phosphate. + +Recently two series of studies, the first by Pappenheimer, Zucher and +McCann and the second by Shipley, McCollum, Park and Simonds have shown +that rats fed on a diet low in calcium but with a sufficient amount of +fat soluble vitamine and phosphorus develop a bone condition with many +fundamental resemblances to rickets. They were also able to produce the +condition with an excess of calcium and deficiency of phosphorus. On the +first diet, the condition differs from rickets in that the arrangement +of the proliferating zone of cartilage cells is maintained and the +evidence of bone resorption in the diaphyses is excessive. A diet +deficient in both calcium and phosphorus leads to an atypical rickets. + +In the animals autopsied at this Garden rickets occurred very much more +frequently in the flesh-eaters than in any of the other dietary groups. +On closer analysis it was found that rickets in almost every case +appeared in the carnivores which did not receive bones as a part of the +food. Rickets occurred frequently in the omnivorous macaques which +however did not show osteomalacia, although they belong to the same +dietary group as the Cebidæ. The reason they did not suffer the latter +disease while adult but had rachitic young is probably due to the fact +that this monkey group, which breeds best in our Garden, receives in +addition to the diet given to Cebidæ one raw egg. This increased the +calcium content of their food more nearly to the requirements of these +mammals. These monkeys also have mouth sacs, which enable them to +acquire more food per kilo of body weight than the smaller Cebidæ which +are not so advantageously equipped. The food even in the amounts +consumed by the macaques is low in calcium, phosphorus and iron. It is +very possible that there are enough of these ingredients present as a +rule, to maintain the animal in organic equilibrium, during normal life, +and possibly even enough to supply the needs of the embryo but not +sufficient to maintain the young during the period of lactation. A few +macaques dying during the delivery of young showed slight osteomalacic +changes in the pelvis. This was notably present in one described in +detail by E. A. Schumann. + +The calcium requirements of the female are always much increased during +pregnancy and lactation due to the withdrawal from the mother to meet +the needs of the embryo and nursling. Forbes and Beegle[68] found that +lactating animals made heavy drains on their storage calcium even when +the diet was liberal and the animal was storing nitrogen. + +Iron is the essential element of hemoglobin and chromatin—the body +constituent most directly concerned with the process of oxidation, +secretion, reproduction and development. The iron of the food is +absorbed from the small intestines, enters the circulation through the +lymphatics, is deposited in the liver, spleen, and bone marrow and +eliminated through the intestinal walls. There is very little iron +reserve in the adult body; and as a result any failure of the intake to +equal the output causes an immediate reduction of the hemoglobin. Voit +found that the iron eliminated in the feces of starving dogs, or dogs on +a diet low in iron comes from the body through the intestinal walls. +Medicinal iron stimulates the production of hemoglobin and red blood +cells but whether it is directly employed in the production of +hemoglobins has not been proved. Undoubtedly most of the extra iron +given with the food passes through the alimentary tract without being +absorbed or metabolized. The greater the amount of iron in the food, the +greater the influence of the inorganic iron. Anemia occurred in all the +animals we examined at least four times as frequently in omnivorous as +in all the other dietary groups, a fact probably explained by the low +content of iron and calcium in this diet. Both Von Wendt[69] and +Sherman[70] demonstrated that larger amounts of iron were required to +maintain the iron equilibrium when the amount of calcium was low. + +Herter has shown that many anemias are associated with intestinal +putrefaction. The carnivores, however, on a diet that putrefies very +easily and on one in which the iron content is apparently of distinctly +lower nutritive value than that of the iron found in milk, eggs and +vegetables, presented an anemic incidence of only 0.32 per cent. This is +probably due to the excellent hygienic care of the meat foods and to the +morphology of the carnivorous intestinal tract, which is short, straight +and fashioned for quick elimination. The cases of anemia steadily +increase among the animals as the conformation of the tract approaches +the omnivorous type with the longer and wider hind-gut. + +Herbivora, obtaining their iron from vegetable sources, are much less +liable to blood disorders. The iron needs of the female are greater than +those of the male because of the drains of pregnancy and lactation. +Young animals demand more iron than adults. All exclusively breast- +feeding animals have a considerable storage of iron in the body at +birth, while those that eat food immediately have no such supply. +Bunge’s[71] experiments showed that breast-fed animals contained about +six times as much iron as the milk that nourished them. The iron content +of all these animals is highest at birth, remains constant during the +suckling period and then rapidly decreases to the adult standard. After +this level is reached the iron metabolized must be supplied from the +food if the hemoglobin is to be spared. + +The functions of all these inorganic substances are intimately +interrelated and in places interchangeable. Calcium is capable of +correcting disturbances of inorganic equilibrium in the animal body +whatever the direction of the deviation from the normal may be. These +interrelationships are most involved in the maintenance of body +neutrality. The normal processes of metabolism involve a continual +production of carbonic, phosphoric and sulphuric acid which must be +immediately disposed of if the neutrality of the body is to be +permanent. + +The factors involved in this are carbonates, phosphates, ammonia and +proteins. Carbon dioxide is the chief excretory product but is at the +same time a normal constituent of the blood and as such, is an important +factor in this physicochemical regulation. There is a tendency for the +respiratory mechanism to hold its carbon dioxide tension nearly +constant. Late investigations have shown that lowering of this tension +is an early sign of beginning acidosis. When food such as protein, is +taken in excess the strongly acid residues are neutralized by the sodium +and potassium carbonates which are eliminated with a corresponding loss +of sodium and potassium. The carbon dioxide tension diminishes, 37.2 per +cent. on a high protein as against 43.3 per cent. on a vegetable diet. +If this excess is long continued, the result may be, and often is, an +increased elimination of the base-forming elements which if not made +good tends to diminish the body’s reserve alkalinity. A diet with a +preponderance of basic elements leads to an alkaline urine with an +increased uric acid solvency and an increased carbon dioxide tension and +reserve alkalinity. A diet with a preponderance in the acid-forming +elements, on the contrary, leads to an increased urinary acidity and +urinary ammonia, decreased ability to dissolve uric acid and lowered +carbon dioxide tension and alkaline reserve. + + +DEFICIENCIES OF VITAMINES. + +Recent investigations have shown that diets furnishing sufficient +amounts of protein, fat, carbohydrate and inorganic salts may yet prove +inadequate for growth or even for maintenance. Hopkins,[72] feeding rats +on purified food mixture was unable to obtain any growth until he added +small quantities of milk or of the ether-soluble portion of milk but +with this addition growth progressed in the normal manner, but it was +out of all proportion to the energy or protein value of the addition. +Five substances of this character, called by Funk[73] Vitamines, have +been described, two of which have definitely established a place as +essential food factors. According to him, pellagra, rickets, scurvy and +beriberi are the result of a lack of these unidentified but specific and +indispensable food complexes. + +The first vitamine isolated was the fat soluble A, an adequate supply of +which is necessary, not only because of its stimulating growth +properties, but because its absence produces a serious condition of the +eyes and, at times, marasmus leading to death. Xerophthalmia is a common +condition in animals on experimental diets. The eyes are swollen, the +cornea inflamed and often opaque while blindness and death invariably +occur unless the dietary error is corrected. McCollum[74] rescued +animals almost at the point of death by butter or other fat rich in this +vitamine. Opacities of the cornea are often seen in the animals in this +and other gardens among ungulates—hay-eating mammals; four advanced +cases were found, three in seed-eating birds and one in a fox on a diet +made up solely of horse muscle. The quantity of vitamine A present in +muscle, hay and seeds is very small. It is supplied in largest amounts +in milk, eggs, glandular organs and leaves, substances which were very +low or absent in the diet of all the affected animals. This +xerophthalmia has been reported in man on several occasions, especially +by Hrdlicka[75] in American Indians, by Mori[76] in 1400 Japanese during +a period of food shortage (this epidemic was cured by the addition of +chicken livers to the diet), by Bloch[77] in forty-seven children of +Copenhagen fed on a fat free milk who were cured by the administration +of cod liver oil. The disease is not however a fat starvation, as it is +entirely uninfluenced by vegetable fats which do not contain this +vitamine. + +Beriberi is an established deficiency disease, frequently seen among the +poorer classes of the Orient whose diet is limited to polished rice and +fish. It has appeared in Labrador coincident with the excessive use of +bolted flour. A similar condition has been induced in pigs and cattle by +a diet made up of an excess of cotton seed meal and tankage. Two forms +of the disease are described: (1) acute or wet, characterized by marked +edema, ascites, hydropericardium, hydrothorax, edema of the lungs, and a +congestion of the spleen, liver, kidney, and heart muscle, (2) chronic +or dry, characterized by polyneuritis. The disease was first produced +experimentally in pigeons by Eijkman[78] in 1897 by means of a diet of +polished rice. The paralysis appeared in 2–3 weeks after the diet was +initiated. Fraser and Stanton[79] in 1907, found that it could be cured +by an alcoholic extract of rice polishings. Funk[80] later determined +the vitamine character of this extract. In pigeons and fowls +experimental feeding usually results in the chronic or polyneuritic +form, expressed by a typical degenerative inflammatory condition of the +peripheral nerves. In pigs, on the contrary, Rommel and Vedder[81] +produced both types, though the acute or wet beriberi appeared more +frequently. In rats the same deficiency causes multiple hemorrhages in +the cerebellum and midbrain followed by a degeneration of the associated +nervous structures. It is possible that the pathology following a lack +of the vitamine B or in fact any of the vitamines will vary with the +different species or with varying demands of different individuals. This +antineuritic vitamine affects more than the nervous system, and it is +possible that all vitamines may have wider effects than are at present +described. + +Scurvy was the first condition to call attention to diet as a cause of +disease. It occurs in man when deprived of fresh vegetables. That faulty +diet was in some way the cause of scurvy has been known for many years, +but only since 1905 has there been any systematic attempt to determine +the peculiar value of the curative foods. At this time Theobald +Smith[82] called attention to a disease suggestive of scurvy which +developed in guinea-pigs fed on a diet of oatmeal. This observation was +confirmed by Holst and Frölich[83] who stated that the disease could be +prevented by the addition of fresh milk or cabbage, because in these +foods there was present an antiscorbutic or C vitamine. This +unidentified substance was easily destroyed or diminished by heat or an +alkaline medium. It was found in rather large amounts in succulent +vegetables and fruits. McCollum[84] and his coworkers showed that the +oat kernel was low in inorganic salts and vitamine A and poor in the +quality of its protein; but with these faults corrected it proved to be +a complete food for rats. McCollum also found that scurvy developed more +readily in animals if the physical properties of the diet favored +constipation. He was able to delay the onset of the disease in guinea- +pigs for a considerable period by the addition of mineral oil which has +no food value, or phenolphthalein, a cathartic. At the same time, +Jackson and Moore,[85] found the cecum of all guinea-pigs dying of +scurvy, packed with putrefying feces. They were able to produce a mild +type of the disease by the injection of the diplococci isolated from the +swollen joints. + +From these observations it seems safe to conclude that scurvy may not be +purely a deficiency disease, or even a simple dietary one, although the +presence of a vitamine influence is not excluded; but it is probably the +result of a bacterial invasion of tissues debilitated by a faulty diet +and by the toxins produced by the putrefactive bacteria developing in a +diet unsuited to the anatomical demands of the alimentary tract. This +theory receives support from the fact that pasteurization destroys all +aciduric bacteria, allowing only the spore-forming putrefactors to +develop; and from the fact that scurvy develops more frequently in +children on stale pasteurized than on stale raw or boiled milk. In this +Garden no suggestion of scurvy has been noted. + +Pellagra is very definitely a disease of poverty endemic for years among +the poor, especially in the mountains of Northern Italy. It has been +under observation in the United States since 1907. So far as is known no +cases have been observed among animals. Opinions differ as to the rôle +of diet in the etiology but the results of recent studies seem to show +that uncomplicated cases of average severity clear up entirely on a diet +rich in animal protein. No vitamine deficiency has so far been +determined. Wilson’s careful studies of the diets known to have produced +the condition show that the etiological factor lies in a deficiency of +the protein molecule. The results of Goldberger[86] corroborate this +fact, and he concludes from his latest studies that “the dominating rôle +of diet in the prevention and causation of pellagra is referable +primarily to the character of the protein supply or to the specific +quality of the aminoacid makeup of the protein supply.” Just what +aminoacid or combination of aminoacids it is, has not been determined, +nor has the possibility of a vitamine alone or in combination with the +aminoacid factor been absolutely excluded. + +The principal influence of the omnivorous diet is toward those +degenerations arising primarily from imbalances in the inorganic makeup, +or to insufficiencies of certain necessary factors. The vitamine +deficiencies are markedly less prevalent in animals than in man whose +food is less often consumed in its natural state. It is now known that +much of the injury and loss of nutritive value in foods is produced by +the processes involved in preparation, preservation, refinement and +storage. Whenever the choice of food is not restricted, vitamine +deficiencies do not occur. The vitamine requirements probably differ in +different species and in individuals from the same species according to +their environmental and individual variations. It is very possible that +if the diet is low in vitamine content there may arise conditions of +relative deficiencies; and McCarrison has shown that a vitamine +deficiency associated with a high fat or carbohydrate content may +disturb the balance of the endocrine glands. It is however to the +inorganic content of the omnivorous food that most of the disturbances +peculiar to this diet are to be assigned. + +With the flesh eating animals and birds the records present a very +different picture. Disorders of the digestive tube, of the storage +organs, of the organs of elimination and of the endocrine glands +predominate. Their diet is low in carbohydrates and, at times, in fats +and very high in protein. Bone supplies the inorganic salts, which in +this Garden is fed only to the larger mammals. The carnivorous birds get +their inorganic supply from mice which are eaten entire. The carnivores +are as a rule large and are given to active fighting or to long flights. +In the wild, very probably there are long periods between feasts, while +in captivity the food is always plentiful and regularly supplied. This +regularity added to the lack of exercise, particularly among the larger +animals, must lead to excessive demands upon the storage and eliminating +organs. Storage is always promoted by rest and liberal diet, and cleared +away by exercise and starvation. The life of these birds and mammals, +moreover favors inactivity of the bowels, which, together with the +highly putrefactive diet adds another serious factor to a problem which +in gardens is almost insurmountable. + + +IRREGULARITIES OF CARBOHYDRATE METABOLISM. + +The carbohydrates are derived from the glucose and glycogen of the meat +and from the protein molecule. They are absolutely less than in the diet +of herbivores but become a factor in the disorders of this group because +of the lack of exercise and the regularity of feeding. In digestion the +carbohydrate becomes available for absorption and bacterial growth in +the upper small intestine and appears on the other side of the +intestinal wall as blood glucose in which form it is burned for energy +or stored as glycogen for the future maintenance of the blood glucose. + +The blood of different animals has a glucose concentration between +0.05–0.1 which for each species is quite constant, as it is regulated by +the coadaptation of four factors: combustion, fermentation of glycogen, +formation of fat, and elimination from the kidney. In excessive feeding +the amount needed for energy is burned, the remainder is stored in the +liver up to its capacity, then in the muscles and other cells, after +which fat is formed and all further excess is eliminated by the kidney. +Overfeeding causes an immediate overloading of the oxidative mechanism +with symptoms of gastric disorder, achylia, and at times acid +fermentation with irritation of the stomach walls and the development of +bacteria in the organ. This is frequently followed by glycosuria, +several types of which are described: (1) associated with an increased +concentration of glucose following excessive ingestion exceeding the +normal glycogenic function of the liver, a form common among the +Herbivora, (2) that due to a reduction of the glycogenic function of the +liver, (3) that associated with disease of the ductless glands in which +the resulting glycosuria probably depends upon the influence of these +glands upon the pancreas, (4) that dependent upon the defect of +glycolysis or to an overstocked liver seen in gout, obesity or +hypertrophic cirrhosis, and (5) renal glycosuria due to a lowering of +the renal threshold and usually associated with gout, arteriosclerosis +or chronic nephritis; this last is best explained on the ground of +increased renal permeability. Normally when the blood sugar +concentration rises above a certain level the elimination _via_ the +kidney begins and continues until the blood has again reached its normal +concentration. The relation of the kidney to glucose concentration is +not constant and variation is always toward the side of lesser +elimination while the kidneys become accustomed to the higher level. + +Diabetes, a disease of the islands of Langerhans in the pancreas, is +essentially a disturbance of sugar metabolism always associated with an +exaggerated and defective fat and protein combustion. It is not only +that the diabetic has lost the faculty of combustion but these +abnormalities all establish states of intoxication to which the diabetic +must sooner or later succumb. Among lower animals the disease is rare. +Dogs are most frequently affected (about 1 in 12,000 deaths). It has +also been described in horses, cattle and monkeys. In our records there +was one case an Arctic fox (_Canis lagopus_) presenting a typical +picture. Degeneration of the islands of Langerhans was seen in three +other animals, but there was no other evidence of diabetes. This disease +is not due to diet but to the absence of a normal ferment +(pancreaticozymo-excitor) for one particular type of food. + + +IRREGULARITIES OF FAT METABOLISM. + +Disorders of fat metabolism are very rare among lower animals +notwithstanding the fact that fat even in the carnivorous diet, +represents about 13 per cent. of the whole intake. It plays two +important rôles in the body, storage for energy reserve, and as a most +essential structure in cellular protoplasm, in which position it joins +with protein in complex combinations of still unknown composition which +present to a striking degree the phenomenon of absorption. Very marked +biological differences exist in the value of fats from different +sources, due to the presence or absence of vitamines. The body fat is +derived from the fat of the diet or is synthesized from glucose. The +former is specific to the fat consumed while the latter is specific to +the animal. In omnivores the type depends upon the varying extent to +which animal fats enter the diet, in carnivores it depends almost +entirely on the fat intake, while in the herbivores practically all the +fat is synthesized from the carbohydrate. On digestion, fat splits, +yielding a glycerol and fatty acid which are collected in the lymph +spaces of the intestinal mucosa, there changing to some complex +combination which is not only soluble but diffusible. + +Fatty infiltration and fatty degeneration are conditions of much +pathological interest and of great frequency in captive animals. The +researches of Mansfield[87] have thrown considerable light upon these +conditions. He found that the total fat content in cases of most marked +degeneration was normal or reduced. The proportion of fat free from +protein was increased and the firmly bound fat decreased. This increase +is due to neutral fat brought from without the organ by the blood when +for any cause the oxidative powers are decreased, and setting free of +the previously invisible intercellular fat and lipoids, which are +normally present in the cells, by autolytic or physicochemical changes. +This condition is pretty evenly distributed among the dietary groups, +the liver being most commonly involved. The hepatic cells are easily +degenerated by the toxins or other harmful substances passing through +the organ and become passive and unable to throw off or to utilize the +deposited fat. In all probability the same general situation occurs in +the atheromatous changes in arteriosclerosis which on this diet shows a +high incidence. The causative agent is probably some poisonous +substance, possibly a protein degradation product, indol, pressor +substance, acting on the intima over long periods, or at irregular but +often repeated periods causing first destruction then fat accumulation. +It is also possible that it may be caused by repeated absorption of some +sensitizing protein. Arteriosclerosis in these animals is often closely +associated with nephritis. + +Obesity may result from excessive ingestion of food in individuals whose +habits are sedentary and whose digestions are active or it may come from +an inherent abnormality of metabolism dependent upon ductless gland +disease. It is very common in castrated animals. The obesity of +overeating is always of milder type than that associated with endocrine +disturbance. + +So far as is known there are two main disorders of fat metabolism—the +failure of the diabetic to form fat from glucose, and acidosis, the +inability of the organism to burn fat beyond betaoxybutyric acid, +acetoacetic acid, or acetone. The symptoms are unsteadiness of gait, +stupor, coma, air hunger, in all of which the essential features are due +to the impoverishment of the body in available bases. In infants this +frequently follows an excessive fat diet. It is also common in +starvation due to the deprivation of sugar. It is associated with +phosphorus poisoning, narcosis, carcinoma, liver disease, inanition, +etc. It has been produced experimentally by the administration of acids +or by foods deprived of their bases. The excess of acid in the body +whether produced in the body or introduced from without must be +neutralized in part by the ammonia manufactured in the ultimate +metabolic transformation of the protein and by the alkaline salts of the +blood and tissues. When alkali is reduced the carbon dioxide accumulates +in the tissues, blocking oxidation. The urine immediately shows an +increase of ammonium salts, a decrease of the urea and an increase in +the output of sodium, potassium, calcium and magnesium, which last two +are drawn from the bones. + +Symptoms do not arise until the fixed alkalies are exhausted; and they +are immediately relieved by the administration of alkalies, except in +those cases of starvation where the administration of sugar and the +subsequent sparing of the fats relieves the situation. In herbivores, +acidosis does not follow starvation, but, on the other hand, it is +markedly easier to excite it in herbivores than in carnivores whose +heavy protein diet produces more ammonia, which better enables the +animals to protect their fixed alkalies. The acid intoxication of +infections arises from different causes and is dependent on the +intensity of the type of infection; but ultimately it also depends upon +the depletion of the fixed alkalies. + + +IRREGULARITIES OF PROTEIN METABOLISM. + +Fat and carbohydrate disturbances are not infrequent in carnivores, but +it is with the protein fraction of the diet that most of the trouble is +connected. Natural foods contain several proteins or groups of proteins, +whose biological adequacy depends upon their yield of aminoacid. +Experiment has shown that many proteins are entirely lacking in one or +more of these essential radicles; and no food can be adequate unless it +contains at least all the aminoacids that the individual animal is +unable to manufacture for itself. So far as is known, no animal can +produce in itself either lysin or tryptophane. Gliadin, the principal +protein of wheat and lacking in lysin, is unable to support growth even +when given in amounts sufficient to insure the storage of nitrogen, and +is associated with a diet adequate in all other factors. Absence of +tryptophane prevents not only growth but maintenance. Any of the +aminoacids, whose radicles are contained in tissue proteins, may +contribute to the maintenance of adult equilibrium; but no growth occurs +unless all the necessary groups are present. Except in laboratories, +diets are never made up of isolated proteins, but they are often +composed of proteins derived from one plant and are often deficient. +McCollum and his associates in their studies showed that while there +were pronounced differences in the composition of many foods used by men +and animals not only in their protein content but in water, fats, +carbohydrates, etc., yet in the combinations found even in rather +restricted diets, the errors, as a rule, corrected each other. + +During digestion the protein molecule is broken down into the component +aminoacids which are absorbed and synthesized in the intestinal walls, +and appear on the other side as the specific blood protein, which serves +as the substrate for the anabolism of all the special tissue proteins. +Excessive protein is stored to a slight extent as aminoacid for the +future maintenance of the blood protein, the integrity of which is +tenaciously protected during hibernations, sexual migrations, and even +during starvation. The animal body tends to adjust its nitrogen +metabolism to its nitrogen supply; the adjustment requires an +appreciable amount of time. A diet changed to a lower nitrogen level +results in a continued loss of nitrogen, increased combustion of fats +and carbohydrates. The animal makes no apparent effort to reëstablish +equilibrium, and sooner or later digestive disturbances and loss of +strength occur. + +If, on the contrary, the protein is steadily increased after an animal +has established equilibrium, the nitrogen metabolism increases and the +level of nitrogen equilibrium rises to higher and higher levels. There +is, at the same time, a lowering of the fat combustion, an increase in +the respiratory quotient and in the heat production. The excess protein +must be split, deaminated, burned and eliminated. Fifty-five per cent. +of the intake is converted into glucose which is burned and the excess +stored as glycogen. The sulphuric acid formed during the protein +cleavage is neutralized by the body alkalies. In these cases the liver +is often congested and enlarged. The urine shows excess of urea and +ammonia. At times the excess, being so great that it cannot be absorbed, +undergoes chemical and bacterial decomposition which causes digestive +disturbances, torpor and constipation. + +The organisms associated with protein food are usually the putrefactive +types which break the protein molecule into the aromatic bodies, +phenols, indolacetic acid, indolpropionic acid, skatol, etc. These +bodies on absorption are believed to give rise to hypertrophy of the +adrenal, interstitial changes in the kidney, and arteriosclerosis. +Another group of substances, pressor bases and amines, are manufactured +by certain anaerobes acting on proteins. These, when fed by mouth, are +detoxicated by the liver cells, but when formed below the portal +circulation, give rise to anaphylactic phenomena—urticaria, etc. Certain +other organisms give rise to soluble toxins as in botulism and +thyrotoxicon poisoning. All these types of toxins will destroy if they +act acutely in sufficient concentration; or as is more common, if they +act persistently over long periods, or at oft recurring intervals they +will cause serious injury to the tissues coming in contact with them, +and have a part in the production of cirrhosis of the liver, chronic +nephritis, myocarditis, arteriosclerosis, etc. + +All foods have a limit beyond which they are excreted untouched or +imperfectly oxidized. Many of these partial oxidation products of +protein are in themselves toxic and may also be a source of these +degenerative organ conditions. The pathological material studied by us +showed a marked decrease in gastrointestinal diseases in close +association with the more hygienic care of the meat foods. + +Always associated with the protein foods are the nucleoprotein +complexes, which are split by both bacteria and digestive juices into +globulins and nucleic acid, and then through the agency of a special +enzyme, into purin bases and uric acid, in which forms they are excreted +in the urine and feces. The oxidation of purins is never complete. + +Gout, representing the pathology of purin metabolism, is a paroxysmal +inflammatory disturbance, due to the deposition of sodium urates in the +joints or in the internal organs, usually accompanied by a fibrosis +especially in the liver, kidney, arteries, etc. The disease occurs +almost exclusively in birds. Isolated cases have been described in dogs, +horses and hogs, but among lower animals it is undoubtedly very rare. In +birds it is most frequent in the carnivores—4 per cent., as against 0.02 +per cent. in all other groups. It is higher in fish-eating birds than +among the flesh-eaters. The avian gout is usually of the visceral type +and was most marked in its distribution over the organs in the Anseres +and Psittaci, birds whose diet apparently is not unduly heavy in +nucleoproteins, but whose tract approaches the carnivorous type. The +only arthritic cases occurred in Boat-billed herons (_Cancroma +cochlearia_), fish-eaters. Our records show examples in Accipitres, +Galli and Columbæ, although the number of cases in the last order were +few and slight in extent. This disease stands in close relation to diet, +as it develops on generous protein food, high in nucleoprotein or +hypoxanthin, especially if this be associated with restricted activity. + +The carnivorous mammals lead in the disease of the thyroid glands. +Thyroid disease occurs among the birds, but is equally distributed among +the dietary groups. Thyroid activity has a marked influence on +metabolism probably through the influence of the iodine-containing +protein of its secretion. There are some experimental evidences in favor +of a detoxicating function of the thyroid, of which the following are +quoted: (1) The effects of thyroidectomy are most marked in the +carnivores; Herbivora are often capable of several years of life without +thyroid tissue; (2) administration of meat to thyroidectomized omnivores +or herbivores caused a marked increase in all symptoms. The importance +of the relation of the meat diet, detoxication and thyroid disease +receives considerable confirmation from the fact that among the 1,860 +mammalian postmortems thyroid disease occurred in 2.6 per cent. of all +mammals, 94.9 per cent. of which were found in flesh eating varieties. +Wells[88] suggested that possibly this could be interpreted as an +indication that toxic materials found in the meat in the intestinal +tract were, under normal conditions, detoxicated by the thyroid. Against +a local neutralization, however, is the improvement following the +administration of dried thyroid substance. The function is either +neutralization of toxic substances or the stimulating action on +intracellular metabolism, both of which might be called into play by an +excessive protein diet. + + +THE CARNIVOROUS DIET. + +The pathology of the more prominent diseases developed in carnivores +points at least to diet as a predisposing or determining factor. This +diet is very high in a distinctly putrefactive protein and yields +products, chemical and bacterial, which are toxic and which give rise to +acute or more often chronic diseases of the alimentary tract and its +adnexa. By reason of the amount ingested, excessive because of lack of +exercise, there is a severe tax on the storage organs and on the +detoxicating glands, as the liver and thyroid. The constant absorption +of these toxic substances gives rise to chronic degenerative or fibrotic +changes in the organs through which they pass: liver, kidneys, arteries, +heart. In birds the degenerative diseases are even more marked than in +mammals on the same diet. The ultimate fault of this diet, especially +for mammals and birds with restricted activity, lies in the production +of toxic bodies, produced either in the incomplete degradation or +oxidation of the protein molecule or as the result of bacterial action +on the protein molecule, a poisonous quality which is probably enhanced +by the chemical changes occurring while the digested protein is passing +through the intestinal mucosa. Garden conditions are such that these +factors are almost unsurmountable unless the substitution of vegetable +protein could be accomplished. Failure is often caused by limited +feeding to carnivores of muscle and bones, whereas they should be +supplied with glandular organs and blood. + + +THE HERBIVOROUS DIET. + +Herbivorous diet must be divided into two groups, (1) that composed of +succulent vegetables, and (2) of grasses, grains and seeds. In the first +group there is an apparent variation in the results found in mammals and +birds. In both there is a marked decrease in the chronic degenerative +pathology. In both, acute gastritis is more prominent, far outstripping +the incidence of this condition in other classes. + +This diet yields a large and quickly available amount of carbohydrate +which in conjunction with the moisture, heat and bacteria which are +unavoidably associated with raw vegetables, makes an ideal situation for +infection. These foods carry many saprophytic bacteria, moulds, etc. In +birds the conditions are aggravated by the injuries that may occur from +the sharp objects picked up with the gravel. The incidence of acute +infection is higher among birds than among mammals of this group, and +often there is involvement of the whole tract. The explanation of the +other pathological findings occurring among birds must be found in the +frequently repeated low grade infections which result finally in the +production of chronic lesions in the digestive tract, liver, pancreas +and kidney. Toxins as an etiological factor cannot be altogether +excluded, but as a rule they are not important because the by-products +of vegetables are distinctly less toxic than those derived from animal +sources. Arteriosclerosis is much less frequent and less intensive in +herbivorous birds than among the carnivorous, probably because of +differences in the concentration and character of toxins in the two +groups. + + +SOFT HERBIVOROUS DIET. + +The diet of succulent vegetables is composed of tubers, edible roots and +leaves. The tubers and edible roots are high in water and carbohydrate +and poor in the amount and quality of the protein, most of which is not +even a true protein but a mixture of aminoacids. The leaves, on the +contrary, are rich in organic ash, especially calcium, sodium, chlorine, +and fat soluble A vitamine, and as a rule contain a good quality of +protein. They often, however, contain injurious substances. This diet, +while measurably less nutritious than that of the carnivores, can +satisfactorily nourish many animals with an extensive intestinal tract +during growth and even throughout their entire life, but proves entirely +inadequate when fed to an omnivorous tract. + + +SEED DIET. + +Closely allied in general character to the diet of succulent vegetables +are the seed diets, eaten only by birds and having no parallel among +mammalian foods. All seeds, in contradistinction to tubers, contain true +proteins which, however, are of poor quality because of the deficiencies +in the aminoacid content. They are as a rule low in the fat vitamines +and in the amount of calcium, sodium and chlorine carried. In three +pathological conditions only do these birds show any oversusceptibility: +(1) Sore eyes, (2) acute enteritis, (3) osteomalacia. Sore eyes were +frequently noted in this group. The lesions were very like those +described in animals deprived of the fat vitamine, which was present in +this food in very small amounts or entirely absent, thus giving a very +plausible explanation of this condition, especially as in some of the +cases no other cause could be found. Gastric disease of any type is rare +in this group because the food at the gastric stage is highly resistant +to bacterial action. In the duodenum, however, the conditions are early +changed because the bacteria carried with the food through the stomach +become active in the presence of available carbohydrate and protein +decomposition products. + +Osteomalacia is confined almost as exclusively to the seed-eating birds +as it was to the omnivorous mammals, and it is also associated with the +same deficiencies, calcium and phosphorus (cf. Tables 19 and 20). It is +also interesting to note that these two diets, the omnivorous and seeds, +yield the greatest number of cases of tuberculosis. Mammals showed 32.6 +per cent., as against 5.8 per cent. in all the other dietary groups, an +observation which becomes more striking when man is added to the +omnivorous group. Seed-eating birds showed 17.2 per cent., as against +6.4 per cent. in other groups. In both diets the fat, fat vitamine and +inorganic salts, especially the calcium, are deficient in amount. In the +wild, birds vary their diet of seeds with insects, worms, soft fruits +and the tender shoots of plants, and at the same time they increase +their inorganic intake by the minerals picked up with the gravel and +from the water which has penetrated the soil. + + +GRAIN AND GRASS DIET. + +The hay-eating animals constitute a large and well studied group— +including practically all the domestic varieties. Table 19 shows that +these animals yield the greatest number of cases of malnutrition, food +poisoning, acute pancreatitis, acute degenerative conditions of liver +and myocardium. + +Recent literature describes many cases of osteomalacia, especially among +horses and cows, in the famine districts of Europe. In our collection of +1,860 postmortems only one case was found, that of an Isabelline gazelle +(_Gazella isabella_), a hay-eating animal, and in this case it was +secondary to infection. + +Arthritis, occurring in 3.4 per cent. of all the autopsies, was almost +entirely confined to the hay-eating animals. The literature describes +many cases of arthritis almost entirely confined to ungulates, of which +many were associated with calving and subsequent infection. +Bacteriological researches have found it most often associated with +streptococci, staphylococci, or Bact. perfringens, organisms that +require a certain amount of carbohydrate for their proper development. +The relation of diet to this condition probably lies only in the fact +that it provides an excessive carbohydrate substrate suitable for the +optimum development of these organisms. Folin and Bergland, noting +glycoresis in Herbivora, thought that it represented the absorption and +excretion of unusable carbohydrate, present in grains, vegetables, +fruits, etc., and that it was sharply separated from the main +carbohydrate metabolism. These products were absorbed from the blood +exactly as they were ingested like lactose, dextrose, etc., are +absorbed, but do not enter into the economy although they might cause +disorders, especially forms of arthritis. + +The grain foods are composed largely of carbohydrates (principally in +the form of cellulose and starch) small amounts of protein and little or +no fat. They have a very low nutritive index so that large amounts must +be consumed to supply adequate calories. This food is constantly +present, and during the enforced idleness of captivity is almost +continuously eaten. Despite these facts, however, malnutrition is +present in 2.2 per cent. of the animals on this food. Associated with +the plentiful food and lack of exercise are overeating and pica. +Overfilled stomachs occurred thirty-four times. They were limited to +these mammals and to the seed-eating birds whose environmental +conditions are practically the same. Pica or excessive appetite for +abnormal food, is also more frequent in these groups, but is usually +associated with badly balanced diets, and thus represents an effort on +the part of the animal to supply its own deficiency. It is present in +osteomalacic monkeys and has been reported in cattle from regions where +osteomalacia is common and following crop failures where the rations are +restricted. In cattle it very often accompanies food poisoning, +especially that produced by ingestion of peat hay. + +Disturbance of the alimentary tract and its adnexa occurs in two forms: +(1) Infection which is quite common and involves the duodenum, pancreas +and liver, and (2) toxic. Compared with other diets alimentary disorders +are not frequent among grain feeders, despite the ease with which grass +foods ferment and the great variety of organisms found in them such as +moulds (aspergillus), Bact. coli, paratyphosus, enteritidis, +suipestifer, oidium lactis, etc. Few bacteria can attack whole protein, +cellulose or starch, and the decomposition products, peptone, glucose, +etc., are not available in any quantity until the lower stomach and +duodenum are reached. The inflammation of the alimentary tracts of these +animals is confined to the fourth stomach and duodenum, with, in many +cases, extension to liver and pancreas. + +Acute and chronic degenerative changes occur very frequently, and as a +rule are the result primarily of absorbed toxins. After ingestion of new +hay this often appears. The toxic substance probably is a terpinol +ester, cumarin, which is produced by an enzyme in the cut grass. + +The result is a gastroenteritis with jaundice, thirst and marked +flatulence. It is very probable that many of the gastrointestinal and +degenerative lesions are the result of the combined action of toxin and +bacteria. + + +FOOD POISONING. + +Food poisoning occurs in all diets, but especially among the grass- +eating mammals. To-day under the general heading of food poisoning are +included those cases due to (1) some injurious substance inherent in the +food itself, true food poisoning, (2) those due to toxic substances +liberated or produced in food contaminated by parasites or bacteria, (3) +those due to bacteria that are carried by food and develop into true +infection after ingestion. Most of the cases of meat poisoning described +in literature undoubtedly belong to this third class, _i.e._, flesh is +infected during the life of the animal or during its preparation for +food and the virus develops in the host after ingestion. A fourth and +more rare class of food poisoning is due to the condition of the +individual consuming the food-protein sensitization. + +Injurious constituents of normal flesh foods are very uncommon. There +are a few poisonous fish, notably the balloon, puffer, and Fuga fish of +Japan, which when eaten give rise to cholera-like conditions ending in +convulsions and paralysis. A marked intoxication has been described in +dogs which have fed upon the Greenland shark. Some fish are poisonous at +certain periods as spawning season, the poison then being confined to +the roe. Still others are harmless unless rendered toxic by some +injurious food. This poisoning of muscle meats is seen in quail and +partridges fed on mountain laurel, in some fish after consuming certain +marine plants, and in cattle poisoned by amanita. + +The most common sources of poisoning are spoiled meat and flesh of +diseased animals, both of which are serious factors in the production of +the gastrointestinal disorders of omnivores and carnivores. Practically +all the reports of meat poisoning from the literature have been traced +to the use of raw or insufficiently cooked flesh, and have yielded on +bacteriologic examination _Bact. paratyphosus_, _Bact. enteritidis_, +_Bact. suipestifer_, _Bact. coli_, or _Bact. proteus_. + +The bacteria may produce toxin in the food previous to ingestion causing +in the host only a severe intoxication. This is the situation developed +after eating sturgeon infected with _Bact. piscidus agilis_, an organism +which manufactures a highly poisonous alkaloid. A similar intoxication +follows the ingestion of potatoes infected with _Bact. proteus_ or +containing the poisonous alkaloid, solanin, which is produced in +diseased and sprouting potatoes. Other examples of this are (1) +ergotism—due to an infection of rye and wild grasses with _Claviceps +purpurea_ which produces three poisonous bodies, ergotinic acid, which +is not poisonous when taken into the stomach, sphacetinic acid and +cornutin which act on the nervous system, brain, cord, vagus and +vasomotor centre giving rise to toxic polyneuritis, and (2) favus, an +acute febrile anemia with jaundice and hemoglobinuria probably due to a +bacterial infection or fungus growth of the bean. Infected food may also +produce soluble heatresisting toxins that produce immediate symptoms and +increase the animal’s susceptibility to infection. This is the more +common finding in cases of poisoning with milk and milk products. Non- +pathogenic saprophytes carried in milk produce (1) a poison closely +allied to tyrotoxicon, (2) a toxalbumin which in itself causes serious +disturbances. Botulism, also probably of this group, is a disease +initiated by a toxin elaborated by _Bact. botulinus_ acting on a +protein. There is, however, some evidence that _Bact. botulinus_ can +also establish a real infection. + +The toxemias from food infected with bacteria may not occur until the +food is ingested or the bacteria implanted. This result occurs in +infections with _Bact. bovis morbificans_, Gärtner’s bacillus, etc., or +after the feeding of meat from animals infected with _Bact. +paratyphosus_ and _enteritidis_. + +The plant poisons are more frequently due to inherent injurious +substances, although even among them, bacterial and fungus diseases play +an important rôle. Among the 16,673 plants indigenous to North America, +almost 500 are more or less poisonous and about 30 are of great economic +importance. The toxic factor may be confined to the leaf, seed or root, +but more often it is associated with all parts of the plant. Through the +efforts of the Department of Agriculture a more or less complete list of +the plants implicated in the poisoning of stock has been compiled. This +list includes the following: _Amanita muscaria_; _A. phalloides_; +_Veratrum viride_; _Phytolacca decandra_; _Agrostemma githago_; +_Delphinium_, 25 varieties; _Astragalus mollissimus_; _Aragallus +lambertii_; _Crotalaria sagittalis_; _Euphorbia lathyris_; _E. +marginata_; _Rhus radicans_; _R. diversiloba_; _R. vernix_; _Aesculus +pavia_; _A. hippocastanum_; _A. glabra_; _A. Californica_; _Cicuta +maculata_; _C. vagans_; _Conium maculatum_; _Kalmia latifolia_; _K. +augustifolia_; _Leucothöe catesbaei_; _Rhododendron maximum_; _Pieris +mariana_; _Datura stramonium_; _Solanum nigrum_; _S. dulcamara_; +_Helenium autumnale_; _Asclepias pumila_; _A. verticullata_; _A. +galoides_; _A. mexicana_; _A. eriocarpa_; _A. speciosa_; _A. fremonti_; +_Eupatorium agertoides_; _E. urticarfolium_; _Isocoma wrightii_; +_Daubentonia longifolia_; _Senecio jacobia burchelli latifolius_.[89] +Some of these as the Amanita are only occasional sources of disaster, +but as they frequently involve man they are important. The _Amanita +muscaria_ symptoms appear very soon after eating the fungus and consist +of a deepening stupor. _A. phalloides_, on the contrary, starts with +severe abdominal pain, cramps, discharges of blood and mucus and later +convulsions. The meat of animals dying from fungus poisoning is +distinctly poisonous. This transfer of poison to the muscles of the +animal partaking of these plants occurs also in poisoning with Kalmia. + +The other plants of this list are closely associated with the grass +foods and are consumed usually when the food on a range is scarce. Some +groups as the Asclepias contain a distinct neurotoxin and give rise to a +condition known as trembles or staggers. It affects mostly cows and +sheep, causing staggering, trembling gait, bloating and salivation and +death with convulsions. There is marked congestion of alimentary tract, +liver and kidney. In the cerebrospinal axis there are marked changes in +the nerve cells of the medulla and spinal cord. The Purkinje cells show +the effect of extreme fatigue. Other plants causing stiffness or +weakness of the extremities, show on microscopic examination no definite +lesions in the cerebrospinal axis. Loco weed—_Astragalus mollissimus_ +and _Aragallus lambertii_—causes maniacal disturbances but no gross +lesions. This weed in Colorado costs the state enormous amounts of money +yearly. + +Helenium poisons domestic animals by means of a toxic glucoside, +dugaldin, which produces stiffness, salivation and nausea with mild +depression (“spewing sickness”). The alimentary tract shows severe +inflammation of the rumen and reticulum which may at times be +hemorrhagic. The liver usually presents an interstitial hepatitis. This +toxin is decidedly hemolytic. The effects of this plant are always +permanent, total recovery being very rare. + +The larkspur (25 different varieties), on the contrary, shows prompt +recovery after treatment, but no establishment of toleration. These +plants give rise to nausea, vomiting and great agitation and destroy +many animals yearly. The poisons are included in four alkaloids, all +spinal cord depressants resembling aconite in general character. + +These poisonous plants all produce more or less gastrointestinal +inflammation and practically all are destructive in their action on the +liver, pancreas and kidney. It is impossible to form even approximate +estimates of the damage done by them because of the general ignorance of +the subject. The Division of Botany has been collecting for the past few +years specific information concerning these plants, but the individual +plants are not equally poisonous, and all animals do not show the same +susceptibility to the poison. _Veratrum viride_, for instance, is eaten +with relish by sheep and elk and is decidedly toxic for the horse. In +many the toxic factor has not been isolated. Some, as Euphorbia, are +poisonous only when fed in honey derived from its flowers. + +The influence of diet on the general health of animals is very far +reaching and very inclusive. Metabolic disturbances are undoubtedly at +times the result of unbalance—deficiencies on the one side, excesses on +the other, at times are probably much more the results of bacterial +invasions aided and abetted by the food administered, at still other +times are poisonous either in their own content or from the degradation +products resulting from digestion or bacterial decomposition. + + + + + SECTION XVI + NEOPLASMS + + +The occurrence of true neoplasms in domesticated animals has always been +well known and thoroughly studied while for beasts in the wild the data +has been fragmentary. That tumors exist in natural environment has been +accepted upon the testimony of hunters but there is an impression, and +nothing more, of their extreme scarcity probably because only younger +vigorous animals come to the attention of the sportsman or collector. +This matter will of course not be settled until some natural historian +with a knowledge of pathology, makes a survey of a large number of +specimens taken during a collecting expedition. Observations in +menageries are valuable to the extent that they show what tumors may +occur, the orders most commonly affected and the incidence under captive +conditions. It is unfortunate that too seldom do we know the history of +our specimens in regard to the age, manner of capture or breeding, data +which if at our disposal would permit of a very fair idea of the +probable incidence in the wild and of the effect of captivity. Some +observations in this direction are however possible by using the figures +of known captivity and breeding. + +The facts gleaned from a study of neoplasms under captive conditions may +be of interest to the experimental pathologist, especially when +considering the relation of the origin from the embryological layers. I +have tabulated this with great care, using Jordan’s[90] table for the +source of the various tissues, and further have studied the destination +of metastatic emboli in terms of the blastoderm. + +The following observations are based entirely upon our own data for +while it might be valuable to include the cases in the literature their +descriptions are often so meagre that they would not combine readily +with our records. Plimmer, Seligmann, and Murray have published in the +_Proceedings of the London Zoological Society_ since 1903, their annual +report of the pathological service in which they have recorded very many +interesting tumors. So too from time to time Harlow Brooks and W. R. +Blair in the _Annual Report of the New York Zoological Park_, have +presented cases occurring in their service. Joest [91] discusses tumors +in the lower animals in a broad way and analyzes their incidence and +characters. C. Y. White and I [92] have already published articles on +this subject. Numerous single references may be found in the _Jahresber. +der Veterinär-Medicin_. + +In so far as the incidence of tumors in wild animals is concerned this +literature can scarcely give an adequate measurement but it would seem +that they are less than in domestic varieties. Exact figures for the +occurrence of tumors in the latter seem not available in the literature, +but one can find that in the Prussian army horses about one hundred are +observed each year. In our 5,365 specimens collected during nineteen +years, 94 tumors in 92 animals have been found, 1.7 per cent. or about +one in every sixty specimens, not at all a low figure. If one were to +include all fibromata of the feet and the blood collections to which the +name angioma might be applied, this incidence would be greater; they are +excluded because few in number and vague in history; only one true +angioma was seen. + +The gross and microscopical appearances of tumors in the lower animals +are essentially the same as one encounters in human beings or at least +it is possible to apply the pathological nomenclature used in human +medicine to all the neoplasms we have discovered. There is appended a +list of all the animals and their tumors, a table of zoological orders, +tumors and organs (Table 21) and an analytical table of the histological +data. (Table 22) + + TABLE 21. + _Table of Orders and Families Showing Type of Tumor and Principal Organ + of Origin._ + + ═══════════════════╤═══════╤═══════╤═════════╤══════╤══════════╤══════ + Order Family │Fibroma│Osteoma│Chondroma│Lipoma│Myoma and │Glioma + │ │ │ │ │Fibromyoma│ + │ │ │ │ │ │ + ───────────────────┼───────┼───────┼─────────┼──────┼──────────┼────── + „ „ │ „ │ „ │ „ │ „ │ „ │ „ + │ │ │ │ │ │ + ───────────────────┼───────┼───────┼─────────┼──────┼──────────┼────── + Primates, │ │ │ │ │ │ + Cercopithecidæ │ │ │ │ │ │ + Cebidæ │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + Lemures, Lemuridæ │ │ │ │ │ │ + │ │ │ │ │ │ + Carnivora, Felidæ │ │ │ 1│ │ │ + │ │ │ │ │ │ + Viverridæ │ │ │ │ │ │ + Canidæ │ │ │ │ │ │ + Procyonidæ │ │ │ │ │ │ + Ursidæ │ │ │ │ │ │ + │ │ │ │ │ │ + Phocidæ │ │ │ │ │ │ + │ │ │ │ │ │ + Rodentia, Sciuridæ │ │ 1│ │ │ │ + Muridæ │ │ │ │ │ │ + Heteromyidæ │ │ │ │ │ │ + │ │ │ │ │ │ + Octodontidæ │ │ │ │ │ │ + Hystricidæ │ │ │ │ │ │ + Dasyproctidæ │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + Proboscidea │ │ │ │ │ 1│ + Ungulata, Equidæ │ 1│ │ │ │ │ + Bovidæ │ │ │ │ │ 1│ + Cervidæ │ │ │ │ │ │ + Camelidæ │ │ │ │ │ │ + Suidæ │ │ │ │ │ │ + Edentata, │ │ │ │ │ 1│ + Dasypodidæ │ │ │ │ │ │ + Marsupialia, │ │ │ │ │ │ + Didelphyidæ │ │ │ │ │ │ + Dasyuridæ │ │ │ │ │ │ + Peramelidæ │ │ │ │ │ │ + Macropodidæ │ │ │ │ │ │ + Passeres, Turdidæ │ │ │ │ │ │ + Crateropodidæ│ │ │ │ │ │ + Tanagridæ │ │ │ │ 1│ │ + Fringillidæ │ │ │ │ 1│ │ + Icteridæ │ │ │ │ │ │ + Striges, Bubonidæ │ │ │ │ │ │ + Psittaci, Loridæ │ │ │ │ │ │ + Cacatuidæ │ │ │ │ 2│ │ + Psittacidæ │ │ │ │ 3│ │ 1 + │ │ │ │ │ │ + Accipitres, │ │ │ │ 1│ │ + Falconidæ │ │ │ │ │ │ + Columbæ, Columbidæ │ │ │ │ │ │ + Galli, Phasianidæ │ │ │ │ │ │ + Fulicariæ, Rallidæ │ │ │ │ │ │ + Anseres, Anatidæ │ 1│ │ │ │ │ + Struthiones, Rheidæ│ │ │ │ │ │ + ───────────────────┼───────┼───────┼─────────┼──────┼──────────┼────── + Total │ 2│ 1│ 1│ 8│ 3│ 1 + ───────────────────┴───────┴───────┴─────────┴──────┴──────────┴────── + + ═══════════════════╤═══════╤════════════╤═══════╤═════════╤═══════════ + Order Family │Angioma│Endothelioma│Sarcoma│Papilloma│Epithelioma + │ │ │ │ │ + │ │ │ │ │ + ───────────────────┼───────┼────────────┼───────┼─────────┼─────────── + „ „ │ „ │ „ │ „ │ „ │ „ + │ │ │ │ │ + ───────────────────┼───────┼────────────┼───────┼─────────┼─────────── + Primates, │ │ │ │ │ + Cercopithecidæ │ │ │ │ │ + Cebidæ │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + Lemures, Lemuridæ │ │ │ │ │ + │ │ │ │ │ + Carnivora, Felidæ │ 1│ 1│ │ │ + │ │ │ │ │ + Viverridæ │ │ │ │ │ + Canidæ │ │ │ 1│ │ + Procyonidæ │ │ │ │ │ + Ursidæ │ │ │ │ │ 1 + │ │ │ │ │ + Phocidæ │ │ │ │ │ + │ │ │ │ │ + Rodentia, Sciuridæ │ │ │ │ │ + Muridæ │ │ │ 2│ │ + Heteromyidæ │ │ │ 1│ │ + │ │ │ │ │ + Octodontidæ │ │ │ 1│ │ + Hystricidæ │ │ │ │ │ + Dasyproctidæ │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + Proboscidea │ │ │ │ │ + Ungulata, Equidæ │ │ │ │ │ + Bovidæ │ │ │ 1│ │ + Cervidæ │ │ │ │ │ + Camelidæ │ │ │ │ │ + Suidæ │ │ │ │ │ + Edentata, │ │ │ │ │ + Dasypodidæ │ │ │ │ │ + Marsupialia, │ │ │ │ │ + Didelphyidæ │ │ │ │ │ + Dasyuridæ │ │ │ │ │ 1 + Peramelidæ │ │ │ │ │ + Macropodidæ │ │ │ │ │ + Passeres, Turdidæ │ │ │ │ │ + Crateropodidæ│ │ │ │ │ + Tanagridæ │ │ │ │ │ + Fringillidæ │ │ │ │ │ + Icteridæ │ │ │ │ │ + Striges, Bubonidæ │ │ │ │ 1│ + Psittaci, Loridæ │ │ │ │ │ + Cacatuidæ │ │ │ │ │ + Psittacidæ │ │ │ 7│ │ 1 + │ │ │ │ │ + Accipitres, │ │ │ 1│ │ + Falconidæ │ │ │ │ │ + Columbæ, Columbidæ │ │ │ 1│ │ + Galli, Phasianidæ │ │ │ │ │ + Fulicariæ, Rallidæ │ │ 1│ │ │ + Anseres, Anatidæ │ │ │ 1│ │ + Struthiones, Rheidæ│ │ │ │ │ + ───────────────────┼───────┼────────────┼───────┼─────────┼─────────── + Total │ 1│ 2│ 16│ 1│ 3 + ───────────────────┴───────┴────────────┴───────┴─────────┴─────────── + + ═══════════════════╤═══════╤═════════╤═══════════╤═════════════╤══════ + Order Family │Adenoma│Carcinoma│ Chorion- │Hypernephroma│Mixed + │ │ │epithelioma│ │Tumors + │ │ │ │ │ + ───────────────────┼───────┼─────────┼───────────┼─────────────┼────── + „ „ │ „ │ „ │ „ │ „ │ „ + │ │ │ │ │ + ───────────────────┼───────┼─────────┼───────────┼─────────────┼────── + Primates, │ 1│ │ │ │ + Cercopithecidæ │ │ │ │ │ + Cebidæ │ │ │ │ 1│ + │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + Lemures, Lemuridæ │ 1│ │ │ │ + │ │ │ │ │ + Carnivora, Felidæ │ 2│ 1│ │ │ + │ │ │ │ │ + Viverridæ │ │ 2│ │ │ + Canidæ │ 3│ 1│ │ │ 1 + Procyonidæ │ 1│ │ │ │ + Ursidæ │ │ 2│ │ │ + │ │ │ │ │ + Phocidæ │ │ │ │ 1│ + │ │ │ │ │ + Rodentia, Sciuridæ │ 1│ │ │ 1│ + Muridæ │ │ 3│ │ │ + Heteromyidæ │ │ │ │ │ + │ │ │ │ │ + Octodontidæ │ │ │ │ │ + Hystricidæ │ │ │ 1│ │ + Dasyproctidæ │ │ 1│ │ │ + │ │ │ │ │ + │ │ │ │ │ + Proboscidea │ │ │ │ │ + Ungulata, Equidæ │ │ │ │ │ + Bovidæ │ │ │ │ │ + Cervidæ │ 1│ │ │ │ + Camelidæ │ │ 1│ │ │ + Suidæ │ │ 1│ │ │ + Edentata, │ │ │ │ │ + Dasypodidæ │ │ │ │ │ + Marsupialia, │ 1│ 1│ │ │ + Didelphyidæ │ │ │ │ │ + Dasyuridæ │ │ 1│ │ │ + Peramelidæ │ │ 1│ │ │ + Macropodidæ │ │ 2│ │ │ + Passeres, Turdidæ │ │ │ │ 1│ + Crateropodidæ│ 1│ │ │ │ + Tanagridæ │ │ │ │ │ + Fringillidæ │ │ 2│ │ │ + Icteridæ │ │ │ │ 1│ + Striges, Bubonidæ │ │ │ │ │ + Psittaci, Loridæ │ │ 1│ │ │ + Cacatuidæ │ │ │ │ │ + Psittacidæ │ 5│ 4│ │ 1│ 1 + │ │ │ │ │ + Accipitres, │ │ │ │ │ + Falconidæ │ │ │ │ │ + Columbæ, Columbidæ │ │ │ │ │ + Galli, Phasianidæ │ │ 1│ │ │ + Fulicariæ, Rallidæ │ │ │ │ │ + Anseres, Anatidæ │ 1│ │ │ 1│ + Struthiones, Rheidæ│ 1│ │ │ │ + ───────────────────┼───────┼─────────┼───────────┼─────────────┼────── + Total │ 19│ 25│ 1│ 7│ 2 + ───────────────────┴───────┴─────────┴───────────┴─────────────┴────── + + ═══════════════════╤═══════════════════════════════════════════ + Order Family │ Organic Source of Tumor + │ + │ + ───────────────────┼────┬──────┬───────┬──────┬──────┬───────── + „ „ │Lung│Muscle│Thyroid│Uterus│Kidney│Bone and + │ │ │ │ │ │Cartilage + ───────────────────┼────┼──────┼───────┼──────┼──────┼───────── + Primates, │ │ │ │ │ │ + Cercopithecidæ │ │ │ │ │ │ + Cebidæ │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + Lemures, Lemuridæ │ │ │ │ │ │ + │ │ │ │ │ │ + Carnivora, Felidæ │ │ │ │ 2│ │ 1 + │ │ │ │ │ │ + Viverridæ │ 1│ │ │ │ │ + Canidæ │ │ │ 3│ │ │ + Procyonidæ │ │ │ │ │ │ + Ursidæ │ │ │ │ │ │ + │ │ │ │ │ │ + Phocidæ │ │ │ │ │ │ + │ │ │ │ │ │ + Rodentia, Sciuridæ │ │ │ │ │ 1│ 1 + Muridæ │ │ 3│ │ │ │ + Heteromyidæ │ │ │ │ │ │ + │ │ │ │ │ │ + Octodontidæ │ │ │ 1│ │ │ + Hystricidæ │ │ │ │ 1│ │ + Dasyproctidæ │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + Proboscidea │ │ │ │ 1│ │ + Ungulata, Equidæ │ │ │ │ │ │ + Bovidæ │ │ │ │ 1│ │ 1 + Cervidæ │ │ │ │ │ │ + Camelidæ │ │ │ │ │ │ + Suidæ │ │ │ │ 1│ │ + Edentata, │ │ │ │ 1│ │ + Dasypodidæ │ │ │ │ │ │ + Marsupialia, │ │ │ │ │ 1│ + Didelphyidæ │ │ │ │ │ │ + Dasyuridæ │ │ │ │ │ │ + Peramelidæ │ 1│ │ │ │ │ + Macropodidæ │ 1│ │ │ │ │ + Passeres, Turdidæ │ │ │ │ │ 1│ + Crateropodidæ│ │ │ │ │ 1│ + Tanagridæ │ │ │ │ │ │ + Fringillidæ │ │ │ │ │ 2│ + Icteridæ │ │ │ │ │ 1│ + Striges, Bubonidæ │ │ │ │ │ │ + Psittaci, Loridæ │ 1│ │ │ │ │ + Cacatuidæ │ │ │ │ │ │ + Psittacidæ │ │ 2│ 1│ 1│ 5│ + │ │ │ │ │ │ + Accipitres, │ │ │ │ │ │ + Falconidæ │ │ │ │ │ │ + Columbæ, Columbidæ │ │ │ │ │ 1│ + Galli, Phasianidæ │ │ │ │ │ │ + Fulicariæ, Rallidæ │ │ │ │ │ │ 1 + Anseres, Anatidæ │ │ 1│ │ │ 1│ 1 + Struthiones, Rheidæ│ │ │ │ │ │ + ───────────────────┼────┼──────┼───────┼──────┼──────┼───────── + Total │ 4│ 6│ 5│ 8│ 14│ 5 + ───────────────────┴────┴──────┴───────┴──────┴──────┴───────── + + ═══════════════════╤═══════════════════════════════════════════════ + Order Family │ Organic Source of Tumor + │ + │ + ───────────────────┼────────────────┬──────┬──────────┬──────┬───── + „ „ │Gastrointestinal│Liver,│Peritoneum│Lymph │Mamma + │ Tract │ &c. │ │Tissue│ + ───────────────────┼────────────────┼──────┼──────────┼──────┼───── + Primates, │ 1│ │ │ │ + Cercopithecidæ │ │ │ │ │ + Cebidæ │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + Lemures, Lemuridæ │ │ │ │ │ + │ │ │ │ │ + Carnivora, Felidæ │ │ 1│ │ 1│ + │ │ │ │ │ + Viverridæ │ 1│ │ │ │ + Canidæ │ │ 2│ │ │ + Procyonidæ │ │ │ │ │ + Ursidæ │ │ │ │ │ 1 + │ │ │ │ │ + Phocidæ │ │ │ │ │ + │ │ │ │ │ + Rodentia, Sciuridæ │ │ 1│ │ │ + Muridæ │ │ │ │ │ 2 + Heteromyidæ │ │ │ │ │ + │ │ │ │ │ + Octodontidæ │ │ │ │ │ + Hystricidæ │ │ │ │ │ + Dasyproctidæ │ │ │ │ │ + │ │ │ │ │ + │ │ │ │ │ + Proboscidea │ │ │ │ │ + Ungulata, Equidæ │ │ │ 1│ │ + Bovidæ │ │ │ │ 1│ + Cervidæ │ │ 1│ │ │ + Camelidæ │ │ 1│ │ │ + Suidæ │ │ │ │ │ + Edentata, │ │ │ │ │ + Dasypodidæ │ │ │ │ │ + Marsupialia, │ │ │ │ │ 1 + Didelphyidæ │ │ │ │ │ + Dasyuridæ │ 1│ │ │ │ + Peramelidæ │ │ │ │ │ + Macropodidæ │ 1│ │ │ │ + Passeres, Turdidæ │ │ │ │ │ + Crateropodidæ│ │ │ │ │ + Tanagridæ │ │ │ │ │ + Fringillidæ │ │ │ │ │ + Icteridæ │ │ │ │ │ + Striges, Bubonidæ │ 1│ │ │ │ + Psittaci, Loridæ │ │ │ │ │ + Cacatuidæ │ │ │ │ │ + Psittacidæ │ 1│ 3│ │ │ + │ │ │ │ │ + Accipitres, │ │ │ 1│ │ + Falconidæ │ │ │ │ │ + Columbæ, Columbidæ │ │ │ │ │ + Galli, Phasianidæ │ │ │ │ │ + Fulicariæ, Rallidæ │ │ │ │ │ + Anseres, Anatidæ │ │ │ │ │ + Struthiones, Rheidæ│ 1│ │ │ │ + ───────────────────┼────────────────┼──────┼──────────┼──────┼───── + Total │ 6│ 9│ 2│ 2│ 4 + ───────────────────┴────────────────┴──────┴──────────┴──────┴───── + + ═══════════════════╤══════════════════════════════════════════╤════════════ + Order Family │ │Notes Extra + │ │ cases not + │ │ tabulated. + ───────────────────┼─────┬────────┬────┬──────┬───────┬───────┼──────────── + „ „ │Ovary│Pancreas│Skin│Testes│Adrenal│Unknown│ „ + │ │ │ │ │ │ │ + ───────────────────┼─────┼────────┼────┼──────┼───────┼───────┼──────────── + Primates, │ │ │ │ │ │ │ + Cercopithecidæ │ │ │ │ │ │ │ + Cebidæ │ │ │ │ │ 1│ │Adenoma of + │ │ │ │ │ │ │ prostrate + │ │ │ │ │ │ │suggesting + │ │ │ │ │ │ │ cancer in + │ │ │ │ │ │ │ places. + Lemures, Lemuridæ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ + Carnivora, Felidæ │ │ │ │ │ │ │Endothelioma + │ │ │ │ │ │ │ of pleura. + Viverridæ │ │ 1│ │ │ │ │ + Canidæ │ │ 1│ │ │ │ │ + Procyonidæ │ │ 1│ │ │ │ │ + Ursidæ │ │ │ │ │ 1│ │Epithelioma + │ │ │ │ │ │ │ of tongue. + Phocidæ │ │ │ │ │ 1│ │ + │ │ │ │ │ │ │ + Rodentia, Sciuridæ │ │ │ │ │ │ │ + Muridæ │ │ │ │ │ │ │ + Heteromyidæ │ │ │ │ │ │ │Sarcoma of + │ │ │ │ │ │ │ bladder. + Octodontidæ │ │ │ │ │ │ │ + Hystricidæ │ │ │ │ │ │ │ + Dasyproctidæ │ │ │ │ │ │ │Squamous + │ │ │ │ │ │ │ carcinoma + │ │ │ │ │ │ │ of larynx. + Proboscidea │ │ │ │ │ │ │ + Ungulata, Equidæ │ │ │ │ │ │ │ + Bovidæ │ │ │ │ │ │ │ + Cervidæ │ │ │ │ │ │ │ + Camelidæ │ │ │ │ │ │ │ + Suidæ │ │ │ │ │ │ │ + Edentata, │ │ │ │ │ │ │ + Dasypodidæ │ │ │ │ │ │ │ + Marsupialia, │ │ │ │ │ │ │ + Didelphyidæ │ │ │ │ │ │ │ + Dasyuridæ │ │ │ 1│ │ │ │ + Peramelidæ │ │ │ │ │ │ │ + Macropodidæ │ │ │ │ │ │ │ + Passeres, Turdidæ │ │ │ │ │ │ │ + Crateropodidæ│ │ │ │ │ │ │ + Tanagridæ │ │ │ │ │ │ 1│ + Fringillidæ │ │ │ │ │ │ 1│ + Icteridæ │ │ │ │ │ │ │ + Striges, Bubonidæ │ │ │ │ │ │ │ + Psittaci, Loridæ │ │ │ │ │ │ │ + Cacatuidæ │ │ │ │ │ │ 2│ + Psittacidæ │ 1│ │ │ 2│ 1│ 5│Glioma of + │ │ │ │ │ │ │ brain. + Accipitres, │ │ │ │ │ │ 1│ + Falconidæ │ │ │ │ │ │ │ + Columbæ, Columbidæ │ │ │ │ │ │ │ + Galli, Phasianidæ │ 1│ │ │ │ │ │ + Fulicariæ, Rallidæ │ │ │ │ │ │ │ + Anseres, Anatidæ │ │ │ │ │ 1│ │ + Struthiones, Rheidæ│ │ │ │ │ │ │ + ───────────────────┼─────┼────────┼────┼──────┼───────┼───────┼──────────── + Total │ 2│ 3│ 1│ 2│ 5│ 10│ + ───────────────────┴─────┴────────┴────┴──────┴───────┴───────┴──────────── + + TABLE 22. + _Analytical Table Showing Data of Incidence, Sex, Breeding, Duration of + Captivity, Metastases and Embryological Origins and Distributions + According to Order._ + + ════════════╤═══════╤═════╤════════╤═══════════════╤══════════╤═══════ + Order │ Total │ Per │ Sex │ Breeding │ Range │Average + │animals│cent.│ │ │ known │ for + │ │ per │ │ │captivity │ tumor + │ │order│ │ │ │animals + ────────────┼───────┼─────┼──┬──┬──┼────┬───────┬──┼──────────┼─────── + „ │ „ │ „ │♂ │♀ │? │Wild│Captive│? │ „ │ „ + ────────────┼───────┼─────┼──┼──┼──┼────┼───────┼──┼──────────┼─────── + Primates │ 2│ .4│ 2│ │ │ 2│ │ │3–4 yrs. │3½ yrs. + Lemures │ 1│ 1.1│ 1│ │ │ 1│ │ │4 yrs. │ + Carnivora │ 17│ 3.5│ 8│ 9│ │ 14│ 3│ │1–18 yrs. │9 yrs. + Rodentia │ 12│ 6.│ 7│ 4│ 1│ 8│ 2│ 2│1 mo.–7 │2 yrs. + │ │ │ │ │ │ │ │ │yrs. │8 mo. + Insectivora │ 0│ │ │ │ │ │ │ │ │ + Chiroptera │ 0│ │ │ │ │ │ │ │ │ + Proboscidea │ 1│_33._│ │ 1│ │ 1│ │ │38 yrs. │ + Hyracoidea │ 0│ │ │ │ │ │ │ │ │ + Ungulata │ 7│ 1.9│ 2│ 5│ │ 5│ 1│ 1│2–16 yrs. │9 yrs. + Edentata │ 1│_6.2_│ │ 1│ │ 1│ │ │10 yrs. │ + Marsupialia │ 7│ 4.│ 6│ 1│ │ 6│ 1│ │1 wk.–12 │5 yrs. + │ │ │ │ │ │ │ │ │yrs. │6 mo. + Monotremata │ 0│ │ │ │ │ │ │ │ │ + ────────────┼───────┼─────┼──┼──┼──┼────┼───────┼──┼──────────┼─────── + Totals │ 48│ 2.58│26│21│ 1│ 38│ 7│ 3│ │ + │ │ │ │ │ │ │ │ │ │ + Passeres │ 7│ .51│ 4│ 2│ 1│ 6│ │ 1│1–14 yrs. │6 yrs. + Picariæ │ 0│ │ │ │ │ │ │ │ │ + Striges │ 1│ .75│ │ 1│ │ 1│ │ │7 yrs. │ + Psittaci │ 26│ 3.7│ 9│ 8│ 9│ 8?│ 16?│2?│5 mo.–9 │3 yrs. + │ │ │ │ │ │ │ │ │yrs. │ + Accipitres │ 2│ 1.│ 2│ │ │ 2│ │ │(1)[93]–4 │ + │ │ │ │ │ │ │ │ │yrs. │ + Columbæ │ 1│ .63│ │ 1│ │ 1│ │ │4 yrs. │ + Galli │ 1│ .33│ │ 1│ │ 1│ │ │? │ + Hemipodii │ 0│ │ │ │ │ │ │ │ │ + Fulicariæ │ 1│_2.8_│ 1│ │ │ 1│ │ │6 yrs. │ + Alectorides │ 0│ │ │ │ │ │ │ │ │ + Limicolæ │ 0│ │ │ │ │ │ │ │ │ + Gaviæ │ 0│ │ │ │ │ │ │ │ │ + Impennes │ 0│ │ │ │ │ │ │ │ │ + Steganopodes│ 0│ │ │ │ │ │ │ │ │ + Herodiones │ 0│ │ │ │ │ │ │ │ │ + Odontoglossæ│ 0│ │ │ │ │ │ │ │ │ + Palamedes │ 0│ │ │ │ │ │ │ │ │ + Anseres │ 4│ 1.2│ │ 3│ 1│ 3?│ 1│ │(1)[93]-10│ + │ │ │ │ │ │ │ │ │yrs. │ + │ │ │ │ │ │ │ │ │(1)[93]-4 │ + │ │ │ │ │ │ │ │ │yrs. │ + Struthiones │ 1│_3.1_│ 1│ │ │ 1│ │ │(1)[93]-5 │ + │ │ │ │ │ │ │ │ │yrs. │ + Crypturi │ 0│ │ │ │ │ │ │ │ │ + ────────────┼───────┼─────┼──┼──┼──┼────┼───────┼──┼──────────┼─────── + Totals │ 44│ 1.23│17│16│11│ 24│ 17│ 3│ │ + ────────────┼───────┼─────┼──┼──┼──┼────┼───────┼──┼──────────┼─────── + Grand Totals│ 92│ 1.7│43│37│12│ 62│ 24│ 6│ │ + ────────────┴───────┴─────┴──┴──┴──┴────┴───────┴──┴──────────┴─────── + + ════════════╤══════════════╤════════════════════════════════════ + Order │Embryological │ Metastases + │ layer │ + │ │ + │ │ + ────────────┼────┬────┬────┼────┬─────┬──────┬───────────┬────── + „ │Ecto│Meso│Ento│Lung│Liver│Kidney│Lymphocytes│Spleen + ────────────┼────┼────┼────┼────┼─────┼──────┼───────────┼────── + Primates │ │ 1│ 1│ │ │ │ │ + Lemures │ │ │ 1│ │ │ │ │ + Carnivora │ 2│ 8│ 7│ 5│ 1│ │ 1│ + Rodentia │ 2│ 7│ 3│ │ │ │ │ + │ │ │ │ │ │ │ │ + Insectivora │ │ │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ │ │ + Proboscidea │ │ 1│ │ │ │ │ │ + Hyracoidea │ │ │ │ │ │ │ │ + Ungulata │ │ 5│ 2│ │ 1│ 1│ 1│ + Edentata │ │ 1│ │ │ │ │ │ + Marsupialia │ 2│ 2│ 3│ 1│ 2│ 1│ 1│ 2 + │ │ │ │ │ │ │ │ + Monotremata │ │ │ │ │ │ │ │ + ────────────┼────┼────┼────┼────┼─────┼──────┼───────────┼────── + Totals │ 6│ 25│ 17│ 6│ 4│ 2│ 3│ 2 + │ │ │ │ │ │ │ │ + Passeres │ │ 7│ │ 1│ 1│ │ │ + Picariæ │ │ │ │ │ │ │ │ + Striges │ │ │ 1│ │ │ │ │ + Psittaci │ 1│ 17│ 8│ │ 2│ │ │ 1 + │ │ │ │ │ │ │ │ + Accipitres │ │ 2│ │ │ │ │ │ + │ │ │ │ │ │ │ │ + Columbæ │ │ 1│ │ │ │ │ │ + Galli │ │ 1│ │ │ │ │ │ + Hemipodii │ │ │ │ │ │ │ │ + Fulicariæ │ │ 1│ │ │ │ │ │ + Alectorides │ │ │ │ │ │ │ │ + Limicolæ │ │ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ │ │ │ + Impennes │ │ │ │ │ │ │ │ + Steganopodes│ │ │ │ │ │ │ │ + Herodiones │ │ │ │ │ │ │ │ + Odontoglossæ│ │ │ │ │ │ │ │ + Palamedes │ │ │ │ │ │ │ │ + Anseres │ │ 4│ │ │ │ │ │ + │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + │ │ │ │ │ │ │ │ + Struthiones │ │ │ 1│ │ │ │ │ + │ │ │ │ │ │ │ │ + Crypturi │ │ │ │ │ │ │ │ + ────────────┼────┼────┼────┼────┼─────┼──────┼───────────┼────── + Totals │ 1│ 33│ 10│ 1│ 3│ │ │ 1 + ────────────┼────┼────┼────┼────┼─────┼──────┼───────────┼────── + Grand Totals│ 7│ 58│ 27│ 7│ 7│ 2│ 3│ 3 + ────────────┴────┴────┴────┴────┴─────┴──────┴───────────┴────── + + ════════════╤═════════════════════╤══════════════ + Order │ Metastases │Embryological + │ │ layer of + │ │ metastases + │ │ + ────────────┼─────────┬────┬──────┼────┬────┬──── + „ │Intestine│Bone│Muscle│Ecto│Meso│Ento + ────────────┼─────────┼────┼──────┼────┼────┼──── + Primates │ │ │ │ │ │ + Lemures │ │ │ │ │ │ + Carnivora │ │ │ 1│ │ 5│ 5 + Rodentia │ │ │ │ │ │ + │ │ │ │ │ │ + Insectivora │ │ │ │ │ │ + Chiroptera │ │ │ │ │ │ + Proboscidea │ │ │ │ │ │ + Hyracoidea │ │ │ │ │ │ + Ungulata │ │ │ │ │ 1│ 1 + Edentata │ │ │ │ │ │ + Marsupialia │ │ 1│ │ │ 2│ 3 + │ │ │ │ │ │ + Monotremata │ │ │ │ │ │ + ────────────┼─────────┼────┼──────┼────┼────┼──── + Totals │ │ 1│ 1│ │ 8│ 9 + │ │ │ │ │ │ + Passeres │ 1│ │ │ │ 1│ 2 + Picariæ │ │ │ │ │ │ + Striges │ │ │ │ │ │ + Psittaci │ 1│ │ │ │ 1│ 3 + │ │ │ │ │ │ + Accipitres │ │ │ │ │ │ + │ │ │ │ │ │ + Columbæ │ │ 1│ │ │ 1│ + Galli │ │ │ │ │ │ + Hemipodii │ │ │ │ │ │ + Fulicariæ │ │ │ │ │ │ + Alectorides │ │ │ │ │ │ + Limicolæ │ │ │ │ │ │ + Gaviæ │ │ │ │ │ │ + Impennes │ │ │ │ │ │ + Steganopodes│ │ │ │ │ │ + Herodiones │ │ │ │ │ │ + Odontoglossæ│ │ │ │ │ │ + Palamedes │ │ │ │ │ │ + Anseres │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + │ │ │ │ │ │ + Struthiones │ │ │ │ │ │ + │ │ │ │ │ │ + Crypturi │ │ │ │ │ │ + ────────────┼─────────┼────┼──────┼────┼────┼──── + Totals │ 2│ 1│ │ │ 3│ 5 + ────────────┼─────────┼────┼──────┼────┼────┼──── + Grand Totals│ 2│ 2│ 1│ │ 11│ 14 + ────────────┴─────────┴────┴──────┴────┴────┴──── + For meaning of italics see foot note Table 1. + + +INCIDENCE OF TUMORS. + +Examination of the table, (21) from the standpoint of differential +percentage reveals that mammals have 48 tumors giving an incidence of +2.58 per cent. whereas birds have 44 new growths equivalent to 1.23 per +cent. Were it not for the high figures for one single variety of bird +(Undulated Grass Parrakeet) this value for Aves would be still lower. At +all events our figures would indicate that the mammal is at least twice +as productive of neoplasms as is the bird. In our material the latter +class has had a better chance than Mammalia to show its susceptibility +since there have been nearly twice as many autopsies. + +Within the classes the comparative figures have less value because of +the smaller and varying numbers. Such high percentages as are shown by +the elephants and armadillos cannot be taken as indicators for their +orders since too few specimens were examined. Judging by orders with +more than one hundred autopsies the rodents stand at the head of the +list followed by the marsupials and carnivores. It is interesting that +the animal nearest to man, the monkey, and with greatest number of +autopsies in its zoological class, has the lowest tumor incidence. +Psittaci lead the avian orders, followed by the Fulicariæ, but as there +are but thirty-five autopsies upon these, the second place rightly +belongs to the Anseres. All the principal orders are represented but the +only one of importance is the leader. The Psittaci are very prone to +have tumors in the renal area, sometimes of the kidney, at others of the +adrenal and occasionally of the sex glands. Some remarks have already +been given to this matter in the sections devoted to the kidney and +genitalia but it will be discussed again under tumor morphology. + +Among these ninety-two animals, one bore multiple tumors, a Jaguar +(_Felis onca_) with adenomata of the liver and uterus and angiomata of +the mesentery. Careful study failed to reveal any parasitism as the +cause of the growths and since the first two were of slightly varying +structure it is not believed that one is a metastasis from the other. + +The sex incidence stands in direct relation to the proportion of total +males and females posted or in other words it is the same for the two. +The figures might be somewhat affected were the gender of all the +parrakeets available but the tumors growing in the upper renal area +frequently destroy the sex gland. + +Definite statements concerning the importance of breeding in the +causation of neoplasms cannot be made since we cannot quote figures for +the percentages of wild- and captive-born of our entire autopsy list. +The data are confused by scanty information concerning the twenty-six +parrots, the history of which is vague and I am perhaps too severe in +accrediting the birth of sixteen of them to captivity. This was done +because of a lack of exact information concerning these specimens and, +because their variety is known to breed when captive by the residents of +their habitat[94], the distribution into wild- and captive-born is based +upon what information we have. If the order Psittaci be subtracted +entirely, it leaves a total of 62 tumor-bearing animals of known +breeding, 49 of which were born in the wild, thirteen in captivity, a +fact which strengthens the thought that unnatural breeding increases the +chance of neoplasms. + +The known length of captivity has also a direct bearing on this point. +The figures given in the columns “known captivity” and “average for +tumor bearers” were compared with figures obtained by averaging the +lives of fifty others (when possible) of the same order or of at least +three times as many as bore tumors. Animals dying from injury were +excluded. With one exception the average for “tumor bearers” exceeded +that for “non-tumor bearers”; the exception, the Ungulata, had the same +average for both groups. It seems then that tumors occur in animals in +captivity longer than the average for their order, or in specimens that +have the power to live under confined conditions until neoplasms +develop. In this respect I recall the statements made by Harlow +Brooks[95] that tumors will probably be found more commonly in animals +when they live in a manner comparable to that of urban man and that +racial degeneracy will favor their development. There is adduced here +perhaps the first definite evidence that long captivity allows tumor +tendency to express itself but it does not prove that confinement +increases tumors. Nor does the expectation of life, average or +potential, stand in any direct and definite relationship to the +frequency of neoplasms. The only clear case of long life and high tumor +incidence is to be found in Parrots; we feel however that some unknown +factor increases tumors of the renal-adrenal region in these birds and +that unqualified statements about age and tumor growth are not +permissible. Since tumors grow in many wild-born specimens, a high +percentage of which become known in the first few years of captivity, is +it not highly probable that tumors are reasonably common in the wild and +that we do not observe enough purely natural specimens to assume an +immunity on the part of free living beasts. + +One of the undesirable features of captive breeding is consanguinity of +parents and there is good reason to believe that tumor susceptibility +can be bred into or out of a line of animals by mating tumor bearers and +non-tumor bearers, the tendency following the rules of Mendelian +inheritance (Slye). Is there any proof that inbreeding does not occur in +the wild and if it do, it is perfectly possible that tumor tendency may +be transmitted as a dominant character; the effect of artificial or +intentional inbreeding in captivity would only offer an opportunity for +a summation of these influences. + +If injury and animal parasitism have any importance in neoplasmata then +this opportunity certainly occurs under natural conditions. Fibiger +observed gastric tumors in rats arising under the influence of nematodes +while Slye and Wells report facial neoplasms in mice apparently arising +at points of old injuries. It seems to me that we have no right to +assume an immunity of wild animals, in their native environment, to +tumors; the incidence is another matter but it may be considerable. + +It was thought possible that there might be some light shed upon the +matter by an analysis of our sarcomatous and epitheliomatous tumors in +wild- and captive-born animals. In our second paper[96] upon this +subject I ventured the statement that sarcomatous growths occurred more +frequently in captive-born, epitheliomatous in wild-born specimens. +Greater data have not borne out this conclusion and information was +sought as to the embryonal derivation of tumor-bearing tissue. Analyzing +the cases in which all the factors could be obtained, it seems that +among seven tumors of captive-bred animals, five came from the entoderm, +two from the mesoderm, whereas in wild-bred animals, of the fifty-seven +tumors, five came from the ectoderm, thirty-two from the mesoderm and +fourteen from the entoderm. These figures do not include the parrots. +The sex values have no significance. + +It is interesting and noteworthy, that, as in the human being, the +majority of the tumors came from tissues arising in the mesoderm and +that the entodermic derivatives received the largest number of +metastases; no ectodermic tissues were sites of secondary tumors. The +visceral seats of metastases are probably of little value for comparison +in so small a number; the lung and liver however occupy the prominent +places. + +Interesting as the foregoing facts may be, they do not shed light upon +the question of breeding and degeneracy in the causation of neoplasms. +Attention is arrested however by the paucity of tumors in derivatives of +the ectoderm since in man new growths are common in the breast, at the +rectal and labial mucocutaneous junctions and on the skin. The immunity +of the ectodermic tissues to secondary growths is very distinct; this +holds true in man. + + +SPECIAL TUMORS. + +The diagnosis of fibroma offers the same difficulty in the zoological +material as it does in man and even more care must be exercised for +solid tumors in certain localities. The bird often presents hard nodular +masses on the palmar and lateral aspects of the feet, sometimes +surmounted by callosities, to which the term fibroma or fibromatous +corns might be applied. Section of some of these will reveal areas of +granulation tissue about points of inflammation so that we have +considered them as infectious or the result of incorrect perches and +excluded them from the tumors. True fibromata have been encountered +thrice but in combination with muscle tissue as a fibromyoma thrice in +addition. The “fibroids” seen in the elephants and armadillo have +already been described. + +The nodular growth sometimes accompanying degenerative disease of the +osseous system followed by attempts at repair as discussed under +osteitis deformans, leontiasis ossium and actinomycosis, are often +productive of masses to which it is easy to apply the term osteoma. If +one demand that an osteoma shall be a distinct neoplastic, localized +bony growth of unnatural or greatly exaggerated structure, then the +tumor is quite rare. We have seen one growing from the vertebræ and +clavicle of a gerbille and a fibro-osteoma on one jaw of an Isabelline +gazelle. The chondromata have been limited to one case, a unilateral +mass growing from the nasal cartilage of a caracal. + +Lipomata are localized collections of fat consisting of cells with +greater fat capacity than normally, sometimes surrounded by an +indefinite capsule. Judging by the observations of Joest and Johne they +are reasonably common in horses and cows. We have not seen a single case +in mammals but eight cases appeared in the birds. These were with one +exception disposed under the skin mostly over the abdomen and chest and +once under the scalp. In a hawk the tumor grew as a pelvic mass +surrounding the cloaca and apparently caused decided obstruction to the +lumen. The lipomata of the Psittaci usually grow as pendulous masses on +the abdominal wall covered by thin, featherless, delicate skin, often +showing dilated veins. Upon section they are rather rich in blood +supply, “angiolipoma,” but fail to show any angiomatous or solid +cellular areas under the microscope. The frequency of the growths in one +variety (Roseate cockatoo—_Cacatua roseicapilla_) led to an attempt to +transplant the tumor. The plant seemed to thrive in the recipient for a +while but soon disappeared. Breeding experiments on the tumor bearers +are now under way. + +Angiomata of lymph channels were observed in the omentum and mesentery +of a jaguar (_Felis onca_); this is the animal with three apparently +separate and distinct tumors. “The omentum is normally fatty and +slightly congested. In its meshes are myriads of tiny cysts containing +gray fluid. The main peritoneal area is negative but in the pelvic +region on anterior rectal wall, in the superior edge of the broad +ligament and in Douglas’ pouch, are cysts from a few millimetres to +several centimetres, with clear contents. The microscopic section of +omentum shows the multiple cysts as cavities of varying size, from that +of an arteriole to the diameter of a two-third lens field. They are +lined with flat, closely placed pavement cells with well stained but +vesicular nucleus. The septa are adult connective tissue. No contents or +granular eosin-staining material. No swollen cells like in adenomata. No +parasites seen.” + +Two endotheliomata have been found, one of the flat variety with warty +excrescences common on serous surfaces, located in the pleura of a +leopard (_Felis nebulosa_), and one of the nodular variety, growing from +the clavicle of a Moorhen (_Gallinula chloropus_). + +The sarcomata present their usual morphology grossly and minutely and +with the exception of the cases arising from the pectoral muscle and +from the genital area offer little of interest. Two instances in the +former location, observed in parrakeets, presented several puzzling +features. The component cells were spindle in shape, similar to a muscle +cell but were fitted with the round or elliptical nuclei of embryonal +cells. In a few places they were exceedingly large and had shadowy +outlines like a syncytium or they would be so arranged as to suggest a +glandular structure. The dominant type of cell was, however, everywhere +the spindle as it is seen in sarcoma. The sarcomata when they occur in +the genital area usually assume the alveolar arrangement and are of the +round or mixed cell variety. Only three of the sixteen sarcomata gave +metastases. + +Papillomata of minor character appear occasionally on the skin of +animals as warts, but only one instance of any greater importance has +been found. The duodenal mucosa of an owl (_Bubo virginianus_) presented +a soft growth which partly obstructed the intestinal lumen. Papillary +adenomata, on the other hand, have been observed several times, but +since they have more importance as irregular hyperplasias of glandular +origin have been included in the next group. An interesting case was +seen in a baboon (_Papio hamadryas_) in which a large part of the +gastric wall was the seat of adenomata, presenting in addition several +distinct papillary outgrowths. A similar picture was found in the +duodenum of the rhea (_Rhea americana_). + +The greatest interest in the adenomata centres around these growths in +the renal area in parrakeets, and as they have much in common with all +the glandular tumors of this region, a general discussion of this +subject may be introduced here. We have observed seven tumors +constructed on a glandular basis of renal or adrenal character. Grossly +these tumors develop as irregular masses usually of distinct brown +color, constructed on a lobular plan, delicate barely visible septa +dividing the growth. They seem devoid of large vessels, a gross +observation confirmed microscopically. There is no criterion to the +naked eye, which will distinguish the variety of epithelial hyperplasia +or permit separation of these neoplasms from some sarcomata; the latter +are usually gray but need not be so. Minutely studied, three of these +tumors proved to be adenomata, all papillary, one cystic as well. Three +had to be denominated carcinoma because of their distinct separate +crowded nests and incomplete acini. The cells comprising these growths +are comparable to the lining elements of the collecting tubules of the +renal lobule in that they have relatively large nuclei and a tendency to +basic staining protoplasm. The adenomatous picture is, however, more +comparable to the cortex than to the medulla. The remaining tumor was a +hypernephroma of the usual large cell, acinus-forming type and seemed to +originate in the adrenal. None of these tumors in the parrakeets sent +out metastases. Other hypernephromata have been diagnosed, to the number +of six. Upon review of their descriptions and sections, the +determinations are to be confirmed. However, it must be recorded here +that none of the three in mammals gave metastases, while two of the +three in birds did so. They are all of the usual type with large +vacuolated cells in glandular groups or strands. + +Three rather interesting examples of epithelioma have been observed. The +first and most important was a basocellular growth of the tongue in a +black bear (_Ursus americanus_). The local damage—ulceration and +infiltration—and swelling sufficient to interfere with deglutition, were +quite considerable. The basal cell nests had penetrated deeply into the +muscle, but extension had taken place only to a single submaxillary +gland. A squamous epithelioma was found on the skin of the thigh of a +Tasmanian devil (_Sarcophilus ursinus_). The construction was somewhat +unusual in that it was cystic but lined with squamous and keratinized +plates. It could not be decided that it originated from glands like a +trichoepithelioma; it was not like a basal cell cancer. No metastases +had occurred. The third case was that of a tumor within the abdomen of +an Amazon (_Chrysotis leucocephala_). It consisted of an illy defined +basement membrane upon which were irregular stratified squamous +epithelial cells. Upon the surface were wavy bands of horny material, +very much like dried and cast-off epithelial scales, except more compact +and extensive. These latter seemed to form the bulk of the mass. Beneath +the membrane a few irregular accumulations of cells bearing a similarity +to those on the surface could be found, but they were probably large +plasma cells. The epithelial layer dipped down like in epithelioma. No +pearls or separate nests were found. While this mass was not localized, +it was doubtless an epithelioma, and should be included in this series. +Its possible origin in the small intestine has been considered. + +The question of the occurrence of tumors in wild animals seems fairly +well settled when twenty-five examples of malignant epithelial neoplasms +can be discovered in fifty-three hundred autopsies. It is interesting to +note the incidence of these tumors in wild- and park-bred animals. +Exclusive of the parrakeets there are twenty-one cancers, seventeen in +known wild-bred, two in known park-bred specimens, and two with breeding +uncertain. The average known duration of captivity of the wild-bred +animals is about four years, while the two park-bred animals lived eight +and eighteen years. Thirteen of the twenty-one cases were males, eight +females. Adenocarcinoma was discovered twelve times, simplex nine times, +medullary and squamous each twice. Three tumors of the pancreas and +mammary gland were seen in which fibrotic or scirrhus areas were found, +but in no case was there detected that hard cicatrizing cancer so +commonly found in the human breast. All the interesting cases of +carcinoma have been recorded in the discussion of organs from which they +took origin. The only case of chorionepithelioma has been reported in +detail on page 308. The two cases of mixed tumors are as follows: Mixed +tumor of the thyroid and adenocarcinoma sarcomatodes in the liver; they +have been discussed in detail on pages 334 and 242 respectively. + +[Illustration: + + FIG. 49.—BASAL CELL CARCINOMA OF TONGUE. BLACK BEAR (URSUS + AMERICANUS). NOTE ULCERATION WHERE PIECE HAS BEEN EXCISED, AND ALSO + NODULAR THICKENING OF WHOLE BASE OF TONGUE. +] + +[Illustration: + + FIG. 50.—MICROSCOPICAL APPEARANCE OF TUMOR IN FIG. 49. +] + +Analysis of the incidence of tumors according to organs is disturbed by +the large number of cases in Psittaci. Including this order the first +place is taken by the kidney, followed by the liver, uterus, muscle, +gastrointestinal tract, bone and cartilage, thyroid, adrenal and lung in +this order. Curiously enough, if these birds be subtracted the degree of +organ susceptibility to new growths is not greatly altered. The lead is +still held by the kidney, the uterus occupying the second place and then +in sequence the liver, gastrointestinal tract, muscle, thyroid and +adrenal. Examination of the figures for mammals shows the uterus to lead +in numbers, followed by the liver, thyroid, and mammary gland. For the +birds the kidney takes the undisputed head of the column with a total of +twelve tumors (27 per cent. of all avian tumors); the next figures are +shown by the liver, gastrointestinal tract and muscle. + + ZOOLOGICAL AND PATHOLOGICAL LIST OF TUMORS + + MAMMALIA + PRIMATES (2) + Cercopithecidæ—Hamadryas Baboon (_Papio hamadryas_) + Papillary adenoma of gastric mucosa + Cebidæ—Brown Cebus (_Cebus fatuellus_) + Hypernephroma of right adrenal + + + LEMURES (1) + Lemuridæ—Ring tailed Lemur (_Lemur catta_) + Papillary adenoma of prostate + + CARNIVORA (17) + Felidæ—Clouded Leopard (_Felis nebulosa_) + Endothelioma of pleura + Caracal (_Felis caracal_) + Osteochondroma of nose + Lion (_Felis leo_) + Malignant adenoma of cervix uteri + Metastases to lung + Jaguar (_Felis onca_) + Fibroadenoma of uterus + Fibroadenoma of bile ducts + Lymphangioma of mesentery + Viverridæ—Indian Paradoxure (_Paradoxurus niger_) + Adenocarcinoma of pancreas + Malayan Civet (_Viverra tangalunga_) + Carcinoma of lung + Canidæ—Corsac Fox (_Canis corsac_) + Adenoma of pancreatic ducts + Red Fox (_Canis vulpes pennsylvanicus_) + Cystic adenoma of bile ducts + Raccoon-like Dog (_Canis procyonoides_) + Adenocarcinoma sarcomatodes of thyroid + Gray Fox (_Canis cinereo argenteus_) + Papillary cyst adenoma of bile ducts + Prairie Wolf (_Canis latrans_) + Sarcoma of thyroid region + Metastases to lungs + Prairie Wolf (_Canis latrans_) + Sarcoma of thyroid region + Procyonidæ—Common Raccoon (_Procyon lotor_) + Adenoma of pancreas + Ursidæ—Polar Bear (_Ursus maritimus_) + Adenocarcinoma of adrenals + Metastases to lungs, lymph nodes, diaphragm + Black Bear (_Ursus americanus_) + Medullary carcinoma of breast + Metastases to lungs + Black Bear (_Ursus americanus_) + Epithelioma of tongue + Phocidæ—California Hair Seal (_Zalophus californianus_) + Hypernephroma of adrenal + + + RODENTIA (12) + Sciuridæ—Beechy’s Spermophile (_Citellus grammurus beecheyi_) + Osteoma of sternum + Gray Squirrel (_Sciurus carolinensis pennsylvanicus_) + Hypernephroma of kidney + Woodchuck (_Arctomys monax_) + Adenoma simplex of liver + Muridæ—Waltzing Mouse (_Mus wagneri rotans_) + Adenocarcinoma of thigh muscles + White footed Mouse (_Peromyscus leucopus_) + Carcinoma simplex of mammary gland + White footed Mouse (_Peromyscus leucopus_) + Spindle celled sarcoma of leg + White footed Mouse (_Peromyscus leucopus_) + Carcinoma of mammary gland + Larger Egyptian Gerbille (_Gerbillus pyramidum_) + Fibrosarcoma of shoulder region + Heteromyidæ—Kangaroo Rat (_Perodipus richardsoni_) + Sarcoma of urinary bladder + Octodontidæ—Coypu Rat (_Myocastor coypus_) + Sarcoma of thyroid + Hystricidæ—Canada Porcupine (_Erethizon dorsatus_) + Chorionepithelioma uteri + Dasyproctidæ—Azara’s Agouti (_Dasyprocta azara_) + Squamous carcinoma of larynx + + PROBOSCIDEA (1) + Indian Elephant (_Elephas indicus_) + Leiomyoma, uterine cornua and fimbria + + UNGULATA (7) + Equidæ—Chapman’s Zebra (_Equus burchelli chapmani_) + Fibroma peritonei with sarcomatous and osseous + change and metastases to lung + Bovidæ—Isabelline Gazelle (_Gazella isabella_) + Osteofibroma of jaw with mucoid degeneration + Nylghaie (_Boselaphus tragocamelus_) + Fibroma uteri + Dorcas Goat (_Capra hircus_) + Lymphosarcoma of mediastinum with metastases + to liver, kidney and lymph nodes + Cervidæ—Common Deer (_Mazama virginiana_) + Fibroadenoma of bile ducts + Camelidæ—Alpaca (_Lama pacos_) + Carcinoma of liver or bile ducts with extension + to intestine + Suidæ—Wild Boar (_Sus scrofa_) + Carcinoma uteri + + + EDENTATA (1) + Dasypodidæ—Nine banded Armadillo (_Tatu novemcinctus_) + Fibroma uteri + + MARSUPIALIA (7) + Didelphyidæ—Common Opossum (_Didelphys virginiana_) + Adenoma of kidney + Common Opossum (_Didelphys virginiana_) + Adenocarcinoma of mammary gland + Dasyuridæ—Spotted tailed Dasyure (_Dasyurus maculatus_) + Adenocarcinoma of intestines with metastases to + lymphatics, liver, spleen, lungs + Tasmanian Devil (_Sarcophilus ursinus_) + Cystic epithelioma of skin of thigh + Peramelidæ—Rabbit eared Bandicoot (_Thylacomys lagotis_) + Carcinoma of lung + Macropodidæ—Red Kangaroo (_Macropus rufus_) + Malignant papilloma of stomach + Metastases to liver, spleen, kidney + Red Kangaroo (_Macropus rufus_) + Carcinoma of lung + Metastases to spleen and gastric wall + + + AVES + + PASSERES (7) + Turdidæ—American Robin (_Planesticus migratorius_) + Hypernephroma of kidney, metastases to intestine + Crateropodidæ—Jungle Babbler (_Crateropus canorus_) + Adenoma of kidney + Tanagridæ—Palm Tanager (_Tanagra palmarum_) + Lipoma of abdominal wall + Fringillidæ—Saffron Finch (_Sycalis flaveola_) + Adenocarcinoma of kidney + Chestnut-eared Finch (_Amadina castanotis_) + Adenocarcinoma of kidney with metastases to lung + Chestnut headed Bunting (_Emberiza luteola_) + Lipoma of scalp + Icteridæ—European Blackbird (_Merula merula_) + Hypernephroma of kidney region with metastases to liver + + STRIGES (1) + Bubonidæ—Great Horned Owl (_Bubo virginianus_) + Papilloma of duodenum + + PSITTACI (26) + Loriidæ—Musky Lorrikeet (_Glossopsittacus concinnus_) + Carcinoma of lung + + + Cacatuidæ—Roseate Cockatoo (_Cacatua roseicapilla_) + Lipoma of abdominal wall + Roseate Cockatoo (_Cacatus roseicapilla_) + Multiple lipomata of abdominal wall + Psittacidæ—Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Glioma of brain with metastases to liver + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Hypernephroma of adrenal + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Papillary adenoma of kidney + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Cystic papillary adenocarcinoma of kidney + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Adenocarcinoma sarcomatodes of liver + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Papillary cyst adenoma of kidney + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Adenoma of kidney + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Adenoma of kidney + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Adenocarcinoma of oviduct + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Carcinoma simplex of liver with metastases to + liver, spleen + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Carcinoma simplex of liver + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Multiple lipomata + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Multiple lipomata + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Sarcoma of pectoral muscle with metastases to liver + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Round cell sarcoma in region of liver, spleen, kidney + Undulated Grass Parrakeet (_Melopsittacus undulatus_) + Carcinoma simplex of thyroid + Blue fronted Amazon (_Chrysotis æstiva_) + Adenocarcinoma (?) of proventricle + White fronted Amazon (_Chrysotis leucocephala_) + Epithelioma in peritoneum (?) + All Green Parrakeet (_Brotogerys tirica_) + Sarcoma of pectoral muscle + Red shouldered Parrakeet (_Palæornis eupatrius_) + Sarcoma of testes + Red shouldered Parrakeet (_Palæornis eupatrius_) + Sarcoma of testes + + King Parrakeet (_Apromictus cyanopygius_) + Sarcoma of ovary + Crested Ground Parrakeet (_Calopsitta novæ-hollandiæ_) + Lipoma of muscle of abdomen and chest walls + + ACCIPITRES (2) + Falconidæ—Red shouldered Buzzard (_Buteo lineatus_) + Retroperitoneal sarcoma + Sparrow Hawk (_Sparverius sparverius_) + Lipoma around cloaca + + COLUMBÆ (1) + Columbidæ—Scaly Ground Dove (_Scardapella squamosa_) + Sarcoma (spindle) of kidney with metastases to tibia + + GALLI (1) + Phasianidæ—Wild Turkey (_Meleagris gallopavo_) + Papillary adenocarcinoma of ovary + + FULICARIÆ (1) + Rallidæ—Moorhen (_Gallinula chloropus_) + Endothelioma of clavicle + + ANSERES (4) + Anatidæ—Red headed Duck (_Fuligula ferina americana_) + Papillary adenoma of kidney + Black Duck (_Anas obscura_) + Hypernephroma of adrenal + Lesser Snow Goose (_Chen h. hyperboreus_) + Fibroma on clavicle + Bean Goose (_Anser fabalis_) + Myxosarcoma of pectoral muscle + + STRUTHIONES (1) + Rheidæ—Common Rhea (_Rhea americana_) + Cystic papillary adenoma of duodenum + + + + + SECTION XVII + THE COMMUNICABLE DISEASES—PART I + + +TUBERCULOSIS. + +Nearly all infectious diseases have either a limited natural zoological +distribution or are encountered chiefly in one order or division. Thus +typhoid fever is peculiar to man, hog cholera to swine, foot-and-mouth +disease to cows. A second group, including for example anthrax, variola, +hemorrhagic septicemia and malignant edema, is somewhat less specific, +and may occur in several varieties. There is no more widespread, +important infection, zoologically, economically and hygienically, than +tuberculosis, and it would seem that all kinds of vertebrates are +subject to it. Its manifestations too, are sufficiently similar to +support the idea that there must have been originally a common ancestor +of the viruses which we now designate separately by a term to indicate +their immediate source (human, avian, etc.), and moreover it has been +shown that any of the artificially separated varieties or subspecies may +under certain circumstances infect all zoological families. + +There is, however, a varying resistance to the tubercle bacillus, +certain zoological groups standing out preëminently as more or less +susceptible to it. There is also a tendency for each animal group to +present features more or less peculiar to itself, but nevertheless the +characteristics, both gross and minute, of the disease caused by the +_Bacillus tuberculosis_ are sufficiently similar to permit close analogy +and to establish a diagnosis when the bacteria are found. + +The data collected at this Garden are well suited to elucidate the +susceptibility of wild animals under captive conditions and to +illustrate the nature of lesions in them. Perhaps they do not offer a +perfect cross section of zoological distribution of tuberculosis because +of the predominance in the display of birds, of monkeys and of +ungulates, but the figures will be found significant in certain +respects. Such records cannot be compared with those obtained for +domesticated animals in farms or breeding places, nor can our material +be used to show the incidence for individual species, such as cows, dogs +and the like, in a manner commonly used in veterinary literature. Those +who are interested in this phase of the problem can find in Lubarsch- +Ostertag’s _Ergebnisse_, 1917–18, No. 2, a summary by Eber of all recent +literature, covering nearly 1,700 references, which really amounts to a +review of all modern knowledge of tuberculosis in the lower animals. The +article does not, however, attempt to compare or contrast the incidence +per order or family in wild varieties since little information is +available on these points. There are no reliable data concerning the +existence of tuberculosis in the wild. It is noted in the report of the +British Tuberculosis Commission that monkeys were received with this +disease; Eber mentions that wild swine from a private preserve presented +undoubted evidence of tuberculosis and another similar experience with +pheasants, but these and other citations can give no proper estimate of +exact conditions nor allow a decision that the infection exists at all +under natural environment for in all cases the association with human +beings or domesticated animals cannot be excluded. Tuberculosis is +usually described as a disease of civilization and its incidence surely +varies directly with crowding. + + +THE TABLE. + +Description of Table 23. The study of our autopsy records was begun by +the preparation of the accompanying table, which is based first upon the +zoological classification per order with subdivisions for families where +there are sufficient examples within important orders, and second, upon +percentage of total cases. For the analysis of the pathological types, +headings of probable origin, gross anatomical lesions and visceral +distribution were then made. The first vertical column shows the total +autopsies per order, and where families are given, for each of them. In +three instances Primates, Ungulata and Galli, not all families are +represented, so that the total for the order is greater than that for +the subdivisions quoted. It is noteworthy that we have had no +tuberculosis among nine families of ungulates; this will be discussed +later. The second column gives the total cases of tuberculosis for the +order and family, respectively, followed by a third line of percentages. +For the analysis of the pathology in these animals all the protocols +were reviewed. Forty-eight of them being found unsuitable, deductions +were made according to the natural group, thereby leaving the number +shown in the fifth column for separation according to origin and type. +Analyses in the succeeding columns are made upon number of cases and not +upon percentages, because of the confusion arising from small decimals. +The actual relationships will be pointed out in the notes. Percentage is +not so necessary because comparisons and contrasts are usually made with +classes or orders where the figures are comparable. + + TABLE 23. + _Analytical Table Showing Incidence of Tuberculosis per Order and for + Some of the Principal Families, to Which are Added Columns Showing + Probable Origin of Infection, Pathological Type of the Disease and the + Visceral Distribution of the Morbid Process._ + + ════════════════════╤═════════╤════════════╤══════════╤════════════ + Order Family │ No. of │ Cases of │Percentage│ Cases not + │autopsies│Tuberculosis│ │sufficiently + │for order│ │ │ described + │or family│ │ │for analysis + ────────────────────┼─────────┼────────────┼──────────┼──────────── + „ „ │ „ │ „ │ „ │ „ + │ │ │ │ + │ │ │ │ + │ │ │ │ + ────────────────────┼─────────┼────────────┼──────────┼──────────── + Primates │ 498│ 192│ 38.5│ 8 + Simiadæ │ 7│ 3│ 43.│ 0 + Cercopithecidæ│ 353│ 171│ 48.4│ 8 + Cebidæ │ 106│ 18│ 16.9│ 0 + Lemures, Lemuridæ │ 86│ 23│ 26.7│ 3 + Carnivora │ 481│ 17│ 3.5│ 4 + Rodentia │ 199│ 5│ 2.5│ 0 + Ungulata │ 365│ 35│ 9.6│ 2 + Equidæ │ 11│ 1│ 9.│ 0 + Bovidæ │ 123│ 12│ 9.7│ 1 + Cervidæ │ 171│ 19│ 11.1│ 1 + Camelidæ │ 25│ 3│ 12.│ 0 + Proboscidea │ 3│ 2│ 66.│ 0 + ────────────────────┼─────────┼────────────┼──────────┼──────────── + Totals for Mammalia │ [97]1860│ [97]274│ [97]14.7│ 17 + Passeres │ 1355│ 18│ 1.3│ 6 + Picariæ │ 87│ 11│ 13.│ 0 + Psittaci │ 698│ 38│ 5.4│ 3 + Loriidæ │ 24│ 3│ 12.5│ 0 + Cacatuidæ │ 80│ 7│ 8.7│ 1 + Psittacidæ │ 585│ 28│ 4.8│ 2 + Striges │ 133│ 6│ 4.5│ 3 + Accipitres │ 196│ 11│ 5.6│ 1 + Columbæ, Columbidæ │ 157│ 50│ 32.│ 5 + Galli │ 299│ 42│ 14.│ 5 + Phasianidæ │ 252│ 22│ 8.3│ 3 + Cracidæ │ 38│ 17│ 44.│ 1 + Megapodidæ │ 5│ 3│ 60.│ 1 + Fulicariæ │ 35│ 9│ _27._│ 0 + Hemipodii │ 2│ 1│ _50._│ 0 + Alectorides │ 37│ 10│ _27._│ 2 + Odontoglossæ │ 6│ 2│ _33._│ 1 + Anseres │ 317│ 16│ 5.│ 5 + Struthiones │ 32│ 3│ _9.4_│ 0 + Crypturi │ 5│ 2│ _40._│ 0 + ────────────────────┼─────────┼────────────┼──────────┼──────────── + Totals for Aves │ [97]3505│ [97]219│ [97]6.2│ 31 + ────────────────────┼─────────┼────────────┼──────────┼──────────── + Grand Totals │ [98]5365│ [98]493│ [98]9.1│ 48 + ────────────────────┴─────────┴────────────┴──────────┴──────────── + + ════════════════════╤════════╤══════════════════════╤═══════════════ + Order Family │Net no. │ Probable origin │Pathological Type + │of cases│ │ + │ in │ │ + │analysis│ │ + ────────────────────┼────────┼──────────┬───────────┼───────┬─────── + „ „ │ „ │Pulmonary-│Intestinal-│ Acute │Massive + │ │aerogenic │ lymphatic │Miliary│caseous + │ │ │ │ │ + │ │ │ │ │ + ────────────────────┼────────┼──────────┼───────────┼───────┼─────── + Primates │ 184│ 86│ 98│ 3│ 52 + Simiadæ │ 3│ 3│ │ │ 2 + Cercopithecidæ│ 163│ 76│ 87│ 2│ 46 + Cebidæ │ 18│ 7│ 11│ 1│ 3 + Lemures, Lemuridæ │ 20│ 6│ 14│ │ 5 + Carnivora │ 13│ 6│ 7│ │ 1 + Rodentia │ 5│ 3│ 2│ │ 3 + Ungulata │ 33│ 27│ 6│ │ 6 + Equidæ │ 1│ │ 1│ │ 1 + Bovidæ │ 11│ 10│ 1│ │ 1 + Cervidæ │ 18│ 14│ 4│ │ 4 + Camelidæ │ 3│ 3│ │ │ + Proboscidea │ 2│ 2│ │ │ + ────────────────────┼────────┼──────────┼───────────┼───────┼─────── + Totals for Mammalia │ 257│ 130│ 127│ 3│ 67 + Passeres │ 12│ 9│ 3│ │ 5 + Picariæ │ 11│ 1│ 10│ │ 2 + Psittaci │ 35│ 13│ 22│ 1│ 9 + Loriidæ │ 3│ 1│ 2│ │ 1 + Cacatuidæ │ 6│ 4│ 2│ │ 1 + Psittacidæ │ 26│ 8│ 18│ 1│ 7 + Striges │ 3│ 3│ │ │ 1 + Accipitres │ 10│ 5│ 5│ │ 2 + Columbæ, Columbidæ │ 45│ 10│ 35│ │ 12 + Galli │ 37│ 10│ 27│ │ 12 + Phasianidæ │ 19│ 2│ 17│ │ 4 + Cracidæ │ 16│ 7│ 9│ │ 7 + Megapodidæ │ 2│ 1│ 1│ │ 1 + Fulicariæ │ 9│ 1│ 8│ │ 1 + Hemipodii │ 1│ 1│ │ │ 1 + Alectorides │ 8│ │ 8│ │ 2 + Odontoglossæ │ 1│ │ 1│ │ + Anseres │ 11│ 2│ 9│ │ 4 + Struthiones │ 3│ 3│ │ │ + Crypturi │ 2│ │ 2│ │ + ────────────────────┼────────┼──────────┼───────────┼───────┼─────── + Totals for Aves │ [99]188│ 58│ 130│ 1│ 51 + ────────────────────┼────────┼──────────┼───────────┼───────┼─────── + Grand Totals │ [99]445│ 188│ 257│ 4│ 118 + ────────────────────┴────────┴──────────┴───────────┴───────┴─────── + + ════════════════════╤════════════════════════╤════════════════════════ + Order Family │ Pathological Type │ Visceral Distribution + │ │ + │ │ + │ │ + ────────────────────┼───────┬──────────┬─────┼─────┬─────┬──────┬───── + „ „ │Nodular│ Chronic │Pearl│Lungs│Liver│Spleen│Lymph + │caseous│ fibrous │type │ │ │ │nodes + │ │ and │ │ │ │ │ + │ │ulcerative│ │ │ │ │ + ────────────────────┼───────┼──────────┼─────┼─────┼─────┼──────┼───── + Primates │ 108│ 16│ 5│ 173│ 122│ 149│ 145 + Simiadæ │ │ │ │ 3│ 2│ 3│ 3 + Cercopithecidæ│ 96│ 16│ 3│ 156│ 111│ 136│ 128 + Cebidæ │ 12│ │ 2│ 14│ 9│ 10│ 14 + Lemures, Lemuridæ │ 15│ │ │ 17│ 14│ 17│ 12 + Carnivora │ 8│ 4│ │ 11│ 4│ 2│ 6 + Rodentia │ 2│ │ │ 4│ 2│ 2│ 4 + Ungulata │ 1│ 24│ 2│ 28│ 7│ 3│ 25 + Equidæ │ │ │ │ │ │ │ 1 + Bovidæ │ 1│ 9│ │ 9│ 4│ 2│ 7 + Cervidæ │ │ 13│ 1│ 17│ 2│ │ 14 + Camelidæ │ │ 2│ 1│ 2│ 1│ 1│ 3 + Proboscidea │ │ 2│ │ 2│ │ │ + ────────────────────┼───────┼──────────┼─────┼─────┼─────┼──────┼───── + Totals for Mammalia │ 134│ 46│ 7│ 235│ 149│ 173│ 192 + Passeres │ 7│ │ │ 9│ 5│ 5│ + Picariæ │ 8│ │ 1│ 2│ 9│ 6│ 1 + Psittaci │ 25│ │ │ 18│ 24│ 14│ 2 + Loriidæ │ 2│ │ │ 3│ 3│ 1│ + Cacatuidæ │ 5│ │ │ 5│ 5│ 2│ + Psittacidæ │ 18│ │ │ 10│ 16│ 11│ 2 + Striges │ 2│ │ │ 3│ 3│ 2│ + Accipitres │ 7│ 1│ │ 8│ 6│ 8│ 1 + Columbæ, Columbidæ │ 33│ │ │ 24│ 40│ 34│ 1 + Galli │ 24│ 1│ │ 20│ 34│ 29│ 2 + Phasianidæ │ 15│ │ │ 7│ 18│ 15│ 1 + Cracidæ │ 8│ 1│ │ 12│ 15│ 13│ + Megapodidæ │ 1│ │ │ 1│ 1│ 1│ 1 + Fulicariæ │ 8│ │ │ 4│ 8│ 8│ 1 + Hemipodii │ │ │ │ 1│ 1│ 1│ + Alectorides │ 6│ │ │ 4│ 8│ 7│ 2 + Odontoglossæ │ 1│ │ │ │ 1│ 1│ + Anseres │ 5│ 2│ │ 4│ 7│ 8│ 1 + Struthiones │ │ 3│ │ 3│ 2│ 3│ 2 + Crypturi │ 2│ │ │ 1│ 2│ 2│ + ────────────────────┼───────┼──────────┼─────┼─────┼─────┼──────┼───── + Totals for Aves │ 128│ 7│ 1│ 101│ 151│ 128│ 13 + ────────────────────┼───────┼──────────┼─────┼─────┼─────┼──────┼───── + Grand Totals │ 262│ 53│ 8│ 336│ 300│ 301│ 205 + ────────────────────┴───────┴──────────┴─────┴─────┴─────┴──────┴───── + + ════════════════════╤══════════════════════════════════════════════════════ + Order Family │ Visceral Distribution + │ + │ + │ + ────────────────────┼─────────┬──────┬─────────┬──────┬─────┬─────┬──────── + „ „ │Intestine│Kidney│ Serous │Bones │Brain│Heart│Pancreas + │ │ │membranes│ and │ │ │ + │ │ │ │joints│ │ │ + │ │ │ │ │ │ │ + ────────────────────┼─────────┼──────┼─────────┼──────┼─────┼─────┼──────── + Primates │ 30│ 84│ 70│ 2│ 2│ 7│ 3 + Simiadæ │ 2│ 1│ 1│ │ │ │ + Cercopithecidæ│ 24│ 76│ 63│ 2│ 2│ 7│ 2 + Cebidæ │ 4│ 7│ 6│ │ │ │ 1 + Lemures, Lemuridæ │ 2│ 7│ 1│ │ │ │ 1 + Carnivora │ 1│ 4│ 3│ 1│ │ │ + Rodentia │ 1│ 2│ 2│ 1│ │ │ + Ungulata │ 1│ 2│ 7│ │ │ │ + Equidæ │ │ │ │ │ │ │ + Bovidæ │ 1│ 1│ 1│ │ │ │ + Cervidæ │ │ │ 5│ │ │ │ + Camelidæ │ │ 1│ 1│ │ │ │ + Proboscidea │ │ │ │ │ │ │ + ────────────────────┼─────────┼──────┼─────────┼──────┼─────┼─────┼──────── + Totals for Mammalia │ 35│ 99│ 83│ 4│ 2│ 7│ 4 + Passeres │ 4│ │ 4│ │ │ │ + Picariæ │ 4│ 1│ 3│ 1│ │ │ + Psittaci │ 12│ 6│ 6│ │ │ 1│ + Loriidæ │ 1│ 1│ 1│ │ │ │ + Cacatuidæ │ │ 1│ 1│ │ │ 1│ + Psittacidæ │ 11│ 4│ 4│ │ │ │ + Striges │ │ │ 3│ │ │ │ + Accipitres │ 4│ 3│ 6│ │ │ 2│ + Columbæ, Columbidæ │ 16│ 13│ 20│ │ │ 1│ + Galli │ 20│ 7│ 15│ │ │ │ 1 + Phasianidæ │ 10│ 2│ 6│ │ │ │ 1 + Cracidæ │ 10│ 5│ 7│ │ │ │ + Megapodidæ │ │ │ 2│ │ │ │ + Fulicariæ │ 3│ 3│ 4│ │ │ │ + Hemipodii │ 1│ 1│ 1│ │ │ │ + Alectorides │ 3│ 3│ 7│ │ │ │ + Odontoglossæ │ 1│ │ │ │ │ │ + Anseres │ 3│ 4│ 4│ │ │ │ + Struthiones │ │ 1│ 1│ │ │ │ + Crypturi │ 2│ 1│ │ │ │ │ + ────────────────────┼─────────┼──────┼─────────┼──────┼─────┼─────┼──────── + Totals for Aves │ 73│ 43│ 74│ 1│ 0│ 4│ 1 + ────────────────────┼─────────┼──────┼─────────┼──────┼─────┼─────┼──────── + Grand Totals │ 108│ 142│ 157│ 5│ 2│ 11│ 4 + ────────────────────┴─────────┴──────┴─────────┴──────┴─────┴─────┴──────── + See page 484, for description of tabulation. + For meaning of italics see foot note Table 1. + These and figures set opposite them are cases not percentages. + +It is generally conceded that the principal and only significant routes +of origin for tuberculosis are via the respiratory and alimentary +tracts. The criteria upon which to decide the route that has been +followed are by no means definite and may not be for any given case +unexceptionable. In birds the alimentary tract is conceded to be the +important one, while in mammals an aerogenic route is believed to be the +rule. However, since feeding experiments have shown that tubercle +bacilli can gain the lungs by passing through the intestinal wall and +abdominal lymphatics without leaving gross traces, the decision that one +or the other route has been taken may be erroneous, and statistics +therefore can often be fallacious. It is usually the rule to assume that +the oldest or best developed lesions occur where the originally settled +organisms exerted their maximum effect. The questions of infection-path +and of original lesion not having been settled it is obvious that +decision as to the route must be in the nature of an estimate. With +these limitations in mind I have divided the cases into probable +respiratory and alimentary origins according to the following criteria. +Where the lesions were wholly respiratory or within the lymph glands of +the trachea and bronchi the decision was not so difficult. Predominance +of the pulmonary disease with recent lesions in other organs was taken +to indicate an aerogenic origin. The chronic ulcerative or fibrous +pulmonary lesions were also ascribed to those beginning in the lungs. +The alimentary tract was considered for this purpose as beginning in the +tonsillar area and ending at the anus. This is as I understand the +customary teaching. When the lymph nodes of the alimentary area were +advanced in the process, the intestinal method was held responsible. It +is of course not to be forgotten that organisms coughed up from the +lungs and swallowed may be responsible for lesions within the alimentary +system. However, a predominance of intestinal, splenic, hepatic and +lymphatic lesions caused me to place the case with those originating +from the alimentary tract. Granting the limitations of our knowledge, of +the criteria and of my own judgment, it is noteworthy that the results +of this division of the table are not contradictory to the usual +teaching, the most conspicuous being the predominance of the alimentary +infection of Aves and in the order Primates, whereas the pulmonary route +has the highest figures for the Ungulata. + +The next subdivision of the table concerns the gross pathological type. +Beginning with the most acute form, the acute miliary, progression is +made in terms of chronicity—then following in order the massive caseous +form including caseous pneumonia, the caseous miliary or nodular form so +well represented by the monkey, then the fibroulcerative type such as +one encounters in human consumption, including also forms in which +fibrosis predominates, and lastly the rather uncommon pearl disease. +This classification has been relatively easy to follow and can be +readily imagined by the reader. There are of course intermediate cases +or transition forms and there have been instances partaking of more than +one character. The groupings present only gross appearances and, with +few exceptions, are not to be taken as direct indications of type +incidence in special groups. + +Visceral distribution is shown in the last gross section of the table; +single cases or unusual locations are not tabulated but will be +separately discussed. The visceral distribution is made upon evident +gross lesions or their discovery in organs whose condition suggested the +need of microscopic study for confirmation. The figures in the table +will be reviewed first upon the incidence as a whole and then between +classes and orders. This will be succeeded by an analysis of the +particulars for each order and then for each of the pathological +headings. + + +TOTAL AND CLASS INCIDENCE. + +The autopsies upon 5,365 animals have revealed the existence of +tuberculosis in 492, a percentage of 9.1. This means that lesions due to +the _Bacillus tuberculosis_ were present, but they were not always the +cause of death, since many specimens have been executed and others have +had sufficient pathology to kill, aside from the tuberculous changes. +Deaths due to the disease alone are difficult to estimate, but seem to +be about 325 or 6 per cent. These figures, while they represent the +total incidence, lose considerably in significance when the factors are +analyzed. Mammalian incidence is 14.7 per cent., Avian 6.2 per cent., +but the former is based upon figures obtained from six of twelve orders +numbering 1,860 animals, whereas the latter represent the cases in +fourteen of twenty orders numbering 3,505 birds. The percentages are +considerably increased by high figures for a few orders, Primates, +Lemures, Columbæ for examples. There are missing from the list very few +orders of which we have any notable number of autopsies, Marsupialia and +Herodiones being the only important ones; it would seem that these +orders have a high resistance to the disease. + +Investigation into the origin of the disease in mammals and birds shows +with definiteness the preponderance of the alimentary route influence in +the latter, but for the former the figures cannot be said to be +conclusive. The bird excretes large numbers of bacilli with the feces +thereby soiling the feed and the ground. This is due to the frequency of +intestinal open lesions and to the really enormous numbers of bacilli +which are in the morbid tissue. I think it can be said with safety that, +other things being equal, the bird excretes bacilli constantly and in +greater numbers than does the mammal, and that in physically comparable +lesions there are more bacilli in the avian than in the mammalian. + +The inconclusive figures for the origin of the disease in the mammal can +be clarified very little by the subtraction from the tables of the +figures for the very susceptible Primates. By doing this it would seem +that the respiratory route dominates as 43 to 29, whereas if the +reasonably susceptible Lemures be also deducted the ratio becomes as 38 +to 15. It would seem that the evidence favors the aerogenic route in the +mammal. + + +PATHOLOGICAL TYPES. + +An inquiry into the gross pathological types reveals at once the +frequency with which the nodular and massive caseous forms appear. If +the number of cases be reduced to percentage it will be found that 59 +per cent. of all specimens presented the nodular variety and 26.6 per +cent. the massive caseous form. These large figures (equaling when +combined 85 per cent.) coupled with the fact that only 12 per cent. of +the total were fibroulcerative and 1.8 per cent. of the pearl type, +would seem to indicate that the nodular and massive caseous processes +are the lesions to be expected in wild animals. Furthermore, if these +nodular and caseous forms speak for recent infection or acuteness of the +morbid process, it would seem that wild animals have a low tissue +resistance to tuberculosis. It is a widespread belief, in some degree +well supported, that a disease new to an animal species is highly fatal +and that the survival of the race depends upon an active self- +immunization or the survival of the pathologically least susceptible. If +tuberculosis be a disease of civilization, these figures would suggest +that it is absent in nature. As a further support of this idea it can be +said that with the exception of two cases in ungulates, no fibroid +tuberculosis, approaching the quiescent type as seen in man and rarely +in domestic animals, was encountered. Very rarely calcareous deposits +will be found in both simian and ungulate lesions but these need not +indicate a tendency to general healing although at that place the +process may be inactive. The bird uses considerable fibrous tissue in +the construction of its tuberculous mass but fibrosis never masters the +situation with the formation of scar tissue sufficient to wall off the +process. Pearl disease, a fibrocaseous condition, is not a healing +fibroid procedure and is, in our material, of no numerical significance. + + +VISCERAL DISTRIBUTION. + +The distribution of the morbid lesions in the viscera presents some +interesting features. In the first place the data leave no doubt that +the most susceptible tissue in the wild animal body is, as in the case +of human and domestic animals, the lung. The susceptibility of this +organ in the two classes is however a different matter since in the +mammal 91.4 per cent. show pulmonary lesions while only 53.7 per cent. +of birds are so affected. Part of the reason for this appears in the +figures for the principal abdominal organs, of which the liver and +spleen occupy the prominent places. The mammalian livers show 58.2 per +cent., the avian 80.3 per cent.; 67.5 per cent. of mammalian spleens, +68.0 per cent. of avian spleens have tuberculous lesions. The figure for +the mammalian spleen is distorted because of the peculiar susceptibility +of this organ in the monkey, it being conspicuously free of lesions in +most mammalian orders. The intestines presented discernible lesions in +practically 40 per cent. of birds but only in 13.5 per cent. of mammals. +Renal involvement was found in 38.4 per cent. of mammals and 22.9 per +cent. of birds. + +A study of the changes in the serous surfaces is complicated by the +difference of anatomy in the two classes. The mammal has separate closed +serous sacs well guarded against invasion from mucous surfaces whereas +in the bird the air sacs and serous cavities are closely related, the +latter being loosely applied to viscera they are intended to cover. +Moreover in Aves direct infection of the air sacs seems a definite +possibility. Notwithstanding the fact that the bird’s sacs and serous +surfaces appear so open to infection there is no great preponderance of +lesions within them—Aves 39.3 per cent. Mammalia 32 per cent. The lymph +nodes were tabulated as a tissue rather than according to location, the +latter method being found profitable for discussion in a few orders +only. As might be expected the abundant lymph nodes of the mammal were +affected out of all proportion to those in the bird. These matters will +be discussed later. The remaining figures on the table have no +comparative value. + + +ORDINATE CHARACTERISTICS. + +The Primates as an order have shown low resistance to tuberculosis, a +fact well known to general observation. How much this is due to the +unsanitary surroundings to which these naturally free active beasts are +subjected, in catching, transporting and storing for sale, must at +present remain conjectural, but they are probably infected with ease as +our experience in this laboratory suggests. Desiring a tuberculous +monkey for certain tuberculin tests, I injected one hundredth of a +milligram of a human culture, known to produce definite lesions in +rabbits; the animal died in three months with advanced general +tuberculosis. The unexpected and interesting feature of our figures is +the susceptibility of different families within the order. The Old World +monkeys, Simiadæ and Cercopithecidæ have a combined incidence two and +one-half times as great as the New World Cebidæ, and the marmosets had +no tuberculosis at all in the thirty-two specimens. Possibly this is a +matter of transportation and handling, which reduces the resistance and +offers chance to infect apes and baboons. The New World capucin monkeys +have their exposure too since many of them are household pets before the +Garden receives them. Their usual life in captivity is however shorter +than that of Old World varieties, they therefore being exposed to +infection for a shorter time. It would seem however that American +Primates are more resistant to the disease than African and +Australasian. + +The form of tuberculosis to which this order is liable is well described +in text-books, it being so characteristic that the term “monkey +tuberculosis” is used to distinguish it. The purpose of the term is to +compare the lesions with certain cases of generalized tuberculosis in +children. It is characterized by a nodular involvement of the liver and +of the spleen particularly, sometimes also of the lungs but in fatal +cases the last organ is commonly the seat of massive caseation or +caseous pneumonia. The prominence of the pulmonary lesions often makes a +decision of origin difficult since important changes may be found in the +liver and abdominal nodes. Blair at New York, and Rabinowitsch at Berlin +are of the impression that many cases of monkey tuberculosis start by +pharyngeal and tonsillar infection because they found cervical adenitis +so commonly. Our records and specimens would support this idea in only +fourteen instances and I am of the impression that the lower intestinal +route is more often responsible, even to a higher figure than is +recorded in the table. This view is based upon the frequent occurrence +of enlarged glands in the mesentery, retroperitoneum and posterior +mediastinum, in the latter location being quite as prominent if not more +so than in the bronchial and tracheal area. Occasionally deposits of +calcareous matter will be found in old caseous glands but in such +animals there has always been some other spot of activity of +tuberculosis. The frequency with which the liver and spleen are affected +gives opportunity for hematogenic spread, a method of no small +importance in the opinion of Eber. The chronic ulcerative form is quite +well displayed in monkeys, interestingly enough to cite an illustrative +case at the end of this division of the discussion. Five cases of +distinct chronic cavitation were encountered; several small recent +cavities were found in the massive caseous pneumonic cases. The two +acute miliary cases and one of the pearl type will be discussed briefly +on a later page. + +Despite the prominence of the liver, spleen and lymph nodes, the lungs +stand ahead of all others by a safe margin of visceral incidence. The +spleen stands in the third place in this order and in the next, Lemures, +but in no other mammalian group does this organ occupy so prominent a +position. The susceptibility of lymphatic tissue in the monkey is +further illustrated by the large number of cases showing lesions in +lymph nodes. It is rather striking however that our material showed very +few active ulcerations in the lymphoid plaques of the intestinal wall +nor indeed do the intestines present a large numerical involvement. +Serous membrane tuberculosis is chiefly that of the pleura, upon which +early precaseous tubercles are frequently found, usually in conjunction +with pulmonary disease. Tuberculous peritonitis of the plastic and +nodular variety occurred only six times, though light adhesions to +nodules in the liver and spleen were quite common. Pericarditis was +found five times, in three of which there was myocardial disease; which +of the two was primary was not indicated in the notes but from present +reading it would seem that the heart muscle was involved first. + +The next order, Lemures, has a susceptibility of about half that of the +monkeys judging by the percentage incidence. Analytically the members of +this group react quite like the preceding order in having the same types +of origin, pathology and organic distribution. Since they are so close +zoologically, present similar lesions and are tested in the same manner +as the monkeys, we group them together and shall proceed to discuss +special cases of interest in both orders. + +Special Cases in Primates and Lemures. Acute general miliary +tuberculosis occurred thrice in Old World and once in New World monkeys. +The first case took its origin in a caseous gland in the bronchotracheal +area, the lung showing a minor degree of involvement with milia but no +older process. The second took its origin in the mesenteric area and the +organs of this section of the body were most affected. The only case in +the Cebidæ seemed to be of intestinal origin since an acute plastic +peritonitis with fluid exudate accompanied the generally miliary +disease. + +Pearl disease of the bovine type has been encountered on four occasions +but it cannot be said to have developed to the state of perfection seen +in the cow. There is lacking the masses of nodules growing together in a +fungoid character usually seen on the pleura and peritoneum. The monkey +form is in isolated nodules of gray-yellow color which may show caseous +centres. The visceral lesions are in firm separate areas not tending to +soften or coalesce. Two of these monkeys died from recent pulmonary +exacerbations. From one of the cases a bovine bacillus, judging from +culture and rabbit virulence, was isolated. + +As a good example of monkey tuberculosis, illustrating at the same time +a chronic ulcerative pneumonitis with cavitation, the following case is +cited: + + + Green Monkey (_Cercopithecus callitrichus_) ♀ . Was coughing and + drooping for two days before death. Chronic ulcerative tuberculosis of + lungs with cavity formation; early conglomerate tuberculosis of liver; + conglomerate caseous tuberculosis of spleen; early conglomerate + tuberculosis of ileum (Peyer’s patches); acute catarrhal enteritis; + miliary tuberculosis of right kidney. The animal is well preserved, + sleek, with a moderate amount of fat. The left pleura is largely + obliterated by adhesions in the lower portion. As lung is freed it is + torn, showing a cavity measuring 3 × 3 × 4 cm., which is filled with a + curdy gray material. Cavity has well defined walls. Rest of lower lobe + in which this cavity lies is solidified, red and edematous and + contains numerous conglomerate tubercles. Upper lobe practically free + of tubercles; shows compensatory emphysema. The right lung closely + resembles the left but lacks the cavity. The liver is enlarged, soft + and friable, of red color, spotted yellow. Serous and section surfaces + show closely packed early conglomerate tubercles. The spleen is of + normal size, soft, has red pulp with large conglomerate tubercles + which project slightly on the capsule. The kidneys are apparently + normal except for the presence of two or three subcapsular large, + solitary tubercles in the right organ. The duodenum has thickened + walls, mucosa bright, brilliant scarlet hue. In the ileum the walls + are thickened, mucosa bright red, agminated follicles hyperplastic + elevated and display several (4–12) miliary tubercles. These may be + seen shining through on the serous surface but there is no peritoneal + tuberculosis. No ulceration of Peyer’s patches. Contents of large + intestine is rather dry and here the mucosa shows exaggerated rugæ + which cannot be smoothed out. Walls are thickened, and ulceration, + while suggested, cannot surely be determined. + + +An interesting case of primary tuberculosis in the larynx detected at +postmortem after a tuberculin injection is as follows: + +[Illustration: + + FIG. 51.—BOVINE TUBERCULOSIS IN THE MONKEY. THIS SPECIMEN SHOWS THE + BOVINE PEARL DISEASE ON THE COSTAL PLEURA, AND SERVES AS WELL TO + ILLUSTRATE THE NODULAR TUBERCLES COMMONLY FOUND IN THE SPLEEN OF ALL + PRIMATE TUBERCULOSIS. +] + + + Black and White Lemur (_Lemur varius_) ♂ . Miliary tuberculosis of + larynx; perilaryngitis and retropharyngeal lymphadenitis. Killed + because of unsatisfactory chart after injection of tuberculin. The + only tuberculous lesion to be found in the body, which is in excellent + shape, is in and about the larynx. The lesions within are on the + epiglottis, false and true vocal cords and the main ventricle. On + either side of the root of the epiglottis, there are a few recent + tubercles. The lesion in the retropharyngeal lymphatics is recent and + diffuse. This is probably primary as it is not known that the + retropharyngeal glands drain to or from the larynx. About the lesions + on the laryngeal mucosa there is an area of congestion probably due to + the tuberculin injection. + + +Local lymphatic tuberculosis of comparative interest was encountered a +few times. Three cases of cervical adenitis, large enough to be visible, +were seen, of which one broke down about two weeks before death, and +discharged. The others did not ulcerate through the skin but, contrary +to the usual rule for the human being, remained as isolated glands only +lightly adherent to one another where they lay adjacent. There was also +seen an ulcerating tuberculous lymph node in the groin of one monkey, +the animal having rather pronounced abdominal and pelvic tuberculosis. +Two instances of tonsillar tuberculosis are recorded, in both of which +the lesion was of some duration and associated with caseation in the +lymph node lying immediately behind and below it. A Guinea Baboon +(_Papio sphinx_) had as an unusual part of his general tuberculosis, an +active caseopurulent collection in the antrum of Highmore, which +attacked the upper maxilla and immediately adjacent muscle; tubercle +bacilli could be demonstrated. + +One of the cases of nodular or massive peritoneal tuberculosis is quite +like the tumor-forming variety of human adolescents; it is as follows: + + + Reddish Macaque (_Macacus rufescens_). Caseous tuberculosis of + mesentery and spleen; miliary tuberculosis of lungs, pleura and liver; + chronic myocarditis. The lymphatic glands of the posterior and + superior mediastinum and bronchi are slightly enlarged, soft and + anthracotic but do not show any tuberculous change. Both lungs are + riddled with small, firm, gray miliary tubercles, some surrounded by a + clear mantle of connective tissue. The intervening lung is practically + normal. Pleura over base of right lung on both surfaces shows small, + pale miliary tubercles. The liver contains various sized miliary + tubercles. There is a large caseous mass in posterior end of spleen + with adhesions to kidney, stomach and colon. Retroperitoneal glands + are much enlarged, firm, homogeneous—probably tuberculosis of a + different type. Lesser omentum contains one caseous gland. Few caseous + glands in great omentum. In the right iliac region there is a large + mass involving many coils of intestine. It is found to arise probably + from the ileocecal glands and can be traced along the mesentery to the + central lymphatic stalk. The mass involved the tissues of the + mesentery and surrounds many coils of intestine. Cecum and first part + of colon can be traced over its right side. Rectum is free except on + right side where it is lightly attached to the mass. Epicardium is + gray and irregularly thickened and the muscle just beneath serous + membrane is pale and streaked with red lines. + + +There have been three cases of tuberculosis of the internal male genital +area, one of which was suspected of having been the primary seat of the +disease; it was described on page 315. The other two could have been +secondary since other points of morbid change were as old or older. One +of these cases formed a tumor as large as a goose egg at the vesical +neck, obstructing the flow of urine and blocking up the seminal vesical, +in consequence of which paralytic distention occurred in the bladder +while the vesicles were tightly filled with inspissated semen. A case of +Fallopian salpingitis has also been cited. Two instances of cerebral +tuberculomata have already been described. + +Carnivora. This order has the reputation of being quite resistant to the +tubercle bacillus, based upon the relative infrequency among cats and +dogs in contrast to cows and swine. Some veterinary statistics cite the +incidence up to 5 per cent., and occasional references may be found to +tuberculosis in circus lions and tigers. Our records would suggest that +in gardens the wild varieties of this order have about as much of the +infection as the domestic carnivores, 3.5 per cent. The group is made of +six Felidæ, one Viverridæ, three Canidæ, six Procyonidæ, and one Ursidæ. +The first family includes a lion, tiger, a jaguar and three smaller +cats. The Canidæ are all small foxes. The Procyonidæ are all coatis. The +features of this order are the occurrence of the fibroulcerative variety +with cavitation in the Felidæ and the caseous nodular abdominal and +glandular disease in the coatis. All these animals, even those of the +last named variety and pathological type, tend to show some tissue +resistance to the tuberculous disease. Connective tissue activity is +characteristic of the process, considerable distortion being produced by +the fibrosis. This feature is borne out where the tissues are studied +microscopically. Definite milia are sometimes found, but they consist of +epithelioid and round cells with imperfect caseation, giant cells being +often missing. About the miliary tubercles a diffuse and not essentially +specific tuberculous granulation tissue is found, mixed with which is +much connective tissue growth. The fibrotic adhesion-forming serous +membrane tuberculosis of carnivores seems worthy of emphasis by the +citing of a case in point. White nosed coati (_Nasua narica_), was +received in poor condition and died in a few days. Upon dissection a +slightly turbid yellowish fluid was found to occupy what remained of the +peritoneal cavity which was reduced in size by dense adhesions of the +intestines into an inflammatory mass. The omentum was a diffuse +thickened apron, also beset with fine tubercles, lying over the mass. +Fine young tubercles could also be found upon the intestines and liver +while the mesenteric lymph nodes were early in caseation; thoracic +organs not infected. + +One of the most interesting cases concerned hypertrophic osteitis in a +chronically tuberculous lion; the feet are discussed on page 346. This +process was described by Marie for human beings many years ago, and was +reported in dogs by Cadiot[100] in 1912. This beast was one of five +large cats which have died from tuberculosis in its chronic ulcerative +form. Three of the cats, one fox and the bear showed definite +cavitations of a ragged loculated form. The cavities were usually of the +multiple variety and were found in the posterior, that is lower lobe. + +Rodentia. The paucity of cases in this order permits little information +to be drawn from the form of tuberculosis. The total seems to have been +swollen by a group of three beavers, all of which came in one shipment. +The remainder were a Capybara and an Agouti. The general type is that of +much caseation with little or no surrounding fibrosis. One illustrative +case is cited: + + + American Beaver (_Castor canadensis_). General tuberculosis. The + animal presents generalized tuberculosis. The regional lymph nodes + show caseous nodules. The right hip joint shows caseous material about + the acetabulum with necrosis and pathological fractures in the os + innominatum immediately above the acetabulum and including its cavity. + Lungs show almost no normal respiratory tissue, the process being a + diffuse precaseous, partly gelatinous pneumonic phthisis. The superior + and posterior mediastina show caseous glands. There is miliary + tuberculosis of the liver. Nodular caseous tuberculosis of the spleen + with small tubercles and some cirrhosis of the intervening tissue. + There are caseous nodules in all perirenal glands and in the kidney + cortices. The psoas muscle glands are densely caseous. The pelvic + organs except about the right acetabulum escape involvement. Adrenals + not opened but probably not involved. + + +Ungulata. This order shows the most definite figures among those for the +order of mammals. Nearly one-tenth of the whole number of specimens have +had some form of tuberculosis and of a very definite character. It is +well at first to mention, however, that only four of thirteen families +are represented, from which four came 328 of the total 365 autopsies. +The remaining thirty-seven were such animals as tapirs, giraffes, swine, +and peccaries, in all of which tuberculosis has been reported from +elsewhere. + +Pulmonary disease with less prominent lesions in other organs, +especially the intestines and their related glands, speaks in favor of +the aerogenic route being the common one. This of course has been a bone +of contention among veterinarians, and I do not presume to settle the +matter with these figures. + +This order resists tuberculosis to a certain degree as attested by the +fibroulcerative character of the majority of the cases. Two instances, +one in a buffalo and one in a deer, showed very highly fibrotic +pulmonary lesions with a partial attempt to surround and wall off +numerous areas of caseation. So too in this order there is a greater +tendency to calcification, both in the intra- and extrapulmonary nodes. +It is to be emphasized that in our material the thoracic lymph nodes are +affected more than the abdominal and regional as 3 to 1. The apparent +immunity of the spleen of this order is well illustrated. + +The paucity of serous surface involvements in the wild Bovidæ and their +prominence in the Cervidæ cannot be ignored in the figures, but it seems +misleading since pleural growths and adhesions are quite common in the +domestic Bovidæ. The case in the Equidæ was that of a Zebra with a large +tuberculous abscess in the retroperitoneal glands forming a tumor in the +left renal region. It was quite well surrounded by fibrosis, and the +infection had not extended; it seemed quite recent. Analysis of the +figures for the remaining three families of ungulates offers little for +contrast and much for comparison; it is the usual picture as seen in the +domestic cow. Some special cases are worthy of review. + +An interesting specimen of softened glands chiefly on one side of the +neck was found in a Fallow deer (_Cervus dama_). It resembled the +juvenile human cases that require surgical attention. Although palpable +lymph nodes can be found in practically all cases of generalized +tuberculosis in the Ungulata, this is the only case in our records in +which they have presented a large tumefaction and broken down. Pulmonary +cavitation is recorded but thrice, one for each of the last three +families. Fibrocaseous tuberculosis of the testes was discovered in a +Nylghaie (_Boselaphus tragocamelus_), but there is no knowledge of +mating or offspring. An ischiorectal abscess was found in an American +Bison (_Bison bison_) showing nodular precaseous tubercles of the lung. +The former was the cause of death. No tubercle bacilli could be found in +the abscess contents, so that the tuberculous basis is inferred, not +proven. Tuberculous salpingitis in a Nylghaie was discussed on page 306. + +Proboscidea. Eber mentions in the article already referred to that there +are three reports in the literature of tuberculosis in elephants. When +looking for an explanation of tuberculosis in this animal it must be +remembered that it is one of the most attractive objects in a zoological +garden and receives perhaps more attention, including feeding, from +visitors than any other specimen. The beast while possessing some tissue +resistance to tuberculosis, is by no means immune thereto, as has been +thought by some persons on account of its reputed longevity, and +therefore he is to be protected from infection just as much as other +animals. It would appear that he may present caseous pneumonia or +nodular caseous disseminated lesions. Our two cases, in animals at the +Garden twenty and thirty-eight years respectively, were both of the +fibrocaseous variety; the lesion was confined to the lungs. A brief +description of their lesions is as follows: + + + Indian Elephant (_Elephas indicus_) ♂ . Chronic polyarthritis. Chronic + myocarditis. Chronic hepatitis (cirrhosis). Parenchymatous nephritis. + Chronic tuberculosis of the lungs, partly encapsulated. Pigmentation + of the spleen. The pleuræ are very fat but the surfaces are smooth and + devoid of adhesions. The lymph nodes of the mediastinum are about + 10 × 20 cm. for the largest while the smaller ones vary around 2 × 4 + cm. They are firm, deep red-brown without clear divisions into medulla + and follicular cortex. There are several large, firm, pale rather + cheesy follicles in all the large ones and a few of the small. These + do not appear like tuberculosis. The lungs are flaccid and soft; gray + and red mottled. The bronchi are firm and stand open. Around one in + the upper lobe of the right lung, there is a large area of cheesy + degeneration around which a zone of connective tissue has formed. This + extends about the bronchus about halfway in a sheath-like manner. + There is also a separate nodule the size of a cherry with a cheesy + centre. The trachea appears normal. Tubercle bacilli could be + demonstrated in the cheesy material. Microscopic section of lung + around the cheesy area shows a low grade chronic granulation tissue in + some places enclosing cheesy masses with giant cells on the margin. + The neighboring septa are slightly thickened and in some places + broken, forming emphysematous cavities. Some of these cavities are + edematous. + + Indian Elephant (_Elephas indicus_) ♀ . Miliary and conglomerate + caseous tuberculosis of lung. Edema of lungs. Endarteritis deformans + of lung. Cloudy swelling of liver. Chronic passive congestion of + liver. Hemosiderin pigmentation of liver. Acute parenchymatous + nephritis. Chronic passive congestion of spleen. Chronic hyaline + perisplenitis. Multiple calcified fibroid tumors of uterus. Leiomyoma + of uterine cornu. Senile atrophy of ovaries. Acute catarrhal + enteritis. There are some adhesions of the upper lobes of the lung to + the ribs. The lungs are large, increased in weight, color pink and + mottled red, air content diminished. There are several masses of + tubercles, each as large as a cocoanut, in both lobes. In one such the + tubercles are yellow and caseous; some are fibroid but none are + liquefied or calcified. The fibrous tissue of the lung parenchyma here + is much overgrown. In one instance the terminus of a bronchus is + solidly plugged by caseous material. Mucosa of bronchi is reddened, + markedly ulcerated, ulcers overlaid by mucopus. + + +INDIVIDUAL FEATURES OF AVIAN TUBERCULOSIS. + +The avian form of tuberculosis is somewhat peculiar in its physical +appearance as well as in its distribution. The isolated nodular type is +far and away more common by more than 100 per cent. than all the other +types combined. These nodules are usually well circumscribed, and to the +naked eye suggest that they have a restraining fibroid wall. This is, +however, not the case, the impression being due to the dense but +actively growing fibrocellular cortical zone of the tubercle. The centre +of the nodule, instead of having the soft character like Camembert +cheese, resembles the firm but brittle American dairy cheese. Upon +opening such an area the central necrotic mass may split away from its +cortex and even shell out, leaving a cavity lined by a gray-yellow +membrane. These characters are best displayed in nodules of moderate +size, the small ones being like the yellow mammalian analogue, the large +being like indefinite cheesy masses. In the surrounding tissue evidences +of inflammatory processes seem decidedly greater in our material than I +am accustomed to see in human and veterinary pathology. This, it seems, +should be emphasized since secondary infection with pus cocci and other +pathogenic germs appears less often in birds than in mammals. + +The difference speaks, therefore for a difference either in the tubercle +bacillus of birds or the avian physiology. Judging by the limited morbid +processes produced by injecting avian bacilli into rabbits and guinea- +pigs the reaction of the bird itself would not seem wholly responsible +for the difference. The local tissue reaction in all avian lesions is +mononuclear and fibrous, softening and pus being rare. It would seem +from this and similar operations that the bird expresses its resistance +to the bacteria by a fibrocellular reaction which goes on to fibrosis +without softening; perhaps this means also that their polynuclears are +not sufficiently active, but the pathogenic power of the bacillus itself +doubtless is individualistic. + +The character of the cheesy degeneration is likewise different from the +mammalian. It seems like an abrupt hyaline necrosis of a large central +mass and not the slower cell death seen in the other types of tubercle. +At times the degenerated area, instead of having the yellowish color of +caseation, will present what we have designated “gelatinous +tuberculosis,” the whole infiltrated area resembling boiled sago or +tapioca. This seems to be a complete homogeneous coagulation or hyaline +necrosis of the whole mass out to the delicate fibrous mantle supplied +by the tissue in which the tubercle lies. + +The organic distribution of tuberculous lesions has already received +some attention and is to be discussed with the orders. There are, +however, some localities affected conspicuously in the bird. The skin +lesions often attract attention during life. They occur around the eye, +at wing joints, on the cresta sterni and on the legs. Parrots and jays +have shown nodular or diffuse growths around the eye, originating both +in the lids and orbit, which on section have proved to be tuberculous. +These seldom ulcerate, but those upon the skin of the breast and wings +tend to have superficial erosions or deep ulcers. The latter lesions are +more common upon pigeons but have been seen in Psittaci and Galli. +Toucans and pigeons when pinioned, have on three occasions shown a +tuberculous mass on the stump. + +[Illustration: + + FIG. 52.—MASSIVE TUBERCULOSIS IN LIVER AND SEVERAL MURAL TUBERCLES OF + INTESTINE. COMMON PEA FOWL (PAVO CRISTATA). +] + +[Illustration: + + FIG. 53.—NODULAR HEPATIC LESIONS IN THE LIVER OF A DOVE. +] + +Two parrots with hyperkeratosis of the beak and of the skin of the feet, +have also had tuberculosis. These have been mentioned in literature as +of tuberculous origin. One case well studied failed to show tubercle +bacilli in the corns. In the absence of tubercle bacilli, one is +inclined to think that this might be explained on the basis of a +circulating toxin such as is assumed to be responsible for hypertrophic +periosteitis. This latter condition has not been seen in birds. + +Still another type of occasional occurrence deserves mention. While most +of the lesions in birds correspond to the description given in the +preceding pages, some lesions fail to degenerate in the centre, +retaining instead a solid homogeneous fleshy character of dull gray- +yellow color. Upon section these have been found wholly cellular in +construction. To distinguish them from the ordinary nodules they have +been designated tuberculomata. Lesions of this kind may occur along the +lymphatic paths, indeed seem more common in the lateral cervical and +thoracic chain, and upon bones and nerves. When they are numerous the +nodular caseous type is inconspicuous. They suggest the bovine infection +(Pearl disease), but one attempt to prove this failed. We are of the +opinion that this is the avian lymphatic form, as our examples +correspond to the literary descriptions of cervical tuberculous +lymphatics in birds. No especial variety of bird is more often affected +by this process. + +Intestinal tuberculosis among the Aves may be said to assume three +forms. The best known, indeed the form usually spoken of as representing +the common picture, is that which produces varying sized nodules upon +the serosa, sometimes associated with adhesions to neighboring +intestines. Just how this type develops is not known. In some quarters +it is believed to originate by the penetration of the tuberculous +granulation tissue from the mucosa through the intestinal wall by +following lymphatic channels and that irregular contractions of the +musculature squeeze the exudate outward under the serosa. Other +observers think that the bacilli are carried _via_ the lymphatics to the +superitoneal tissue, there starting the tubercle. The truth of the +matter will probably be that both methods are operative although we have +seen more cases suggestive of the second than of the first explanation. +When these peritoneal nodules are numerous and prominent, mucosal ulcers +are uncommon and _vice versa_. + +The second form is the ulcerative, flat ragged or crateriform defect +situated in a diffusely thickened wall. This was well illustrated in +cases of pulmonary infection in doves and guans, suggesting reinfection +of the gut tract from swallowed tubercle bacilli or a backward +development of the disease after the lungs were nearly solid. + +The third form of tuberculous enteritis is quite interesting and +striking. It is best seen in the duodenal loop but may occur anywhere. +Diffuse thickening of the enteric wall is noted, and when palpation is +practiced a resilient but leathery sensation is obtained. Careful +inspection reveals the mucous surface to be velvety, a condition due to +a swelling, that is widening, of the villi which retain their erect +position and, when washed in flowing water, will be seen to move like a +field of grain in a breeze. The serosa may be, usually is, negative. +Studied microscopically the peculiarity of this form is in the +development of tubercles and diffuse cellular exudation in the villus +stalk, sometimes extending into the submucosa also. Round cell masses +like lymph follicles are sometimes prominent. This form is not +associated with any peculiar organic distribution so far as my studies +go. + +[Illustration: + + FIG. 54.—TUBERCULOUS MASSES OF INTESTINAL WALL SHOWING OUTWARD GROWTH. + SOMETIMES THESE MASSES OBSTRUCT THE LUMEN. +] + +Passeres. The peculiarity of this order seems to be in the predominance +of the pulmonary route as origin of tuberculosis. Perhaps in no other +order has there been such extensive and advanced lesions as in these +little birds. Sometimes one whole lung will be solid while its fellow +will be half occupied by caseous material. The doves alone seem to +approximate the Passeres in ability to live with so much tuberculous +exudate. + +Picariæ. Specimens from this order illustrate well the intestinal origin +and distribution of tuberculosis. There was, among these birds, one case +showing tuberculomata which was, because of its gross anatomy, listed as +the pearl type. Its description is as follows: + + + Lesson’s Motmot (_Momotus lessoni_). The region above and behind the + right clavicle in front of the brachial plexus on the internal surface + of the thorax, exterior to the first and second ribs, and on the + internal surface of the ribs at the junctions of ribs with the alæ of + the sternum, there are many small, irregular, smooth, firm, yellowish + white nodules varying in shape from spherical to sweet potato and in + size from 3 × 3 mm. to 3 × 7 mm. These are found quite homogeneous on + cross section. They do not resemble tubercle or mould infection but + make one think of neuromata. There are also a few present in the left + lateral air sacs, close to but not joining the intestine. The lungs + are apparently normal. Histological section of the masses described as + distributed along the nerves consist of sharply outlined but not well + encapsulated masses made up of irregularly disposed bunches of large + cells with vesicular nuclei in a stroma of loose connective tissue + very inconspicuous in amount. There is also quite a number of small + round cells and a few leucocytes. The large cells first described have + the nucleus eccentric for the most part. Many of them have two nuclei + and a few three and occasionally a giant cell is observed. Blood + vessels have a very delicate wall and are frequently encountered in + the centre of these masses. Atypical mitoses can be found. Here and + there a seal ring placement of the nucleus can be found. A few + eosinophiles are present not definitely placed. Necroses, with large + quantities of nuclear fragments, are scattered irregularly through the + mass. The diagnosis rests between an infectious granuloma, false + neuroma and sarcoma. Tubercle bacilli were found by stain in great + numbers both within and without the cells. + + +Psittaci. Tuberculosis occurs in this order somewhat more frequently in +the varieties whose habitat is the Eastern world, although South +American birds also suffer from it in the characteristic manner. There +seems to be no difference in the pathology of these two groups. Parrots +present very beautifully the separate solid or semisolid nodules of +avian tuberculosis, whether they be in the lungs, liver, or spleen. When +the lung becomes riddled with masses, coalescence occurs and the whole +mass turns into a cast of the hemithorax. Lesions in the liver are +mostly isolated, but the spleen often appears like one large pink +tuberculous nodule. The liver occupies as usual the first place in +organic incidence. + +Striges. Owls (and Struthiones—see below) present the interesting +exception to the rule of intestinal origin of tuberculosis in birds. +Perhaps the platting is incorrect but the birds in the order under +discussion had older and much more advanced lesions in the lungs and +thoracic serosa than they did in the abdominal organs. That this was +true in all three examples is in itself noteworthy. Perhaps they possess +less pulmonary and more intestinal resistance. One of these birds showed +a small recent cavitation in the posteroinferior angle of one lung. + +Accipitres. With one exception the cases of this order occurred among +the Falconidæ, that is in hawks, buzzards, and eagles. Their lesions are +usually generalized as indicated by the figures for visceral +distribution, but that half the number should have the oldest, most +prominent lesions in the lungs is curious. Their intestinal tuberculosis +seems mostly of the diffuse infiltrative type. + +Columbæ. These birds are obviously the most susceptible of all the +varieties of which there are sufficient autopsies to make a comparison. +Generalized nodular lesions emanating from the intestinal tract comprise +their usual form, while most of the hepatic lesions are small miliary +and nodular; occasionally one sees caseous masses destroying large +sections of the organ. Their intestinal lesions may assume any of the +three forms described. + +Galli. This is an order of something over the average percentage +incidence for the birds but containing families that seem very +susceptible to tuberculosis. The small number of Brush Turkeys +(_Catheturus lathami_) had 60 per cent. of the disease, while South +American Cracidæ had 44 per cent. These two groups raise the incidence +for the order. Galli as a group have generalized nodular tuberculosis +originating by the intestinal route. This is especially seen in the +Phasianidæ, while the very susceptible Cracidæ have much more prominent +lesions in the lungs, often of a massive caseous type. It is really +astonishing at times how much of the pulmonary tissue is occupied by +infiltrate before death has supervened. + +Fulicariæ are represented by a special contingent of rails and +gallinules. Avian characters are well illustrated in the order. So too +the succeeding order, Alectorides, another variety of shore birds, run +true to the avian form. It is interesting to note that in the two cases +from each of these orders tuberculosis and aspergillosis have been +combined. The former has assumed the firm nodular type, while the +mycosis has been of the air sac variety. The following case is worth +citing as possibly illustrating infection _per cloacam_. There is, +however, no trace of this bird having been with a male with the disease. + + + Demoiselle Crane (_Anthropoides virgo_) ♀ . General tuberculosis + including the oviduct. All organs are thickly beset by caseous + tuberculous nodules except the lungs which have only a few scattered + ones. The oviduct is, for its lower two-thirds, much enlarged, firm, + tough, pale yellow, thickly beset with caseous nodules; upper parts + uninvolved. The kidneys are definitely enlarged, irregular, almost + mulberry-like, brownish yellow, firm and tough. On section the lobules + are irregular, connective tissue increased, urates in pelves. + Tubercles in intestines seem to be wholly peritoneal. This seems like + a tuberculosis of genital origin judging from condensation of + tubercles in the lower abdomen (mass around cloaca). The ovaries are + not involved. Lungs and thoracic air sacs relatively free. The + pericardium shows a whitish thickening of both layers due to the + presence of whitish granules like urates. Histological section of + kidney shows the capsule not greatly altered. Glomeruli largely + negative but a few show hyaline capsular thickening of vacuoles in + tufts or fibrosis in tufts or obliteration of whole structure. Tubules + largely degenerated, distended or distorted. Interstitial tissue + between the tubules definitely but irregularly increased. No real + attempt at regeneration. Few vessels show perivascular fibrous change. + One tubercle seen. + + +Anseres. These birds present no especial features so far as percentage +or organic incidence are concerned. The individuals are mostly geese and +swans, ducks being somewhat more often affected by mycosis than by +tuberculosis. However, both these diseases tend to assume the nodular +type in Anseres so that the diagnosis should be supported by +bacteriological discovery of the respective organisms. + +Struthiones. The marked feature of this order is the prominence of the +isolated and confluent nodules in the lungs, of apparently greater age, +certainly of great size, than similar lesions in the abdominal viscera. +Caseation of the avian variety is well illustrated in these birds. The +thyroid body was involved in two of the three cases, the ovary in one. +The representatives of the Crypturi, two tinamous, came at the same time +and lived only a few months. Miliary tuberculosis of the small +precaseous variety was the form exhibited by both specimens. + + +HISTOLOGY OF THE TUBERCULOUS LESIONS. + +The initial and characteristic unit of tuberculosis, the miliary +tubercle, seems to be constructed upon the same general principles in +all cases of the disease and in all members of the zoological groups in +our study and in a manner entirely comparable to that well known for man +and for the domestic animals. There are, however, certain minute +differences which are interesting and may at some time become important. +It is customary to speak of the bovine tubercle and of the human +variety, but there are also slight variations of the microanatomy of +each of these, while one may find on occasion a tubercle of the human +type in a cow and _vice versa_. Not all the domestic animals show the +bovine form, although in sheep and swine it is approximated very +closely. In the horse there is much greater tendency to a central +softening and fibrosis is not so common as in the bovine tubercle. I +have attempted to study the histological anatomy of each of the +zoological orders, but it has not resulted in any profitable discovery. +It is, however, possible to contrast the type commonly found in monkeys +with that characteristic for man and the ungulates and also to emphasize +the construction of the avian tubercle that it may be distinguished from +mammalian tuberculosis and from avian mycosis. + +[Illustration: + + FIG. 55. DIFFERENT VARIETIES OF THE MILIARY TUBERCLE. + + A.—THE BOVINE FORM SHOWING THE NUMEROUS LANGHANS’ GIANT CELLS, THE + ABUNDANT SMALL EPITHELIOID CELLS. THE MODERATE NUMBER OF SMALL ROUND + CELLS, AND THE ACCOMPANYING CONNECTIVE TISSUE INCREASE. THERE IS + MODERATE CASEATION. +] + +[Illustration: + + FIG. 55. DIFFERENT VARIETIES OF THE MILIARY TUBERCLE. + + B.—THE HUMAN TUBERCLE WITH CENTRAL COMPLETE NECROSIS. TYPICAL GIANT + CELLS, ABUNDANT EPITHELIOID CELLS AND THE RELATIVELY NARROW SMALL + ROUND CELL MANTLE. +] + +[Illustration: + + FIG. 55. DIFFERENT VARIETIES OF THE MILIARY TUBERCLE. + + C.—THE TUBERCLE FREQUENTLY FOUND IN MONKEY TUBERCULOSIS. WITH RAPIDLY + ADVANCING CENTRAL NECROSIS ENCLOSING MUCH CHROMATIN DEBRIS. THE + ABSENCE OF LANGHANS’ GIANT CELLS. THE PRESENCE OF LARGE, PALELY + STAINING EPITHELIOID CELLS OF LANGHANS’ TYPE AND THE VERY SLIGHT + CIRCUMFERENTIAL REACTION. +] + +[Illustration: + + FIG. 55. DIFFERENT VARIETIES OF THE MILIARY TUBERCLE. + + D.—AN AVIAN TUBERCLE WITH CENTRAL SHARPLY MARGINATED NECROSIS + CONTAINING MUCH CHROMATIN DEBRIS. THE IRREGULARLY ARRANGED + POLYNUCLEAR CELLS TYPICAL OF AVIAN TUBERCLES. THE SMALL NUMBER OF + REGULARLY ARRANGED EPITHELIOID CELLS. THE PAUCITY OF SMALL ROUND + CELLS AND THE PRONOUNCED CONNECTIVE TISSUE MANTLE. +] + +The tubercle of the Primates is a loosely constructed affair lacking the +fibrous mixture of the bovine and the close cellular packing of the +human form. Studied from the periphery to the centre, there will be +found very little fibrocellular reaction in the immediately surrounding +organ, while the mantle of round cells, rather prominent in the human +tubercle, is often quite inconspicuous. The principal cellular component +of the miliary granuloma is the large pale endo- or epithelioid cell, +which is abundant, loosely arranged and without apparent purpose. In the +centre is an irregular necrosis usually retaining some chromatic matter, +probably the remains of recently destroyed nuclei, but this caseous +midpoint does not assume the dense acid staining common for many milia. +Giant cells of the Langhan’s or foreign body type are often entirely +missing, and when present are scanty. There may be large cells, +resembling the aforementioned epithelioid cells, with two or even three +large palely staining nuclei, but these latter are arranged irregularly +and not like the spokes of a wheel near the cell wall. + +This picture suggests a rapidly growing inflammatory mass and indeed +this is the type that tuberculosis follows in monkeys. In a few cases +gross evidence of fibrosis in the serous surfaces and in the lungs has +been observed, but they are too rare to permit one to think that +connective tissue activity is an important part of the reaction of this +beast to the disease. + +The avian tubercle as it rests in the tissue seems like a sharply +outlined almost encapsulated body. This is in part due to the +homogeneity of its structure and in part to the fibrocellular +condensation around the caseous part of the growths. Examined from +without inward, there is a round cell mantle, between the elements of +which course fine but easily perceptible fibrils; elastic tissue has +been seen among them. The small cells continue more deeply than the +fibres, to be succeeded in prominence by epithelioid cells of rather +dense character, the nuclei especially seeming quite rich in chromatin +and round. The rotundity of the nuclei remains not only in the single +separate cells forming the middle zone of the cellular cortex, but can +be found in the nuclei of the compound or giant cells which comprise the +internal layer lying upon the necrotic centre. These giant cells are +characteristic for the avian tubercle in assuming a form like syncytia +with nuclei arranged in irregular radiating columns. This internal large +cell area may completely surround the central necrosis or it may be +interrupted by the large single cells. Tubercle bacilli are more common +in and between single cells than multinuclear ones. Within the cellular +zone lies the necrotic centre, often, indeed usually, full of chromatic +debris. This centre is commonly quite amorphous but occasionally one +will see what is probably the remains of a coarse coagulum. Between the +necrosis and the cells one usually finds a split, a sort of separation +of the gangrenous from the living part. Old tubercles with denser +fibrous capsule retain this microanatomy in part, but the cellular zone +gradually becomes thinner and thinner until all that remains is a narrow +cortex of round cells and imperfectly retained multinuclear cells. + +Tuberculous granulation tissue without definite milia consists entirely +of the round cells with small vacuoles and a fine but definite fibrosis. +Tuberculomata consist of cells of varying sizes with small round nuclei. +Interstitial fibrosis is delicate and barely visible unless especially +sought. Giant cells may be encountered but are not so large as in milia. +Necrosis occurs but not in an orderly manner in relation to cells as in +an isolated tubercle. Tubercle bacilli are very numerous. + +[Illustration: + + FIG. 56.—PHOTOGRAPH OF YOUNGEST AVIAN TUBERCLE AFTER COMPLETE + FORMATION. +] + +[Illustration: + + FIG. 57.—TUBERCULOMA, A SOLID TUMOR-LIKE MASS, CONSISTING OF CLOSELY + PACKED LARGE CELLS FITTED WITH RELATIVELY SMALL ROUND LOOSE NUCLEI. + THESE CELLS ARE CROWDED WITH BACILLI. +] + + +TYPES OF BACILLARY INFECTION. + +According to experimental and statistical research, all the tubercle +bacilli of the higher vertebrate classes can be infective for any member +of these classes. Thus, for example, human bacilli have been found in +many orders of mammalia and in birds. The bovine form has been found in +swine. The lesson from this is that while the special predilection of a +variety of the tubercle bacillus may be for one kind of animal, it is +potentially a virus for other kinds. Hygienic principles have therefore +been laid down at the Garden which aim at the protection of all +specimens from every variety of tubercle bacillus. For this reason and +because the laboratory has not attempted extensive research on +bacteriology, few type determinations have been made and those at hand +offer nothing new or unusual; they are noted here as a matter of record. +Bovine bacilli have been judged by their slow growth and infectivity for +rabbits, human bacilli by the reverse of these characters. Avian +tubercle bacilli can be cultivated with reasonable ease directly from +lesions not bearing a mixed bacterial flora, and grow in a yellow, +moist, even, spreading colonization. In our two attempts at infection of +guinea-pigs, no success was had, although Rabinowitsch and others had no +difficulty in so doing; this strain may vary in virulence as do other +tubercle bacilli. No avian culture was obtained from a mammal, but a +bovine was found in a parrot and a human in a duck. Bovine bacilli were +isolated once from a monkey (see page 496) and in another case of +lymphatic type, bacilli of the short heavy blunt shape, supposed to be +characteristic of this variety of the germ, could be stained. Monkey +tuberculosis in our experience is usually due to the human tubercle +bacillus, judging by the staining characters and two successful +cultures. + + +DISCOVERY OF TUBERCULOSIS DURING LIFE. + +Fully developed chronic tuberculosis may be recognized with reasonable +ease in the human being and some domestic animals. The diagnosis rests +largely upon the history and symptoms and partly upon the appearance of +the individual and upon signs elicited by physical examination. There is +good reason to believe that these latter methods are entirely applicable +to certain wild animals, notably those that can be caught and held +quiet, but because of their naturally great reserve many specimens offer +little reason for suspicion as to their tuberculous condition until near +death. Certain ungulates with chronic pulmonary disease get thin and +weak but remain on their feet with good appetite and satisfactory +discharges for many months. Primates, Carnivora, Rodentia and Aves not +uncommonly come to autopsy with very good coats and without great +emaciation and yet are heavily infected. It can be stated with fair +positiveness that no chain of historical data or gross observations are +certainly known to us as indicative of tuberculosis in the wild beast. +Coughing is not necessarily characteristic of chronic pulmonary +infection, although when continuous it rouses considerable suspicion, +especially in the Ungulata. It is to be interpreted with care in all +animals that have loose bedding as bits of straw or seeds get into the +throat causing irritation; the dust of hay may cause coughing in horses. + +However much chronic or fatal tuberculosis may be interesting from the +standpoint of pathology or of zoological or visceral incidence, the most +important factors in our knowledge of the disease are its early +recognition and treatment, either for curative or hygienic purposes. +Since we have learned that advanced lesions may exist in an animal +without materially affecting its external appearance and behavior, it +naturally follows that early cases, possibly of an “open” or infectious +character are still less likely to give evidence of their existence. +This is well recognized by veterinarians as being true of cattle, but is +perhaps less well known, or possibly admitted, by those who handle the +very susceptible monkey. + +Upon a visit to a foreign garden I was told that experience alone is +sufficient to enable an observer to detect tuberculosis, and that the +disturbance entailed in physical examination and tuberculin tests is +prejudicial to the well-being of all varieties, but especially the +delicate ones. I learned later that they had the disease in their +exhibition cages all the time but decided to put their method to the +test. Shortly after my return from abroad a splendid specimen of Grivet +Monkey (_Cercopithecus sabæus_) was condemned by the tuberculin test. He +was well studied by the superintendent and two very experienced keepers, +all of whom pronounced him one of the finest specimens they had ever +seen, and stated that he was behaving quite normally. Despite their +protests he was sacrificed, tuberculosis with early cavitation being +found in the upper lobe of the left lung. Incidentally vague physical +signs were found by auscultation, but as the monkey was unruly and had +long pectoral hairs little weight was placed on the observation. +However, it is frequently possible to make very thorough physical +examination of the lungs of the more tractable specimens, diagnoses of +pneumonia and bronchitis being frequently made in this and other parks, +so that treatment may be instituted. + + +IMPORTANCE OF TRANSMISSION AND KNOWN SUSCEPTIBILITY. + +Some light upon possible reasons for the poor condition of an individual +animal is of course shed by a knowledge of the disease to which that +particular variety is most susceptible, to which may be added the data +obtained from previous deaths in the same group or enclosure. Thus, for +example, a sickly monkey would be suspected of having tuberculosis or +early osteomalacia, whereas no suspicion of these diseases would fall +upon the marsupials. The same position would be assumed if a dove and a +heron were out of condition. + +In so far as enclosures are concerned, the matter is somewhat different. +Whenever a case of tuberculosis occurs in a cage, the remaining +specimens if any are removed and the place cleaned by soap and water and +disinfectant and paint. The naked flame from a blast lamp is used when +possible. Out-of-doors enclosures are vacated, spread with lime and +allowed to lie fallow for as long a time as practicable. These methods +have been in the main successful in clearing a cage of the disease, and +all our experience demonstrates the effect of cage hygiene and the +selection of non-infective replacements. A few places such as those +occupied by doves and guans have not been freed of infection, if one +judge by its appearance when new specimens are placed in them, but they +may of course be due to the infection from elsewhere. The history of +seven years in the new bird house where the hygienic conditions are +excellent, seems to indicate that a cage thoroughly cleaned is no longer +a source of danger, and that a repetition of tuberculosis in such an +enclosure is due to its importation with new exhibits. + +The spread of the disease to nearby cages seems to depend upon two +factors. If the number of cases has been large and the infection +virulent, immediately adjoining cages are involved, but the tendency to +spread is directly proportional to the proximity of orders or families +that have a high susceptibility for tuberculosis. This second factor +seems to be the more important and is illustrated by our experience in +one corner of the new bird house. In this area are exhibited certain +doves and pheasants, among which are many cases, while the passerine +varieties nearby are little affected. So too in the flying cage the +disease has occurred in varieties with high general susceptibility. +There are at the present writing ten orders on exhibition in this large +enclosure and there have been more. An occasional case of the disease +occurs, but only in the orders which show it elsewhere. The Herodiones, +of which we have had nearly one hundred autopsies and many now are on +exhibition, are always well represented in this cage and yet show no +tuberculosis. In the ten orders mentioned above three show no cases of +the disease. + +These observations illustrate the spread of tuberculosis, especially to +the most susceptible varieties, and how non-susceptibles under good +hygienic conditions fail to become infected even when infected animals +are near them. The freedom of activity in the large enclosure is +doubtless an important factor. + +The history of the past three years with regard to the control of +tuberculosis in the small cages shows that twenty-nine were infected, +but by the measures employed nineteen have remained free of the disease +for one year; three of the remaining ten are known to have received +newly arrived and possibly infected specimens. + +The accredited method of transmission in birds, the swallowing of +material soiled with the feces richly laden with germs, is the principal +reason why infected enclosures and their immediate environment are the +principal breeding places for tuberculosis. To be sure air currents may +blow the virus around, allowing it to light upon food in other cages but +this cannot be a great menace if for no other reason than that we have +had no epizoötic outbreak of the disease, when there were groups of +deaths in doves and guans. + +Evidences with which to trace transmissions are much clearer in the +birds than in the mammals with the exception of monkeys and some +ungulates. Of course cases are perhaps too few in the carnivores and +rodents to permit correct deductions but it is very rare that more than +one case occurs in the same enclosure containing groups of these +varieties. Nor do animals in adjoining cages seem to “catch” the +infection. This observation does not suggest that any relaxation of +hygiene need be allowed but probably it implies that not many bacilli +are excreted by these animals; they cough very rarely. Groups of +ungulates (bison and deer) are often known to be infected but just how +it has arisen is seldom clear. Transmission from monkey to monkey has +been observed so frequently that it cannot be doubted, nor will anyone +wonder at it if reflection is given to the close personal contact of +these animals during their natural behavior. They huddle, pluck lice +from one another, take food from the mouth of another, bite and perform +many other actions greatly facilitating the transfer of any virus. +Bacilli may also be disseminated by coughing, drooling and with the +fecal discharges, for which latter there seems ample opportunity since a +notable percentage of cases have intestinal lesions. Monkeys do not seem +to raise sputum and expectorate it but they do eject saliva from their +lips. + +Contraction of the disease from infected cages is believed to have +occurred at least once in our experience but the lesson of complete +sanitary cleaning of the enclosure learned from that happening, seems to +have enabled us to forestall its repetition. + + +THE TUBERCULIN TEST. + +Tuberculosis presents the greatest single problem among the specific +infectious diseases which the director of a menagerie must attempt to +solve. Even though one may possess a knowledge of its zoological +distribution, clinical characters and pathological effects, these are +insufficient criteria for its detection at a stage when the animal might +be saved by treatment or, what is most important, removed from its +companions that they might be protected. To this end there remains but a +single procedure for the discovery of the existence of tuberculosis—the +use of tuberculin in one of its forms by one of its methods of +application. The use of this test in veterinary medicine needs no +commentary, having made its place in clinical and hygienic practice for +a quarter century or more. Armed with the knowledge of the satisfactory +use of the toxins of tubercle bacillus in cows, Dr. Penrose, Dr. C. Y. +White, Dr. A. E. Brown and Dr. Leonard Pearson began in 1901 a series of +experiments with old tuberculin of Koch which have led to the +development of a technique for its use in the detection of infected +monkeys. These interesting and instructive animals, being known as +highly susceptible since most of the collection died of the disease in +those days, and being handled with reasonable ease by experienced men, +were investigated as the most important specimens upon which to perfect +the method. Other varieties have been studied since and I shall refer to +them individually. The greatest amount of work and the most conspicuous +success attended the observations upon monkeys and the results of this +study are now in daily use in this Garden. + +The work, conclusions and results, originated by Doctor Penrose, Doctor +White, and Doctor Brown can be described as one of the most completely +satisfactory series of observations in scientific medicine. Applying the +principle that a tuberculous animal reacts to the injection of +tuberculin by a temperature rise, the normal temperature curve of the +monkey was studied, that of the tuberculous monkey determined by killing +many specimens. This enabled them to state which animal was infected, +which was not and to place on exhibition only healthy specimens. Added +to this, strict hygienic principles in the housing and handling of the +animals have resulted in the elimination of the disease from our +exhibition house. Occasionally a case may develop, perhaps from feeding +by visitors, but the matter is no longer a problem. I know of no more +complete and satisfactory experiment and its practical application than +this work, which is condensed in the succeeding paragraphs.[101] + + +THE TEMPERATURE OF MONKEYS. + +The success of the tuberculin test in the lower animals as in man +depends chiefly upon the alterations in temperature following the +injection of the toxin. It is generally admitted to-day that a healthy +animal’s temperature will not be affected by the introduction of this +material. There are in addition changes in the pulse and respiration +rate and in the physical signs but these are detected with difficulty +and are much less definite than thermometric records. The first +essential was therefore a thorough familiarity with the normal +temperature of the monkey, a requirement which met with considerable +difficulty from the beginning since the earliest observations revealed +puzzling irregularities. This necessitated the establishment of certain +regulations of technique which, after the preliminary tests, have been +found satisfactory enough to continue until the present day. All monkeys +are received in the quarantine rooms of the laboratory where they are +observed by the officials of the Garden and of the laboratory and there +they remain in separate cages until passed, as free from tuberculosis, +to the exhibition house. + +The handling of monkeys for the purpose of taking temperatures is a +matter of no small importance since excitement will quite definitely +increase the registration. We have been fortunate enough to have in +charge of this work since its inception the same man, Keeper McCrosson, +who is thoroughly experienced in the care of these beasts and who can +catch and hold them with a minimum of disturbance. To him and to the +interested laboratory helpers much credit is due. Small specimens like +capucins and spider monkeys are caught with the gloved hand or with the +protection of a piece of heavy cloth. Larger specimens may be caught in +a net while strong monkeys are fitted with a collar and chain by which +they are pulled into the corner of the cage and held, while the door is +opened to permit a helper to catch the feet and arms. Two experienced +men can take the temperature of any monkey that can be handled at all +safely. The knowledge of how to do such work reduces the excitement of +the animal and renders more accurate the observation of its temperature. +During the period of temperature-taking food is given in small +quantities and only after the record is made. + +Temperatures are taken in all animals by rectum,[102] the thermometer, a +separate instrument but always the same for each animal, well greased +with plain vaseline, being passed along the anterior rectal wall and +allowed to register for twice its indicated speed. During the +preliminary work, special instruments of officially standardized +accuracy were obtained by Doctor Brown but once the normals were +obtained, ordinary good thermometers registering from 94°F. to 108°F. +have been employed. If the record vary very much from the expected, such +as the figures obtained at the same time on the preceding day, or if the +rectum be crowded with feces, the instrument is shaken down and +reintroduced. In order to facilitate timing of exposures we use sand +glasses of three minute run. + +After some experimentation by taking records at various times of day it +was found that monkeys as a group do not have a uniform temperature +during twenty-four hours but register a higher figure during daylight +than during darkness. This is probably due, as I shall discuss, to the +period of activity, not to the time of day. Figures obtained at various +hours indicated that the highest and lowest temperature would be +obtained if records were made at four-hour intervals at three, seven and +eleven o’clock AM. and PM. To give the normal temperature of a monkey, +the kind and the time of day are necessary adjuncts. Reference to forty- +eight hour charts which are used for the illustration of normal records, +and for contrast with tuberculin reactions later, will convey to the +reader a better idea of the normal daily rhythm of the simian heat +regulating system than would verbal description. + +[Illustration: + + CHART A. ORANG UTAN (Simia satyrus). Non-tuberculous at death. +] + + + NOTE.—In the temperature charts degrees indicated by circles and + connected by dashes are from records made after diagnostic tests by + injecting tuberculin. + + +The anthropoid apes (Curves A and B) have on the whole a mean +temperature nearer the human being than do the lower monkeys, but they +too present daily variables far greater than man. The high point of +their curve, at three PM., is in the neighborhood of 100°F. the lower +point around 97.5°F. From these charts and other records it can be said +that while the higher apes have a daily temperature curve with its high +point at three PM. and its low point at three AM., there is in them not +by any means the regularity of curve to be found in Cercopithecidæ and +Cebidæ. Our records of temperatures in the Hylobates (_Gibbons_) are not +extensive enough to quote but what we have approach those of the lower +monkeys. + +[Illustration: + + CHART B. CHIMPANZEE (Pan niger). Non-tuberculous at death. +] + +Graphic curves of the normal temperatures of the various genera of +Cercopithecidæ and Cebidæ present striking similarities in the +regularity with which the daily rhythm is performed. In the seven genera +of which we have accurate records the normal high points fall between +102°–103°F. and the low points between 99°–100°F. while the curve of the +four-hourly steps is closely comparable. The curves D to J are +composites from charts of animals that have been tested with tuberculin, +which thereafter died or were killed and found free from tuberculosis. +Not every individual chart that may come to hand necessarily follows the +exact course detailed in these illustrative curves but these latter +offer a guide as to what is to be expected of the different varieties. +They show unequivocally the V-shaped curve of the temperature of the +monkey during twenty-four hours. + +[Illustration: + + CHART C. Composite chart of twenty-two non-tuberculous Lemures. +] + +The Callitrichidæ or Hapalidæ have failed to show tuberculosis in our +Garden and little has been done upon them. As a matter of record there +is reproduced the only satisfactory chart at hand (K) taken very early +in the researches. It shows a similarity to those of the higher monkeys; +because of its very high afternoon record the animal was killed; no +tuberculosis was found. + +[Illustration: + + CHART D. Composite chart of eighteen non-tuberculous Cercopithecus. +] + +The Lemures, being close to the Primates zoologically and presenting a +high incidence of tuberculosis, were included in this study. +Observations upon their normal temperature were hampered more than upon +that of monkeys and even to-day we cannot feel the same confidence in +the records. Irregularity is most marked and they seem easily disturbed +by handling. Chart C shows a composite temperature for forty-eight hours +of twenty-two proven non-tuberculous Lemures. The tendency for the +“night drop” is certainly existent but with much less definiteness than +in the Primates. + + +CONDITIONS WHICH MODIFY THE TEMPERATURE. + +[Illustration: + + CHART E. Composite chart of seventeen non-tuberculous Macacus. +] + +Observations by A. E. Brown[103] and by Simpson and Galbraith[104] would +seem to indicate that the diurnal variation in monkeys is due to +periodicity of activity. Doctor Brown found that the temperature of a +night monkey is reversed, that it is higher during the dark than the +daylight hours. See chart of Potto (_Perodictus potto_) chart L. The +Scotch observers report that if the activity of day monkeys were +reversed, daytime being made artificially dark and activity forced +during the night, the temperature curves were likewise reversed. + +[Illustration: + + CHART F. Composite chart of eleven non-tuberculous Papio. +] + +Perhaps the most important discoveries of these investigators concerned +the influence of excitement upon the temperature records. These +observers indicate definitely that the greater the physical activity and +nervous excitement the higher the thermometric record. We have noted +that the substitution of a strange keeper who may not be gentle and +tactful with the monkeys can serve to raise the temperature above the +records obtained by an experienced man with whose methods the animals +are familiar. + +A knowledge of these facts dictates at least two important precautions +on our part—our specimens must be kept under identic conditions peculiar +to their kind, and surroundings must be established offering comfort +with a minimum of annoyance in transfer and handling. To this end all +specimens upon receipt are put into separate cages suitable to their +size and allowed to become accustomed to their surroundings for several +days before attempt at temperature-taking is made. Mention has already +been made of the experience and interest of the principal keeper; the +regularity of records is an attest to his work. Daily three o’clock +afternoon temperatures are taken first to accustom the animal to the +matter, before test records or tuberculin injections are made. + +The existence of pathological states undoubtedly affects normal +temperature curves and tuberculin reactions. Gastroenteritis has the +effect of increasing the whole level and of making irregular the midday +and afternoon records. Respiratory tract disease cannot be said to have +a very definite effect; its most frequent influence seems to be to drive +the night records lower so that there is a long fall between seven and +eleven PM. and a long rise between seven and eleven AM. + + +THE TEST. + +The preliminary rest of the new arrivals having passed daily three +o’clock afternoon temperatures are taken until an even level is +obtained; this requires usually four days but in very nervous specimens +it may be much longer. The afternoon temperature course provides not +only a means of teaching the monkey what is coming but supplies us with +a high point record for comparison. When a new variety is received, a +full normal twenty-four hour record is usually made. This preparatory +routine being fulfilled, the animal is injected under the skin of the +thigh or flank with freshly diluted mixed bovine and human tuberculin. + + +THE DOSAGE. + +Early trials with this substance revealed the fact that a dosage based +upon the weight in comparison to man failed to elicit a definite +response whereas if based upon relative weight of cow was too large. The +finally determined quantity was arrived at, as was the case in early +human and bovine work, by experiment and trial and was as follows: A +monkey of five to ten pounds (2.3 to 4.5 kilos) received an initial dose +of 1. milligram and for each additional five pounds (2.3 kilos) 0.5 mg.; +this is 0.2 to 0.4 mg. per kilo. The amount given to man varies from 2. +to 5. mg.; if the body weigh 60 kilos this is 0.03 to 0.08 mg. per kilo. +Cows are given usually in this country 400 mg. or, for a cow of 250 +kilos, 1.6 mg. per kilo. In the early work, doses comparable to the +figure for man failed, whereas at least two animals died very quickly +after 1.+ mg. per kilo; 5. mg. was the original high dose. While the +death of a monkey after a large dose was of no moment and was perhaps +desirable, it would only be the heavily diseased specimens and this +would give no criterion upon which to judge the appropriate dose for +all. Experience seems to warrant us in continuing with our present +figures since all tuberculous monkeys have reacted to it. Subsequent +cases for retest are increased from 50 to 100 per cent. depending upon +the size of the monkey, the very robust and vigorous ones receiving an +increase represented by the higher figure. One monkey injected eight +times has risen from 1. to 24. mg. with constantly a negative response +over a period of nine years. + +Doses for Lemures are relatively higher, averaging 1.5 mg. or about 0.5 +mg. per kilo; they are increased in the same manner as above. + + +THE TEMPERATURE TAKING. + +Injections are usually made in the late forenoon, temperature records +being started at the usual three PM. hour and continued at four-hour +intervals for forty-eight hours, giving thirteen records over two days, +a time period presenting two complete cycles of diurnal variation. This +was found necessary because certain cases do not react during the first +day. Explanation of this was sought in the nature of the lesion but +could not be found further than that mild early lesions may give it but +it cannot be read as indicative of low activity since one case of +laryngeal tuberculosis had this “delayed reaction.” At times it has +seemed to occur when the injection fluid formed a blister under the +skin, a pocket in the areolar subcutaneous tissue, whence absorption +would be slow. Whatever the correct explanation, experience has +justified the recording of temperatures for full forty-eight hours. + +[Illustration: + + CHART G. Composite chart of five non-tuberculous Cynopithecus. +] + +[Illustration: + + CHART H. Composite chart of eleven non-tuberculous Ateles. +] + + +THE REACTION. + +The experience gained with these monkeys supported definitely the +general opinion that tuberculin injected into healthy animals will not +disturb the temperature but will produce decided changes in that of +tuberculous animals. The reaction in the tuberculous animals may assume +several characters, of which usually two are combined in a chart. The +commonest and most convincing is a definite rise in the first twelve +hours, amounting to one degree or more; rarely it may be three degrees +(W). This is followed either by a maintenance of a high level or an +attempt to perform the night drop. It may be said that in general there +is an abortive attempt in nearly all tuberculin reactions to simulate +the V of the normal cycle; this can be seen in charts M, N, O and P. +Another rise may be attempted during a similar period of the second +twenty-four hours or the whole course may at that time approximate the +normal. A modification of this type of reaction is the performance of +the whole daily rhythm on a high level, set, as it were, by the initial +three PM. record. This form is confusing at times and has been +responsible for at least one of our mistakes. Combined with this high +level of curve is a tendency for the second twenty-four hours to be +higher than the first day (See Variegated Cebus Q and Sooty Mangabey R +and Chacma Baboon W). The second type of reaction, illustrated by chart +S, fails to resemble the normal daily cycle of the monkey temperature +but has sudden rises and falls as its characteristic feature. We have +learned to look with suspicion on all charts with sudden marked changes +of record even if they follow in the main a rhythmic course. The sudden +fall exhibited by a very sick monkey illustrated by Grivet Monkey (T) +and Campbell’s Monkey (U) is a bad sign. It has been met more often in +advanced caseous pulmonary tuberculosis than in any other tuberculous +lesion. On two occasions it has been seen in the absence of tuberculosis +so that retest is indicated if the specimen be valuable; such animals +however rarely survive the disturbance incident to the test as they are +usually suffering with some serious disease. Illustrative charts of +several positive reactions serve to elucidate their character better +than description. If comparison and contrast of the normal and post- +injectional temperature be made, the conclusions are definite. + +[Illustration: + + CHART I. Composite chart of eight non-tuberculous Cercocebus. +] + +[Illustration: + + CHART J. Composite chart of twenty non-tuberculous Cebus. +] + +It cannot be said that any type of reaction indicates a particular form +of disease although the last type, the falling of the temperature beyond +the thermometric registration point, usually means advanced lesions +especially of the caseous pneumonic form. A very small lesion may give a +definite reaction as in Cebus (V). + +[Illustration: + + CHART K. GEOFFROY’S MARMOSET (Leontocebus geoffroyi). Non-tuberculous. +] + +The examples given are those of a definite character but there are many +charts that vary from the normal upon which a decision is extremely +difficult to make. Such animals are held in quarantine to be retested +after the lapse of three months. Early in the work a suspected specimen +was reinjected after two weeks, failed to give a reaction but died in +about two months of tuberculosis. The nullification of the test by +previous injections of tuberculin is well known. Three months’ interval +permits a disappearance of the non-sensitivity and allows any latent +tuberculosis, possibly stimulated by the toxin, to develop. Repetition +upon the same monkey has occurred as high as ten times without apparent +harm. + +[Illustration: + + CHART L. POTTO (Perodicticus potto). Healthy. +] + +There are sometimes in human beings local reactions at the point of +injections. These have been entirely lacking from our monkey specimens. +Nor have we ever seen secondary tuberculous lesions appear at the point +of the needle-stick. Aseptic syringes and generally cleanly technique +have also protected against local abscesses. When an animal is injected +he may scratch or pick at the spot for a minute or two but thereafter +seems to ignore it entirely. + +[Illustration: + + CHART M. MONGOOSE LEMUR (Lemur mongoz). Tuberculous. +] + +[Illustration: + + CHART N. BLACK HANDED SPIDER MONKEY (Ateles geoffroyi). Tuberculous. +] + + +RESULTS. + +The value of the test can best be estimated by a recital of the +mortality of monkeys, from tuberculosis, since its inception. Before the +test was started practically every monkey in the collection for +sufficient length of time to be exposed died from the disease. The +average duration of exhibition life of all specimens up to 1903 did not +exceed eleven months. The time has risen almost uninterruptedly until +now it is thirty-five months. There are, at time of writing, sixty-eight +specimens in the cages which have been on view from one to one hundred +and eighty-five months with an average of fifty-four months. These +figures speak for themselves as evidence of the reduction of infection. +The average mortality from enteritis and degenerative bone disease has +remained about the same through all these years. Percentage figures such +as are recorded in our yearly report are misleading because all monkeys +written into the property record of the Garden are listed and since some +of these specimens remain in quarantine, they do not properly belong to +the exhibition collection. Up to 1906 when the test technique was +perfected nearly all deaths were due to tuberculosis, the figure for +1906 (including experimental animals) being 78 per cent. However from +February 1906 to October 1907 and from then until May 1910 no case of +tuberculosis occurred in the exhibition cages and both deaths at these +given times seem like infection from visitors. During the next three +years thirteen monkeys died of the disease in the exhibition and many +more in quarantine. By 1913 the outbreak was stamped out. Its +explanation is not so very far to seek. In the fall of 1910 we obtained +some suspected monkeys which were kept in one of the quarantine rooms. +After repeated testing two were passed. From them five cases are known +to have originated and it was not until in 1912 when the whole +exhibition house was cleaned of specimens, thoroughly disinfected and +fumigated and until every specimen was retested, that the infection +passed. In 1914 no cases occurred, while in 1915 a case either slipped +through undetected or was a visitor infection; 1916 two cases, 1917 one +case, 1918 one case (see orangutan charts), 1919 and 1920 none and 1921 +one case, 1922 no cases. Since 1912 the whole monkey collection has been +tested every two years, a method which enabled us to catch a small group +in 1916 and has protected the collection since then. Three of the six +monkeys specified above were never placed free in the general cages of +the exhibition house, they being segregated in smaller cages. One, the +orang, was with its mate in an isolated cage. The other two were in +larger cages and their history suggests visitor infections. + +[Illustration: + + CHART O. RHESUS MACAQUE (Macacus rhesus). Tuberculous. +] + +[Illustration: + + CHART P. ORANG UTAN (Simia satyrus). Tuberculous. +] + +We have never underestimated the possibility that an occasional very +early case might evade detection by this test but we believe the history +just outlined warrants us in depending upon it for the protection of the +exhibition. By the tuberculin test we have detected the existence of the +disease in twenty-three per cent. of specimens. Every condemned +specimen, forty-one, showing tuberculosis, gave a positive test. Fifteen +monkeys condemned on their temperature charts failed to show the +disease. Eight per cent. of the tests resulted in suspicious charts, and +the animals finally died of the disease in quarantine. Fifty-six +tuberculous monkeys died on exhibition, of which thirty-one were +original there and twenty-five their contacts. Twelve of the thirty-one +were in the early stages of the work, thirteen due to our misadventure +of 1910 and the remainder, six, scattered over nine years. + +[Illustration: + + CHART Q. VARIEGATED CEBUS (Cebus variegatus). Tuberculous. +] + +[Illustration: + + CHART R. SOOTY MANGABEY (Cercocebus fuliginosus). Tuberculous. +] + +Another interesting experience concerns the exhibition of a group of +Rhesus Macaques in an open “band stand” cage. The idea arose in an +attempt to find a separate exhibition space for some good specimens that +gave unsatisfactory charts, with the purpose of applying at the same +time the “open air” treatment if tuberculosis existed. The experiment +has been entirely successful since in the eleven years during which this +enclosure has been used there has been but a single case of tuberculosis +among twenty-six monkeys. Curiously enough this exception gave a good +chart and we suspect it was a visitor infection; no secondary case arose +from it. The animals housed in this cage keep in excellent condition, +their coats responding to our severe winter by increasing in thickness +and glossiness. Frozen toes, fingers and tails are sometimes seen but +these monkeys seem just as happy as the others. Breeding is active and +the young are lusty and husky. Practically the only deaths are due to +accident, or to abuse of old and less vigorous members of the colony. We +are unable to give comparative exhibition periods and death rates for +monkeys in the large house and this open cage because some specimens +have been changed from one to the other but it is certain that the +appearance of the “band stand” monkeys is better than those in the house +and there are four of eleven animals in the former which have been there +eleven years and only four among the seventy in the exhibition house for +that length of time. + +[Illustration: + + CHART S. VERVET MONKEY (Cercopithecus lalandii). Tuberculous. +] + +[Illustration: + + CHART T. GRIVET MONKEY (Cercopithecus sabæus). Tuberculous. +] + +The results of the foregoing work seem to demonstrate that the +tuberculin test permits the separation of tuberculous and non- +tuberculous monkeys and that its employment serves the purpose of +maintaining a healthy exhibition by excluding infected specimens. These +experiences form further corroboration of the facts that tuberculosis +begets tuberculosis, that a healthy individual is not a source of +infection. It follows that an obviously tuberculous animal should not, +need not, be a source of danger; the hidden or unrecognized case is the +menace. There is little or no problem when an unequivocally good or bad +temperature record is obtained; it is when there are slight variations +from the standard for the group that decision as to the disposition of +the specimen must be made. Nearly always such specimens are retested +until the records are definite. If they be constantly irregular the +animal is either sacrificed or exhibited in a separate cage far from +other monkeys. It is by the sacrificing of infected specimens or the +segregation of suspected ones that our collection is kept clear of +disease. + +[Illustration: + + CHART U. CAMPBELL’S MONKEY (Cercopithecus campbelli). Non-tuberculous. + (See page 533). +] + +Hygiene of a general character must be maintained also. Our quarantine +rooms are disinfected by formaldehyde and mechanical cleansing after +every case detected as tuberculosis, and painted every two years. +Monkeys associated with infected ones, are retested and then given a +bath of carbolized water before being put on exhibition. The exhibition +house is mechanically and chemically disinfected at the injection time +each two years. All keepers are examined for tuberculosis upon beginning +their employment and those handling monkeys, periodically thereafter. +When a case of tuberculosis dies, all animals in the same and adjoining +cages are removed for retest and the enclosure scrubbed and disinfected. + +[Illustration: + + CHART V. WEEPER CEBUS (Cebus capucinus). Tuberculous. +] + +There is a source of tuberculosis upon the importance of which we can +only speculate—the visitor. There were two isolated cases in animals +which had passed the test with unexceptionable charts, three and four +months on exhibition; curiously enough no other cases occurred in their +cages. These we have laid to visitor infection since no previous +exposure can be traced for the specimens and no secondary cases +occurred. + +I can conclude this discussion of the tuberculin test and of the control +of tuberculosis by its use, by mentioning the possibilities for the +solution of the problem in man. While the eradication of the disease +cannot be accomplished as easily as if a potential source could be +eliminated by sacrifice, it will come in direct relation to the +earliness of detection of infection and isolation of the sources of +danger. Not so much the cough-racked consumptive but the unrecognized +early lesion whose bearer hawks and spits in public places or at home, +unaware of his malign power! + +[Illustration: + + CHART W. CHACMA BABOON (Papio porcarius). Tuberculous. +] + + +THE SKIN AND EYE TESTS WITH TUBERCULIN. + +The first of these can be dismissed briefly, for in a few cases it was +absolutely of no value. A known tuberculous monkey was injected _into_ +the skin of the chest with 0.5 mg. of old tuberculin. The small bleb +disappeared in a few hours and was followed by no reaction whatsoever. +Other attempts likewise failed, some of them I believe due to the +technical difficulty of injecting into the skin. This tissue is very +thin, delicate and loose at the less hairy places where a reaction might +be read—arm, chest, abdomen. The hairless parts of the rump might be +used, but are so often scratched and soiled with dirt that readings +might be misleading. The Von Pirquet test was done on the first +mentioned specimen and was likewise negative. His tuberculin test was +afterward positive. + +[Illustration: + + CHART X. BLACK APE (Cynopithecus niger). Tuberculous. +] + +The ophthalmic reaction is highly spoken of in the New York Zoological +Park and has been used elsewhere. It was tried by me at the time Doctor +Blair first discussed it, but with variable results. One set of two +monkeys was treated with Calmette’s purified tuberculin into the +conjunctival sac and given a subcutaneous dose of old tuberculin. +Another set received 1 per cent. old tuberculin into the conjunctivæ and +the usual subcutaneous dose. Although all these monkeys gave a +temperature reaction only one gave a conjunctival reaction. Fearing that +the two tests simultaneously might be an unfair trial, another poor +specimen was given an eye test which resulted negatively; a later +subcutaneous test and autopsy revealed the disease. Because of these +experiences and the fear that any reacting conjunctivæ might become +secondarily infected from the uncertain personal hygiene of the beast, +we decided to omit this method and rely upon the temperature test. + + +PATHOLOGICAL EFFECTS OF THE INJECTION OF TUBERCULIN. + +It is generally believed that tuberculin injected into tuberculous +animals, in doses large enough to produce a marked reaction at the site +of disease, may stimulate the process to growth and spread and that +certain parenchymatous organs in such bodies undergo degenerative +changes. We can give little information concerning the first point +because known infected animals have not been sacrificed during the test +and we are not informed of the degree of morbid lesion in those dying, +since we had no previous knowledge of its existence. + +[Illustration: + + FIG. 58.—EFFECT OF TUBERCULIN ON THE KIDNEY. AN UNUSUALLY SEVERE + REACTION IN THE RENAL TUBULES AND INTERSTITIAL TISSUE FOLLOWING A + TEST DOSE OF TUBERCULIN. SUCH A MARKED CHANGE SUGGESTS THAT IN THIS + CASE PRE-EXISTING RENAL DAMAGE WAS AGGRAVATED. THE ANIMAL WAS + TUBERCULOUS BUT HAD NO LESIONS IN THE KIDNEY. +] + +An interesting and practically useful observation has, however, been +made upon the kidneys of several monkeys dying shortly after tuberculin +injection. It consists in a marked cloudy swelling of the renal +epithelium and a congestion or even thrombosis of the glomerular +capillaries, accompanied sometimes by increase of nuclei in the tuft and +by amorphous material in the space of Bowman. Grossly such kidneys are +but little changed, albeit the cortical zone may be dull and opaque and +swell out slightly on section; very occasionally bloody streaks may +separate the cortical and medullary striæ. In a few kidneys there have +been suggestions of preëxisting nephritis but usually the findings are +confined to those given above. At all events true glomerulonephritis is +not often found. Monkeys which have this condition may or may not +exhibit a behavior suggesting its existence. Sometimes it will be noted +that the animal is dull and eats little, at other times the keeper will +report that the cage is seldom wetted and we know of cases in which only +an ounce or two of urine has been passed in a day. Two monkeys were +distinctly ataxic and incoördinate and one of these had a convulsion. +From one a specimen of urine showed albumen but no casts. + +These signs of renal affection are not always alone nor are the kidneys +necessarily the only part diseased since postmortem records show a +variety of accompanying lesions, bronchitis and enteritis, for example. +There are, however, several cases dying in a few days after tuberculin +injection, both with and without tuberculosis, in which the renal +changes were quite prominent; two examples, without tuberculosis, +exhibited the damage to the kidneys very well and with no other evident +visceral pathology. The relation of cause and effect may not be +unequivocal, but these findings suggest that the condition of the +kidneys deserves attention when tuberculin is to be injected. My +associate, Dr. Corson-White, is firmly convinced that the substance +whips up a preëxistent parenchymatous disease and wants to see a +urinalysis from every monkey that is in any way abnormal. + + +THE TUBERCULIN TEST IN OTHER ANIMALS. + +Two cases of tuberculosis occurred in White nosed Coatis (_Nasua +narica_) so that it was decided to test their neighbors in the next +cage. There is reproduced a composite (Y) of the temperature record of +three of these animals after receiving 2 mg. of tuberculin under the +skin. No tuberculosis was found in them at death, all dying within two +years. The similarity to the primate type of temperature curve is +striking. + +Chart Z shows the course of temperature before and after tuberculin +injection in a Bactrian Camel (_Camelus bactrianus_) ♀ which lived for +some months and showed no infection at autopsy. + +Charts AA and BB show the temperature ranges of respectively a healthy +and a tuberculous Bison (_Bison bison_.) + +Chart CC is that of a Malayan Sambur Deer (_Cervus equinus_) which died +a week after injection, showing fibrocaseous tuberculosis. The failure +to make an initial rise is noteworthy, but the fall in temperature may +be explained by the severity of the lesions and the approaching death. + +Chart DD represents daily and post-injection records of a Virginia Deer +(_Cervus virginianus_) which at death was found free of the disease. +Chart EE is that of a healthy American Elk (_Cervus canadensis_). + +[Illustration: + + CHART Y. Composite chart of three non-tuberculous coatis. +] + +[Illustration: + + CHART Z. BACTRIAN CAMEL (Camelus bactrianus). Non-tuberculous. +] + +[Illustration: + + CHART AA. AMERICAN BISON (Bison bison). Non-tuberculous. +] + +[Illustration: + + CHART BB. AMERICAN BISON (Bison bison). Tuberculous. +] + +[Illustration: + + CHART CC. SAMBUR DEER (Cervus equinus). Tuberculous. +] + +[Illustration: + + CHART DD. VIRGINIA DEER (Mazama virginiana). Non-tuberculous. +] + +[Illustration: + + CHART EE. AMERICAN ELK (Cervus canadensis). Non-tuberculous. +] + + + + + SECTION XVII—PART 2 + MYCOSIS + + +This is a general term applied to the infections with Hyphomycetes, but +in the zoological material discussed here it refers chiefly to the +growth of aspergillus in the air sacs and viscera of birds. A few cases +of cutaneous mould growth have been seen in mammals but are of trifling +importance; brief mention will be made of them on a later page. + +Under the names of Aspergillosis and brooder pneumonia, the infection +with _Aspergillus fumigatus_, _A. glaucus_ and others is well known to +breeders of chickens, ducks and ostriches. Literary references to its +occurrence in zoological collections are numerous, but there seems to be +no record indicative of its frequency in the various orders nor +discussion of the pathological types best exhibited by different birds. +There has indeed been some discussion of the actual entity, mould +disease, the picture found at autopsy being referred to secondary +contamination with fungi in the presence of bacterial infection. +Experiments by DeLong and others have been indifferently successful in +the production of the disease by inhalation of mould spores. The +appearance of groups of cases in breeding places, apparently all +exhibiting the same organism, in the absence of other varieties of avian +epizoötics seems to warrant the conclusion that the hyphomycetes can at +least be associated with a fatal morbid lesion of quite uniform +character whether or not they be the original invaders. + +Judging by our experience it would seem probable that the aspergillus +can, under conditions not fully explained, cause inflammation of the +avian air sac and tubercles in viscera, in the absence of other evident +causes of illness and death. Over three-fourths of our cases have no +other diagnosis than “mould disease”; this may be in part due to +overlooking other things, but to a much greater extent to the very +extensive mould growth which obscures all other changes. That +unexplained preparatory conditions may exist is indicated by general +observation and some experimental work. Whereas in breeding +establishments this disease occurs in epizoötics, or in groups of cases, +with us it is enzoötic, constantly present, never, however, bursting +forth in virulent form with high mortality. Nor is the condition highly +contagious. + +In an attempt to explain its source I examined over forty varieties of +feed and found therein several strains of aspergillus and of mucor; the +latter occurs occasionally in the avian air sac. The infective material +is therefore constantly present, and it would seem that if it were +capable of initiating a fatal disease many more cases should come to our +attention. Perhaps these moulds do gain access to the avian air sac and +are killed off, or only assume a pathogenic rôle when they are in large +numbers or a preëxisting disease assists them. Since our records do not +support the idea that a preceding condition must exist for a growth of +mould to be successful, and yet pathological and experimental +observations suggest that something helps its colonization in the air +sac, what are such conditions? Moulds grow on feed and litter in which +birds pick; from this it is quite possible for a piece of grain or even +inorganic matter laden with spores to be inhaled and lodged in a +secondary alveolus near the air sac whence extension into the air spaces +could occur. In addition I think it quite conceivable that a whole +colony of mould might be inspired with the same result, the mechanical +obstruction being sufficient physical damage to incite inflammation. The +continuous moist surfaces of the bronchial passages and air sacs afford +conditions favorable to the growth of mould and as inflammation is not +vigorous, little resistance is presented to its spread. + +The mode of operation of these hyphomycetes has usually been assumed to +be a mechanical one, local colonization replacing healthy tissue or +spreading along surfaces so that function is physically impossible. A +support of this idea is to be found in the fact that inflammation, as +produced by schizomyces, is trifling or absent; the necrosis that occurs +is due to choking off of tissue by the intricately tangled masses of +mycelia and blocking off of air or blood supply. The existence of an +infiltrating and necrotizing form in some parrots and gallinaceous +birds, suggested to me that a toxin might be responsible for some part +of mould action. Proof for this speculation was sought by injecting into +the pectoral muscles of pigeons an emulsion of a dead mould and a +filtered broth culture. Necroses occurred but only to an extent which I +interpreted as due to the physical destruction of muscle by the injected +material; they were larger with the dead mould than with broth filtrate. +I concluded therefore that aspergillus perhaps has no toxin as usually +described for bacteria. + + +TYPES OF MYCOSIS. + +Avian mycosis occurs in three different forms, two of which are probably +of similar nature and two are frequently combined. The first variety, +most often seen in gallinaceous and anserine birds, consists of +thickening and opacity of the air sac walls, upon the surface of which +either a curd-like pseudocoagulum or a velvety or fluffy mould growth +appears. This variety usually begins about the anteroinferior pulmonary +stoma on the right side extending thence to the related sac, upward +toward the wing and downward to the abdominal spaces. Occasionally the +middle thoracocervical space is involved, probably _via_ the opening in +the syrinx. Extension takes place by the way of normal passages, but +when the growth is dense it also seems to occur by continuity through +tissue. This variety may or may not be associated with the second, an +infiltrative type of lesion best seen in the lung. Under what seems to +be a true picture of mycotic pneumonia, dirty gray consolidated areas +will be found around the bronchial space, infiltrating in all directions +and without definite boundaries. A similar lesion has been seen also in +the liver on rare occasions, but the lung is its usual seat. Judging +from microscopic appearances this is a process complicated by the +addition of bacteria. + +[Illustration: + + FIG. 59.—NODULAR OR TUBERCULAR MYCOSIS IN THE LUNGS OF A DUCK. ONE- + HALF OF THE LUNG IS CUT AWAY AND LAID ON THE INTESTINES TO CONTRAST + THE PLEURAL AND SECTION SURFACES. +] + +The third variety is nodular or tubercular mycosis, a process of +probably more chronic nature since around the isolated lesions +connective tissue is perceptible, it being absent or inconspicuous in +the other types. The formation of gray or yellow-white nodules from a +few millimetres to a centimetre in cross section, is the characteristic +production in this variety. Lungs, liver, spleen, intestines and air +sacs are involved in about this order. Attempts at explanation of this +peculiarity of growth were made in the direction of identification of +the species of mould, kind of bird and probably degree of resistance. No +conclusions could be drawn since the same variety of mould was found in +this as in other types; no bird showed a special susceptibility or +resistance to it. It is quite difficult to obtain a culture from nodular +mycosis, it being necessary to crush or grind the solid masses before +making cultural implants. This variety should always be differentiated +from tuberculosis by staining for the organisms. + +Histologically studied these three types are not as easily separated as +the gross appearances would warrant one to expect. The original mould +nodule begins in essentially the same manner in all, a small +colonization of mycelia and spores which grow centrifugally, but ever +becoming more intricately wound in their first location. As the tissue +is invaded, total necrosis takes place, no recognizable cellular +architecture being left. When fully formed the mycotic tubercle consists +from the centre outward of a necrotic mass, in which spores and mycelia +stain indifferently well, surrounded by a dense zone of fully formed +mould beyond which mononuclear cells and a few loose fibrils may be +found. The circumferential tissue of the viscus supplies a mild +congestion and perhaps a moderate connective tissue capsule. Giant +cells, as known for tuberculosis, do not appear. + +Where the process involves loose tissue like the lung, especially when +growing rapidly, the sporulating heads of the mycelia stretch out in +advance of the main mass and resemble rays. So too in a rapidly growing +nodule radiating mycelia are sometimes seen but never with the +regularity of arrangement typical for actinomycosis. Diffuse and +irregular mycelial spread is characteristic of the second or +infiltrative type of lesion and between the mould stalks one may +discover well preserved tissue cells and at times bacterial forms like +cocci or bacilli. This picture, suggesting as it does bacterial +admixture and more active inflammation, leads one to the conclusion that +the morbid process in which it is found does not represent mould disease +_per se_, but a mixed infection. Whether or not the bacterial disease +exists first and paves the way for the mould I am unprepared to say; I +am inclined to the view that mycosis can start by itself. + + +INCIDENCE IN AVIAN ORDERS. + +Mycosis may be said to occur in all birds although the appended list +fails to show cases in a few of the orders included in this study; the +sum total of autopsies from missing orders is only 45, so that they may +be ignored. + + ═══════════╤═══════════ + │ per cent. + Passeres │ 3.7 + Picariæ │ _1.2_ + Psittaci │ 3.9 + Striges │ 6.7 + Accipitres │ 5.1 + Columbæ │ .6 + Galli │ 2.7 + Fulicariæ │ _8.6_ + Alectorides│ _2.7_ + Gaviæ │ _10._ + Impennes │ _40._ + Herodiones │ _2._ + Anseres │ 6. + Struthiones│ _9.4_ + ───────────┴─────────── + For meaning of italics + see foot note Table 1. + +[Illustration: + + FIG. 60.—MICROSCOPIC APPEARANCE OF ONE OF THE NODULES. NOTE THE + CENTRAL NECROSIS AND THE CLOSE FIBROCELLULAR PACKING IN THE + RESTRAINING CAPSULE. +] + +[Illustration: + + FIG. 61.—MYCELIAL GROWTH IN AN ALVEOLUS IN THE RAPIDLY SPREADING + VARIETY OF PULMONARY MYCOSIS. SEVERAL FRUIT-HEADS ARE VISIBLE. +] + +These figures hardly permit conclusions as to relative vulnerability +unless the large percentage of cases for the small number of Impennes, +Gaviæ and Struthiones be permitted to stand. Judging from orders upon +which there are at least one hundred autopsies, owls, ducks and eagles +are most likely to suffer with mycosis. The percentages are, however, +not very convincing, and it would seem better with these data to +conclude for the present that any variety of bird is susceptible to +mould. Ostriches have long had the reputation of succumbing to this +affection, so that their outstanding position in the list is more easily +credited. + +It was to be hoped that the various susceptibilities would assist in an +explanation of the genesis of mould disease, but the result of the +analysis is suggestive only in one direction which can be stated quite +briefly. Ostriches, owls, shore and swimming birds have large stomata +between the lungs and the lateral air sacs and show a high mould disease +incidence. The natural thought is that access of mycelia and spores to +the air sacs is facilitated. More comparative data is being assembled +upon this point. Water birds are more susceptible to mould than land +birds; the percentages based upon cases and totals for orders is 5.4 to +3.7. + +The hygiene of mycosis is that of scrupulous cleanliness. Being hampered +by incomplete knowledge as to its genesis one can only apply common +sense measures. The germs having been found upon all the vegetable +feeds, it naturally follows that they cannot be eradicated, but their +colonization in large numbers can be prevented by repeated cleansing or +sterilization of bins and pans so that no mouldy or musty material is +given to the animals. At times of serious outbreaks sterilization by +burning all old feed, starting fresh with good material in bins painted +or saturated with disinfectant and then deodorized, is the only +salvation. Where the blast lamp can be applied, it is the safest +procedure. Autoclave sterilization should be thorough if practiced. By +constant vigilance we believe that our large exhibition house is +protected, but the sanitation of the pond, where many ducks have the +disease, can never be so satisfactory. + +Mycosis among mammals as an organic pathological entity is certainly a +rare condition, indeed almost always to be considered an accidental or +secondary one. In so far as human pulmonary disease is concerned it is +among the pathological curiosities deserving of individual report. +Moulds of several varieties have been found in intestinal ulcers, in +cranial sinuses and in the ear, while generalized mycosis from thrush +and favus are reported (cases of thrush in kites with fatal outcome has +been described on page 168). Cutaneous infestation with mould is quite +another matter for ring worms and similar conditions are now believed to +be due solely to the penetration by spores and mycelia into the +superficial dermis and into hair follicles. Numerous small lesions have +been detected on dogs and cats that correspond to the ring worms +described for them; to these we have devoted little study, because when +discovered the animal is removed, treated or killed to protect others. +Doctor Weidman has discovered several varieties of hyphomycetes which he +will report upon at a later time. No case of generalized mould disease +has been found in mammals, but Doctor Weidman has discovered a hitherto +undescribed mould in ulcers and cutaneous abscesses of seals; no +extension beyond subcutaneous areolar tissue occurred in these cases. + +Botryomycosis, while not strictly belonging to the foregoing group, may +be mentioned here because of its nodular tumor-forming superficial +growths. The case to be cited certainly belongs to this illy defined +group of diseases even if the organism was not isolated. It cannot be +accepted as wholly demonstrated that the disease described under this +name is always the same or that it has a single cause. + + + California Hair Seal (_Zalophus californianus_) ♀ . Had sore spots on + side for several months. Ate well up to three days before death but + ate something to time of death. + + DIAGNOSIS.—Chronic enteritis with acute hemorrhagic exacerbation. Low + grade chronic diffuse nephritis. Botryomycosis. General condition + poor, subcutaneous fat practically absent. On the left side of the + thorax there is a warty and nodular thickening of the skin overlying + diffuse and flat thickening of subcutaneous tissues. There are warty, + pustular, fistulous communications in four places between surface and + deep mass. They are covered over with light crust. On dissection mass + is found to be in subcutaneous tissue well outlined and encapsulated + and consisting on section of dense, white, firm trabeculæ forming a + mesh around yellow, soft areas which can be squeezed out. An adjoining + lymph node is much enlarged, dense, tough, resilient, on section + showing great connective tissue increase and solid brown medulla. The + thyroids are solid, brown, 3. x 2. x .6 cm. and 3.7 × 1.8 x .6 cm. + Trachea and bronchi contain pink froth but mucosa is negative. + Anterior edges of lungs are distinctly emphysematous. Remainder of + lung is uniformly congested and lobules are quite prominent. No + consolidations. Bronchial lymph nodes are slightly large, anthracotic + and wet. The heart is dilated, filled with mixed clot, muscle firm and + deep brown color. The liver surface is smooth, edges sharp, size + normal, color dull brown with greenish cast, consistency firm and + tough. Section surface is glistening, smooth, moist, lobules + indistinct but probably normal. The gall-bladder is full of fluid + yellow bile. The common duct is patulous. The spleen is of normal size + and shape, capsule opaque gray. The trabeculæ are prominent, the pulp + stippled rusty brown. The kidney is of normal size, capsule is smooth, + strips easily leaving a smooth purple surface. The organ is firm. The + lobules and lobular markings are distinct. The adrenal has a narrow + regular brown cortex and gray homogeneous medulla. The stomach + contains whole fish. The mucosa shows digestion, congestion and mucus + formation. Beginning at the pylorus and extending to the colon the + mucosa is swollen and edematous, yellow brown. In the lower part it is + quite firm and opaque. In the upper part it is more translucent except + where there are diffuse hemorrhagic mottlings of the submucosa. Here + and there are shallow erosions but no ulcers. The lymphatics of the + mesentery are definitely enlarged, white, pale and very firm. Smear + from the surface of the growth in side fails to show any definite + yeasts or moulds by Loeffler’s or Gram’s stains. It is largely made up + of polynuclear cells with many large mononuclears, many of which are + phagocyting polynuclears and nondescript bodies. Cultures failed to + grow. Microscopic section of liver shows marked congestion with slight + hydropic degeneration of the epithelium. The kidney capsule is not + thickened. Interstitial tissue not grossly exaggerated but connective + tissue nuclei fairly numerous. Some tufts have decidedly more + elongated nuclei than others and connective tissue around the stalk + vessels seems hyaline. Capsule for most part not thickened but space + contains cells and detritus in many instances. Epithelium of the + tubules for the most part swollen, loosened and without nuclei. Some + imperfectly formed casts. The intestine shows distinct congestion of + the whole mucosa with here and there definite small hemorrhages well + out in the villi. Slight round cell increase but no definite fibrosis. + In submucosa around vessels connective tissue is hyaline in many + places. The tumor on side consists of dense strands of connective + tissue forming alveoli of varying size containing an exudate of fibrin + and cells, about three-fourths of the latter being mononuclears. + Neither connective tissue nor cells are arranged in a characteristic + or peculiar manner so the observer is forced to conclude that this is + one of the conditions of the group called Botryomycosis. + + + + + SECTION XVII—PART 3 + THE STREPTOTHRICOSES + + +The organisms belonging to the genera Streptothrix, Actinomyces, +Discomyces and Nocardia as named by various authors have in common the +power to produce local chronic inflammation of gradually spreading +character and chronic course. Their most conspicuous representative, the +ray fungus, is best known as the producer of lumpy jaw in cattle and as +an occasional pathogen in man. Other members of the group cause certain +lymph-channel disease in domestic animals and pulmonary disease in man. +Pathogenic power, it is believed, lies in the ability of these organisms +to colonize and irritate, thus producing continuously enlarging +tumefactions, no evidence being at hand that any of them produce a toxin +either in their surroundings or within their own bodies. Because of +their constant irritation, bacterial mixed infection often ensues so +that purulent degeneration may occur at the original site of disease and +thence may spread via the blood vessels, or by continuity of tissues or, +if the mucous membrane of the pharynx be diseased, by the air passages. + +The study of the genesis of actinomycosis is by no means a closed one. +While it is believed that pastures and fodder carry the organism and +that it gains access to the tissues by passing into small wounds that +are made by sharp sticks or grain beards, the exact origin of the +disease is not understood. The original lesion is certainly trifling and +the fully developed one may not be discoverable until it is well under +way and causes external deformity. Even when sloughing has occurred, the +disease is not very communicable. The method of contraction of lymphatic +streptothricosis in cattle is believed to be from other cases _via_ skin +wounds or if abrasions be soiled by infective dirt. Just how human +beings contract these infections, in the absence of infected cattle is +unknown, but for the pulmonary form the route usually followed in +tuberculosis is probably taken. + +The material of our zoological collection permits few observations of +value upon “lumpy jaw” but we have encountered a streptothricosis of +kangaroos which may throw some light upon the whole subject and to these +cases I shall devote considerable space since no description of it +occurs in the literature. + + +ACTINOMYCOSIS. + +This disease has been diagnosed with certainty in two American Tapirs +and with reasonable satisfaction in three deer. Two Malayan Tapirs have +also had lumpy jaw clinically but the organisms were not found. It is +interesting and noteworthy that other zoological collections have +observed the disease in this same animal, a fact which suggests the high +susceptibility of the tapir to actinomycosis. There are recorded in the +protocols a few times sluggish ulcers on the tongue in other ungulates +but I am not prepared to label them as actinomycotic since on one +occasion smears and sections were studied with great care and nothing +found to justify such a diagnosis; nor were there maxillary or pulmonary +lesions. Before passing to a discussion of the diagnosis and morbid +characters it seems worthy of emphasis that our cases of this disease +should appear in one family of Perissodactyla and in one family of +Artiodactyla, in the latter not affecting Bovidæ, the family to which +domestic cattle belong. + +The diagnosis of lumpy jaw depends upon the growth of tumors in the neck +and maxillary regions which tend to break down and discharge a thick pus +containing “sulphur granules,” little masses of necrotic matter +surrounding colonies of the ray fungus. When these conditions are +fulfilled, the matter is easily enough settled. This was possible with +the tapirs but in the deer the conclusion was not so easily reached and +the diagnosis had to be made partly by exclusion. Anatomically the gross +and microscopic appearances of lumpy jaw in the tapirs follows the text- +book descriptions but our cases in the deer deserve separate comment. +Whether or not these differences mean a peculiarity of resistance on the +part of the animal or a new variety of streptothrix only further study +can settle. + +The beginning of the lesion in the deer was in the jaw bone as +circumscribed or fusiform swellings appearing on the under surface. +Growth usually progressed into the pharyngeal cavity and backward under +the ear, but a large tumor stretching down the neck was only observed +once. Suppuration and ulceration occurred twice but only once were +bacteriological observations possible before death, and then they were +negative. The fatal outcome seemed to be due to inanition, possibly +because the animal could not eat, for respiratory tract involvement was +only present once and then to a trifling degree. At autopsy, actinomyces +in ray form were found in one animal only, the diagnosis resting upon +histology in the other two. Nor did the degenerated centre of the +swelling contain the sulphur granules in any case. + +The microscopic characters of the tumors resembled those of giant cell +sarcoma and chronic rarefying osteoperiosteitis with areas of round cell +infiltration but no granulomata as are occasionally seen in lumpy jaw. I +have always felt that a “giant cell sarcoma” with inflammation when +seated in the jaw of a lower animal should be looked upon with grave +suspicion and be searched diligently for fungi. The organisms could not +be found in sections of any of these cases, although present in the pus +from a pocket in one. Reference has been made in discussing tumors of +the bones in gazelles and opossums to their resemblances to osteofibroma +and actinomycosis. The diagnoses were made after long study of the notes +and sections. Actinomycosis is usually unilateral while leontiasis +ossium is commonly bilateral; the tumors have not broken down nor spread +into the neck. In one macerated jaw bone the osteoporosis and +hypertrophic periosteitis were comparable to those of the bovine form +but the masses were not so extensive as is common for domestic cattle. + +Treatment of this disease was attempted in the tapirs but not in the +deer; the latter are too nervous to be handled repeatedly with safety to +themselves. Following the usual method, potassium iodide was +administered in saturated solution on bread, beginning at twenty grains +thrice daily and rising in two cases to sixty grains thrice daily. It +cannot be stated that any material improvement followed this heavy +dosage although in one case the disease was very protracted—some six +months, so that it may have modified the progress of the lesion. +However, other things were done for the beast so that the effect of any +one kind of treatment is difficult to evaluate. It was noted that iodide +served to keep the stools quite loose and that its withdrawal was +followed by constipation; upon resumption of the drug normal bowel +movements appeared. Every soft spot was opened surgically to allow the +pus to drain away. A vaccine of _Act. bovis_ was prepared and injected +under the hide beginning at 0.5 mg. and rising to 2.5 mg. in five doses +after which the animal became so unruly that the injections had to be +discontinued. On the whole we are not impressed with the probability of +success in the treatment of actinomycosis in tapirs. In the future we +propose to try operation and the use of Dakins solution or Dichloramin +T. + + +STREPTOTHRICOSIS OR NOCARDIOSIS OF KANGAROOS. + +A fatal disease of Australian marsupials characterized by swellings and +ulcerations about the lips, teeth, tongue and cervical tissues is known +apparently all over the world by observers of these animals in +collections. From commercial shippers of animals, from zoologists and +naturalists we have reports that wherever kangaroos and wallabies are +exhibited this disease makes its appearance and carries off a +considerable percentage of the collection. A fully developed case bears +a noteworthy resemblance to lumpy jaw, being called “jaw disease” by +non-medical observers. However, it is highly probable that, while the +most conspicuous morbid changes occur around the jaw, the agent +provocative of the disease is capable of causing different pathological +effects and that certain cases of septicemia and gastroenteritis are due +to it; Doctor Blair of New York concurs in this opinion. Our study of +the problem would inculpate a variety of Nocardia, possibly assisted by +certain schizomyces. I have seen in the literature, but unfortunately +cannot locate, a reference to an article by a Russian who observed the +disease and was convinced that its cause is to be found in a +streptothrix[105] obtainable from the necroses in the soft tissues of +the jaw, a view entirely in accord with our findings. + +The disease is not very communicable because its appearance in a pen +need not be followed by secondaries in the mates of the sick beast. It +appears chiefly in newly acquired specimens but may develop sporadically +in those exhibited a long time and apparently not associated with recent +acquisitions. This suggests two or three possibilities. It may be +imported by new arrivals, or newcomers may meet a germ to which they are +unaccustomed and therefore less resistant, the strange surroundings +reducing their opposition to it. Old specimens may have enough +resistance to withstand infection entirely or only succumb to large +doses. Lastly one comes to the explanation commonly employed for +actinomycosis, the presence of the organisms in fodder or pasture, +perhaps all the time, but gaining entrance to the animal’s body _via_ +wounds made by sharp sticks or the beards of grain. + +While circumstantial evidence offers some support to this general idea, +it cannot be accepted as proven. I have not made studies of the feed for +the purpose of isolation of the streptothrix but cultures from the lips +and gingival margin of healthy and infected animals were made for its +cultivation. These attempts were fruitless, and without wonder since the +germ when isolated from a fully developed case is quite finical in its +manner of growth; there are so many kinds of bacterial life that they +may easily overgrow the one in quest. So, too, cultures made directly +from subcutaneous necrotic areas may not always give a positive growth +although smears from the same material may reveal numerous threads under +the microscope. + +The idea that sharp grasses are responsible for the origin of Kangaroo +disease finds a protagonist in Dr. A. S. LeSouef, Director of the +Zoological Garden at Sidney, Australia, a gentleman whose judgment +carries weight. He writes: “We have found that it is entirely due to +getting spear or barley grass in their food; owing to the formation of +the mouth, this grass gets wedged in between the teeth and the cheeks, +penetrates the flesh and allows the bacteria to get a footing, this in +time heaps up on the inside and forms an abscess that bursts exteriorly. +Formerly all the Australian Zoos lost animals through this cause, but +now, through being very careful not to give any rough spined grasses, we +never have the trouble.” Since receiving this letter we have removed +straw bedding, and feed only soft alfalfa which is carefully inspected +for foreign substances. During this time we have had two cases but the +period of observation is too short for final judgment as to the value of +feeding grasses without sharp beards and spines. The appearances of +cases sporadically without reference to the arrival of new specimens, +the low communicability of the disease, its beginning in the jaw in most +cases and the prominence of pulmonary and gastric lesions, all seem to +support the thought that the virus is received with the fodder or drink. +The anatomy of the kangaroo’s buccal cavity favors the collection of +material between the gums and cheeks and between the root of the tongue +and the molars, while the “hare lip” also affords a crevice in which +food particles or foreign bodies may accumulate. These three places seem +to be the starting points of most of the cases. + + +THE COURSE OF THE ATTACK. + +Despite careful watching of the exhibition specimens it is often +difficult to detect the beginning stages of the disease. Since our last +outbreak it has been the practice to examine all kangaroos thrice yearly +by catching them, inspecting the buccal membranes, teeth, tongue and +nose and by palpating the jugular and sublingual regions. This procedure +succeeded in catching one very early case from which the original +changes can be described. + +The animal appeared in generally good condition but close inspection +revealed a “running nose,” a purplish mottling along the gingival margin +of one lower jaw below which was a doughy swelling; no internal +ulceration had appeared nor was there a visible change in the external +contour of the jaw. Within a few days a small fusiform lump appeared +along the body of the lower maxilla which spread gradually backward, the +nearby soft parts becoming involved very shortly. This particular animal +died without ulceration but with evidences of septicemia. Usually at the +time that the lump is noticeable the animal loses appetite, becomes +inactive and seems depressed; no especial change in the coat need be +perceptible although it may be lusterless or at times ruffled. In the +cases with great involvement of the cervical tissues, dyspnœa is an +early sign but I lay this more to pulmonary disease than to mechanical +obstruction of the upper air passages. The loss of appetite is in large +part due no doubt to the discomfort of chewing and swallowing in the +presence of an inflammatory mass in the neck. The eyes usually remain +normal until quite late. No change in the character of the droppings is +recorded. + +A slightly different course is followed by the cases that have the +primary lesion in the “hare lip” and nose; from these the masses along +the jaw may be entirely missing. After an initial stage of “running +nose” with or without swelling of the upper lips and alæ of the nose, +the animal rapidly goes down hill, with dyspnœa, loss of flesh, perhaps +loose stools, lusterless eyes and a “dead” coat, a series of signs +indicative of a septicemic state not pronounced in the first variety; +any form of this infection may however present course and pathology of a +septicemic character. If the beast live long enough ulceration may +appear on the upper lips or a large area of necrosis between them may be +discovered. + +There have been in our series two cases, believed to be due to the same +virus, which gave a picture of septicemia with pulmonary localization; +they will be discussed in detail later but are of interest here because +they were not known to be sick until the day before their death. A +similar failure to evince signs of sickness is found in the +gastrointestinal cases, those with ulcerations in the stomach and +perhaps an accompanying catarrhal intestinal inflammation. At most the +report will be that the specimen was “off its feed.” + +[Illustration: + + FIG. 62.—KANGAROO STREPTOTHRICOSIS. ULCERATIVE AND NECROTIZING PROCESS + IN “HARE LIP” AND IN MUCOSA AND BONE OF ANTERIOR PORTION OF HARD + PALATE; TEETH HAVE FALLEN OUT ON LEFT SIDE. +] + +The signs of Kangaroo disease with exception of those applying directly +to the nose and jaw are therefore very vague and one is limited to +observation of the contour of the head and of the discharge from the +nostrils. Because of the indefinite nature of the earliest changes, the +duration of the disease cannot be stated with accuracy but from the time +that the swellings are perceptible it is not very protracted if no +treatment be given. Some cases die in four or five days while others may +last up to three weeks and we believe that two of our cases may have +been existent longer than that. It is impossible to estimate the +duration of the septicemic and gastric forms although the latter, +judging by the appearance of the ulcers, are believed to be chronic. We +believe that frequent inspection and the precautions as to the character +of fodder are the only special hygienic measures indicated. + + +THE INCIDENCE OF THE DISEASE. + +Not the least puzzling character of the disease is the variability of +its appearance. There have been groups of cases in our records; for +example the following periods showed several while the intervening years +lacked them entirely—1905, 1907–8, 1911–2, and 1920–1. The second and +fourth outbreaks were definitely related to a new arrival but the +records do not show that such was the case for the other two. Mr. Joseph +who supplied us with many specimens, tells us that he has had an +experience of fifty-four cases in 200 kangaroos and then failed to +encounter the disease for years. Perhaps this irregularity of appearance +has something to do with the character of food supplied to the animals. + +Among seventy deaths of Macropodidæ we have had thirty-three cases of +the varieties which I have included in this infection, made up of the +following forms: cases limited to the jaws, pharynx and neck, six; cases +of this sort with extension to lungs and stomach, ten; cases of this +sort with general spread suggesting septicemia, five; gastrointestinal +and hepatic, eight; nasal and sinus infection without necrosis in the +jaw and with general spread including the lungs, four. The total +incidence in Kangaroos is therefore 47 per cent., the necrotizing forms +being 30 per cent., the gastrointestinal 11.4 per cent. + + +THE PATHOLOGY. + +The essential features of the necrotizing variety of this disease are +similar to those of actinomycosis—an inflammation giving rise to much +fibrous tissue overgrowth enclosing pockets of softening, the whole +process causing a deforming tumefaction. While primarily developing in +the soft parts, this streptothricosis behaves like the ray fungus in +that it spreads not only along clefts of tissue but directly through +muscles and organs and even bones. Rarefying osteitis with irregular +attempt at repair in the form of productive periostitis may be found in +both infections. There is however a greater tendency to ulceration and +general disease in the marsupial form, variations which seem referable +to secondary invaders. When however the massive tumorous, necrotic and +ulcerative characters of this streptothrix disease are insignificant or +absent, the pathology is modified to the extent of obvious bacterial +mixed infection, there then being catarrhal and fibrinous inflammations +with degenerations of the viscera. + + +BACTERIOLOGY. + +Since the pathology varies with the bacteriology as seen at this +laboratory, it is well to pause at this time in a discussion of the +former subject to introduce a brief statement of our findings in the +latter, leaving however a full description thereof for later paragraphs. +It is relatively easy to find in smears from necrotic masses threads of +streptothrix, straight or curved with heavy blunt, but not bulbous, ends +and never branched. Similar forms may be found in the necrotic tissue, +both free in the softened area and near the margin of the healthy +tissue, as irregular colonies growing in a tangled mass from the edge of +which radiating threads may be seen. It has not been possible to find a +“ray” growth with anything like the regularity so characteristic of the +actinomyces nor do the ends present the bulb distinctive of that +organism. Branching has been found once only, it being very uncommon in +tissues although beautifully developed in cultures. While not especially +sought, cocci and bacilli have not been seen, by Gram stains, within or +immediately around the streptothrix colonies. Surrounding the mycelial +groups is a necrotic zone about which is a loose connective tissue full +of mononuclears and a few polynuclears. The centre of the colony is made +up of tangled mycelial threads and necrotic debris. From uncontaminated +necrotizing masses we have obtained cultures three times out of very +many attempts. + +[Illustration: + + FIG. 63.—KANGAROO STREPTOTHRICOSIS. ANTEROPOSTERIOR SECTION OF HEAD, + SHOWING MASSIVE TUMEFYING PROCESS IN LOWER JAW BONE. +] + +When ulceration or suppurative softening has taken place mixed infection +with lower bacterial forms naturally occurs and the whole picture +changes. Pulmonary complications, with or without evident ulceration in +the pharynx, also admit other bacteria. Streptothrical forms are often +easy to detect in stained smears and in cultures but the very extensive +bacterial flora soon overgrows them and attempts at isolation are +fruitless. Under the best of conditions their colonial development is +slow and tiny until they are well accustomed to saprophytic life. The +complicating bacteria that have been identified are _Streptococcus +pyogenes_, pneumococcus, pyocyaneus and colon bacilli to which may be +added moulds of the Aspergillus group but these all have been variable +in numbers and appearance; the most frequent and therefore probably most +important secondary invader is an organism we have not been able to +identify. + +This germ, a tiny, Gram-negative, non-motile rod with a tendency to +bipolar staining, will appear in smears from an ulcerated necrotic mass, +from the nasopharyngeal exudate and from pulmonary lesions and may +develop upon agar or blood media for the first generation but refuses to +grow after that despite our best efforts. At present we hope to have it +by growing material a long time in blood broth. Microscopical +examination has not revealed it in the tumor-forming variety but on one +occasion it was found in the lung; its Gram-negative characters make its +detection in tissue very difficult. For obvious reasons the importance +of this germ cannot be estimated but it seems from the frequency with +which it is encountered that in some manner the streptothrix may be +aided by this unidentified bacillus especially in the ulcerative and +septicemic varieties of Kangaroo disease. + +In so far as the diagnosis of this infection in the uncomplicated form, +like lumpy jaw, is concerned the finding of streptothrix by stain seems +adequate and its presence in the gastric ulcers and hepatic necroses +identifies this variety. The most difficult question to decide is the +identity of the cases without one or the other of these distinctive +features but with mucocatarrhal or purulent nasosinusitis followed by +pneumonia or septicemia, and of cases of primary pulmonary involvement. +These instances have been diagnosed as belonging to the same category +because of the presence of streptothrix in the exudate at the site of +the important lesions and because the type of lesion is similar to that +which complicates accepted characteristic cases. Inability to reproduce +experimentally any of these infections limits our criteria for judgment +in the matter. I am inclined to view these septicemic cases therefore as +initiated by the streptothrix, growing in the nose and sinuses or +inhaled into the lungs, aided by lower bacteria, an unidentified Gram- +negative bacillus being the most important. + +Having reviewed briefly the bacteriology of Kangaroo disease, its strict +pathology may be discussed more definitely in terms of the type of +infection. Reference has already been made to the method of pathogenesis +employed by the streptothrix and its congeners. Whether or not a toxin +is elaborated by these organisms is an unsettled question, especially +for the marsupial variety because as yet it cannot be made to produce +lesions in other animals. It is highly probable that all these organisms +find colonization easy in the animal’s body once they get well settled, +and that they act mechanically, producing necroses by their growth and +by attracting leucocytes in such large numbers that digestion of +devitalized tissue occurs, to an extent that resembles pus. The +inflammatory tissue is not distinctive, except in so far that fibrosis +enclosing pus pockets is peculiar to it. In softer tissue, like the +liver, fibrosis is not so prominent, whereas diffuse and irregular +spread is more pronounced. At the margin with the healthy tissue, +reactive, that is resistant, inflammation is no more in evidence than +within the tumor growth itself and as a matter of fact the tissues do +not seem to put up a good fight against the spread of the inflammation. + +[Illustration: + + FIG. 64.—KANGAROO STREPTOTHRICOSIS. STOMACH, SHOWING TWO ULCERATIONS + AND DEEP INFILTRATIONS OF THE WALLS. +] + +Histologically, aside from the finding of the streptothrix colonies, +there is nothing distinctive, the peculiar expressions of the disease +being most manifest in their gross characters. For the purpose of +describing the pathological features, the cases have been divided into +the necrotizing form around the jaw, a similar process in the stomach +and liver, necrotic cervical cases followed by lung involvement, the +nasal variety upon which pneumonia succeeds and a septicemic form +arising from any locality. Illustrative cases will be cited for each of +these forms, a method of presenting the pathology thought to be superior +to a general discussion. + +The first illustrative case is one localized in the tongue and +pharyngeal wall; it is quoted because of its strict localization. + + + Great Gray Kangaroo (_Macropus giganteus_). Sick four days, tongue + swollen so he could not eat. + + DIAGNOSIS.—Necrotizing process of floor of mouth and pharyngeal wall, + dilatation of heart, passive congestion of liver, acute diffuse + nephritis, inflammatory edema of lungs. General condition good. Jaws + and teeth negative. Floor of mouth firm in places, boggy in others, + but generally infiltrated. Anterior two-thirds of tongue purple and + green as if gangrenous. Root of tongue and adjacent floor of mouth + yellowish, wet as if from recent coagulation necrosis. In the muscle + of the tongue a line of demarkation is shown at end of hemorrhagic + zone behind which muscle is fairly good. Sides of pharynx, palate, + tonsillar region show superficial pseudomembranous inflammation and + yellowish gray, wet infiltration of muscles. Epiglottis purple and + swollen to twice normal size. Laryngeal mucosa deeply injected, + swollen and covered with tenacious gray mucus. Trachea and bronchi + deeply injected and slimy. The lungs are uniformly deeply injected and + along course of bronchi in lower lobe, lung tissue is distinctly more + boggy than elsewhere. On section this area is slightly paler and more + granular than the rest of the lung. Lung is everywhere slightly + edematous. The bronchial lymphatics are swollen, pale pink and + edematous. The heart is dilated acutely judging from the left + ventricle wall which is nowhere over 1 cm. The liver is slightly + enlarged, surface smooth, edges sharp, color deep purple, section + surface very bloody. The spleen is soft, capsule smooth, pulp + homogeneous purple, follicles not visible, trabeculæ normal. The + kidney is slightly large, capsule smooth, strips easily leaving purple + surface. The cut surface swells out, has irregular striæ, congested + lines between, glomeruli visible and large. Smear from centre of + tongue muscle shows staphylococci in some places in colonies, and + long, slender rods. + + +The following case is one of gastric, intestinal and hepatic +involvement, apparently primary, the last possibly arising by a +hematogenic or lymphogenic route. Judging by the slides of the gastric +wall the process started deeply and broke through the mucosa. This +cannot be asserted definitely since kangaroos are susceptible to +gastritis so that the streptothrix may have been implanted upon a +preëxisting inflammation. + + + Black Wallaby (_Macropus ualabatus_). Congestion and edema of lungs, + abscess of stomach and liver (streptothrix), ulcerative enteritis, + necroses of spleen and lymph nodes, congestion of kidney. The animal + is thin, hair loose. The mouth and nose seem to be absolutely healthy. + The weight of the lungs is increased by congestion, they are solid, + homogeneously red, with no air in any lobe except at edges. A piece + cut from centre of lung sinks quickly in water. The trachea contains + frothy blood. The heart muscle is soft, flabby and lustreless, + chambers dilated, valves normal. The liver is of normal size, firm, + smooth surface, sharp edges, red-brown color. The small sublobe of the + liver which lies between the gall-bladder and the pyloric end of the + stomach shows a large abscess 4 × 3 cm., apparently starting in the + substance of the liver _via_ the bile ducts. This is certainly not + extension from the stomach abscess as the liver lying against the + stomach is nearly normal. The abscess is sharply circumscribed with a + zone of congestion about it. Aside from congestion the rest of the + liver is normal. The common bile duct is large and freely patulous. + The capsule of the spleen is thick, consistency firm, pulp deep red, + irregularly mottled by pale areas of necrosis. The kidney capsule is + smooth, strips easily leaving a smooth, brown surface. The organ is + firm. The section surface is glistening, the cortex wide and + congested, the medulla normal. The adrenal medulla is deep purple with + congested line between it and the pale cortex. Most of the gastric + mucosa seems good. At about the middle of the lesser curvature is an + ulcer about 4 cm. across. The shelving edges are covered with + apparently normal mucosa. The centre contains bloody pus and nodular + masses of the submucosa extending in finger-like projections through + the pus. At one point on the greater curvature there is a small pocket + of pus on the serous side which has not ulcerated through to the + mucosa nor broken into the peritoneum. The large intestine is deep red + and the follicles appear from the serosa as darker areas. On the mucus + side the follicles have ulcerated, having a necrotic centre and + shelving edges. The rest of the mucosa in the neighborhood is swollen + and deep red. The colon mucosa is dry and the contents are hard, dry + “baked” feces. The main pancreatic duct and the common bile duct form + a thick, firm, cord-like mass running through the pancreas and + enlarging the papilla of Vater into the duodenum. All abdominal lymph + nodes are large, firm and on section mottled with red areas. Culture + from the liver abscess failed to grow. Histological section of lung + shows moderate congestion, collapse of alveoli or their filling by + edema, epithelial and small round cells. There seems to be no fibrin. + This could be an early stage of pneumonia. Bronchi are for the most + part negative, little peribronchial round cell infiltration. No + streptothrix in two areas of round cell infiltration or in bronchi. + Liver section shows a part of the liver destroyed by hemorrhage, + degeneration and necrosis. The abscess consists of necrotic matter + surrounded by a zone of about equal numbers of mono- and polynuclears + and around this a loose fibrocellular zone. Streptothrix abundant in + the abscess. Lymph nodes show chronic inflammation and coagulation + necrosis without abscess formation. No streptothrix in areas of + necrosis. Kidney is very much congested with little or no damage to + secreting parts. Spleen shows enormous congestion, moderate amount of + pigmentation, connective tissue both trabeculæ and through pulp + increased, no areas of necrosis. In the stomach the mucous membrane + shows slight cellular activity and some degeneration—this amounts to a + true catarrhal gastritis especially in view of the submucous cellular + infiltration and the granulation tissue which has separated the + muscularis and involved most of the connective tissue. The edge of the + necrotic part begins abruptly, the mass of necrosis lying on an active + fibrocellular submucous and muscular layer. Streptothrix can be seen + at edge and in necrosis. + + +Pneumonia originating either by inhalation or _via_ the blood stream, is +illustrated in two stages by the succeeding cases. The first history +illustrates the pulmonary involvement as secondary to necrotic +streptothricosis around the jaw and tongue while the second animal’s +disease began in the nose and related sinuses. These two protocols +provide material for a discussion of two phases of the subject. + +The character of the early bronchopneumonia in the first is +peribronchial, and there is distinct indication of a generalized process +suggesting a hematogenic origin, whereas there is but one area of +bronchopneumonia in the second—a necrotizing lesion beginning in the +bronchus. Streptothrices are rare in the first case but reasonably easy +to find in the second. This latter is one of the cases which seem to +support the idea that nasosinusitis may have a streptothrix as its basis +in the absence of the usual picture of necrotizing “lumpy jaw.” These +cases also indicate that pneumonia may originate either by inhalation or +by the blood stream, and that perhaps the hepatic lesion may have the +latter origin. There have been two instances of necrotizing +periarthritis, in one of which the threads could be found. This also +suggests that spread through the blood stream can occur, possibly in +this respect to places where previous injury prepares for the reception +of the organisms. + +[Illustration: + + FIG. 65.—KANGAROO STREPTOTHRICOSIS. ULCERATION IN GASTRIC WALL AND + MASSIVE NECROSES IN LIVER. +] + +[Illustration: + + FIG. 66.—KANGAROO STREPTOTHRICOSIS. SECTION OF LUNG SHOWING EARLY + ABSCESSES AND NECROSES, ONE WITHIN A BRONCHUS, ONE IN + SEMICONSOLIDATED PULMONARY TISSUE. NOCARDIAL STRANDS COULD BE FOUND + IN BOTH AREAS. +] + + + Thigh striped Wallaby (_Macropus thetidis_). Streptothricosis of soft + tissues of jaw. Early bronchopneumonia. Acute fermentative gastritis. + Acute general infiltrative enteritis. Cloudy swelling of myocardium. + The general condition of coat and of nutrition is good. The jaws are + wide and the maxillocervical region full, both due to an indurative + inflammation of the gums, tongue, floor of mouth and upper cervical + tissues. At either side of the tongue and running around body of + maxilla both sides, the inflammatory tissue becomes softer and there + is an area about one inch long where it is soft, gray and contains + yellow gray bodies in a grumous matrix. The teeth seem sound as do the + external buccal tissues. The nasopharynx is free from induration. The + bone on the left side shows a periosteitis with involvement of the + superficial layers of bone, while on the right side the periosteum is + swollen and opaque but the bone is free. The thyroid is imbedded in + the edematous infiltration of the lower cervical tissues. The pleuræ + are free of fluid and adhesions. Lungs are collapsed, uniformly pink + somewhat emphysematous at places but give the impression of being + lumpy. On palpation numerous nodular areas are detected. These prove + to be peribronchial areas of gray-red solidity which swell out on + section. The bronchus contains a gray and bloody thick mucoid matter. + There is distention of the mesenteric vessels especially near the + enteric insertion. The liver surface is smooth, edges very sharp, + consistency firm, tough, resilient, color deep red, the section + surface is glistening, moist, opaque, architecture probably normal. + The gall-bladder is distended with viscid green bile; the common duct + is patulous. The spleen has a rough, thin capsule, consistency tough + and resilient, the section surface is mottled red with purple points; + on section two small, pale objects seem to be squeezed out. The kidney + capsule is smooth, strips easily leaving a smooth, deep red surface, + the consistency is soft, the cortex is deep red, then a purple line + between it and the red medulla, striæ invisible. The stomach contains + frothy grayish mush. The mucosa is finely mammillated, deep pink until + the last third when it becomes deep red, deeply injected and somewhat + thickened. The pylorus is closed. Externally the gut is congested, in + places translucent but for most part seems thickened by reddish + swelling of both external layers and mucosa. The mucosa is granular or + pebbly with here and there a small bloody suffusion. The histological + section of lung shows alveoli open, septa relatively thin but somewhat + congested, bronchi mostly open and connective tissue not increased. + Some few bronchi, especially the larger, show a slight catarrhal + bronchitis but mostly an infiltrative peribronchitis. The nearby veins + and arteries show the most striking change, there being in nearly all + of them a distinct thrombosis without circumferential pneumonia. In + one place a distinct peribronchial pneumonitis was found. The kidney + shows very marked congestion of all parts, causing compression, + cloudiness and granularity of the epithelium. Glomeruli and connective + tissue about normal. The intestinal serosa is negative save for + congestion. Submucosa is densely infiltrated with mononuclears, some + in definite groups. Section does not show areas mentioned in notes but + these could be accumulations of cells with congestion. No streptothrix + forms. Section from the infectious focus of face consists of active + granulation tissue, densely injected and filled with mononuclears of + two types, one the lymphoid cell, the other of the young connective + tissue type. Areas of grouping like abscesses are seen and some + necroses. Streptothrix in small numbers in the cellular collections. + + Nail tailed Wallaby (_Macropus unguifer_). Kangaroo disease of nasal + region. Necrotizing bronchopneumonia (Aspergillus fumigatus and + Micrococcus albus). Acute diffuse splenitis. Congestion of liver and + kidney. The general condition of coat and nutrition is good. The face + is wide just below the eyes. About the “hare lip” and the nose the + soft tissues are soft, gray, necrotic. All the internal nasal tissues + seem swollen, gray-red. There is subcutaneous edema, bloody in places, + around the right face, eye and jugular angle. Tissues of nasopharynx + swollen, deeply injected and covered by a thick mucus. Pharyngeal and + buccal cavities negative. Tonsillar areas pink and flat. Larynx and + trachea slightly swollen but pale on mucosa. Salivary glands and + cervical glands normal in size and pale pink. Pleuræ pale and empty. + Lungs swollen out uniformly, quite cottony except at lower right base + where there is a nodule about 3 × 5 cm. firm and doughy. On section it + is found to be a peribronchial consolidation of pale reddish gray + color and indefinite outline. The bronchus itself is deeply congested + and contains a grumous mass. The peribronchial lymph nodes are small, + soft, pink, homogeneous. The heart is negative. The liver is large, + surface smooth, edges sharp, color deep purple, consistency soft. + Section surface is glistening, smooth, moist, very dark purple with + obscure markings. The gall-bladder contains fluid brown bile; common + duct is patulous. The spleen is soft, tough, capsule pebbly, section + surface is mottled, light and deep pink, follicles and trabeculæ not + distinguished. The kidney capsule is smooth, strips easily leaving a + smooth purple surface, section surface is glistening, deeply + congested, striæ obscure but seem normal, glomeruli not visible, organ + is soft. The gums and teeth are not involved in the mycosis. The + stomach contains mushy digesting food. The mucosa is mottled pink, + soft, digesting, at lower half submucosa is deep pink, a few small + ecchymoses. From pylorus to ileum, serosa is deeply injected, + edematous, mucosa swollen and edematous, deep pink, loosened in + places, but translucent. Below this the mucous membrane becomes + smooth, flat, pink-yellow. Lower ileum and colon contain rather firm + fecal balls. Follicles nowhere prominent. The pancreas is small, soft, + yellow pink. The follicles of the mesentery are small, pink gray and + homogeneous. Smears from the bronchopneumonia show a threadlike Gram- + positive form and a few Gram-negative rods. Cultures from lung show + _Aspergillus fumigatus_ and _Micrococcus albus_. Nose too foul for + culture. Histological section of lung shows the alveoli mostly open + but the septa widened by congestion. Blood vessels are open and + contain recent clots; one vessel near lesion below is thrombotic. The + two large bronchi in section show catarrhal bronchitis and + infiltrative peribronchitis of which the latter is more severe and + advanced. Beside the larger is a necrotizing pneumonitis from which + nearly all the architecture has disappeared. The exudate is chiefly + mononuclear around the edges; centre no cellular identity. Another + mononuclear process not connected with bronchus in section is found + with an early necrosis. Streptothrix strands may be found in the + bronchial exudate and near the margin of the necrotic patch. They do + not grow in colonies however. The spleen shows general congestion + without pigmentation. Follicles large, solidly lymphoid. Connective + tissue about normal. The kidneys show marked congestion everywhere. + Capsule and intrarenal fibrous tissues about normal. Very severe + congestion which seems to have caused compression and granularity of + the epithelium. + + +The last case, judging by stained smears, is one of pure nasosinusitis +from streptococci and streptothrices. Cultures were not tried because of +the enormous bacterial flora. + +[Illustration: + + FIG. 67.—KANGAROO STREPTOTHRICOSIS. LOW POWER PHOTOMICROGRAPH OF A + NOCARDIA COLONY WITH NECROSIS WITHIN AND AROUND IT. THIS WAS FOUND + IN A SECTION FROM THE LIP OF THE SPECIMEN SHOWN IN FIG. 62. THE + BLACK BORDER CONSISTS OF PARALLEL THREADS SO CLOSELY PLACED THAT + THEIR SEPARATION UNDER THE CAMERA IS PRACTICALLY IMPOSSIBLE. THIS + TYPE OF COLONY RESEMBLES THE “RAY” COLONY OF ACTINOMYCES. +] + + + Robust Kangaroo (_Macropus robustus_). Acute purulent ethmoiditis. + General acute purulent anterior cranial sinusitis. Acute necrotizing + glossitis and pharyngitis. Cloudy swelling of kidney. The face seems a + little full and the subcutaneous tissues slightly edematous. The + nasopharynx contains a thick tenacious mucopus. Ethmoid and frontal + sinuses and turbinate spaces contain a thick purulent matter, the + mucosa being densely injected, swollen and velvety. Pharyngeal wall + and right half of posterior half of tongue are involved in a dull + brown and necrotizing process, quite sharply outlined by zone of + congestion. This process is comparable to the necrotizing gingivitis + seen in front of jaw in kangaroos. Larynx, trachea and lungs seem + uninvolved save for slight generalized congestion. Cervical lymph + nodes especially those about the larynx are definitely enlarged, soft, + moist and brown. Mediastinal nodes slightly enlarged, soft and pink. + The heart is negative. Liver normal. Spleen is soft, homogeneous dull + red. The capsule of the kidney is smooth, strips easily leaving a + purple surface. The glistening section surface swells slightly, vasa + recta are congested, striæ wide and pale, glomeruli not visible; + consistency is resilient. The mouth and teeth are not involved in the + process mentioned above. There is a small quantity of properly + digesting food in the stomach. Stomach and intestines negative. Brain + not involved. No extension from anterior cranial sinusitis. Smears + from the mucopus confirm the gross appearance and contain short chains + of streptococci and large diplococci. Smear from cut surface of tongue + shows innumerable small bacilli and diplococci but especially mycelia + with rather heavy clubbed ends but without true branching. One group + was found arranged like ray fungus. It is noteworthy that there is no + aspiration pneumonia and very slight evidences of septicemia. + + +BIOLOGY OF N. MACROPODIDARUM. + +The original discovery of the streptothrical forms was made in stained +smears from necrotizing lesions. They were considered as secondary +invaders until repeated observations of a similar character aroused the +suspicion that they stood in some important relationship to the lesion. +Early attempts at their cultivation were made under anaerobic +precautions, a method now known to be almost certainly doomed to failure +because a strain long under cultivation requires two to three weeks to +make an appreciable growth in the absence of air. Finally in 1911 a +successful cultivation occurred by searing the surface of an unopened +mass in a freshly dead animal and planting bits of the interior upon +aerobic blood serum plates. Colonies grew after three or four days and +from them the first strain was started. It grew for several generations, +long enough for the preparation of a vaccine, which will be described +later, when by mischance it was lost. In 1920 another successful +cultivation occurred, this time by incising a mass in the soft +sublingual tissue and plating in the same manner; upon this culture the +biology is described. Smear preparations offer no more than has already +been mentioned. + +Colonies develop upon blood serum plates as opaque, pale yellow, +circular, discrete masses with a slightly depressed uneven centre, but +without umbilication. They remain smooth and slightly glistening for +several days, then become slightly wrinkled and twisted with a more +definitely raised edge and a tendency to an uneven sinking in of the +centre. Transfers to agar slants show wrinkled continuous opaque, dull +yellow, sharply outlined growths which soon wrinkle, fold, and twist +like certain tubercle bacillus cultures. Spreading occurs, but is slow +after forty-eight hours. As medium becomes drier it is possible to see a +thin, colorless, wrinkled film stretching out from the main growth. If +the medium be dry or old or if only a small portion of seed material be +used and this scattered over the surface of the slant, discrete colonies +arise. These are circular, seldom exceeding 3 mm., dirty yellow-white, +distinctly umbilicated and without clear film of spreading around them. + + + In nearly all quite old cultures, a white chalky efflorescence appears + over the surface. + + The morphology of the young agar culture is chiefly mycelial or + filamentous, whereas from a culture on dried media and those showing + efflorescence, the organisms are short, heavy, deeply granular and of + the mycobacterial type. + + Glycerine agar.—Corresponds to agar. + + Blood agar.—Similar to agar but much less luxuriant. + + Blood serum.—Limited dirty yellow, raised, dull, wrinkled and + granular, tightly adherent to the medium. + + Potato.—Spreading, dirty yellow, much wrinkled, friable, tightly + adherent. + + Gelatine.—Limited growth as a wrinkled, tough scum only on surface. + + +[Illustration: + + FIG. 68.—KANGAROO STREPTOTHRICOSIS. HIGHER MAGNIFICATION OF EDGE OF + STREPTOTHRIX COLONY, FIG. 67. IT SHOWS THE DEEPLY STAINING MYCELIA + SEPARATING MUSCLE FIBRES WHICH ARE DEGENERATING. +] + + + Litmus milk.—No change for six days, then beginning slight alkalinity + which increases very little, shows digestion of the caseinogen, + slight, thin filmy growth on surface. + + On media such as litmus lactose agar and old Endo it grows slowly on + surface and assumes the color of the medium. + + Broth.—Only surface growth appearing during early generations, after + 3–6 days as a wrinkled, pale yellow scum very much like the tubercle + bacillus growth; later generations grow perceptibly in one to three + days. Medium perfectly clear. If a large mass be seeded into neutral + broth there is a perceptible increase in the growth after ten days. + The medium thereafter tends to a faint turbidity. Titration of broth + growth after twelve days shows alkalinity requiring 0.3 cc. decinormal + acid, while the control tube incubated same length of time showed an + acidity requiring 0.57 cc. of decinormal NaOH. + + On the following sugars there is a slight surface growth without + change in the color, Andrade indicator—dextrose, lactose, saccharose, + maltose, mannite, dextrin, galactose, salicin. + + Cultures observed on two per cent. neutral agar. + + + A.—Stained by Loeffler’s stain. + + + Twenty-four hours.—Shows threads growing out from a central amorphous + mass, but the whole does not retain the regularity or parallelism of + actinomyces. Threads are poorly stained and rather disconnected but + not jointed. Small number of metachromatic bodies apparently in older + individuals, certainly in the better formed ones. No intercalary + spores, unless the metachromatic bodies be so considered. Individual + threads measure from one-third to one micron in width. Metachromatic + bodies measure on the average one micron. + + The threads in the forty-eight hour preparation seem distinctly wider, + up to one micron and possibly become heavier toward the end, but do + not have a distinct bulbous extremity. + + In three days the threads are much longer, show distinct branching and + a tendency to transverse segmentation. More than one metachromatic + body may be present in one segment. + + Four days.—Still coarser, short segments have appeared separately. + Metachromatic body is coarser and blacker; some of the masses have + gone to pieces and show only a diffusely staining smudge of + metachromatic bodies. The short segments show a tendency to grow out + into threads. + + Fifth day.—Condition is much the same plus many young, delicate, + poorly staining threads. + + Sixth day.—The same but all seem to be somewhat wider and diffusely + staining. + + Seventh day.—More diffuse staining and decidedly fewer metachromatic + bodies. + + A.—Stained by Gram’s stain. + + Twenty-four hours.—All forms are light purplish. The threads stain + much more clearly than by Loeffler’s and show distinct transverse + segmentation of rather uniformly long bacilliform shape. Metachromatic + bodies not so distinct but seem larger where found. Coarser threads + have swellings in some of the areas which are not segmented and this + type seems to have more branching and metachromatic bodies; in other + words it would seem that this is a form that reproduces by budding or + intercalary spore formation. + + Forty-eight hours.—Much the same, more long threads with transverse + division, somewhat more delicate, generally fewer coarse threads with + swellings and spores. Still pale purple and not distinctly Gram- + positive. + + Three days.—Condition much the same. + + Four days.—Two forms present—definitely Gram-negative delicate slender + threads, nearly Gram-positive, and heavier, curved and twisted long + bacillary forms, some streptococcoid threads and a few bulbous short + threads. Very few metachromatic bodies. + + Five days.—Condition much the same except that the delicate threads + are inconspicuous and the darker purple bacilli have increased. + Metachromatic bodies increased as have swellings in coarser threads. + + Six days.—Much the same but for the appearance of young, delicate + definitely Gram-negative threads. There are fewer metachromatic bodies + and internal spores. + + Seven days.—The same. + + + B.—Grown on Loeffler’s blood serum.—Loeffler’s stain. + + + Twenty-four hours.—Delicate, poorly stained short threads, few tiny + metachromatic bodies. + + Two days.—Not well stained, relatively short threads show numerous + metachromatic bodies varying from exceedingly tiny dots to coarse + granules wider than the thread. These may be numerous in the same + segment and form a row from six to ten. Many short bacillary forms. + + Three days.—Poorly stained, metachromatic bodies apparently more + numerous but much smaller. + + Four days.—Almost entirely short, heavy bacillary forms, some of which + are very like diphtheria bacillus in the irregularity of width; many + metachromatic bodies, distinct branching, some of the small heavy ones + have fusiform swellings; practically no long, heavy threads. + + Five days.—Essentially the same, individual elements slightly larger, + fewer but coarser metachromatic bodies, more numerous round forms + suggesting large pale cocci. + + Six days.—Much the same but elements shorter, smaller and some more + segmented. + + Seven days.—More long forms of uniform staining but still a majority + of coccoid or short bacillary forms with irregular staining and + metachromatic bodies; no long threads. + + + B.—Gram’s stain. + + + Twenty-four hours.—Pale purple, almost Gram-negative, long, slender + but well outlined threads, a few coccoid forms, practically no + granules. + + +[Illustration: + + FIG. 69.—KANGAROO STREPTOTHRICOSIS. PHOTOMICROGRAPH SHOWING THE + SEPARATE THREADS OF NOCARDIA IN A SOFT NECROTIC LESION. +] + + + Two days.—Very pale, almost Gram-negative threads, very many coccoid + forms and short rods, considerable segmentation of the longer threads. + + Three days.—Increase in short, heavy bacillary forms with bulbous + ends, deeply stained ones and the granules being lightly Gram- + positive; long, slender threads are disappearing. + + Four days.—Almost exclusively short, heavy forms with bulbous ends + with coccoid forms, heavier forms almost definitely Gram-positive, + granules Gram-positive. + + Five days.—Much the same but more segmentation in the bacillary forms, + coccoid forms become more numerous. + + Six days.—Individuals are somewhat longer but there are many rods with + fusiform swellings containing granules; coccoid forms present in + chains sometimes. + + Seven days.—More long rods or short threads, pure coccoid and + bacillary forms. + + The morphology upon bouillon depends somewhat on age and upon the + location. Upon the surface the long branching mycelial type appears + early and persists until the whole surface is covered whereupon the + segments divide into coccoid elements with metachromatic bodies. If + heaping-up develop the coarse grains on the mass consist of granular + or coccoid rods. When growing in the depth the coccoid form is the + predominant one, only a few delicate mycelia, usually Gram-negative, + being found. + + The Gram character of the organism should be emphasized. The young, + delicate mycelia are negative or take a very feeble blue stain. The + heavy bacillary forms are Gram-positive. Like the ray fungus the heavy + ends are sharply Gram-positive, but unlike it, there has never been + seen a Gram-negative bulbous capsule around this end. + + +The determination of this organism was undertaken from the +classifications of Petruschky (Kolle-Wassermann), of Castellani in +Castellani and Chalmers’ _Tropical Medicine_, and of the Society of +American Bacteriologists. In the first classification it corresponds in +some ways with _Streptothrix hominis_, and in some ways with +_Streptothrix capræ_. As for the second authority it falls into the +Nocardiaceæ, section parasitica, subsection I, in that a distinct earthy +odor is absent and that there is no liquefaction of coagulated protein. +It resembles several of the species given in this subsection, but does +not correspond exactly with any of them. Consultation of the +classification of the American Bacteriologists would place it among +Mycobacteriaceæ. The facts that it is strongly aerobic, produces whitish +efflorescence which may possibly be aerial hyphæ and breaks up into +short segments, place it in the genus Nocardia. It seems, however, to +belong to a division of Nocardia which is close to the Mycobacterium +since the short elements are swollen, cuneate and usually heavy, which +is unusual in the more typical Nocardia. It is not, however, acid fast +and therefore cannot be classified among the Mycobacteria. This culture +seems to be a variety not heretofore described, and since its +association with the disease is so definite, whether or not it be the +cause, the name NOCARDIA MACROPODIDARUM is proposed, because the +kangaroos belong to the order Marsupialia, family Macropodidæ. + +The discovery of these organisms within tissues is by no means easy even +though the larger colonies may be located by staining. If Loeffler’s +method be used the central mass stains quite diffusely and the spreading +mycelia around the edge stain faintly. For study purposes this stain is +preferable to Gram-Weigert, since despite the positivity of the +cultures, the blue dye can be removed very easily from sections and only +with great care will enough remain to permit tracing of the separate +threads; with Gram stain no detail can be made out in the centre of the +colony, it being a diffuse blue. Careful search near the edge of these +necroses will usually succeed in the discovery of a few mycelia +stretching in between the mono- and polynuclears of the low grade +inflammation. This is best seen in the margin of gastric ulcers, but may +also be found in the cervical masses. When searching in the pulmonary +tissues the organisms are to be found in the bronchial exudate or at the +edge of pneumonias. In one nasal mucosa the mycelia were dispersed, not +growing in colonies as in localized inflammations. + + +EXPERIMENTS AT THE REPRODUCTION OF THE DISEASE. + +When the first culture was isolated it was injected into guinea-pigs; +its loss stopped further work because it could not be regained from the +animals. The present culture had been injected into guinea-pigs, +rabbits, opossums—all with negative results; such an experience is not +unknown for actinomyces. Intraperitoneal, intravenous methods having +failed, inoculation was made into the gums of rabbits and of opossums +with no result, even after traumatizing the mucous membrane. The +injection of about 5. mg. of a twenty-four-hour agar culture was made +directly into the masseter muscle of an opossum without producing even a +lump at the site. Atomizing a culture into the nose and throat of an +opossum seemed also without effect. Injection of cultures into the nose, +gums and labial tissues of a wallaby have been negative; nor has any +perceptible effect followed the atomizing of a heavy nocardial +suspension in broth into the trachea of this animal. + +The results of these experiments are in accord with those of many +similar attempts to reproduce actinomycosis. Perhaps in Kangaroo disease +the small Gram-negative bacillus is a necessary factor. + + +SPECIFIC PREVENTION AND TREATMENT. + +Encouragement that we were upon the right track was, however, found in +another direction. Improvement in human and bovine actinomycosis having +followed the use of vaccines, it occurred to me to try this method as +treatment and prophylaxis. The first culture to be isolated was just at +hand, so that it could be used at once. Five injections were given under +the skin of the thigh to a recently developed case of the ulcerative +gingival variety, a noticeable improvement occurring almost at once, and +at death there was an apparent cure of the local lesion. However, the +accompanying protocol made at the time tells the whole story, no +adequate explanation being at hand. + + + Red Kangaroo (_Macropus rufus_). Disease of the mouth first noticed + March 31, 1912, died September 13, 1912. Necrotizing osteitis, + arthritis and periarthritis of left ankle, subacute fibrinous right + pleuritis, hemorrhagic bronchitis with atelectasis in right middle + lobe, abscess of right middle lobe; passive congestion of lungs, + liver, kidney, chronic splenitis, chronic general lymphadenitis. The + animal is in general good condition except for a fusiform swelling + about the left heel with evidence of fracture. The necrotic process in + the hare lip, nose and palate has entirely disappeared. One front + incisor has gone and the other is loose. There is a scar on the under + part of the soft palate in a small healed channel between palate and + floor of nose. There is no evidence of pyorrhœa. Cervical and axillary + lymph nodes are much enlarged, pale yellow, firm and of the appearance + like early stages of Hodgkin’s disease. Fascias of cavities congested. + The lungs are mottled purple, air content decreased, section surface + purple, exuding frothy blood. The whole right lung is covered with a + thick fibrinous exudate, most intense over middle lobe at site of + atelectasis. There are light scattered adhesions. The anterior margin + of the lung is adherent to the pericardium which is covered in the + front by exudate. Upper and lower lobes show hypostatic congestion. + Middle lobe has separate bronchus filled with necrotizing blood clot + extending into a smaller bronchus with complete occlusion. The alveoli + supplied by the last show atelectasis like hemorrhagic infarct. There + is a small subpleural abscess near the margin of this atelectatic + area. The bronchial lymph nodes are slightly enlarged, mottled yellow + and pink, firm with large, diffuse follicles. The pericardium contains + 2–3 cc. clear fluid. The heart muscle is pale, purple and soft. All + the vessels are full of currant jelly clot. On the posterior surface + of the aorta internally about an inch above the valves there is a + patch of roughening with a suggestion of thickening and opacity. It is + comparable to the early stages of syphilitic aortitis. The liver is + normal in size, surface smooth, edges sharp, consistency firm and + friable, color purple. The section surface is glistening, smooth, + moist, and shows passive congestion. The gall-bladder contains fluid + brown bile and the common duct is patulous. The spleen is slightly + enlarged, firm and tough, capsule wrinkled. Section surface is mottled + red and purple with irregular gray trabeculæ and faint scattered + follicles with diffuse margins. The kidney capsule is smooth, strips + easily leaving a smooth brown surface. Organ is firm. The section + surface is glistening with a line of passive congestion with distended + vessels between the cortex and medulla which are of normal widths. + Intestines seem normal throughout. The pancreas is firm, pale pink, + slightly edematous. The mesenteric lymph glands are moderately + enlarged, yellow, firm, homogeneous with congested centres. About the + left ankle joint there is a necrotizing infection which has involved + the bone causing a pathological fracture of the lower end of the + tibia. Smears from the periarthritis, pleuritis and blood clot in the + bronchus show streptothrix, a short colon-like rod and a coccus in + fours—a picture precisely like that obtained from the jaw bone cases. + In addition to the above there is a very distinct encapsulated + pneumococcus form in smears from the blood clot in the bronchus. This + is the animal which was vaccinated with a culture made from the depths + of a necrotic mass, upon which treatment she rapidly improved and as + seen from the above notes recovered from the palate condition. Why she + should have a second infection apparently with the same organism is + difficult to determine. Possibly the second batch of vaccine was not + sterile, it not having been controlled because the first batch of + vaccine was sterile after one hour at 60° C. Possibly the animal was + sensitized and a few bacteria settled in the leg. It was along this + leg that the inoculations were made. + + +We permit ourselves the facetious observation that that vaccine +prevented the labial and cervical variety for five years, because during +that period it stood in the icebox, and there was no case of that +particular form to which to give it, although a few of the nasal and +gastric varieties occurred. It was recontrolled and did not show living +organisms. That it should have cured the disease in the jaw and +apparently later permitted a lighting up of a septicemic and pulmonary +form with necroses in the leg is difficult to explain. + +Just recently we have used a vaccine from the current culture upon +another case beginning in the gums and jaw bones. This case was detected +early and was treated with ascending doses beginning at 0.3 mg. and +running up to 10. mg. At first there was some improvement, but the +animal finally died from pulmonary complications. The course of the +disease, however, instead of being three weeks, as is the customary +duration, lasted two months, an extension of the course which has made +us hopeful. These two experiments, indefinite though they be, have +offered encouragement and seem to supply a little additional support to +the idea that the organisms stand in etiological relationship to the +disease. + +The employment of the vaccine has been extended to its use as a +prophylactic in animals exposed to the disease or specimens that have +slight reddenings or erosions on the buccal mucosæ suggesting possible +early stages of streptothricosis. Five animals have now had a course of +vaccine injections, ranging in number from 5 to 10 and in quantity from +0.3 to 2.4 mg. over a period of a month. Fourteen months have elapsed at +the time of writing and only one case has developed, but this of course +cannot settle the efficacy of the method; perhaps it would be safer to +demand that no case should ever appear in a treated animal, while the +disease did appear in the untreated. + +The preparation of the vaccine is by no means a simple matter, since the +surface growth upon solid media is so tenacious. Methods such as are +employed for the tubercle bacillus have to be used. The first two +vaccines were made by scraping off surface colonies from agar and +grinding with glass balls. One successful batch was made recently by +simply triturating the colony directly on the agar slant, but the latest +method seems to offer the simplest and most generally satisfactory way. +Neutral broth is placed in flasks containing glass beads and sterilized +in the incubator. This is seeded with the Nocardia, incubated at 37° C. +until the surface is covered, heated to 60° C. in a steam sterilizer and +tested for sterility. If growth occur it is reheated until dead, +whereupon the broth is syphoned off, the growth emulsified by whirling +the flask, thus grinding the bacterial mass by the glass beads. +Sufficient saline is added to make a workable emulsion, and the fluid +then poured into bottles. Control by reculturing is again done, and if +the fluid be found sterile, 0.5 per cent. trikresol is added to keep it +so. These organisms cannot be counted accurately because of the +variation in length, their budding and coccoid forms. Standardization is +done by weight. A definite equal quantity of the suspension and of the +saline used to make it are evaporated to dryness in weighed vessels and +the whole then weighed. The difference is the weight of the organisms +suspended in the saline. Such a fluid can be diluted so that a given +bulk will contain a convenient weight of germs. The one now in use +contains 8. mg. per cubic centimetre. Dosage as indicated above usually +begins at 0.5 mg., a quantity which does not produce any local +inflammation at the site of injection. It is perhaps well to adopt a +quantity of 0.1 mg. per kilo as the initial quantity. + +The Garden has encountered no case of the remaining important chronic +infections, glanders, lymphangitis, and infectious abortion. + + + + + SECTION XVII—PART 4 + ACUTE DISEASES RESEMBLING THE SPECIFIC INFECTIONS OF DOMESTIC ANIMALS + + +Specific communicable diseases are sometimes divided into those most +often encountered as “herd diseases” and those which appear as single +cases or in small groups. This would seem to imply that the first behave +as easily disseminated epizoötics, their virus passing from animal to +animal simply by proximity or by casual contact whereas the transfer of +infective material is less readily accomplished by the second group, +often demanding special assistance. Foot-and-mouth disease, pleural +pneumonia, cattle plague, and influenza illustrate the epizoötics while +tetanus, rabies, quarter-ill, malignant edema, and infectious vaginitis +are examples of less easily transferred processes. + +It is not intended that these remarks shall cover all possible means of +transmission but instead they are intended to focus attention upon the +sources of viruses whereby animals become infected. An original case +must always be present in order for spread to occur. Where animals are +being added to a herd a new comer may be diseased or the carrier of a +virus; when animals are transported for sale or other reason, infection +may be met in a new stall, conveyance or pasture; contaminated food may +be offered. In menageries, with specimens, single or in small groups, +and arrivals always quarantined before other animals are exposed, acute +specific infections seldom appear. It is also improbable that a wild +animal, infected at its source or in some dealer’s place, would survive +the journey and arrive in an infective condition. Consultation with the +reports of other gardens fails to discover records of any serious +outbreaks of epizoötic disease except for fowl cholera and distemper, +examples of infection with the bipolar organisms of the Pasteurella +group, believed responsible for the hemorrhagic septicemias; instances +of the occurrence of the group specified secondly—anthrax and the like— +are also reported. This represents fairly well our own experience. + +The bacteria variously named _Bac. avisepticus_, _ovisepticus_, +_bovisepticus_, _canisepticus_, etc., grouped by Ligniere under the name +Pasteurella, are doubtless of considerable importance and are probably +quite widespread in natural surroundings. The viruses of the epizoötic +conditions like cattle plague and influenza are apparently more +definitely parasitic, requiring for their persistence ever renewed +transfer from host to host. The former infections we have met in +repeated single isolated cases and in small groups, whereas no cases of +the specific epizoötics have been diagnosed. + +Hemorrhagic septicemia, a denomination very descriptive of its +pathological picture, has been encountered in many varieties, +carnivores, ungulates, primates, rodents, and birds. The diagnosis +depends upon the presence of hemorrhages with edema, degenerations of +the parenchymatous organs, more or less respiratory catarrh to which may +be added relatively mild gastrointestinal inflammation; the bacteria are +found in the circulating blood and in exudates. A description of these +organisms is not profitable, they being well known in veterinary +pathology. What is more important, significant and supportive of the +opinion expressed above concerning the widespread distribution of the +virus, is the incidence of the infection. Exclusive of the condition +known as fowl cholera, it has appeared among mammals and birds as single +cases with one exception—that of two Barbary apes which had been in +separate cages side by side. The total of cases with determined +bacteriology is eleven, with undecided bacteriology but suggestive +pathology nine additional. No pertinent history in common can be found +in the records of the determined cases, except perhaps that they were +all animals which had been in the collection at least three months, a +period which would seem to exclude the probability of an imported +infection. Because of the isolated character of the cases and +impossibility of making a clinical diagnosis, no attempt at specific +nomenclature as used in veterinary medicine has been made, hemorrhagic +septicemia seeming to cover its identity and nature. + +The disease known as fowl cholera is practically always associated with +the bacteriological discovery of a member of the hemorrhagic septicemia +group while its pathology corresponds with that of mammalian infection +with these germs. Enteritis is a prominent feature. This disease has +appeared thrice among our parrots carrying off from six to ten birds +before hygienic measures became effective. In all three our cultures +showed the bipolar organisms. Besides these specific outbreaks numerous +isolated cases of acute general infection have occurred among small +passerine and picarian birds which could not be determined as +hemorrhagic septicemia by bacteriological methods although superficially +resembling it in gross pathology; they yielded to the same hygienic +measures. Perhaps we were dealing with fowl plague, a disease believed +to be due to a filterable virus. That this is the case is strongly +suggested by an outbreak of fowl typhoid in the parrots, from some fatal +cases of which we were able to isolate _B. sanguinarium_, and by a group +of deaths in small parrots from which no specific organism could be +recovered. + +The identification of these supposedly specific diseases—plague, +typhoid, septicemia, leucemia—by pathological criteria is by no means +simple even if we have at hand the complete description of Moore, of +Hutyra and Marek, of Ellermann and of Ward and Gallagher. Bacteriology +must decide and cultures should be made upon bodies recently dead. In +addition to the above infections we have had two small outbreaks of +psittacosis in parrots from which it was possible to isolate the +specific organism. On both occasions there was more than one death +before the specific nature of the disease was identified yet, +noteworthily, no spread to the other birds in the same exhibition house +occurred. + +Distemper, a disease variously held as due to cocci, to influenza-like +organisms and to a filterable virus, may appear in sporadic or epizoötic +form. The diagnosis during life is not so easy unless all the cardinal +features are present, while after death the same thing holds good. I am +inclined to think that from the standpoint of diagnostic accuracy, the +term is used much too loosely, a ready excuse for such laxity however +being that it stimulates to greater care in hygiene. Whether or not _B. +bronchi-_ or _canisepticus_ be the cause of the disease, organisms +corresponding to it can be found in stained smears from nearly every +case in which the respiratory, cutaneous, nervous and internal signs +suggest the disease. To make a diagnosis of distemper it is my practice +to require at least three of the cardinal clinicopathological features, +whereupon, if the bacterial findings be as described, the denomination +is permitted. This was dictated because during the period, now happily +well in the past, when the cats and dogs suffered frequently with +enteritis, nasopharyngeal signs occasionally presented themselves or +spasms were reported, but no skin eruptions appeared, yet seldom were +all of these signs combined nor could we find the bipolar organisms. I +note that in 1915 Doctor Blair of New York observed a toxic enteritis +resembling but not identical with distemper. As with our cases he failed +to find that the condition was communicable. We ascribed our cases to +spoiled food—fowl heads or dirty horse meat (see page 179). Our +acceptable examples of distemper number three, two ferrets and a lynx, +but very suggestive cases were found in foxes, wolves and raccoons. +Since writing the above notes, sixteen wolves, foxes and wild dogs died +in an outbreak of distemper imported by a newly arrived specimen +admitted to the colony by mistake. When we were aware that the disease +had appeared antiserum was administered therapeutically to all that were +sick and prophylactically to all the rest—large doses, 25–35 cc., were +given for treatment, smaller quantities, 10–20 cc., being used as a +preventive. Seven sick animals recovered and no animal (8) given serum +prophylactically became sick. This experience encourages us to think +that with antiserum and rigidly enforced quarantine rules, distemper +will not be a serious matter to handle. + +The hygiene of the foregoing conditions is of a general character— +removal of the specimens when known to be sick, thorough cleansing of +the cages, segregation of mates or of neighbors when this is +practicable, burning of refuse, liming of the ground and such other +measures as the local conditions may indicate. + + +DIPHTHERIA. + +Although no cases of mammalian diphtheria have been observed, three and +possibly four birds have suffered with this disease. The three +acceptable cases were in cassowaries (_Casuarius occipitalis_) occupying +adjoining cages and sickening within a few weeks of one another. Just +how the infection was brought to them must remain a mystery since no +additions had been made to the group for some time previously. All three +birds were observed during life, and from the first case the _Bac. +diphtheriæ avium_ was isolated; in smears from the other two similar +bacteria were seen but isolation was unsuccessful. The two acutely fatal +cases showed large pseudomembranous collections on the nasopharyngeal +mucosa and beneath the tongue while the nares were occluded by the same +material. Plaques of membrane were also found on the surface of the +esophagus and proventricle. The exudate ran out of the mouth and formed +dried crusts upon the cervical skin. Pseudomembranes of a continuous +character were lacking in the third bird, their place being taken by +small yellow or yellow pink nodular elevations, apparently just beneath +the surface, here and there upon the reddened, slimy buccal, lingual and +pharyngeal mucosæ. Crusts upon the skin of the neck also formed in this +case. + +These cases are of interest not only because of their appearance without +satisfactory explanation but because one improved very much after +injections of human diphtheria antitoxin, this remedy being used because +we were then unaware of the existence of an avian diphtheria antitoxin. +No claim can be made _post hoc ergo propter hoc_ that the human +antitoxin helped the attack—it may have been mild—but the experience is +worth recording. Dosage was as follows: December 3, 3,000 units; +December 8, 1,500 units; December 21, 5,000 units; December 27, 5,000 +units. Shortly after the inception of the treatment the bird was noticed +to eat better and to be more lively; this was followed by a reduction in +the mucous strings in the mouth and the crusts upon the skin. This +improvement continued and the bird seemed well in about two months but, +after the lapse of three months more, a mucous nasopharyngitis was again +observed. Despite two injections of 5,000 units human diphtheria +antitoxin the bird succumbed five days after the beginning of this +attack. Autopsy revealed much the same condition as was found in the +first birds and from the larynx the _Bac. avium_ was isolated. Another +case suggestive of diphtheria was seen in a hornbill but antemortem +observation being impracticable and postmortem decomposition being +advanced when autopsy was performed, the diagnosis could not be +confirmed. + +An unusually well developed case of molluscum contagiosum was seen in +the Wild Turkey (_Meleagris gallopavo_) recorded here by photograph and +in the form of notes upon the histology made by Doctor Weidman. + +The bird’s head was affected universally from beak to ears by horny +nodules up to the size of a pea. They were so large and numerous around +the eyes as to completely close them. There were no lesions elsewhere on +the body, none of the other turkeys were similarly affected and though +watched, none have since developed a similar condition. Histological +examination shows a keratosis, many of the cells showing characteristic +“molluscum bodies” which appear the same and behave the same +tinctorially as the human examples. This turkey case differs from the +human, however, in that there are none of the pocket-like epithelial +extensions deep down into the corium and this turkey case may be very +useful in the further study which is contemplated to show that such +things as molluscum bodies are not sufficient of themselves to stamp a +dermatosis as a pathological entity, but that they are general +pathological processes which may occur in a number of different +diseases. The disease has been reported in sparrows, pigeons, but never +so far as I can find, in turkeys. + +A few isolated cases of infectious disease are included here as a matter +of record although they may not be especially significant or important. +Rabies was found in a pair of deer which had been bitten by a stray dog. +The period of excitement was relatively long, while the paralytic stage +was only a few hours. Negri bodies were found. Tetanus killed a Persian +Wild Ass (_Equus onager_) the infection wound seeming to be a bruised +and abraded area on the rump. From the contused muscle tetanus bacilli +were isolated. A gas-bacillus infection, emanating from the vagina which +was protuberant and lacerated because of injury by mates, was seen in a +pregnant llama (_Llama lama._) On two occasions nodular masses have been +found under the skin of seals, not unlike the one studied by Doctor +Wiedman and thought by him to be due to moulds. These two have, however, +failed to show mycelia or yeast-like bodies, and one thinks only of +placing them in the group of botryomycosis. I have never seen a case of +this disease, so that I am forced to rely upon literature, a method that +inspires no especial confidence in the diagnosis. The bacteria usually +held responsible for botryomycosis could not be isolated. Just what can +be done for the condition is difficult to state, since seals are +scarcely tractable animals. + +[Illustration: + + FIG. 70.—MOLLUSCUM CONTAGIOSUM. WILD TURKEY (MELEAGRIS GALLOPAVO). +] + +The following case has some features like paralytic hemoglobinuric fever +and is reported as a matter of record. The long standing gastroenteritis +may have been the basis for the intoxication which led to the paralysis +and muscular degeneration. This laboratory has now under way studies +upon the laming of ungulates, accompanied by weakness of the hind +quarters, but no conclusions have been reached. It is interesting to +note that Hutyra and Marek quote Johne as having seen a case of +hemoglobinuric paralysis in a zebra in 1879. + + + Burchell’s Zebra (_Equus burchelli burchelli_). The only symptom + observed in this animal was gradually increasing lassitude which was + first noticed about three months ago; toward the end he habitually + stood with tucked tail and nose to the ground as if asleep. He ate + well and digestion appeared good, but he became very weak as shown by + his inability to rise when he got down on the third and second day + before he died, although on both occasions he was able to stand when + lifted. Injury, hemorrhage in thigh muscles, chronic gastritis, + sciatic neuritis. Œstrus larva in stomach, ascaris in intestine. Both + lungs are widely distended and the caudal half of both is the seat of + passive congestion. Upper lobes are slightly edematous. No + consolidations. Heart normal. Abdomen contains about two quarts of + clear straw colored fluid. Liver is of normal size, smooth surface, + sharp edges, firm, friable. On section it is very bloody, veins + distended, some with clot. Architecture normal. Spleen is of normal + size, soft, tough, capsule rough. Section surface is homogeneous, pulp + purple, trabeculæ normal, follicles not visible. The kidney capsule is + smooth, strips easily leaving a smooth brown surface, firm. Striæ + normal, rather wide, glomeruli not visible. Stomach is filled but not + distended with partly digested straw. Mucosa of cardia dry, roughly + irregular, some irregular mammillations. Two flat papillary growths. + Œstrus larva attached to a smaller elevation. The mucous membrane of + the fundus is soft, moist, irregular, in some places, translucent, in + others opaque; near pylorus mucous membrane is swollen edematous, + pink, slightly eroded at pyloric valve. Small intestine has smooth, + flat, pale yellow translucent mucosa. Lumen filled with mucopurulent + matter like mixed egg. Ileum slightly congested but mucosa firm and + translucent. Pancreas is soft, slightly uniformly congested. All + mesenteric lymph glands are slightly enlarged and edematous but with + normal architecture. In the posterior thigh muscles beside the sciatic + nerve, most marked on the right side, is a large hemorrhagic + infiltration. There is edema of muscles and intermuscular septa all + about this area extending upward as well as to pelvis and psoas + muscle. This latter within the abdomen shows slight blood stained + edema. No other muscle shows this hemorrhage. Microscopic section of + liver and kidney are negative aside from congestion. The stomach shows + very irregular epithelial covering, in some places wholly desquamated. + Where this is most marked there is a dense round cell infiltration in + the villi with some increase in the connective tissue cells. This + chronic inflammatory reaction is present in all fields, most marked, + of course, in upper layers of mucosa. Glands are distorted and upper + epithelium of them is polychromatophilic. The intestine shows similar + changes in less intense manner. + + +Waterfowl Epizoötic. There is reproduced here an account of an +unexplained epizoötic among ducks and geese from the _Annual Report of +the Zoological Society_ for 1916. Nothing additional has been learned +and no repetition has occurred since the drainage and cleaning of the +lake. + + + There began on August 27 a series of deaths among the waterfowl and in + one month there were lost forty-one specimens including both ducks and + geese. Four additional cases were scattered through the next four + months, the last case dying January 11, 1916. All of these came from + the lake, none being from the adjacent stream for rare waterfowl or + from the more distant stream into which the lake drains. The symptoms + were most marked and striking. In the early stages the wings drooped, + then the legs became weak followed by inability to raise the head. In + the latest cases the voice (ducks) lost its normal character and + became hissing. The mind appeared clear for the eyes were bright, + feathers unruffled and the bird attempted to escape when approached. + Diarrhœa was present, dejecta thin, watery white, no admixture of + mucus. Autopsy findings were not frank. At most some swelling of the + spleen and a little pale thickening of the intestinal wall constituted + the picture. Smears from intestine and nasal mucosa showed no + protozoa. The blood taken from the living sick ducks showed no + parasites or anemic changes in either raw or variously stained + preparations. From the spinal cords of three ducks a 50 per cent. + glycerine emulsion was prepared and was injected into the cerebral + substance and abdomen of domestic ducks with negative results. A + variety of different bacterial cultures was obtained from the liver, + spleen, blood and congested nasal mucosa of several birds dead with + the disease and injected into domestic ducks with negative results. + Histological sections were cut from the important organs of thirteen + birds. The kidneys, lungs and pancreas showed no abnormalities. The + heart muscle in some cases and also some of the skeletal muscles + showed Zenker’s hyaline degeneration together with minor hemorrhages + and edema. Several of the proventricles showed low grade inflammatory + signs toward the gizzard. The intestines regularly showed lymphatic + infiltrations of the villi most marked toward the tips but without + congestion. The lumen showed no parasites, bacteria or protozoa. Liver + showed in almost every case pigmentation by hemosiderin at times as + heavy as that seen in pernicious anemia. The finer bile ducts here + showed peripheral round cell infiltrate, which was not continued into + the major ducts as determined by serial sections. Parenchymal cells + were cloudy and swollen. Spleen showed in early cases + polymorphonuclear infiltrate of the follicles, in later cases atrophy + of follicular splenocytes and more or less pigment occurred in both + stages. The spinal cord and various peripheral nerves showed no + inflammation or degeneration as determined by the appropriate special + nerve stains. The above clinical, histological, protozoological, and + bacteriological examinations having failed to detect the cause and the + epizoötic now being over, its nature becomes a matter of deduction. + The only constant features of any importance were the paralysis, the + intestinal round cell infiltrate and thickening, the pigmentation of + the liver and degeneration of skeletal muscles. Of the various + possibilities, beriberi was early considered. This is not possible + because the food of the birds was a varied one and furthermore none of + the nerve degenerations of beriberi were noted. Second, acute + bacterial or protozoal infections are unlikely because no constant + primary lesions were discovered at autopsy, the numerous cultures + failed to produce the disease and other birds living on the stream + draining the lake were not similarly affected. Third, a food + poisoning. This is possible first because paralytic symptoms were + present such as are seen in vetch and mussel-poisoning and secondly + because the epizoötic ceased when the birds were taken from the lake + and placed upon the grass. If this be the case the toxic material + produced the paralysis by direct action upon the muscle fibres just as + that of typhoid fever does and must have caused hemolysis as shown by + the hepatic pigmentation. The source of this food poisoning is + conjectural. Perhaps a dead fish decomposed in the water or there were + some algæ with poisonous properties present. The outbreak has a + resemblance, but only a superficial one, to infection with one of the + group of botulism bacilli. The cause of the trouble must be considered + as undetermined. + + +Enterohepatic Disease. Since the normal drainage from the intestinal +tract passes so largely through the liver, there is little to wonder at +in morbid lesions of the latter organ consequent upon disease in the +former. Not only does this succeed upon bacterial infection of the +digestive tube but also upon infestation with animal parasites, under +the latter condition forming changes of much more considerable extent, +at least in gross bulk, than in the former. Changes in the liver +secondary to enteric disease from bacterial infection take the form of +cholangitis, thrombosis, degenerations and probably cirrhosis while +abscesses and necroses succeed upon protozoal or metazoal parasitic +involvement. The latter is exemplified by amebic abscess in man and +other mammals and by “blackhead” and “quail disease” in birds; it is to +the latter conditions that attention is now directed. The chapter upon +the cause of these diseases has yet to be completed, although many reams +have been written about it, while the transmission is fairly well +understood and the pathology well described. My purpose here is to +discuss our experience with the two above mentioned diseases which, +while far from conclusive, may assist somewhat in explaining their +etiology. There is also reproduced our original report upon quail +disease from the Society’s Report of 1915, giving data and figures. +Blackhead has been found in five wild turkeys. An unusual case in a +Berwick’s Swan is recorded since it bears a striking resemblance to the +disease. + +The points at issue in the determination of the etiology of blackhead +are the importance of _Heterakis papillosa_ in the ceca and the +frequency and activity of ameba or histomonas. In three of the five +cases of the disease in turkeys the nematode was found macroscopically +in the ceca, in two it was not; in one its absence was confirmed +microscopically. In two of the turkey cases, forms corresponding to the +ameba or histomonas were discovered while the descriptions of the +hepatic lesions in two birds use the term coccidia which, from a +revision of the slides, is probably incorrect although some of the +parasites seem to be possessed of a doubly contoured refractile margin. +The larger, more diffuse and ameba-like forms in the intestinal wall +suggest that the hepatic inclusions belong to the same group. In only +one case was exhaustive search made for coccidia, and without success; +the material was not preserved. In two turkeys entirely free of lesions +distinctive of blackhead, cecal nematodes (one heterakis, one unknown) +are recorded, and in the intestinal wall of another, also free from the +disease, forms indistinguishable from ameba could be discovered.[106] + +The protocol of the Berwick’s Swan is interesting because the full +fledged disease is not known in this bird. While this case is not by any +means typical, the chronic cecitis and ameba-bearing necroses in the +liver stamp it as of a kind with the true infection of turkeys. Perhaps +the resistance offered by the swan effected a modification of the +disease, preventing the usual necrotizing enteritis and turning it into +a chronic interstitial variety. + + + Berwick’s Swan (_Cygnus berwicki_). About a month before death passed + several large clots of blood. Acute catarrhal enteritis, mural + endocarditis, chronic colitis, chronic nephritis, passive congestion + and necroses in liver, acute follicular splenitis, edema of lungs, + chronic pericarditis, chronic salpingitis, hydrothorax, + hydropericardium, hydroperitoneum. Tissues generally are slightly + yellow. In serous cavities of thorax is about three ounces of clear + fluid. Lungs are distended, subcrepitant, pale red and gray, highly + edematous. The pericardium contains about one-half ounce of clear + watery fluid. Epicardium is glistening, congested, irregularly + thickened especially near the blood vessels. The heart is contracted, + slightly large, pale brown-red muscle. On the posterior surface of the + right ventricle extending from the auricular opening to the pulmonary + valve is an irregularly curved line of grouped, recent red vegetative + granulations. Valves negative, they and chambers competent. Aorta + negative except heavily blood stained. Liver is slightly large. What + of the liver remains undamaged is homogeneous deep purple. Major + portion of right lobe badly contused; this seems to have been partly + antemortem because there is blood staining and mottling under capsule. + In view of colon finding and history of possible injury it is probably + the result of degenerations in the liver plus slight trauma. There are + several small, pale gray, well outlined, homogeneous areas probably + necroses in the liver. The spleen is slightly large, soft, egg-shape, + capsule smooth. Section surface shows bright red homogeneous pulp with + clearly cut, large follicles. The kidney capsule is smooth, surface + smooth brown, consistency firm and tough. The section surface gives a + dull gray-brown appearance, seemingly from connective tissue. Markings + indistinct. Oviduct is negative except over a distance of an inch near + the cloacal opening. Here there is a compound curve with constriction + to almost obliteration of lumen. This does not seem to be connected + with the colonic trouble. The stomach is negative containing only a + few small pebbles. Beginning at the pylorus and extending through the + whole of the small gut is a recent, moderately severe catarrhal + enteritis with so much exudate as to form almost a cast of the tube. + Colon and cloaca show an infiltration of submucosa with areas of + hemorrhage. Mucosa swollen as if by edema, glistening and covered by + bloody mucus. Ceca negative except that they seem to have been closed + as their contents are scanty and firm. Histological section of cloaca + shows it to be the seat of a chronic inflammation which has + constricted and distorted the tubules into simple masses of nuclei. + Marked polynuclear and round cell infiltration of mucosa and + submucosa. This is apparently due to ameba-like bodies—a large vacuole + with a delicate limiting membrane and a piece of diffuse chromatin in + the centre—a few of which may be found deep in the mucosa. Liver shows + marked passive congestion, here and there areas of necrosis with some + fatty infiltration. Small groups of ameba-like bodies can be found + apparently lying in sinusoids of liver and in neighborhood of + necroses. + + +Quail disease, since the careful work of Morse in 1907, has been thought +by most observers to be due to an organism of the colon group, but I am +informed recently by the Pennsylvania State Board of Animal Industry +that coccidia have been found often enough in the droppings and in the +morbid lesions to warrant a suspicion of their etiological importance. +Although they were not especially sought in the work about to be +reported, their presence probably would not have escaped detection +during that investigation. I have recently had occasion to examine three +birds with lesions identical with those accepted as characteristic of +quail disease, one of which was subjected to the proverbial “fine tooth +comb” methods; no coccidia were found in the liver or intestinal +lesions. + +The idea that quail disease, with its ulcerative typhlitis and +necrotizing hepatitis, is identical with blackhead or at least that if +the latter be due to protozoa, the former is also, requires no special +stretch of imagination to one familiar with the morbid lesions. A +decision is the more difficult because of one’s inability to reproduce +quail disease at will and the none too great certainty of the +intentional production of blackhead. At all events the transmission is +potentially the same, ground or food soiled with droppings, indicating +that hygienic measures should take the form of segregation and +disinfection. Here follows the report of our original observation: + +“An epizoötic disease has decimated three newly imported lots of quail, +Scaled quail (_Callipepla squamata_), Gambel’s quail (_Lophortyx +gambeli_) and Texas bobwhite (_Colinus texasus virginianus_). On January +5, 1915, the first lot of twenty-four quail arrived from northern New +Mexico _via_ Kansas City; on January 11th a second lot of twelve +bobwhite arrived from Brownsville, Texas, _via_ Kansas City; the first +of this lot died the day after arrival with lesions of this infection. +From this lot of birds the first lot was probably infected, the first +death occurring on January 20th, no other deaths having occurred in the +first lot since arrival. On January 21st the third lot of twelve quail +arrived direct from Mexico. The first of this lot died of the disease on +January 24th. Some birds were also sent at the time of the arrival of +the third consignment, to Doctor Kalbfus of the State Game Commission. +It is to be emphasized that to date no cases of infectious enteritis +have occurred in the lot sent to Doctor Kalbfus. The first case appeared +at this Garden on January 12th, more than a week before the third lot +arrived. It would seem that the disease was brought to the Garden by the +second lot of birds, and that they picked it up on the way from Texas to +Kansas City to Philadelphia. The birds made a stop at Kansas City. The +birds died at long intervals for the first two weeks, but late in +January and early in February several died each day. The last death with +characteristic lesions occurred February 11th. After the epidemic +reached its height it subsided very quickly. + +“During the illness the birds exhibited very few symptoms, indeed some +of them were not known to be sick. A few sat huddled in a corner with +ruffled feathers and drooping head; the stools were little if any +altered as far as could be determined among so many in the enclosure. At +death the birds were in good condition, feathers fairly smooth, skin +clear, body plump and fat in good amount—not abundant, nor were the +animals emaciated. The principal lesions were enteritis, degenerative +necroses and abscesses in the liver, congestion of all the viscera and +plastic peritonitis in a few. A small number showed congestion of the +lungs and two had patches of pneumonia. Many but not all of the birds +had Heterakis in the ceca. The process seemed to start as a focal +necrotizing lesion in the mucosa or submucosa of the ileum just above +the ceca and colon; many had lesions in the ceca and as far down in the +colon as the cloacal dilatation. Among the animals dying late in the +epidemic several showed lesions involving the whole small intestine, a +few indeed with greater involvement of the duodenum than of the lower +parts. + +“Judging from the gross and microscopical appearances it seems that the +virus causes at first a cellular infiltrate in the mucosa or submucosa +upon which necrosis shortly supervenes. The overlying mucosa soon +degenerates, and the surface is covered with an indefinite slough. In +other cases, especially early in the epidemic, the process extended +outward and appeared as muscular or subperitoneal necrotic areas before +the mucosa was much involved. At all events necrosis was an early change +in every case. The blood vessels were usually thrombotic. In the cases +that spread toward the peritoneum a plastic peritonitis of varying +severity was present. The focal liver lesions were not present in every +case. They took the form of focal necroses or abscesses. Some fatty or +parenchymatous degeneration was always present. The liver lesions +probably started as inflammations of the veins from which necrotizing or +infiltrative lesions spread. The splenic lesions were those of lymphoid +hyperplasia, only distinctive in the enormous number of large lymph +cells. Typical microscopical changes are as follows, quoted from one of +the autopsy protocols: The lung showed moderate congestion with here and +there a little epithelial swelling and a mild bronchitis and +peribronchitis. The type of bronchitis is infiltrative rather than +catarrhal. The heart muscle showed granular degeneration of the fibres +with breaking up or irregularity of the striæ. Some increase in +interfibrillar nuclei and especially those of the capillaries. There is +moderate congestion. Epi- and endocardia are slightly raised as if by +edema. Here and there slight fragmentation of fibres. The liver cells +are granular and some show fat droplets. There is moderate congestion +and more than the normal number of round nuclei between the columns. +Here and there are focal necroses of varying sizes without +circumferential reaction. Here and there are also some small collections +of round cells near to which the liver nuclei are large and show +attempts at regeneration. In these collections but not in the necroses, +bacillary forms may be found. There is no reaction on the part of the +bile ducts. The larger vessels are thrombotic, and in one section a +thromboangiitis was found. One stretch of early plastic perihepatitis +was found. The kidney showed slight granularity with slight cloudy +swelling of the epithelium. The nuclei of the glomeruli are prominent. +There is moderate congestion. The spleen showed distinct large lymph +cell hyperplasia with relative inconspicuousness of small round cells. +The follicles are very diffuse, their centres filled with large lymph +cells. The cords are hyperplastic and the sinuses compressed. Moderate +congestion; no unusual blood destruction; one area of hyaline necroses +found. The proventricle and gizzard are negative with the probable +exception of active desquamation on the surface of the former. The outer +coats of the duodenum are negative except for slight richness in nuclei. +The deep mucosa is very rich in nuclei and red blood cells. The outer +parts of the villi are either swollen with a cellular infiltrate or by +an area of granular necrosis, or have disappeared. It would seem that +the surface of the mucosa rapidly degenerates and desquamates. Bacteria +are very numerous. The adjacent pancreas is negative. The ileum showed +round cell infiltration of the deep mucosa, swelling of the villi and a +desquamation of the surface. One ulcer was found having its base on the +swollen muscularis and being covered with necrotic slough. Adjacent +peritoneum is slightly infiltrated, but chiefly congested and edematous. +This ileum lesion seems to be the characteristic one of the disease. +Bacteriological observations were made upon cultures obtained from the +intestinal mural lesions, the peritoneal exudate, the liver necroses, +and the heart’s blood in eleven cases. In seven cases I was able to +isolate a motile rod like the _B. coli communis_ and in four cases a +non-motile rod of the _Bact. aerogenes_ type. The former is quite +similar to the _B. scoticus_ (Migula) reported in Grouse disease. + +“We obtained from Doctor Kalbfus of the Pennsylvania State Game +Commission, four perfectly healthy birds for experimentation. A culture +of the isolated germ was injected into two of them and mixed with the +food of the remaining two. It does not seem profitable to cite the +details of the work as the results were entirely negative, no lesions +resulting that bore the slightest resemblance to the spontaneous +disease. The birds either lived indefinitely or succumbed to wholly +foreign conditions. This negative experiment is of course no proof that +the organism is not the cause of quail disease, for the methods employed +might not be the correct ones to propagate the virus or the germ may +have lost its virulence during the laboratory culture work. However, as +some observers have not reported this bacillus in the disease this germ +loses something in importance by the negative inoculation experiment. + +“Judging from reports and based upon the observations of Morse upon +Grouse disease it would seem that the incubation period of the disease +is about eight to ten days. However, one of the third lot of our birds +died within three days of its arrival at this Garden, and therefore +within three days of its exposure to the second arrivals; if it be +correct that this second lot brought the disease and the third lot did +not have it, it would seem that the incubation period can be as short as +three days; how long it may be is only suggested by the fact that some +of the third lot did not die for three weeks after arrival and exposure. +All the Gambel’s and scaled quail succumbed to the disease, but two of +the twelve bobwhite survived. It would seem that although these last +birds probably introduced the disease, they still possessed more +resistance than the others, for the second death among them occurred +seventeen days after the first death. The epidemic as we have seen it +here seems to be the same as Grouse disease of Scotland and as the +Grouse disease in this country as reported by Morse (Bureau of Animal +Industry Report 109, May 18, 1907). + +“The means of transmission of the disease is not exactly known, but is +in all probability by a pollution of the food, the water supply or the +ground. Since the lesions are so marked in the lower ileum, cecum and +colon, a possible transmission by cohabitation must not be entirely +overlooked. There does not seem to be any means of limiting the epidemic +in a flock by segregation or sacrifice of the infected birds, because +symptoms are few and do not appear until shortly before death. Each bird +would have to be put into a separate cage until proved infected. +Scrupulous cleansing of the enclosure is desirable, but its efficiency +is difficult to estimate.” + + + + + SECTION XVIII + THE ANIMAL PARASITES, THEIR INCIDENCE AND SIGNIFICANCE + + + FRED D. WEIDMAN, M. D. + +It is quite to be expected that animal parasites would be found in the +animals of zoological gardens, garnered as these beasts are from all +parts of the world, tropical and otherwise. It inevitably follows that +many of the forms should be strange and new, enticing one to the +fascinating determination of their identity, life history and hygienic +importance; and, developing from all this, one can easily imagine how +limitless the opportunities are for scientific work in parasitology in a +laboratory like ours. + +As in other biological fields, the taxonomic range of parasites here is +wide. It extends from the lowly protozoa to the insecta, and, dropping +to the smaller subdivisions, includes not only most of the genera +familiar to human parasitology but many known only among the lower +animals. From the standpoint of the host, the biologic state of +parasitism extends from the lowest protozoa to homo. + +The above will suffice to indicate the wide range of parasitism in +animals, but the extent of work actually done thus far in wild animal +material is a different story. Collated, consistent studies, so far as I +am aware, have been undertaken only at the London Garden, here at +Philadelphia, and at Washington, D. C., by Dr. Charles W. Stiles and +Albert Hassal. The data, collected by the last mentioned workers are +incidental to the Index Catalogue of Veterinary and Medical Zoology, and +embrace only the (index) phase indicated by the title, but it is so +valuable, and withal so altruistic, that it must be credited. What other +work there is is scattered where—not in literature—general biological, +medical and veterinary. That at London has been conspicuous through the +observations of Plimmer and of Beddard on filariæ and cestodes +respectively, while the work of Nicoll must not fail of mention. + +That the reader may the better appraise the sections of our own work +which are to follow I wish at once to indicate their material basis. +Ordinarily only the larger parasites are looked for at the autopsy table +and there must be special indications to demand search for the finer +ones. Those of microscopic size, or so minute as to be overlooked in the +guise of seeds, vegetable fibres, etc., have not, both here and +elsewhere, been routinely studied as have macroscopic ones.[107] From +our autopsies there have accumulated records of nearly 900 parasites— +some determined generically, others but as to order. The parasites have +in greatest part been preserved and are available for further study; in +the past, special groups have been culled out from time to time and +examined. Where conditions have been pressing, as in certain epizoötics, +investigations have amounted to more than observations and descriptions, +and received detailed laboratory examinations with more or less animal +experimentation as the occasion demanded. + +The foregoing may suffice to apprise the reader that the subject of wild +animal parasites has been but broached so that data are especially +incomplete on life histories—a phase most important in relation to +hygiene; but in spite of this and although the statistics are only +approximate, as is the case in most parasitological work, these data +have attained to sufficient proportions to justify at least a beginning +in the matter of collating and generalization. At any rate the time has +arrived to establish at least a nucleus for the accretion of data, which +can be later subjected to confirmation or correction. We draw just a +grain of comfort from the knowledge that the more fully worked field of +human parasitology is also vulnerable to criticism of very much the same +order. + + +THE VALUE OF PARASITOLOGICAL STUDIES IN ZOOLOGICAL GARDENS. + +The foregoing chapters have made clear two fields of practical +usefulness of any study in such gardens. These—hygiene in relation to +the animals and comparison in relation to human beings—need therefore +only to be mentioned at present since it is obvious that both benefit by +our parasitological work. But there is yet a third—a scientific phase of +parasitology which may be considered purely academic. It consists in +morphological and other studies necessary for the identification of the +parasite, the determination of its life history, etc. These last studies +may still in a restricted sense include a modicum of the practical in so +far as they have a bearing on the disease with which they are +associated. But on the whole they are a source of danger for us since +such things as studies on the finer structures of worms, taxonomic +arrangements, descriptions of new species of commensals, etc., being +alluring, are likely to lead one so far afield that eventually an +attitude of stubborn resistance will have to be assumed in order to +conserve that precious, volatile laboratory asset—time—for the more +crying, practical problems ever reaching out to us. + +However, in parasitological investigations as in other scientific work, +immediate abstract information may at some time prove to be of greatest +practical value. Thus for example if we can discover the exact facts +concerning one phase of the life history of a certain parasite, it may +be possible by hygienic measures, to break the cycle of development of +the parasite at one point thereby preventing its completion. This +information is perhaps obtained most readily in experimentation upon the +rôle of lower animal forms in the pathogenesis of disease but where +reliable evidence is lacking, help may be had by comparison with others +in the same taxonomic group. Undoubtedly systematic classification will +go far to help solve many of these riddles. + + +PATHOGENICITY OF ANIMAL PARASITES IN GENERAL. + +The first question which arises in this connection concerns the actual +ability of animal parasites to produce disease in wild animals. At once +it will be seen that this must be a relative matter, for no one on one +side would contend that every symbiont in an animal is harmful—parasites +_sensu stricto_—nor on the other that none could possibly be, _i.e._, +that all are always commensals. It is evident that the issue boils down +to questions as to the extent to which they are harmful. Before +attempting the answer let us consider the means by which the parasites +may conceivably produce disease. + + +MODES OF DISEASE PRODUCTION (PATHOGENESIS). + +The medical reader is familiar enough with the pathogenic powers of some +animal parasites, but may be sufficiently interested to glance over +specific wild animal instances illustrating them while they are being +listed for those less familiar with this subject. + +1. MECHANICAL OBSTRUCTION. + +I refer here particularly to simple blockage of normal body passages as +the result of bulk or mass. This occurs more commonly in the intestines +than elsewhere on account of the greater frequency, greater numbers and +larger size, in general, of parasites inhabiting this tract. Thus, we +have recorded a liothrix (_Liothrix luteus_)[108] where the combination +of a small host and consequently narrow gut and comparatively large +parasite induced obstruction. Plimmer[109] records microfilaria clogging +the brain capillaries. Shipley[110] mentions two specimens of _Ascaris +lumbricoides_ obstructing the nares of a chimpanzee (_Pan niger_). +Blockage may also be produced secondarily to the presence of the +parasite, even in the absence of notable numbers of them, and quite +apart from the element of verminous bulk. This occurs through +inflammatory swellings which the worms excite. We saw many serious +grades of this in our spiroptera epizoötic, the lumen of the +proventricle being narrowed by swelling of the mucosa and more or less +occluded by exudate and necrotic mucous membrane. + +Yet another direction wherein a mechanical rationale pure and simple +obtains is by the production of diverticula. Worms encysted in the gut +wall may, by weight alone or by excitation of peristalsis, cause the +wall to bulge outwards (or inwards even) like a pocket. Such a +diverticulum has been noted in the gut of a Pale Cebus (_Cebus +flavescens_)[111] parasitized by acanthocephalus, but in this case there +were adhesions to the nearby stomach, and it is possible that in this +individual case the diverticulum was a traction one, _i.e._, pulled out +by the anchorage of adhesions externally. + +[Illustration: + + FIG. 71.—ACANTHOCEPHALUS (THREE SPECIMENS) PROJECTING FROM THE INCISED + INTESTINES OF A PIGMY MARMOSET. COMPARE THE SIZE OF THE PARASITES, + WHICH MAY BE DISTINGUISHED BY THEIR ANNULATIONS, WITH THAT OF THE + INTESTINES. +] + +[Illustration: + + FIG. 72.—BLOOD-RED NEMATODES PROTRUDING FROM FRONTAL SINUSES OF COMMON + OPOSSUM (DIDELPHYS VIRGINIANA). THE SKULLCAP HAS BEEN LIFTED OFF AND + THE POSTERIOR WALLS OF THE SINUSES BROKEN. +] + +2. MECHANICAL IRRITATION.—In those instances where inflammation is the +manifestation which reflects the simple mechanical effects of parasites +it will be difficult indeed to prove, in the present state of our +knowledge, that it is not rather the effect of associated toxic +substances or excreta elaborated by the parasite. But instances of a +purely mechanical irritation there must be, although one can scarcely +put the finger upon them and say that this or that individual inflamed +mucosa did not become so from a toxic cause. Omitting these then, the +more certain, purer, more unequivocal examples will be those where +physiological processes become exalted as the result of the parasitic +irritation. An example in point is a case of volvulus in a Screech Owl +(_Otus asio asio_).[112] Here it is probable that the parasites excited +the gut to undue peristaltic action, and that during this process it +became twisted. Worms in such passages as the nose and nasal sinuses (I +have seen blood-red filariæ in the frontal sinuses of an opossum) +undoubtedly produce nervous effects by their presence and movements. +Those in the subcutaneous tissue (filariæ of wild cats) probably also do +so. It is difficult to judge those cases where doubtfully sensitive +parts are the ones affected. Probably the intestinal and intraperitoneal +worms, and less certainly the generally-migrating ones analogous to +_Filaria loa_, produce no nervous effects mechanically. + +3. PRODUCTION OF HEMORRHAGES.—Hemorrhages large enough to kill suddenly +are theoretically possible, since worms occasionally produce aneurysms +which may rupture; we have seen such an accident in a Paradoxure +(_Paradoxurus leucomystax_). But certainly it is the long continued, +wasteful small hemorrhages that are important, inducing an anemia often +of severe and fatal grade. The hookworms are the shining offenders here, +yet we have seen very much the same effect from Acanthostoma in the +intestine of monkeys. Œsophagostomum has also been incriminated at the +London Garden in young Rhesus Macaques (_Macacus rhesus_)[113] where the +young forms of the parasite did the damage as they burrowed into the +wall of the gut. + +4. OPENING UP AVENUES OF INFECTION.—This may be accomplished either by +passage of parasites from one position normally containing bacteria to +another which is susceptible to infection, or by devitalizing a tissue +which is ordinarily resistant to infection; _i.e._, creating a _locus +resistentiæ minoris_. The intestinal tract is the most common organ +concerned, but the illustrations to follow will give variety. Thus, the +mature examples of œsophagostoma in young rhesuses just referred to +above burrowed into the gut wall and led to both local and general +peritonitis. In one of our “spiroptera” parrots the worm had passed +through the proventricular wall and a chronic fibrosis resulted around +it. At the autopsy on a Rhesus Macaque Doctor Fox found a localized +abscess adjacent to the gut wall, and in it a whipworm was imbedded. +Passing from these examples of intestinal worms, I can mention the loss +of a valuable Philippine Spotted Deer (_Cervus alfredi_) as the result +of secondary infection of a cysticercus cyst of the lesser omentum which +led to a nearby peritonitis. Lung infections are not uncommon. +Murray[114] records that forty-four out of eighty-five young rhesus +monkeys dying from pneumonia showed an acarian, and he ascribed the +pulmonary irritation to certain crystals in the excreta of the mite. I +have studied a case of bronchopneumonia in a prairie dog where great +numbers of an arachnid were present. The reports of the London +Zoological Society are replete with notes of round worm pneumonias of +reptiles. These pulmonary cases must result from decreasing of tissue +resistance by the presence of the worms, and are easy to understand, +much more so than the intestinal infections when one recalls how +sensitive lung tissue is to foreign bodies, and that there seems to be +no indication that this tissue becomes accustomed to infestation such as +may be argued for the gut. All these citations must convince us that +parasites are most important predisposing agents to infection, and that +this is one of the most sinister phases of animal parasitism. + +5. DESTRUCTION OF TISSUE.—This heading does not refer to the +comparatively trivial effects that accompany the more acute +inflammations secondary to parasites, albeit certainly the absorption of +their disintegrative tissue products has some effect on the economy; but +our ideas of such are so vague as to justify their being disregarded +here. What I refer to is the more massive destruction such as may occur +in the blood, for instance, from the action of protozoa. There is also +loss of mucosa in those chronic infestments of the stomach where we find +excessive fibrous tissue overgrowth. The most striking example of tissue +destruction we have seen was in the cirrhotic livers of prairie dogs +affected by _Hepaticola hepatica_, where in extreme cases, the amount of +functionating liver substance was reduced to a very small fraction of +its normal bulk.[115] + +6. TOXINS.—We have no direct evidence to offer that noxious products of +parasites are concerned in producing disease in wild animals. The local +effects of such toxins are not distinctive enough—individual enough to +toxins or to the animal body—to separate them from the effects of such +accompanying factors as bacterial inflammations; nor can we separate the +general effects of these toxins from what might have been, for instance, +the effects of an accompanying anemia of hemorrhagic or other origin. +From a knowledge of what happens in human prototypes though, there is +scant doubt that some one of the multitudinous species must be capable +of producing toxins, but just which varieties are concerned cannot be +listed by anyone. By analogy we can at most only suspect the hookworms +and the dibothriocephalidæ. Under this same category of the toxins come +the worm-products which are reputed to have a destructive effect upon +the digestive enzymes in the gastrointestinal tract of the host, and +which would thereby interfere with the proper assimilation of pabulum, +resulting in malnutrition. For the same reasons as above indicated for +the toxins one is unable to speak for or against these “anti-enzymes.” + +7. PRECLUSION OF NUTRITION.—This must be a very unimportant phase of the +activity of intestinal parasites, when one compares the bulk of food +which passes through the bowel and the average number of worms present; +and the same holds good for some interstitial parasites like the adult +filariæ. Even in amazingly heavy infestments of the intestines one will +be constrained to dismiss this idea when he compares the bulk of +parasites with that of the host, and recalls what the physiologist terms +the “factor of safety” inherent in this tract as elsewhere. But in the +case of blood parasites the matter may be different. Here we are +concerned with the withdrawal of refined foodstuffs—those which have +been worked over and over by subtle internal metabolic processes; and we +are not so sure, especially on recalling the enormous numbers of +parasites usual to blood infestments, that there is the capacity on the +part of these internal processes to meet increased demands that we count +upon for the intestinal functions. It is much more serious to be +deprived of the finished product than of the crude because it means the +undoing of “digestive” work all along the line, from gut to tissue cell. +Furthermore, a blood infestment guarantees that the parasite has been +feeding upon and depriving the animal of the precise foodstuffs the +cells require, and not by any chance upon, even in part, intestinal +substances that were wastes or residues. If we except the blood +parasites, then, it seems safe to conclude on the whole that the amount +of pabulum used by parasites is unimportant to the animal. + +Having reviewed the manner in which parasites may conceivably be +harmful, it is time to return to the question of the actual exercise of +these powers. + +The older appraisal of parasites in animals, namely that they were +rather innocent of disease production, was suggested by and borrowed +from the veterinarian, probably being engendered in him by their +frequency in what appeared to be normal domestic specimens. Yet it is +only proper to add that one of our former pathologists, and sometime +professor of veterinary pathology, Dr. C. Y. White, is a medical man and +is of much the same opinion. Older writers regarded worms even as +“guardian angels” of children. Very recently Schwartz[116] reviews some +work in this connection showing that, _in vitro_, some cestode extracts +were inhibitory to certain bacteria (_B. anthracis_, _B. pyocyaneus_ and +_B. dysenteriæ Shiga_). This relationship is so different from natural +conditions as to need no further comment. + +At the London Garden the view appears to be different. In the 1910 +report they charge five deaths against perforation by worms of the +stomach and intestines; in the 1911 report they record giant toads dead +from lung infestment; in 1912 “eighteen cases of enteritis were due to +worms”; and in 1917 they mention pneumonia in a toad and perforation of +the stomach of a puma. These reports represented evidently the more +striking, unequivocal examples of death from parasites which had +outspoken anatomical expressions, and omitted those in which the more +subtle agencies of parasitic pathogenesis were concerned. Their +experience has apparently been much the same as ours. + +The ideal approach to a decision in reference to the importance of +parasites would appear to be a mathematical one, something as follows: +First, to determine what species infest animals and how commonly, then +to decide which ones are pathogenic and thirdly to estimate the severity +of the disease induced; so that finally, by an analysis and comparison +of the three results—a comparison and analysis judicial in the broadest +sense—we might hope to come to an opinion. Let us consider the three +avenues in order. At the first glance it must be evident that a list of +all possible parasitic varieties does not exist and may never be +compiled. The most that can be done is to tabulate the findings in +scattered laboratories, data usually recorded in terms of the individual +observer’s studies and often inadequate to give the compiler all the +facts desired. The same remarks apply to the percentage incidence of +parasitism. Not to prolong the academic discussion, suffice it to say +that very much the same obstacles present in the second avenue—that of +pathogenicity of the individual species. Our own data referring to this +second heading will be presented later, but after the failure of the +first avenue, the second and third lose greatly in value. At best, +statistics can be only suggestive. Unless critically and suspiciously +interpreted, and with a full appreciation of their limitations from a +foreknowledge of the way in which they were compiled, they would only +delude the reader and offend science, and so we abandon this line of +reasoning. + +At present the best results of the study of pathogenesis by animal +parasites will probably be reached by a combination of methods, as +follows: + +1. Direct. How commonly do we see clinical symptoms and morbid +anatomical changes that are incontrovertibly due to the parasite? We +restrict ourselves here to a narrow group of infestments indeed, and +think of such diseases as trichosomiasis in prairie dogs and +spiroteriasis in parrots. + +2. By comparison with analogous infestments of domestic animals and man— +more thoroughly studied and therefore more accurately appraised, in +general, as to pathogenicity; a comparison from the standpoint of +disease production rather than natural habits of the parasite. Example, +coccidiosis and hookworm disease in foxes and dogs. + +3. By inference through deduction. This is the most unsatisfactory +consideration of all, and should be well checked up and discounted. Here +we would evaluate the known propensities of the parasite first, such as +its size, motility, anatomic position in the host and the general +pathological traits of the genus and family to which it belongs, etc., +and then compare these verminous properties with those of the host—its +size, temperament, physical stamina, etc. This third consideration must +necessarily overlap with or be supplementary to the first two. For +example, this consideration would have to be resorted to in many cases +of ascaris infestment where anatomical changes are generally not +demonstrable. + +Acting on these three considerations, and after twelve years of +observation on parasites here in the Garden, a fresh review of our +records, and a recent review of the accessible relevant parasitological +literature I have come to the conclusion that, considering wild animal +collections the world over, there is no justification for an +unqualified, definite answer to the question of pathogenic parasitism +that will meet all conditions. We lack data on too many species that are +not sufficiently represented in collections or indeed not represented at +all. It is the liability to infestment of each order or family of beasts +that will have to be determined, and, depending on the assortment each +garden has on exhibition, will the importance of parasites to the garden +as a whole vary. + +Speaking for the Philadelphia Garden, I have come to the conclusion that +on the whole parasitism does play an important part of our annual +losses. The financial loss which could be charged against spiroptera +alone is in the four figures, to say nothing of the difficulty of +replacement of rare species. And while touching the financial phase let +it be added that scientific work done now, it must be remembered, is not +restricted to the present time or place, but is to be measured in +dollars and cents with the yard stick applied to the future, and in +other places than that where the initial work is done. Even if we cannot +answer the question of the matter of importance the world over we can +guarantee that it is sufficiently so in the Philadelphia and London +Gardens to warrant a rigid supervision for parasitism; and since the +other larger collections are probably made up of similar animals, albeit +in different proportions, we surmise at least that it is likewise so +with them. + +IMPORTANCE OF PARASITES IN OTHER FIELDS.—In addition to their importance +to exhibitions, animal parasites of wild animals are important first to +man. The animal hosts may serve as porters of infestation, and interfere +with attempts at eradication of the disease. The experience of the +European with African sleeping sickness attests to this. Not to go +farther than immediate examples I wish to note in this connection the +occurrence in this Garden of scabies in an orang which was transmitted +to a keeper, and of amebic dysentery in monkeys. Leiper[117] has called +attention to a guinea-worm in a leopard. + +Parasites are important to certain wild animal industries. The ones that +have come to my attention are the fur seal (_Otoes alaskanus_) industry +of the Pribiloff Islands and fox-farming in Newfoundland. In both of +these instances the hookworm was concerned and entailed losses of +thousands of dollars. Lucas, who conducted a United States Government +commission to the seal grounds and after whom Stiles named the parasite, +has left very full notes of the former disease. I have identified the +same infestment in a young California hair seal (_Zalophus +californianus_) which was born and died in this Garden. This indicates +that the parasite might perhaps be found farther down the Pacific coast +than hitherto suspected. + +To hunters parasitism of animals must be important, but to an unknown +and undoubtedly unimagined extent. The grouse plague of Scotland[118] is +an example to point. Who knows but that the disappearance of some of our +game animals, particularly birds, was not due more to disease than to +the ravages of man? There is at least food for thought here. + +OCCURRENCE OF ANIMAL PARASITES IN THE WILD.—It would be unbelievable +that parasitism did not exist in the wild. It seems proper, however, to +record some evidence. Diesing’s _Systema Helminthum_ is replete with +references to Natterer’s Brazilian expedition. Nicoll speaks of a German +expedition to Spitzbergen in 1898, and a Swedish one to Egypt in 1901, +in both of which large numbers of parasitic forms were collected. +Nicoll[119] found _Trichosoma hepaticum_ in a hare shot in the wild, and +liver-flukes[120] in a kestrel shot on the coast of Scotland. +Leiper[121] found nine species of worms in hippopotami during an +expedition to Uganda, and[122] states that thirty-seven species of +helminths were collected on an Antarctic voyage by Surgeon Atkinson. In +an investigation of Grouse disease in Scotland, Fantham found many +different blood and intestinal parasites. Dr. Charles B. Penrose tells +me that all of the white-tailed deer he shot in the valley of the Swan +River, Montana, were infested with liver-flukes, so much so that the +liver was literally riddled by the disease, and yet the deer were fat. +The black-tail deer of the same valley were not thus parasitized and +were not as fat. In our own Garden we have found many tapeworms in wild +cats[123] which had been too recently captured for the worms to have +developed in captivity. Such instances might be still further +multiplied. + +A more important consideration is the fate of the parasites thence +introduced into our Garden. Do they disappear of themselves? Naturally +we can never make sweeping predictions, for future events will depend +upon the life history of the individual parasite concerned. But by and +large, once introduced it is better to assume the attitude of pessimism, +and resign oneself against spontaneous disappearance and, what is worse, +realize that the parasitism is likely to become indigenous. We have +several pieces of evidence, however, that the infestment may +occasionally quite disappear. Thus, I have seen _Coccidium bigeminum_ +spontaneously disappear from a Swift Fox (_Canis velox_) and _Spiroptera +incerta_ from a Macaw as proven at autopsy. Nicoll[124] remarks that +certain trematode infestations were heavier in newly arrived animals +than in ones long resident in the Garden. This is conceivable on the +basis of individual worms dying out, _i.e._, fulfilling their life spans +without the host becoming reinfested with fresh parasites. Precise +information on the subject is supplied by Ackert[125] who found that +cestodes disappeared from chickens in six to eight months when the birds +were confined, _i.e._, protected from reinfestment. Moreover, it is +known that worms can escape during acute infections, the infectious +state of the economy producing conditions obnoxious to the parasite. We +hear of many instances of their expulsion in human feces and vomitus +during malaria and the exanthemata of childhood and know of similar +discharge from animals during the death agony. I cite these data largely +because they explain the scarcity or absence of parasites at autopsy in +animals which were known to have been clinically infested. + +FREQUENCY OF PARASITISM IN WILD ANIMALS + +There can be little doubt that wild animals are more frequently infested +than man, and furthermore with a larger number of parasites. I have no +statistical basis for these opinions—they rest on personal observations +of human and animal autopsies, and reports of findings in the tropics +and elsewhere. They have therefore but the value of an individual +opinion. I should estimate rather cautiously that wild animals are +infested at least two or three times as frequently as man and much more +heavily. + +The first step in the discussion of the incidence of parasites must be +that respecting the (host) classes and smaller taxonomic divisions—of +course as they have been studied in this Garden. Certain statistical +limitations were experienced and can be summarized as follows: + +Data are not available on a sufficiently large number of animals to +justify conclusions as far down as genera and species, except for such +commonly and generously exhibited forms as monkeys and parrots. I have +therefore in tabulating and reviewing our records, distributed the +animals only as far as families—not into genera and species. The table +(24) to follow will be found not to contain every family because to do +so would needlessly enlarge it. Accordingly I have followed the policy +of only indicating those genera and species showing either frequent or +important infestment. I shall refer to those groups later as +“susceptible” groups. If no family is recorded in the table it means +that we have had no important numbers of infestments in it. The +“remarks” column shows the individual parasite that has been +particularly frequent or otherwise important. If there are no remarks it +means that the species of parasites found have been scattering. + + +RESULTS OF REVIEW AND TABULATIONS. + +We now pass to an analysis and discussion of the findings brought out in +the previously mentioned review of our records and in Table 24. Viewed +broadly we find that there is a wide variation in the susceptibility of +different families to infestment. Those that are susceptible may be +located by consulting the table, and each will therefore not be +separately culled out and subjected to needless repetition. A few points +are however worthy of separate mention. While there is a familial or +generic susceptibility within certain orders it is unwise to generalize +too broadly. Thus for example the Corvidæ have a high percentage in +incidence for tropidocerca, syngamus and periproventricular worms, many +families of Ungulata harbor echinococcus, and Carnivora are prone to +show ascarids. On the other hand, among the copious exceptions to this +may be cited the irregular liability to infestment exhibited by the +Galli. Four varieties of these birds are represented but there are +missing such important kinds as curassows, guans, guinea fowl and +peafowl. + + TABLE 24. + _Incidence of Parasites in Animal Groups._ + ══════════════════════╤═══════════════════════════════╤════════════════════ + Animal │ MAMMALIA │ Remarks + ──────────────────────┼───────────┬────────┬──────────┼──────────────────── + „ │ Number of │ Number │Percentage│ „ + │Autospecies│Infested│ │ + ──────────────────────┼───────────┼────────┼──────────┼──────────────────── + Primates │ [126]538│ 51│ 9.4│ + Cercopithecidæ │ │ │ │ + Sooty Mangabey │ 34│ 4│ 11.8│ + Cercocebus │ │ │ │ + fuliginosus │ │ │ │ + Rhesus Macaque │ 60│ 6│ 10.│ + Macacus rhesus │ │ │ │ + Callitrichidæ │ │ │ │ + Marmosets │ 43│ 7│ 16.3│ + Cebidæ │ │ │ │ + Squirrel Monkeys │ 8│ 3│ 37.5│ + Other Cebus │ 87│ 10│ 11.5│Eight had Filaria + Monkeys │ │ │ │ gracilis. + Lemures │ 86│ 6│ 7.│ + Carnivora │ 498│ 84│ 16.9│ + Felidæ │ │ │ │ + American Wild Cat │ 28│ 11│ 40.│Stomach and + │ │ │ │ intestines, 22; + Felis ruffus │ │ │ │Bronchi, 4; Muscles, + │ │ │ │ 7. + Spotted Wild Cat │ 5│ 4│ 80.│ + Felis ruffus │ │ │ │ + texensis │ │ │ │ + Canada Lynx │ 10│ 4│ 40.│Ascarids only. + Felis canadensis│ │ │ │ + Lions │ 10│ 3│ 30.│Ascarids in stomach + │ │ │ │ and + Felis leo │ │ │ │intestines. + Ocelot │ 15│ 5│ 33.│Uncinaria. + Felis pardalis │ │ │ │ + Canidæ │ │ │ │ + Gray Fox │ 28│ 1│ 4.│Cestodes. + Canis cinereo │ │ │ │ + argenteus │ │ │ │ + Red Fox │ 17│ 2│ 12.│Uncinaria. + Canis vulpes │ │ │ │ + pennsylvanicus│ │ │ │ + Swift Fox │ 5│ 2│ 40.│Uncinaria. + Canis velox │ │ │ │ + Gray Wolf │ 18│ 2│ 11.│Ascarids. + Canis mexicanus │ │ │ │ + Mustelidæ │ │ │ │ + American Badger │ 17│ 7│ 41.│Physaloptera. + Taxidea taxus │ │ │ │ + Procyonidæ │ │ │ │ + Raccoon │ 42│ 2│ 5.│ + Procyon lotor │ │ │ │ + Ursidæ │ │ │ │ + Bears │ 37│ 6│ 16.│Ascarids. + Otariidæ │ │ │ │ + Hair Seal │ 20│ 1│ 5.│Uncinaria. + Zalophus │ │ │ │ + californianus │ │ │ │ + Rodentia │ 198│ 32│ 16.│ + Sciuridæ │ 44│ 4│ 9.│Scattered through + │ │ │ │ four + Castoridæ │ │ │ │different genera. + American Beaver │ 17│ 4│ 23.│In three cases + │ │ │ │ oxyuris + Castor │ │ │ │and flukes in cecum. + canadensis │ │ │ │ + Hystricidæ │ │ │ │ + Canada Porcupine │ 47│ 17│ 36.│Cestodes 8, filaria + │ │ │ │ 11, oxyuris 9, + Erythizon │ │ │ │in peritoneal cavity + dorsatus │ │ │ │ also intestine. + dorsatus │ │ │ │ + Hyraces │ 7│ 2│ 28.│Cestodes in bile + │ │ │ │ ducts. + Cape Hyrax │ │ │ │ + Procavia capensis │ │ │ │ + Ungulata │ 365│ 44│ 12.│ + Equidæ │ │ │ │ + Zebras │ 7│ 7│ 100.│Nematodes, + │ │ │ │ intestine. + Cervidæ │ │ │ │ + Axis Deer │ 6│ 1│ 17.│C. tenuicollis. + Cervus axis │ │ │ │ + Barasingha Deer │ 8│ 0│ │ + Cervus duvanceli│ │ │ │ + Eld’s Deer │ 6│ 0│ │ + Cervus eldi │ │ │ │ + Fallow Deer │ 20│ 1│ 5.│Echinococcus cysts. + Cervus dama │ │ │ │ + Hog Deer │ 21│ 0│ │ + Cervus porcinus │ │ │ │ + Japanese Sika Deer│ 14│ 0│ │ + Cervus sika │ │ │ │ + typicus │ │ │ │ + Red Deer │ 14│ 0│ │ + Cervus elaphus │ │ │ │ + Elk │ 29│ 2│ 7.│Trichocephalus. + Cervus │ │ │ │ + canadensis │ │ │ │ + White tailed Deer │ 33│ 2│ 6.│Echinococcus in lung + │ │ │ │ (2). + Mazama │ │ │ │ + virginiana │ │ │ │ + Mule Deer │ 8│ 5│ 62.│Four Cyst. + │ │ │ │ tenuicollis. + Mazama hemionus │ │ │ │ + Camelidæ │ │ │ │ + Llama │ 14│ 2│ 14.│ + Lama glama │ │ │ │ + Camels │ 9│ 4│ 44.│Hydatid cysts. + Suidæ │ 19│ 2│ 10.│ + Edentata │ 16│ 2│ 12.5│ + Armadillos │ 10│ 2│ 20.│ + Marsupialia │ 175│ 45│ 26.│ + Didelphyidæ │ │ │ │ + Common Opossum │ 84│ 40│ 48.│Physaloptera, 38; + │ │ │ │ oxyuris, 5; + │ │ │ │ cestodes, 5; + │ │ │ │ nematodes in + │ │ │ │ lungs, 3; cysts in + │ │ │ │ peritoneal areolar + │ │ │ │ tissue, 2; + │ │ │ │ trematodes in + │ │ │ │ ileum, 1. + Didelphys │ │ │ │ + virginiana │ │ │ │ + Macropodidæ │ │ │ │ + Kangaroos and │ 70│ 0│ 0.│ + wallabies │ │ │ │ + ──────────────────────┼───────────┴────────┴──────────┼──────────────────── + │ AVES │ + Passeres │ │ │ │ + Corvidæ │ │ │ │ + Common Crow │ 16│ 7│ 44. }│Tropidocerca and + │ │ │ │ occasional + │ │ │ │ intestinal + │ │ │ │ cestodes. Syngamus + │ │ │ │ in crows. Few + │ │ │ │ filaria. + Corvus │ │ │ }│ + brachyrhynchos│ │ │ │ + brachyrhynchos │ │ │ }│ + Magpies │ 28│ 18│ 64. }│ + Jays │ 41│ 22│ 55.│Periproventricular + │ │ │ │ filaria, + │ │ │ │ strongylus. + Pies, choughs, │ 35│ 12│ 33.│There is a striking + etc. │ │ │ │ consistency of + │ │ │ │ infestment in the + │ │ │ │ different members + │ │ │ │ of Corvidæ both as + │ │ │ │ regards degree of + │ │ │ │ infestment and + │ │ │ │ species of + │ │ │ │ parasite present. + Sturnidæ │ │ │ │ + Starlings │ 63│ 19│ 30.│Periproventricular + │ │ │ │ filaria largely. + Turdidæ │ 25│ 8│ 33.│Periproventricular + │ │ │ │ filaria largely. + │ │ │ │Thrushes and Robins. + │ │ │ │ None in American + │ │ │ │ thrushes, one in a + │ │ │ │ robin. + │ │ │ │Finches. Not + │ │ │ │ examined closely + │ │ │ │ at autopsy, but + │ │ │ │ there is a + │ │ │ │ scattering of + │ │ │ │ periproventricular + │ │ │ │ filaria and + │ │ │ │ intestinal + │ │ │ │ cestodes through + │ │ │ │ most of the + │ │ │ │ species. + Canaries │ 24│ │ │Were free from + │ │ │ │ parasites. + Picariæ │ │ │ │ + Picidæ │ │ │ │ + Woodpeckers │ 4│ 2│ 50.│ + Rhamphastidæ │ │ │ │ + Toucans │ 30│ 9│ 30.│Spiroptera largely. + Striges │ 142│ 2│ 7.│Remarkably free of + │ │ │ │ parasites. + Psittaci │ [127]774│ 124│ 16.│ + Loriidæ │ │ │ │ + Lorys │ 24│ 5│ 20.│3 spiroptera, 1 + │ │ │ │ hemoproteus, 1 + │ │ │ │ intestinal worm. + Cacatuidæ │ │ │ │ + Cockatoos │ 4│ 2│ 6.│2 spiroptera. + Crested Ground │ 45│ 4│ 9.│4 spiroptera. + Parrakeet │ │ │ │ + Calopsitta novæ- │ │ │ │ + hollandiæ │ │ │ │ + Psittacidæ │ │ │ │ + Old World (Totals)│ 453│ 65│ 14.3│ + Undulated Grass │ 121│ 2│ 1.6│1 spiroptera, 1 + Parrakeet │ │ │ │ coccidium. + Melopsittacus │ │ │ │ + undulatus │ │ │ │ + Pennant’s │ 21│ 6│ 29.│6 spiroptera. + Parrakeet │ │ │ │ + Platycercus │ │ │ │ + elegans │ │ │ │ + Rosehill Parrakeet│ 48│ 21│ 44.│20 spiroptera, 1 + │ │ │ │ cestode. + Platycercus │ │ │ │ + eximius │ │ │ │ + Other old world │ 86│ 12│ 14.│12 spiroptera. + parrakeets │ │ │ │ + Old world parrots,│ │ │ │ + lovebirds, │ 74│ 13│ 18.│13 spiroptera. + eclectus. │ │ │ │ + New World (Totals) │ 321│ 69│ 21.5│ + Macaws │ 26│ 9│ 34.│9 spiroptera. + Conures │ 62│ 16│ 26.│15 spiroptera, 1 + │ │ │ │ hemoproteus, 1 + │ │ │ │ blood larva. + Amazons │ 164│ 27│ 16.5│24 spiroptera, 3 + │ │ │ │ nematodes. + Other new world │ 69│ 17│ 10.│7 spiroptera. + parrots │ │ │ │ + Accipitres │ [127]201│ 13│ 6.7│ + Falconidæ │ │ │ │ + Buzzards │ 55│ 4│ 7.3│ + Eagles │ 44│ 1│ 2.3│ + Serpentaridæ │ │ │ │ + Vultures │ 29│ 1│ 3.4│ + Miscellaneous │ 73│ 7│ 9.6│4 were blood + │ │ │ │ protozoa. + Galli │ 299│ 42│ 14.│ + Phasianidæ │ │ │ │ + Pheasants │ 95│ 20│ 21.│Heterakis in ceca. + Partridges │ 14│ 3│ 21.│ + Quail │ 70│ 10│ 14.│Heterakis. + Megapodidæ │ │ │ │ + Wild Turkeys │ 39│ 7│ 18.│Intestinal cestodes. + │ │ │ │ Coccidia twice. + Columbæ │ [128]163│ 14│ 9.│Mostly intestinal + │ │ │ │ cestodes, but + │ │ │ │ several + │ │ │ │ spiroptera. + Fulicariæ │ [128]38│ 7│ 18.│ + Alectorides │ [128]41│ 10│ 25.│ + Gaviæ │ [128]21│ 3│ 14.│ + Steganopodes │ [128]22│ 1│ 5.│ + Herodiones │ [128]105│ 21│ 20.│ + Anseres │ [128]319│ 28│ 8.8│ + Swans │ 48│ 7│ 14.│No significant + │ │ │ │ groupings. + │ │ │ │ Parasites + │ │ │ │ scattering. Few + │ │ │ │ intestinal + │ │ │ │ cestodes. + Geese │ 83│ 13│ 15.6│ + Ducks │ 188│ 8│ 4.│ + Struthiones │ 36│ 1│ 2.8│ + ──────────────────────┴───────────┴────────┴──────────┴──────────────────── + +Nor do all members of a genus necessarily show the same susceptibility, +and the heterakis infestment in the pheasants illustrates this matter +very well. It was limited almost entirely to two species—Amherst’s and +Golden, whereas several frequently exhibited species showed none. The +following table brings this out in more detail: + + TABLE 25. + _Heterakis in Pheasants._ + ════════════════════════════════════════════╤════════╤════════╤════════ + Species │ Total │Infested│ Per + │ │ │ cent. + │ │ │infested + ────────────────────────────────────────────┼────────┼────────┼──────── + Golden Pheasant (Chrysolaphus amherstiæ) │ 18│ 12│ 67 + Amherst’s Pheasant (Chrysolaphus pictus) │ 16│ 5│ 31 + Silver Pheasant (Gennæus nycthemerus) │ 19│ 1│ 5 + Reeves’ Pheasant (Phasianus reevesi) │ 16│ 1│ 6 + Ringnecked Pheasant (Phasianus torquatus) │ 12│ 0│ 0 + Swinhoe’s Pheasant (Gennæus swinhoii) │ 10│ 0│ 0 + ────────────────────────────────────────────┴────────┴────────┴──────── + +Enzoötics and environment played no part in the above figures. We have +had no real heterakis enzoötics, for in but two instances did three +heterakis deaths occur in a year, and two deaths per year have occurred +in but four instances in the past twenty years. During this time there +have been sufficient animals on exhibition and subjected to autopsy to +indicate definitely that the two species named—Amherst’s and Golden, +must be considered as more susceptible than the other varieties. Nearly +all of the heterakis in quail likewise occurred in one species—seven of +the ten cases occurred in a total of twenty-three Scaled Quail—but in +these birds the infestment appeared in enzoötic form and cannot be +viewed as indicating a preference for a species. + +Psittaci are on the whole, not susceptible to worms. It is true that we +suffered a serious outbreak of spiropteriasis a few years ago, but if we +consider this a closed chapter we can accept the above generality as +stated. Among 774 parrots autopsied we have encountered but one cestode +and three intestinal round worms. + +The deer, likewise, are singularly free from intestinal parasites. I +gave the detailed records of these animals in Table 24 to emphasize the +scarcity of parasites even when fairly numerous specimens had been +available for examination. + +Other interesting features in the table are the outstanding infestments +of squirrel monkeys and marmosets among the monkeys, of gastric and +intestinal worms in the wild cats, and intestinal worms in the zebras. + +The foregoing has had to do with parasitism from the standpoint of the +host. The next phase, that of the individual parasite itself, interests +more the strict parasitologist than the general zoologist; however, both +will see how it may have a very practical value. + + TABLE 26. + _Distribution of Parasitic Cases According to Parasitic Groups._ + ═════════════════════════════════════╤════════════════╤════════════════ + Nematodes │ 183[129]│ + Spiroptera │ 145│ + Filaridæ │ 138│ + Ascaris │ 30│ + Physaloptera │ 28│ + Uncinaria │ 25│ + Tropidocerca │ 23│ + Heterakis │ 22│ + Trichocephalus │ 11│ + Syngamus │ 9│ + Trichina │ 2│ + Hepaticola │ 2│ + Other Miscellaneous │ 4│ + Total Nematodes │ │ 622 + Cestodes │ 165[129]│ + Echinococcus │ 9│ + Cysticercus │ 7│ + Tænia │ 4│ + Miscellaneous │ 3│ + Total Cestodes │ │ 188 + Trematodes │ │ 22 + Acanthocephalus │ │ 4 + Protozoa │ │ 14 + Arthropods │ │ 6 + Unclassified │ │ 34 + ─────────────────────────────────────┼────────────────┼──────────────── + Grand Total │ │ 890 + ─────────────────────────────────────┴────────────────┴──────────────── + + +INCIDENCE ACCORDING TO PARASITIC GROUPS. + +Inasmuch as it has been physically impossible to determine specifically +and classify efficiently the accumulations of verminous material from +our autopsies I will not be able to tabulate parasitic groups even as +closely as I did in the “animal host” table. Nevertheless sufficient has +been done to illuminate in part certain phases of parasitism and to +prevent a summary dismissal of the subject. Reviewing our cross index I +have distributed the data into the following Table 26, the parasites +being listed in the order of their frequency. It may serve only as a +panorama of the situation, inasmuch as determinative study of a group +amounts to a research in itself, and the multiplicity of them precludes +a consistent study of every one. The data are based upon “cases of +parasitism.” That is, each and every worm species occurrence has been +counted, regardless of whether it was the same species that has been +concerned over and over again, or in different anatomical positions (of +different individual hosts, of course) or whether it was in association +with other parasites. + + +ANALYSIS OF TABLE 26. + +There is a grand total of 890 cases of animal parasitism embraced in the +above table, which is a sufficiently large number to give representative +value to some phases of the analysis. + +In the first place nematode worms occur about three times as frequently +as all other forms of parasites. In gardens where spiroptera has not +figured so largely the proportion might be reduced to about two to one. +Cestodes rank a poor second, trematodes a worse third, and +acanthocephali a very bad last. This order agrees with our figures of +1913[130] and with the small series of Nicoll.[131] The latter worker +found that the order was not changed when pains were taken to include +also such smaller worms as could only be obtained from the host by using +sieves, etc. Cestodes were not likely to be overlooked, but very small +trematodes and nematodes were easily passed over. + + +VISCERAL DISTRIBUTION. + +As to the individual organs which are most commonly parasitized our +records show that with Aves as well as Mammalia the intestines are the +parts most commonly affected. The stomach ranks second for both—the +proventricle rather than the gizzard of birds corresponding, +parasitologically speaking, to the stomach of mammals. We have found but +one parasitic species in the gizzard of birds, _i.e._, immature forms of +_Spiroptera incerta_ lying under the chitinous lining of the gizzard and +only discoverable after the lining has been peeled off. The peritoneum +comes third (air sacs of birds) due to the presence of filaridæ, and the +blood fourth for the same reason. It is to be emphasized that, in our +data, identical organs of mammals and birds should be about equally +liable to infestment with the possible exception of the lungs. But in +view of the small number of cases available there is no justification +for speculating about the reason for this last difference, albeit the +radical difference in the anatomy of the two classes is very inviting. + +Now that our spiroptera enzoötic has subsided, the order above given +will be changed, and in view of like disturbing factors other gardens +should not expect the same order to hold invariably for their +collection, since their enzoötics will depend somewhat on the +preponderance of animals of one or another family which are likely to +compose their exhibits. A single such enzoötic may suffice to disarrange +the whole fabric, and if two or three are taken into account the order +of organ involvement can be quite disrupted. To attempt to construct +statistically an “order of frequency involved” which would stand for +every garden would only lead to interminable adjustments on the basis of +animals exhibited and of parasitic enzoötics, so that I have finally +been reduced to a combination of our Garden statistics and the +bloodparasitic ones of the London Garden. Doing this I have arranged in +Table 27 the frequency of organ involvement as follows and estimated the +percentage of animals infested. These figures are computed upon a +different basis from that of Table 24. They naturally cover all animals +and not the “susceptible” ones as in Table 24. + +[Illustration: + + FIG. 73.—HUGELY DISTENDED PROVENTRICLE OF PARROT DYING WITH + SPIROPTERIASIS. COMPARE ITS SIZE WITH THAT OF THE HEART WHICH IS + ABOVE AND TO THE LEFT, AND THAT OF THE GIZZARD BELOW AND TO THE + LEFT. +] + + TABLE 27. + ═══════════════════════════════════╤═══════════════════════════════════ + Mammalia │ Aves + ───────────────────────┬───────────┼───────────────────────┬─────────── + │ per cent. │ │ per cent. + Intestines │ 9.0│Blood │ 6.5 + Stomach │ 3.7│Intestines │ 3.5 + Peritoneum │ 2.3│Proventricle │ 1.7 + Blood │ 1.5│Air sacs │ 1.3 + Lungs │ 1.0│Liver │ 0.3 + Muscles │ 1.0│Gizzard │ 0.3 + Liver │ 0.5│Scattering │ 0.4 + ───────────────────────┼───────────┼───────────────────────┼─────────── + Total │ 20.0│Total │ 14.0 + ───────────────────────┴───────────┴───────────────────────┴─────────── + +The effect of this is at first sight startling in that it places the +blood parasites of birds so far in the fore, but it must be at once +recalled that the inquiries upon the blood parasites were much more +searching—microscopic, than in the case of the other organs. If similar +methods were applied to the others their percentage of parasitism might +be notably raised—particularly that of the intestines. + + +SPECIAL PARASITOLOGIC CONSIDERATIONS. + +At this point the statistical considerations of parasitism will give way +to descriptions of certain specific infestments that have given us more +or less concern. + +The occurrence of single parasitic varieties or of well known species in +an isolated host may occasionally be of practical importance, but +usually they amount to little more than an academic study, whereas the +repeated discovery of single parasitic kinds, or infestment of similar +hosts, especially when grouped, raises the matter to a very practical +level demanding attention. Such findings being not infrequent in our +experience, it has been possible to study our material in a manner +designed to show the frequency of various parasites in a certain host, +the susceptibility of certain animals to parasites in general and the +infestment of dissimilar hosts by the same parasite. The more important +of these now follow. + + +AVIAN SPIROPTERIASIS. + +This disease concerned parrots particularly but toucans, pigeons, and +such widely separated species of birds as the starling, quail, thicknee +and barbet have been occasionally affected. To the naked eye the +parasite resembles the human hookworm, but differs in location, being a +resident of the proventricle where it produces a swelling of the mucosa +which interferes with the passage of food. Up to a hundred worms may be +present in the one bird, and immature forms are occasionally found under +the chitinous lining of the gizzard. The parasite burrows into the +mucous membranes, occasionally penetrates quite through the wall into +the air sacs, and on one occasion induced an adenomatous hyperplasia of +the mucous membrane, and an adjacent “peritonitis.” Mucus is sometimes +present in the droppings. Death may occur either acutely, or with +emaciation. Spiroptera incerta Smith[132] is the common parasitic +species of parrots, but I have found at least one other as yet +unidentified species in the toucan, and there are probably more. In the +eight year period 1906–1913 from 25 to 50 per cent. of our dead parrots +showed this parasite every year, the total loss being 113 birds for this +period—a most important infestment. + +[Illustration: + + FIG. 74.—HISTOLOGIC SECTION THROUGH PROVENTRICULAR WALL OF PARROT, + SHOWING SECTIONS OF SPIROPTERA IN THE LUMEN AND MUCOSA. THERE IS + SOME GLANDULAR HYPERPLASIA (ADENOMATOID) AND NECROSIS OF THE LUMINAL + PORTIONS OF THE MUCOSA. +] + +[Illustration: + + FIG. 75.—INFLAMMATORY ROUND CELL INFILTRATION AROUND NERVE TRUNK IN + WALL OF PROVENTRICLE. PARROT DEAD WITH SPIROPTERIASIS. +] + +We approached the problem by diagnosing and isolating the infested birds +through a microscopic examination of droppings, finding that by boiling +the droppings in 5 per cent. NaOH solution we clarified them and made +examination easier and more certain without at the same time destroying +the parasitic ova. The result of the examination of all our parrots was +the isolation of 14 per cent. of the parrot population; and as these +died off the diagnosis of infestment was found confirmed at autopsy in +every case. The parrot house was thoroughly renovated and no newly +arrived parrots were admitted until after quarantining and examining +droppings for ova. The toucans and other species, being housed +elsewhere, were not quarantined. Following this, we were gratified to +experience no more spiroptera deaths in parrots for seven years. Then, +in 1920 and 1921, a new outbreak occurred in four toucans and several +other scattering species, including two parrots; but none of these came +from the main parrot house and probably represented a fresh importation. +We attempted to cure the isolated verminous birds by medication but were +unsuccessful. Likewise attempts at determining the life cycle of the +parasite brought us no farther than that the ova developed larvæ in +moist sand in six days. Feeding of ova, freshly passed and larvated did +not produce infestment in parrots or pigeons. On the whole we can quote +our experience with spiroptera as a most satisfactory example of the +value of hygiene and as a result which could never have been +accomplished by medication. + + +HEPATICOLA (TRICHOSOMA) HEPATICA IN PRAIRIE DOGS. + +Bancroft[133] and Hall[134] have given us details concerning this +parasite and the disease it causes. It is threadlike, several inches +long, and permeates the livers of the gray rat, white rat and wild +hare.[135] We first saw it in the more or less cirrhotic livers of +several prairie dogs; later we observed it in a beaver and the gray rats +of the Garden. In the prairie dogs and beaver the liver resembled that +of fatty cirrhosis and was so considered on naked eye examination at our +first autopsy. We were only set right when we came to the histological +examination. It was remarkable how well conditioned some of the prairie +dogs were in in the face of very extensive liver destruction; but on the +other hand some were emaciated and a few of the spontaneously diseased +showed at autopsy an enormous ascites. The outstanding features at +autopsy were the large size of the liver and its pallor and hardness; +and fine yellow lines could sometimes be made out twisting over the +surface. + +The disease affects wild rats differently from prairie dogs. In both the +spontaneous and experimental disease the infestment was insignificant, +amounting to perhaps three or four foci the size of a split pea near the +anterior margins of the liver. Diagnosis may be easily confirmed by +crushing the yellow infested portions of the liver between glass slides +and examining microscopically for ova. + +We have seen such a small number of cases of this disease because so few +prairie dogs reach the autopsy table, yet there must be some important +mortal factor in our prairie dog enclosure, for the Superintendent +states that the population there does not increase in spite of the +frequent births and additions from dealers. The animals almost +invariably die under ground and their bodies are not recovered. + +In order to test out the origin of the infestment we trapped two of our +exhibition specimens, and the liver of both was found infested on +surgical examination whereas six newly purchased ones had normal livers. +The latter were secured fresh from their native habitat in the West, and +their livers were examined through long surgical incisions and found +free of infestment. Later we fed the ova (embryophores) from rat livers +to these prairie dogs and on destroying them found them infested. We +were also successful in transmitting the disease in the opposite +direction, _i.e._, from prairie dog liver to white rat. From all this we +feel sure that the prairie dog disease in our Garden was transmitted +from the rat and that here is another reason for rat extermination in a +zoological garden. + +[Illustration: + + FIG. 76.—OVA OF HEPATICOLA HEPATICA IN LIVER OF PRAIRIE DOG. THEY HAVE + BIPOLAR OPENINGS. THERE IS DESTRUCTION OF LIVER TISSUE AND A LITTLE + INFLAMMATORY REACTION OF CELLULAR CHARACTER, BUT NO IMPORTANT + FIBROSIS. +] + +[Illustration: + + FIG. 77.—UNCINARIA SMITHI COILED IN INTRAHEPATIC BILE DUCTS OF + GIRAFFE. NOTE MARKED PERIDUCTAL FIBROSIS IN THE NEIGHBORHOOD OF THE + PARASITES. +] + +The adult _Hepaticola hepatica_ of prairie dogs I have not seen in +sufficient entirety to compare with the rat species and therefore cannot +affirm that the two are identical species. It is presumably like that of +the rat, being threadlike and most difficult to separate from the liver +substance through which it ramifies. At maturity it dies and +disintegrates, leaving the ova distributed more or less in tracts +through the liver substance, so that we are limited to a certain period +wherein to obtain the mature form. The ova are not passed into the +intestine, but remain _in situ_, just as in the case of hydatid disease, +and therefore diagnosis cannot be achieved by examination of feces. For +the disease to be transmitted the host must die and its carcass be eaten +or otherwise so disintegrated that the ova are distributed abroad. +Another interesting observation is the long incubation period of the +ova. Confirming Bancroft, we found that the ova only became larvated +after they had lain in water at least three months. + + +HOOKWORMS. + +These important parasites have been taken from several foxes: Gray Fox +(_Canis cinero argenteus_), Arctic Fox (_Canis lagopus_), Swift Fox +(_Canis velox_), Red Fox (_Canis vulpes pennsylvanicus_), a Gray Wolf +(_Canis mexicanus_), divers members of the Felidæ-Eyra (_Felis eyra_), +Jaguarundi (_Felis jaguarundi_), American Wild Cat (_Felis ruffus_), +Spotted Wild Cat (_Felis ruffus texensis_), Ocelot (_Felis pardalis_), +from two Giraffes (_Giraffa Camelopardalis_, _Giraffa capensis_), a +Malayan Tapir (_Tapirus indicus_), and a young California Hair Seal +(_Zalophus californianus_). It has been a most serious infestment in +American wild cats (_Felis ruffus_ and _Felis ruffus texensis_)—animals +which generally also harbor other species of worms. In view of the +petechial hemorrhages of the intestines and analogous circumstances in +dogs and human beings, it must be conceded that this worm is pathogenic. + +At this point it is fitting to note the infestment as it affects hair +seals. The parasite concerned, _Uncinaria lucasi_, has long been a +scourge among the fur seals (_Otoes alaskanus_) of the Pribiloff +Islands. Its punctures are bloodless, being signalized instead by small +edematous plaques in the intestinal mucosa, The animal we autopsied was +a young California Hair Seal born in the Garden, and is singularly the +only hair seal in which we have seen it. The natural habitat of the hair +seal is the coast of California which means that the range of _U. +lucasi_ may extend farther southward than at first suspected. We have +none of the northern variety. + +I point out two giraffe cases only because they are unique as to the +organ (liver) affected. So far as I know, mature hookworms have never +been reported from other organs than the intestines. + +From the prophylactic standpoint it will be advisable to have as little +moist earth as possible, particularly sandy ground, in and around the +enclosures for the above mentioned susceptible animals because it is in +such soil that the earlier stages of the life cycle of the parasite are +passed. + +We have never found any of the human hookworm species in our animals, +but it must be recognized that transmission is possible to a certain +degree. _Anchylostoma ceylanicum_ Lane[136] was found in man, cats, +dogs, and a lion; Leiper[137] reports _A. duodenale_ in a dog, and von +Linstow[138] states that the latter parasite also occurs in the +chimpanzee. + +AMEBIC DYSENTERY IN MONKEYS.—We recently lost six monkeys in a small +outbreak of this disease—four black spider monkeys (_Ateles ater_), a +Pinche marmoset (_Leontocebus edipus_), and a woolly monkey (_Lagothrix +lagotricha_). Except for non-characteristic looseness of stools, there +were no symptoms until the usual terminal lethargy set in. Living amebæ +were found in feces. At autopsy only the colon was found to be +anatomically affected. It was hugely distended, fully an inch in +diameter, and there were numerous confluent ulcers of the mucosa covered +by a thick slough. The liver showed no abscesses. In the histological +sections amebæ were found in the interstices of vital gut tissue just as +they are in corresponding human lesions. I have not diagnosed the +species yet, but can vouch that it is not _Endameba histolytica_ or +_coli_. + +[Illustration: + + FIG. 78.—MICROSCOPIC SECTION OF LIVER OF GIRAFFE, SHOWING SECTIONS OF + UNCINARIA SMITHI IN BILE DUCT AND MARKED FIBROSIS AROUND THE DUCT. +] + +[Illustration: + + FIG. 79.—COLON OF MONKEY DYING WITH AMŒBIC COLITIS. HIGHLY ELEVATED + SLOUGHS COVER THE ULCERS. +] + +According to Leidy’s recommendation, grated nutmeg was administered and +was followed by an improvement in symptoms. The animals became brighter +and the stools firmer, but the amebæ were not eradicated. Emetin +hypodermically and by mouth had no obvious effects on the disease or the +amebæ. One monkey thus treated with nutmeg recovered, but died the next +year of another affection and disclosed the scars of the old ulcers in +the colon. Our experience with this disease, however, is not unique. At +Washington, D. C.,[139] eight spider monkeys were affected, and sporadic +cases come to light from the West Coast[140], Manila, Khartoum and +Ceylon. Prowazek’s report concerned a young orang[141]. Liver abscesses +in addition to the intestinal lesions were found by three different +observers. + +As to the transmissibility of monkey amebiasis to man, reporters are +divided. Both sides are probably right, in as much as _Endameba +histolytica_ was concerned in some cases and non-human species in +others. It is an infestment to be feared, and calls for examination of +stools from such newly arrived animals as are known to be susceptible +(spider and woolly monkeys, orangs). + +PARASITES OF MARMOSETS AND SQUIRREL MONKEYS.—I give a special place to +this subject because Table 24 shows that these monkeys are so commonly +infested and because they are so commonly used as household pets. In +this connection the questions arising are, first, whether the infestment +is a menace to life, and second, whether it is existent outside the +Garden or only acquired here. The following lists set forth the +parasitic status as shown at autopsy. The figures indicate how long the +animal lived in the Garden: + + ═════════════════════════════════════════╤═══════════════════════════ + Marmosets │ Squirrel Monkeys + ─────────────┬───────────────────────────┼─────────────┬───────────── + Infested │ Not infested │ Infested │Not infested + ─────────────┼───────────────────────────┼─────────────┼───────────── + 1 day│ 6–15 days ( 4 animals)│ 2 days│ 3 months + 1 day│ │ │ + 2 months│ 1 month ( 6 animals)│ 14 days│ 3 months + 6 months│ 3–5 months ( 9 animals)│ 26 months│ 5 months + 12 months│ 6 months ( 2 animals)│ │ 14 months + 12 months│ 7 months ( 2 animals)│ │ 15 months + 12 months│ 8 months ( 1 animal)│ │ + 13 months│ 9 months ( 2 animals)│ │ + │ 10 months ( 1 animal)│ │ + │ 12 months ( 1 animal)│ │ + │ 14 months ( 1 animal)│ │ + │ 15 months ( 1 animal)│ │ + │ 17 months ( 1 animal)│ │ + │ 18 months ( 2 animals)│ │ + │ 20 months ( 1 animal)│ │ + │ 21 months ( 1 animal)│ │ + ─────────────┼───────────────────────────┼─────────────┼───────────── + Totals 8 │ 35 animals│ 3 animals│ 5 animals + animals │ │ │ + ─────────────┴───────────────────────────┴─────────────┴───────────── + +Reverting to the questions above raised, the data show that some of the +animals were certainly infested on arrival here, and that others +probably were; but since these animals were not examined for parasites +on arrival in the Garden the duration of infestment remains unknown, and +accordingly we are not justified in going farther in our conclusions. In +the case of the marmosets, though, if we confine ourselves to the non- +parasitized animals, it would appear that the “acclimatization” period +is within the first six months. I have attempted to arrive at a +conclusion on this basis, but the average lifetime of the four +parasitized marmosets which survived this period is the same as that of +the sixteen non-parasitized survivors, and we do not know at what time +the parasitized ones contracted the disease. + +[Illustration: + + FIG. 80.—ARACHNID (PNEUMONYSSUS FOXI) IN LUNG OF ADULT MONKEY (MACACUS + RHESUS). IT OCCUPIES THE CENTRE OF A CYST WHICH IMMEDIATELY + UNDERLIES THE PLEURA SEEN AT UPPERMOST PART OF THE ILLUSTRATION. +] + +CYSTICERCUS TENUICOLLIS.—We have noted this bladder worm in the Aoudad +(_Ovis tragelaphus_), Red River Hog (_Potamochœrus porcus_), +domesticated Angora Goats and several deer (_Cervus alfredi_, _Capreolus +capreolus_, _Mazama mexicana_, _M. hemionus_) located with one exception +in the peritoneal cavity or membrane. One of the mule deer (_Mazama +hemionus_) exhibited the parasite also in the lung and liver. This +parasite is discussed because the very valuable Philippine spotted deer +(_Cervus alfredi_) died from a peritonitis secondary to an infected cyst +in the lesser omentum, and because the parasitism (_Tænia marginatum_) +is contractible from canidæ which are also on exhibition in the Garden. +It happens that the spotted deer did not become infested from the dogs, +but it is quite probable that the goats did, since they passed many +times daily in front of the wolf cages, drawing the children’s carriages +over the walks, and were stabled nearby. We have not discovered any of +the other tapeworm cysts in deer which might be transmitted to them from +the canidæ. Camels which are parked directly opposite them have only +exhibited echinococcus cysts, yet we have never found its adult form +(_Tænia echinococcus_) or its ova in the canine feces. The danger of +fatal disease from _C. tenuicollis_, even though the infestment be +present, is remote; but we feel that it is better, if possible, not to +exhibit the canidæ adjacent to susceptible animals. + +PULMONARY ACARIASIS IN MONKEYS.—We have seen but two instances of this +affection in the Philadelphia Garden. The offending parasite in our +animals was a new species, _Pneumonyssus foxi_ Weidman[142]. It occurred +sparingly in small cysts under the pleura and was certainly benign in +our cases. The importance of the infestment consists in part in that +these lesions may be mistaken for tubercles. + +At the London Gardens[143] acariasis was found in forty-four young +rhesuses dying of pneumonia, and the observers ascribed the inflammation +to irritation of certain doubly refractile crystals which occurred in +the excreta of the mite. There are four other recorded instances of such +disease in monkeys, all caused by different species of parasites. + +As to pathogenesis of these arachnids, the London experience is most +illuminating in that it was young rhesuses that were affected. Our +specimens were mature, and nothing was stated to the contrary in the +other reported cases from various parts of the world. The parasites are +perhaps inhaled from the straw used as bedding, since such vegetable +material is a common habitat for mites. If the resultant acute pneumonia +is weathered the relics might remain only in the form of the subpleural +and parabronchial cysts such as we have seen at the Philadelphia Garden. + +I am the more willing to accept the possibility that the simian +arachnids can induce an acute pneumonia after studying a very definite +case of bronchopneumonia in a prairie dog, which was induced by +_Cytoleichus penrosei_ Weidman 1916.[144] + +PERIPROVENTRICULAR FILARIDÆ OF BIRDS.—Every year we report a number of +cases (up to twenty-three) of these worms, probably several species, +coiled under the serosa of the air sacs and most commonly around the +proventricle. Tentatively we have recognized two forms, a shorter (an +inch or so long) and a longer (three to four inches). The latter is most +inextricably coiled, but the former may be teased out. Microfilaria +occur in the blood of the latter cases, but not in that of the former. +The adults have been observed to penetrate from their position in the +air sac serosa into the lumen of the proventricle (goose), to have +caused rupture of the inferior cava (bulbul), to be associated with +subserous cysts of the intestine (weaver) and with profound anemia +(liothrix). The birds affected are mostly small, inexpensive ones, but +the infestment is important because of its frequency and deserves study +of the means of transmission. + +[Illustration: + + FIG. 81.—ARACHNID (CYTOLEICHUS PENROSEI) IN A BRONCHOPNEUMONIC FOCUS + IN THE LUNG OF A PRAIRIE DOG (CYNOMYS LUDOVICIANUS). +] + +[Illustration: + + FIG. 82.—FILARIAL WORM COILED NEAR PROVENTRICLE OF A FINCH. +] + +PHYSALOPTERA IN OPOSSUMS AND BADGERS.—These worms were frequent findings +for a period of years and were particularly impressive on account of the +large number of parasites present. The stomach often contained scores, +more or less securely attached to the mucosa by the head. The worms +average an inch or two in length and perhaps an eighth of an inch in +thickness. _P. turgida_ is the only species we have identified (three +examinations). As to pathogenicity we have not observed that definitely +constant lesions are induced by the parasites. In several instances the +gastric mucosa has shown the mosaic appearance indicative of chronic +gastritis, a condition not necessarily incited by, but certainly +aggravated by, these worms; at least significant is the habit of the +worm to imbed its head in the gastric mucosa. In one instance the +microscope has revealed a most severe fibrosis of the submucosa. The +fibrosis was not so much diffuse as it was local or nodular, and in +favorable places the ova of physaloptera could be discovered in the +centres of the nodules, and thus betrayed the previous presence of the +adult worm there. In this individual animal the case against the +physaloptera is clinched by direct evidence. In other cases we have +circumstantial evidence. Whereas it is not a deeply burrowing parasite, +it is still a penetrative one, and this is sufficient to compromise the +all important “integrity of the mucosa.” It should therefore be +considered pathogenic in all cases, because open to suspicion in several +directions—abstraction of tissue juices, irritation by its products or +movements and by opening up an avenue for bacterial infection. + +TROPIDOCERCA IN BIRDS.—This is a blood-red nematode of the size of a +mustard seed to that of a peppercorn which inhabits the depths of the +proventricular mucosa. At first sight its spheroidal form suggests that +of a fluke, but under the microscope it is found to be a nematode hugely +ballooned out by ova, and coiled up into a ball. In spite of its +dangerous appearance—being red—it is most likely quite innocuous, for +microscopic sections show no sign of inflammation around the worm. +Moreover, we know that a Concave Casqued Hornbill (_Dichoceros +bicornis_) now on exhibition has harbored the worms, as indicated by ova +in the droppings, for eight years and yet seems perfectly well. I have +made wax reconstructions of three of the worms and find that the coils +are not very intricate and that they assume no regular or constant +arrangement. + +SYNGAMUS TRACHEALIS.—Our worst experience with this picturesque parasite +was in common crows (_Corvus b. brachyrhynchos_). In 1914 and 1915 alone +we lost five such birds. Some geese, swans and a pheasant complete the +short list of birds affected in addition to the crows. In no case was it +a young bird that was affected. Shipley[145] reports this parasite in +two grouse at the London Gardens, and Plimmer’s tables show that three +deaths were directly charged against them in one year[146]. + +EXTRA-INTESTINAL TAPEWORMS.—This discovery is worthy of record because +it is rare for cestodes to appear anywhere save in the intestines. We +have observed three instances where they had backed up into the bile +duct—twice in the Cape Hyrax (_Procaria capensis_) and once in a +Livingston’s Eland (_Taurotragus oryx livingstonii_). At the London +Gardens they were mentioned in the gall-bladder of a wallaby and in Cape +Hyraces. Beddard[147] carefully describes four new species of these +cestodes from the hyrax. + +[Illustration: + + FIG. 83.—PHYSALOPTERA IN STOMACH OF COMMON OPOSSUM (DIDELPHYS + VIRGINIANA). THIS IS NOT AN EXCEPTIONAL DEGREE OF INVOLVEMENT. +] + +[Illustration: + + FIG. 84.—ONE OF THE FIBROUS NODULES IN THE GASTRIC SUBMUCOSA OF AN + OPOSSUM. AN OVUM OF PHYSALOPTERA IS SEEN PRECISELY IN THE MIDDLE OF + THIS ILLUSTRATION. +] + + TABLE 28. + _Occurrence of Blood Parasites._ + (Adapted from Plimmer, nine year period) + _Animals examined—12,241 Mammalia—2,924 Aves—6,619 Reptilia—2,698._ + ══════════════════════════════════╤══════════════════╤════════╤════════ + Parasite. │ Host │ No. │ % + │ │Infested│Infested + ──────────────────────────────────┼──────────────────┼────────┼──────── + 1. Hemogregarines │Reptilia │ 316│ 11.8 + 2. Microfilaria │Mammalia │ 33│ 1.1 + │Aves │ 191│ 3. + │Reptilia │ 24│ 1. + 3. Hemoproteus │Aves │ 140│ 2.1 + 4. Trypanosomes │Mammalia │ 1│ 0.003 + │Aves │ 28│ 0.4 + │Reptilia │ 4│ + │Amphibia │ 3│ + 5. Plasmodia │Mammalia │ 2│ + │Aves │ 39│ 0.6 + │Reptilia │ 5│ + 6. Leucocytozoa │Aves │ 16│ 0.2 + 7. Intestinal organisms[148] │Reptilia │ 16│ 0.5 + 8. Toxiplasma │Mammalia │ 1│ + │Aves │ 1│ + │Reptilia │ 1│ + 9. Spirochæta │Mammalia │ 1│ + 10. Babesia │Mammalia │ 1│ + 11. Hæmocystidium │Reptilia │ 1│ + ──────────────────────────────────┼──────────────────┼────────┼──────── + Grand Total │ │ 824│ + ──────────────────────────────────┴──────────────────┴────────┴──────── + + SUMMARY OF TABLE 28. + ═══════════════════════════════════╤═══════════╤═══════════╤═══════════ + │Parasitized│ Animals │ % + │ │ examined │Parasitized + ───────────────────────────────────┼───────────┼───────────┼─────────── + Mammalia │ 39│ 2,924│ 1.5 + Aves │ 415│ 6,619│ 6.5 + Reptilia │ 367│ 2,698│ 14.0 + ───────────────────────────────────┼───────────┼───────────┼─────────── + Total │ 821│ 12,241│ 6.7 + ───────────────────────────────────┴───────────┴───────────┴─────────── + +FILARIASIS IN WILD CATS (_Felis ruffus_).—This parasite was named +_Filaria fasciata_ because it coils in the fascia between the muscles— +generally those of the thigh and abdomen. The worms are easily detected +on skinning the animal and separating thigh and other muscles. +Microfilaria were always present in the blood. The grade of +pathogenicity is only conjectural. + +PERITONEAL FILARIA IN MONKEYS.—Thread worms have been encountered eleven +times, largely in Cebidæ. In several instances _F. gracilis_ has been +the species identified, always inhabiting the peritoneal cavity, and in +one instance also the lung. Microfilaria were always present in the +blood. We have never seen lymphangitis or elephantiasis in our filarial +cases. + +BLOOD PARASITES.—I justify this paragraph on the basis of the usefulness +it might have in the clinical direction, for while the taking of blood +specimens is not as easy as with man it can still be done with some +animals. From time to time we have encountered blood parasites in this +Garden, but the large numbers occurring in the experience of special +searchers in the London Garden and Plimmer’s particular interest in this +direction make their data much the more valuable. In one report of 6,430 +animals examined he found 7 per cent. infested with blood parasites of +one sort or another. I have constructed the foregoing table (28) from +his various reports to show which animal classes were affected by the +several blood parasites. + +This table (28) brings out that considering them as a whole and without +respect to host, just as the animals come day in and day out to the +autopsy table, blood parasites will be met in 6.7 per cent. of all +cases. They are seen most commonly in the form of hemogregarines of +reptiles (2.5 per cent. of all animals and 12 per cent. of all reptiles) +while microfilaria run a close second, being found in 2 per cent. of all +animals but much more commonly in birds. Hemoproteus of birds while +ranking third, should be emphasized on account of its acknowledged +blood-destructive properties. The remaining infestations were too +infrequent to be useful statistically. + +Turning to individual groups of blood parasites, microfilariæ of birds +deserve special comment. They occurred four times more often in birds +than in other animals, or, put in another way, one out of every twenty- +two birds was affected, and only one out of every ninety other animals. +The high figure for birds is significant in relation to what we have +already said about periproventricular filaridæ in our Garden, indicating +that the same infestment probably also exists in London. + +[Illustration: + + FIG. 85.—ADAPTATION FROM RECONSTRUCTION OF TROPIDOCERCA CONTORTA. THE + WORM LAY IN THE WALL OF THE PROVENTRICLE OF A LOUISIANA HERON (ARDEA + TRICOLOR RUFICOLLIS). +] + +[Illustration: + + FIG. 86.—CESTODES (THREE) PROJECTING FROM THE SEVERED END OF THE BILE + DUCT OF A CAPE HYRAX (PROCARIA CAPENSIS). +] + +A point brought out by Plimmer is to the effect that, of the several +blood parasites, the microfilariæ were the least harmful, and that of +these the adult forms were the only ones to produce symptoms; yet in one +place[149] he records microfilaria as plugging the cerebral capillaries +of birds. This is a very important lesion if permanent, and especially +so when affecting cerebral capillaries as do the organisms and pigment +of malaria. The adult forms were found in one-fourth of the cases where +microfilaria were demonstrated. + +As to the pathogenicity of these blood parasites in general, it will be +unsafe to arrive at a definite conclusion, recalling the pitfalls that I +have already outlined in discussing pathogenicity of parasites in +general. Keeping in mind the wonderful adaptability on occasion of +animals to unfavorable circumstances we must hesitate to declare +unqualifiedly the importance of even blood parasites as morbid agents. +Where the parasite is known to destroy the blood cells of birds and +mammals it is otherwise, but even here experimental work would be +necessary to settle the question. The element of “racial” immunity and +of phylogeny is the fly in the ointment of our deductions. + + +TRANSMISSION OF ANIMAL PARASITISM FROM WILD ANIMALS TO MAN. + +Examples of direct transmission will be only occasional, due to the +relatively infrequent contacts between the two hosts. Pets threaten the +most. Several such examples have been touched upon in the preceding +pages and it but remains to gather them into one place. There is one +concrete instance in the form of clear cut simian scabies being +transmitted to a keeper in this Garden[150] and a similar lot fell to +the keeper of a wombat at the Paris Garden[151] as well as to the +taxidermist who preserved its skin. We know that the skin and feathers +of our parrots and pigeons harbor mites[152] (plumicoles of Megnin) and, +recalling the occasional cases of poultrymen’s itch, a transient +affection might be conceded from pet parrots and other birds. Pediculi +are not as numerous on monkeys as popularly supposed—we see very few at +the autopsy table. We have seen _Trichinella spiralis_ in the polar bear +(_Ursus maritimus_)—an animal whose flesh is edible. The hydatid cysts +in the camel appear unimportant, but in the livers of deer it is +otherwise. Neither of these infestments is dangerous if the meat is +sufficiently cooked before eating. + +Hookworm disease points thus far only to _Anchylostoma duodenale_ in the +chimpanzee and _Uncinaria ceylanicum_ in the lion and tiger. Both serve +as reservoirs of the disease, the ova being discharged by way of the +feces. Similarly the _Strongyloides intestinalis_ infestment which we +have seen in the orang might be transferred to man. Indirectly, +Europeans traveling in Africa have made the crucial test that certain +ungulates and other wild animals of Africa are the reservoirs of +_Trypanosoma gambiense_, the parasite of the well known African sleeping +sickness; for this example the blood stream of the beast is the +reservoir and a biting insect the means of transmission. + +The above examples are cited to emphasize the possibility that parasites +of wild animals may have a pathogenic significance for man. They do not +exhaust the subject. Many more instances might be cited but the +foregoing bring out the important ones which have come to our attention. + + +TREATMENT. + +The recognition of the existence of parasites during the life of an +animal, especially those of the skin and intestinal tract whose +discovery is easiest, suggests that some means of combating them should +be employed. But we are by now quite satisfied that medicinal and +disinfective therapeutic procedures, while they have their field of +usefulness, are much less to be depended upon for the protection of +exhibits than are preventive measures of general hygienic nature. Under +the latter heading come the prompt removal of excreta, frequent changes +of drinking water, routine examinations of feces of certain varieties, +autopsy examinations and incineration of autopsy remains—all of which +are part of the requirements of common cleanliness and general disease +prevention. I wish to amplify the matter of disposal of feces and +general cage-police. Our ideas as to what constitutes thoroughness in +this work have changed considerably since Fulleborn’s recent +demonstration that ascarid ova[153] could live in formaldehyde for four +or five years, and the older one of Galli-Valerio[154] that those of +_Hepaticola hepatica_ lived one month in 2 per cent. formaldehyde +solution. Evidently the same substances which disinfect do not +invariably disinfest; and if the occasion should arise for the most +exacting control in this respect, a special investigation of the +susceptibility of the individual ova in question would have to be +undertaken. + +In addition to these general measures we have put up certain special +safeguards against parasites. Thus, each specimen of the large Carnivora +(lions, tigers, leopards, etc.), has received routinely a dose of +santonin every month over a period of several years. We have no figures +on which to base comparison with previous periods, but an examination of +feces of all the inmates of the Carnivora house in 1916[155] showed that +less than one-third of the animals were infested, and of these all save +the jaguars showed either small numbers of ova in the feces or +relatively non-pathogenic forms. The jaguars had been badly infested for +many years with dibothriocephalus. Prior to this examination we had been +under the impression that nearly every one of the felidæ ordinarily was +infested and if this impression was well founded, due credit must be +given, in company with general hygienic precautions, to the routine +santonin dosages. It goes without saying that where animals are detected +at autopsy with unequivocal transmissible and dangerous parasites +(coccidia, amebæ, etc.), the contacts are isolated, examined and if +necessary treated for the affection or even sacrificed. + +To continue the preventive measures, it would be most desirable to +examine at least the blood and feces of all newly arrived animals, but +at present this is not practicable on account of the labor involved in +the laboratory and in collecting the material, and because all animals +do not stand the restraint involved when blood specimens are being +taken. At present we are limiting special examinations to the droppings +of newly arrived parrots and toucans for _Spiroptera incerta_ and to the +feces of certain monkeys for amebæ. + +Further preventive measures will depend on the nature of individual +infestments as they crop up. Food inspection, screening, sulphur dips, +etc., are but a few examples of what might be found necessary +hygienically after investigating or establishing the life cycle of our +numerous parasitic groups. However we cannot forbear to emphasize again +the value of the blast lamp and of paint in the hygiene of animal +enclosures—means we believe to be much more potent and quite as +practicable as chemical disinfectants. + +[Illustration: + + FIG. 87.—TRICHINELLA SPIRALIS IN MUSCLES OF POLAR BEAR (URSUS + MARITIMUS). THIS WAS AN OLD INFESTMENT, AS INDICATED BY THE THICK + AND HYALOID CHARACTER OF THE CAPSULE. +] + +Turning now to the active curative side of the subject, what medical +means we have against parasites appertain for the most part to the +intestinal ones. The treatment of tapeworms is very hazy and +unsatisfactory—areca nut is perhaps more useful in animals than any one +other drug. For round worms santonin is most to be depended on although +turpentine is useful against the round worm of the Equidæ. The dosage of +santonin per month has been—for large bears, ten grains; for lions, +tigers, large pumas, six grains; for jaguars, leopards, hyenas, four +grains; for wild cats, etc., two grains. The dose of areca nut +recommended for Carnivora is two grains per pound of body weight. Since +ungulates do not stand areca nut well, iron sulphate may be used. For +animals the size of a horse the dosage is two drams, and to this one or +two grains of arsenic trioxide may be added. On the basis of very +carefully controlled experiments on dogs, Hall recommends carbon +tetrachloride for hookworms in these animals—0.3 mils per kilo of body +weight, without purging. Its efficacy has been confirmed lately but we +have not had the occasion to test it. + +From time to time we have broached other lines of medication against +worms which may be worth while relating if for nothing more than to +illustrate the uncertain ways of our vermifuges when applied to wild +animals. + +I can speak first of thymol as employed on parrots parasitized by +_Spiroptera incerta_. The first thing that impressed us was the large +dosage which birds could endure. The lethal dose for pigeons was four +grains, suspended in mucilage of acacia. After we had established that +certain parrots withstood fourteen grains in mucilage, we administered +on one occasion twelve grains and on another sixteen grains, suspended +in glycerin. The drug is reputed to be absorbed when exhibited in the +latter vehicle and we hoped to get a certain anthelmintic effect on the +parasites from the blood side as well as from the lumen of the gut. The +bird itself, a very heavily infested cockatoo, showed no ill effects and +passed two dead female spiroptera and enormous numbers of ova. But +thereafter it passed even greater numbers of ova than before (we +estimated 182,000 per day for this bird over a five day period and +288,000 on a single subsequent day), and was obviously unimproved by the +treatment. The explanation of failure was clear, for the worms can +retire into the protecting mucus or mucous membrane lining the +proventricle until the thymol has passed by, and even though paralysed +may not be flushed out. In a later test on a toucan which died twenty +minutes after thymol administration we found at the autopsy that worms +deeply imbedded in the proventricle were translucent and motionless from +the effects of the thymol-glycerin mixture, _i.e._, saturated with the +medicament and apparently dead. Twenty minutes later they were placed in +normal salt solution in the incubator, and next morning were found +actively motile. Thymol evidently does not kill—it only stupefies, and +in the absence of means for flushing the parasites out, as we do in +human hookworm cases, this class of vermifuge will have to be abandoned +in work against this parasite. + +Not with any serious hope of success, but feeling that arsenic was the +most promising drug available for parenteral use, we tried atoxyl +hypodermically and arsphenamine intravenously but without success. The +only positive results were to emphasize the tolerance of some lower +animals to arsenic. Thus in preliminary work pigeons received sixty +drops of Fowler’s solution by mouth without embarrassment, but five +minims killed a pigeon when administered hypodermically. The organic +arsenical, arsphenamine, was withstood intravenously by pigeons in six +times the proportional human dosage. + +One of our drug trials was instructive in that it worked quite a +different effect from that in man, besides being most amusing. In +earlier diagnostic work on spiroptera we tested the practicability of +examining the vomitus for the worms, hoping thereby to get a greater +concentration of ova, which would facilitate the microscopic +examination. Hypodermic injections of apomorphine (0.1 grain) into an +amazon did not induce vomiting from the gizzard as hoped—only a +regurgitation from the crop, but it did cause some dizziness and most +ludicrous talking and laughter. + +To illustrate further the difficulties of animal medication I quote our +experience with four red howling monkeys (_Alonatta seniculus_). One of +these died of intestinal obstruction from large ascarids—the case which +has been already cited. Ova were found in the stools of the remaining +three, and one of the monkeys was treated twice with santonin. It died +in thirty hours after the second dose—not of santonin poisoning, for +none of the clinical symptoms were present, but most likely from +absorption of toxic substances originating in the decomposing ascarids +which crowded the gut. It profits not to destroy these parasites, then, +unless we feel assured that they may thereafter be removed immediately. + +If, for the sake of brevity, I were asked to state in a single sentence +the practical status of animal parasitic disease in this Zoological +Garden I would put it thus: Since there are various animal parasitic +diseases continuously present here of which we know, and since fresh +ones are from time to time cropping out, and since these are on the +whole of economic importance, it behooves us to continue and extend our +efforts against an issue extant—somewhat through therapeutic means, but +far more through clinical laboratory examinations, careful autopsy +searches, and by rigid general hygienic measures such as cage-police, +new quarters, isolation, or if necessary, destruction of the exhibit. + + + + + INDEX + + + Abortion, 305 + + Abscess of liver, 231 + of lung, 155 + + Acariasis, lungs, 647 + of monkeys, 647 + + Actinomycosis, 138, 568 + in deer, 368, 568 + tapirs, 568 + treatment, 570 + + Adenoma, 474 + + Adrenal body, 336 + + Alimentary tract, 166 + + Amblyopia, 403 + + Amœbæ, 606, 644 + dysentery from, 644 + + Amyloid, liver, 227 + spleen, 128 + + Anatomy of labor, 290 + + Anchylostomum, see hookworms + + Anemia, 87 + primary, 98 + secondary, 88 + + Aneurysms, 65, 80 + + Animal Parasitism, hygiene, 656 + prevention, 656 + treatment, 655 + + Animal Parasites, 614 + disappearance of, 627 + frequency, 628 + of groups, 633 + in blood, 652 + incidence, 628–636 + modes of action, 617 + occurrence in wild, 627 + transmission animals to man, 653 + visceral distribution, 637 + + Angina pectoris, 49 + + Aorta, 72 + fatty deposits in, 71 + + Arteries, 66 + + Arteriosclerosis, 71 + + Arteritis, 70 + + Arthritis, 347 + gouty, 347, 411 + + Ascending nephritis, 276 + + Aspergillosis, 558 + + Aspergillus, varieties, 558 + + Ataxia, 375 + + Atrophy, acute of liver, 228 + + Autopsy list, 47 + + Avian spiropteriasis, 172, 640 + + + Bacterial flora, 418 + + Basal cell carcinoma, 475 + + Beriberi, 439 + + Biliary tract, 225 + calculi, 238 + + Birth canal, 287, 296 + comparative anatomy, 287 et seq + obstructions to, 306 + + Blackhead, 206 + + Bladder, gall, 224, 238, 239 + urinary, 286 + + Blood, diseases of, 83 + + Blood formation in birds, 98 + + Blood vessels, 66 + + Bone marrow, 83, 109, 111 + + Bones, diseases of, 343 + effects of trauma, 343 + tumors of, 368 + + Botryomycosis, 564, 602 + + Botulism, 604 + + Brain, 385 + tuberculosis of, 378 + tumors of, 384 + weight of, 385 + references to, 387 + + Breast, 312 + + Bronchi, 141 + + Bronchiectasis, 144 + + + Cage palsy, 349 + + Calculi, biliary, 238 + renal, 282 + + Carcinoma, 476 + basal cell, 475 + + Cataract, 403 + + Cecum, 211 + + Cestodes, 637 + + Cholangitis, 239, 256 + + Cholecystitis, 239 + + Choledochitis, 239 + + Cholelithiasis, 238 + + Chondroma, 472 + + Cloaca, 211 + + Coccidiosis, 606 + + Cirrhosis of liver, 232 + + Comparative anatomy of uterus, 287 + of pelvis, 297–303 + + Conjunctivitis, 402 + + Constipation, 209 + + Constitutional diseases, 410 + + Convulsions, 373 + + Cornea, 403 + + Coronary arteries, 49 + + Cowper’s gland, 313 + + Cretinism, 320, 331 + + Cysticercus tenuicollis, 647 + + Cystitis, 286 + + Cytoleichus penrosei, 647 + + + Deficiency diseases, 438–443 + + Degenerations of kidney, 269 + of liver, 228 + + Diabetes, 412 + + Diet, carnivorous, 452 + herbivorous, 452 + grain, 455 + seed, 454 + soft, 453 + omnivorous, 402 + relation to disease, 415 + alimentary tract, 417 + + Dilatation of heart, 54 + + Diphtheria, 600 + + Dislocations, 345 + + Distemper, 599 + + Diverticula of intestine, 219 + + Diverticulitis, 219 + + Dysentery, amœbic in monkeys, 644 + + Dystocia, 292 + + + Ear, 409 + + Echinococcus, 647 + + Emphysema, 161 + + Encephalomyelitis, 380 + + Endocarditis, 52 + + Endometritis, 305 + + Endothelioma, 165, 474 + + Enteritis, 177 + in Aves, 202, 205 + Mammalia, 185 + + Enterohepatitis, 605 + + Epithelioma, 475 + + Esophagus, 169 + + Exophthalmic goitre, 320, 323, 329 + + Eye, 402 + tuberculosis of, 402 + + + Fallopian tubes, 305 + + Fat infiltrations of kidney, 268 + liver, 226 + metabolism, 445 + + Fibroma, 472 + + Filaria, fasciata, 651 + gracilis in monkeys, 651 + in blood, 652 + fascia, 651 + muscles, 651 + wildcats, 651 + periproventricular, 648 + peritoneum, 651 + + Food, 415 + definition, 415 + in relation to alimentary tract, 417 + + Food, disease, 422 + poisoning, 457 + + Fowl cholera, 598 + plague, 598 + typhoid, 598 + + Fractures, 344 + + + Gall stones, 238 + + Gas-bacillus infection, 602 + + Gastritis, 204 + + Gastroenterocolitis in Ungulata, 194 + in Marsupialia, 198 + + Gangrene of lung, 155 + + Giraffe, hookworm in, 644 + + Gout, 53, 410 + + + Heart, dilatation of, 54 + hypertrophy of, 54 + diseases of, 48 + effects of, 55 + effect of strain, 55–59 + weight of, 63 + relative vulnerability of, 61 + + Hemorrhagic septicemia, 598 + + Hemoglobinuric fever, 603 + + Hemorrhoids, 218 + + Hepaticola hepatica, 641 + + Hepatitis, 228 + + Hernia, 216 + + Heterakis in avian ceca, 606 + + Hookworms, 643, 654 + in giraffe, 644 + + Hypernephroma, 339, 341, 342, 475 + + Hypertrophic periosteitis, 346 + + Hyperthyroidism, 320 + + Hypertrophy of heart, 54 + in Aves, 60 + + Hypothyroidism, 320 + + + Ileus, 213, 261 + + Infantilism, 433 + + Infiltrations of kidney, 268 + liver, 226 + + Inorganic salts in diet, 427 + + Intestinal obstruction, 212 + tract, 177 + inflammation of, 181 + mechanical obstruction of, 212, 617 + relation to food, 422 + + Intestines, diverticula, 219 + tumors of, 220 + + Iridocyclitis, 402 + + + Kangaroo disease, 570 + bacteriology, 576, 586 + course of attack, 573 + pathology, 575 + prevention, 572 + treatment, 591 + + Kidney, 263 + abscess, 268, 278 + calculi, 282 + degenerations of, 269 + hemorrhages, 271 + hypertrophy of, 267 + infiltrations of, 268 + tumors, 284 + weight of, 265 + + + Labor from a comparative standpoint, 290 + obstructions to, 306 + + Laryngitis, 139 + + Larynx, 138 + + Leontiasis ossium, 359, 472 + + Leucemia, 104 + in birds, 108 + lymphatic, 105 + myeloid, 109 + + Leucocytes, 84–86 + + Limberneck of ducks, 604 + + Lipoma, 472 + + Liver, 222 + abscess, 231 + acute atrophy, 228 + amyloid, 227 + cirrhosis, 232 + degenerations, 228 + fatty changes, 226 + infiltration, 226 + inflammation, 228 + chronic, 232 + necrosis in, 230 + tumors, 240 + + Lungs, 146 + abscess, 155 + congestion, 148 + gangrene, 155 + infarct, 160 + tumors of, 162 + + Lymphadenitis, 117 + + Lymphatic leucemia, 105 + tissue, 114 + hyperplasia of, 115 + in pharyngeal wall, 115, 138 + + Lymph nodes, 114 + tuberculosis of, 121 + tumors of, 122 + + Lymphomatosis, 118 + + + Malnutrition, 424 + + Mammary gland, 312 + + Marmosets, parasites of, 645 + + Marrow of bone, 83, 109, 111 + + Meningitis, 376 + + Metabolism, carbohydrate, 443 + fat, 445 + inorganic, 427 + protein, 447 + + Miliary tubercle, avian, 512 + bovine, 510 + human, 511 + monkey, 511 + + Miscarriage, 305 + + Molluscum contagiosum, 601 + + Mönckeberg sclerosis, 74, 76 + + Monkey’s temperature, 520–528 + + Moon blindness, 405 + + Muscles, 370 + + Mycosis, 137, 558 + of esophagus, 168 + histology of, 561 + hygiene, 563 + incidence, 562 + of lung, 562 + method of action, 560 + pharynx, 168, 564 + types of, 560 + + Myelitis, 350, 381 + + Myeloma, 111 + + Myocarditis, 52 + + Myocardium, 49, 50, 65 + + Myxœdema, 320, 331 + + + Necrosis, liver, 230 + spleen, 130 + + Nematodes, 636 + + Neoplasms, 462 + incidence of, 463, 468 + embryonic origin, 471 + in captivity, 469 + in the wild, 462, 476 + metastasis, 471 + visceral origin, 477 + + Nephritis, 271 + ascending, 276 + effects of, 280 + histology of, 279 + toxic, 275 + + Nervous system, 372 + + Nocardia macropodidarum, 585 + + Nocardiosis, 570 + + + Obesity, 446 + + Ophthalmia, periodic, 405 + + Osteitis, 346 + + Osteitis deformans, 359, 431 + + Osteoma, 368 + + Osteomalacia, 349 + + Ovary, cysts, 307 + + + Pachymeningitis, externa, 331, 377 + + Paget’s disease, 359, 431 + + Pancreas, 244 + degenerations, 250 + tumors, 259 + + Pancreatitis, 250 + + Parasites, see animal parasites, 614 + + Parovarian cyst, 307 + + Pasteurelloses, 597 + + Pearl disease, 491, 501, 505 + + Pellagra, 441 + + Pelvis, comparative anatomy, 297–303 + + Penis, 313 + + Pericarditis, 53 + + Pericardium, position of effusion in, 54 + + Periosteitis, hypertrophic, 346 + + Periproventricular worms, 648 + + Perisplenitis, 131 + + Peritoneum, 260 + tumors, 262 + + Peritonitis, 260 + + Pharyngitis, 168 + + Pharynx, 168 + + Phimosis, 313 + + Physaloptera turgida, 649 + in opossums, 649 + + Plants, poisonous, 459 + + Pleura, 163 + + Pleuritis, 164 + + Pneumonia, 149 + broncho, 152 + fibrinous, 151, 153 + in Aves, 153 + origins of, 154 + lobar, 151 + + Pneumonokoniosis, 159 + + Pneumonyssus foxi, 647 + + Poisonous plants, 459 + + Poliomyelitis, 380 + + Prostate gland, 313 + enlargements of, 314 + tuberculosis of, 315 + tumors of, 314 + + Proventricle, 171 + worms in, 172, 640 + + Psittacosis, 208, 597 + + Pyelonephritis, 277 + + + Quail disease, 608 + + + Rabies, 602 + + Rachitis, 349, 429 + + Rectum, prolapse of, 218 + + Reproductive organs, female, 287 + male, 317 + + Respiratory tract, 134 + + Rhinitis, 135 + + Rickets, 349, 429 + + Renal calculi, 282 + + + Salpingitis fallopii, 305 + + Santonin, 657 + + Sarcoma, 471, 474 + + Scurvy, 440 + + Seminal vesicles, 315 + + Sinusitis, 135 + + Skeleton, 343 + + Spinal cord, 373 + + Spiroptera incerta, 638, 640 + detection, 640 + eradication, 640 + in parrots, 172, 208, 640 + + Spiropteriasis, 172, 640 + + Spleen, 114, 122 + amyloid, 128 + congestions, 125 + enlargements, 124 + hemorrhage, 125 + inflammation, 126 + in anemia, 130 + in hepatic cirrhosis, 130 + necrosis, 130 + size, 124 + tuberculosis of, 132 + + Squirrel monkeys, parasites of, 645 + + Starvation, 425 + + Stomach, 174 + tumors of, 176 + ulcers of, 175 + + Streptothricosis, 567 + + Suprarenal body, 336 + + Syngamus trachealis, 140, 650 + + + Tænia echinococcus, 647 + + Tape worms, 637 + in liver, 650 + + Temperature of monkeys, 520–528 + + Testes, 313 + tumors of, 313 + + Tetanus, 602 + + Thrombosis, 69 + + Thymol, 657 + + Thymus, 120, 336 + + Thyroid body, 316 + atrophy of, 330 + hyperplasia of, 325 + size of, 318 + tumors of, 333 + + Tonsils, 115, 138 + + Trachea, 140 + + Tropidocerca contorta, 649 + + Tubercle bacillus, types of, 513 + + Tuberculin test on monkeys, 518 + other animals, 549 + dose, 529 + effect on kidneys, 548 + eye, 546 + reaction, 530 + skin, 546 + + Tuberculoma, 505 + + Tuberculosis of brain, 378 + avian characters, 503, 512 + Carnivora, 498 + control, 514–548 + diagnosis of, 514 + discovery during life, 514 + distribution in birds, 504 + + Tuberculosis of eye, 402 + gelatinous, 504 + histology, 510 + hygiene, 516 + in Aves, 503 + in Mammalia, 492 + in Primates, 492 + in various avian orders 506–510 + incidence, 489 + intestinal in birds, 505 + Lemures, 495 + lymph nodes, 121, 494 + nonsusceptible animals, 490 + ordinate characters, 492 + frequency, 489 + pathological type, 490 + Proboscidea, 502 + Rodentia, 499 + routes of infection, 485 + + Tuberculosis, sanitation of cages, 516 + susceptible animals, 490, 515–517 + Ungulata, 500 + visceral distribution, 491 + + Tumors, see neoplasms + + + Ulcer, gastric, 175 + + Uncinaria, 643 + + Uremia, 281 + + Urethra, 315 + + Uterus, comparative anatomy, 287 + inflammation, 305 + tumors of, 308 + + + Vitamins, 438 + + + Waterfowl epizootic, 604 + + + Zoological list, 43 + + + + +A LIST OF THE PUBLICATIONS FROM THE LABORATORY OF COMPARATIVE PATHOLOGY + OF THE PHILADELPHIA ZOOLOGICAL SOCIETY 1909–1923 + + + 1. Results of Tuberculin Tests in Monkeys at the Philadelphia + Zoological Garden, by C. Y. White, M.D. and Herbert Fox, M.D. + _The Archives of Internal Medicine_, December, 1909, Vol. 4, pp. + 517–527, Chicago, Illinois. + + 2. Note on the Occurrence of a Ciliate (_Opalinopsis nucleolobata, + n.s._) in the Liver of a Mammal (_Canis latrans_), by Allen J. + Smith, M.D. and Herbert Fox, M.D. _University of Pennsylvania + Medical Bulletin_, February, 1909, Philadelphia, Pennsylvania. + + 3. The Tuberculin Test in Monkeys: with Notes on the Temperature of + Mammals, by Arthur Erwin Brown, D.Sc., C.M.Z.S., Sec. Zool. + Soc., Phila. _Proceedings of the Zoological Society of London_, + 1909, pp. 81–90. + + 4. Observations on the Occurrence of Neoplasms in Wild Animals, by C. + Y. White, M.D. and Herbert Fox, M.D. _Proceedings of the + Pathological Society of Philadelphia_, February, 1910. + + 5. Observations on the Comparative Anatomy of the Female Genitalia, + by Edward A. Schumann, M.D. _American Journal of Obstetrics and + Diseases of Women and Children_, Vol. LXIV, No. 4, 1911, New + York. + + 6. Observations Upon Neoplasms in Wild Animals in the Philadelphia + Zoological Garden, by Herbert Fox, M.D. _The Journal of + Pathology and Bacteriology_, Vol. XVII. (1912), pp. 217–231. + England. + + 7. A Study of Metazoan Parasites Found in the Philadelphia Zoological + Garden, by Fred D. Weidman, M.D. _Proceedings of the Academy of + Natural Sciences of Philadelphia_, March, 1913, pp. 126 to 151, + Philadelphia, Penna. + + 8. The Pathology of the Thyroid Gland in Wild Animals, by Herbert + Fox, M.D. _Journal of Comparative Pathology and Therapeutics_, + Vol. 27, p. 23. Edinburgh, Scotland. + + 9. The Mechanism of Labor From the Standpoint of Comparative Anatomy, + With a Report of Cases of Dystocia in Wild Animals, by Edward A. + Schumann, M.D. _American Journal of Obstetrics and Diseases of + Women and Children_, Vol. LXIX, No. 3, 1914, New York. + + 10. Cirrhosis of the Liver in Wild Animals, by Herbert Fox, M.D. _New + York Medical Journal_, December 19, 1914. + + 11. The Dynamics of the Female Pelvis; Its Evolution and Architecture + with Respect to Function, by Edward A. Schumann, M.D. _American + Journal of Obstetrics and Diseases of Women and Children_, Vol. + LXXI, No. 1, 1915, New York. + + 12. _Pneumonyssus foxi, Nov. Sp_. An Arachnid Parasitic in the Lung of + a Monkey (_Macacus rhesus_), by Fred D. Weidman, M.D. _Journal + of Parasitology_, September, 1915, Vol. II, pp. 27–45, Urbana, + Illinois. + + 13. _Cytoleichus penrosei_, A New Arachnid Parasite Found in the + Diseased Lungs of a Prairie Dog, (_Cynomys ludovicianus_). + _Journal of Parasitology_, December, 1916, Vol. III, pp. 82–89, + Urbana, Illinois. Fred D. Weidman, M.D. + + 14. A Method of Obtaining Duplicate Reconstructions from the One + Series of Wax Plates, by Fred D. Weidman, M.D. _New York Medical + Journal_, March 3, 1917, New York. + + 15. Papers: Read at the Meeting of the Pathological Society at the + Philadelphia Zoological Garden. + + Pancreatitis in Wild Animals, by Herbert Fox, M.D. + + Report of an Enzootic of Parasitic Proventricular Worms + (_Spiroptera incerta_, Smith) of Parrots, with Control of Same, + by Fred D. Weidman, M.D. + + _Coccidium bigeminum_, Stiles, in Swift Foxes (habitat Western U. + S.), by Fred D. Weidman, M.D. + + Distribution of Uncinaria Among the Lower Animals, by Fred D. + Weidman, M.D. + + An Arachnoid (_Pneumotuber macaci_, Landois and Hœpke?) Parasitic + in the Lungs of a Monkey (_Macacus rhesus_), by Fred D. Weidman, + M.D. + + A Note Upon the Lesions of the Female Genitalia in Wild Animals, + by Edward A. Shumann, M.D. + + Amblyopia in a Young Monkey (_Macacus nemestrinus_), by H. M. + Langdon, M.D. and W. B. Cadawalder, M.D. + + Remarks on Examinations of a Series of Brains, by W. B. + Cadawalder, M.D. + + _Journal of Comparative Pathology and Therapeutics_, December, + 1915, Vol. XXVIII, Part 4, pp. 298–336, Edinburgh, Scotland. + + 16. Reversionary Pseudobile Canaliculi Formation in the Cirrhotic + Liver of a Vulpine Phalanger, by Fred D. Weidman, M.D. _New York + Medical Journal_, March 9, 1918, New York. + + 17. A Contribution to the Anatomy and Embryology of _Cladorchis_ + (_Stichorchis_) _Subtriquestrus_, Rudolphi, 1814 (Fischoeder, + 1901), by Fred D. Weidman, M.D. _Parasitology_, Vol. X, No. 2, + January 22, 1918, Cambridge University Press, London, England. + + 18. Nutritive and Blood Changes in Rats on Cancer-Inhibiting and + Cancer-Stimulating Diets, by E. P. Corson-White, M.D. + _Pennsylvania Medical Journal_, March, 1919, Vol. XXII, p. 348, + Athens, Penna. + + 19. Pemphigus in an Orang Utan Infested with Strongyloides + (intestinalis?) and Dying from Advanced Tuberculosis, by Fred D. + Weidman, M.D. _Journal of Cutaneous Diseases_, March, 1919, Vol. + XXXVII, pp. 169–173, Chicago, Ill. + + 20. Arteriosclerosis in Wild Animals, by Herbert Fox, M.D. _American + Journal of Medical Sciences_, June, 1920, No. 6, Vol. CLIX, p. + 821, Philadelphia, Penna. + + 21. Osteomalacia in Wild Animals, by E. P. Corson-White, M.D. + _Archives of Internal Medicine_, November, 1922, Vol. 30, pp. + 620–628, Chicago, Illinois. + + 22. Osteitis Deformans in Monkeys, by E. P. Corson-White, M.D. + _Archives of Internal Medicine_, December, 1922, Vol. 30, pp. + 790–796, Chicago, Illinois. + + 23. Certain Dermatoses of Monkeys and an Ape, by Fred D. Weidman, M.D. + _Archives of Dermatology and Syphilology_, March, 1923, Vol. 7, + pp. 289–302, Chicago, Illinois. + + 24. Acute Papular and Desquamative Exanthem in an Orang Utan, by + Herbert Fox, M.D., and Fred D. Weidman, M.D. _Archives of + Dermatology and Syphilology_, April, 1923, Vol. 7, pp. 462–464, + Chicago, Illinois. + +----- + +Footnote 1: + + Those who are interested in the subject of disease in its effect on + evolution are referred to Morley Roberts, _Proceedings, Zoological + Society, London_, 1918, p. 247. + +Footnote 2: + + _Proceedings, Zoological Society, London_, 1911. + +Footnote 3: + + _Proceedings, Zoological Society, London_, 1911, p. 425. + +Footnote 4: + + _Proceedings, Zoological Society, London_, 1911, p. 620. + +Footnote 5: + + _Br. Med. Jour._, 1910, 2, 1161. + +Footnote 6: + + _Proc. London Zool. Soc._, 1907. + +Footnote 7: + + Total is the number of individual animals showing lesions, not the sum + of the listed changes. + +Footnote 8: + + _Comptes Rendus Soc. Biol._, T, 62–206. + +Footnote 9: + + This is done by determining the percentages of hypertrophy and + dilatation for the total number of each class examined at autopsy. + +Footnote 10: + + _Arch. für. Ges. Physiologie_, 1908, 125, 507 + +Footnote 11: + + dal Piaz: Papers from the Department of Anatomy, University of + California, 1912. Bergmann: _Dissertation_, Munich, 1884. Loer: _Arch. + f. die gesamte Physiologie_, 1911, V. 140–293. Grober: _Arch. f. die + gesamte Physiologie_, 1908, V. 125–507. Grober: _Deutsch Archiv f. + Klin. Med._, 1907, V. 91, 502. Welcher and Brandt: _Arch. für + Anthropologie_, 1903, V. 28. Vierordt: _Tabellen_, 1906. Parrot: + _Zoologischer Jahresbericht_, 1893. Hasenfeld and Romberg: _Arch. f. + Exp. Path. und Pharmacol._, 1897, V. 39–333. Joseph: _Jour. Exp. + Med._, 1908, V. 10–521. + +Footnote 12: + + These values are obtained in part from the literature, in part from + our own specimens. At this laboratory the hearts of animals killed or + dying from a short illness, organs showing no pathological change, + were removed by cutting at the base of the vessels, washed free of + blood and weighed. The weight of the whole animal was obtained after + death. + +Footnote 13: + + These figures are obtained by determining mathematically the + percentage of each feature in each class and then reducing the numbers + to their lowest value. + +Footnote 14: + + _Verh. deutsch Path. Gesel._, 1906, X, 149. + +Footnote 15: + + With Coronary sclerosis only. + +Footnote 16: + + With Coronary sclerosis only. + +Footnote 17: + + _Proc. London Zool. Soc._, 1916. + +Footnote 18: + + _The Leucoses of Fowls_, London, 1922. + +Footnote 19: + + Lubarsch-Ostertag, _Ergeb. aus der Allg. Path._, 1908. + +Footnote 20: + + Vide Sisson’s _Veterinary Anatomy_ and Owen’s _Anatomy of the + Vertebrates_. + +Footnote 21: + + Ball, _Jour. Vet._, 1907. + +Footnote 22: + + See Magnan, _Compt. Rendus d. l’ Acad. de Science_, 1910 and 1911, + Vol. 150, 151, 152. + +Footnote 23: + + _C. R. Soc. de Biologie_, Paris, T. 73–526. _Bull. Mus. Hist. Nat., + Paris Ann._, 1911, 492 et seq. + +Footnote 24: + + See Woodland, _Proc. London Zool. Soc._, 1906, and MacLeod, _Chemical + and Physiological Medicine_, Chicago, 1923. + +Footnote 25: + + _Proc. Zool. Soc. London_, 1905. + +Footnote 26: + + _Bull. Soc. Anat._, 1898, 73, 491 + +Footnote 27: + + _Amer. Med._, 1903, 996 + +Footnote 28: + + _Surg. Gyn. and Obst._, 1919, 28, p. 529. + +Footnote 29: + + _Jour. A.M.A._, 1921, 77, 194. + +Footnote 30: + + _Ibid._, 197. + +Footnote 31: + + Garrod, _Schorstein Lect._, 1920. + +Footnote 32: + + _Anatomical Record_, 1917, 13, p. 305, On the morphology of the renal + tubule in the vertebrates. + +Footnote 33: + + Policard, _C. R. Assoc. Anat._, 1910, 12, 57. + +Footnote 34: + + Huber, _Anat. Record_, 1916, 10, 201. + +Footnote 35: + + _Bull. Mus. Hist. Nat._, 1911, 493 and 1912, 527, and C. R. Acad. Sc., + 155, 182. + +Footnote 36: + + _C. R. Soc. Biol._, 1898, 5, 188. + +Footnote 37: + + _Monatsh._, 1893. + +Footnote 38: + + _Inaug. Diss. Giessen_, 1911. + +Footnote 39: + + _Arch. f. Tierheilk._, V. 38–99. + +Footnote 40: + + Comparative Anatomy of the Female Genitalia, _Am. Jour. of Obstet._, + Vol. LXIV, No. 4, 1914. Mechanism of Labor from a Comparative + Standpoint, _Ibid._, Vol. LXIX, No. 4, 1914. Dynamics of the Female + Pelvis, its Evolution, etc., _Ibid._, Vol. LXXI, No. 1, 1915. + +Footnote 41: + + _Proc. L. Z. Soc._, 1919, p. 16. + +Footnote 42: + + _Journ. Phys._, Vol. 34, 295. + +Footnote 43: + + _Am. Jour. Phys._, Vol. 30, 129. + +Footnote 44: + + Carlson, Rooks and McKie, _Loc. cit._ + +Footnote 45: + + Vincent and Jolly, _Loc. cit._ + +Footnote 46: + + See Blair and Brooks, Osteomalacia of Primates in Captivity, _Ninth + Annual Report, New York Zoological Society_, 1904, p. 135. + +Footnote 47: + + Campbell and Cleland, _Jour. Comp. Path. and Ther._, Vol. 32, p. 95. + +Footnote 48: + + _Med. Chir. Trans._, Vol. 60, 37, 1877. + +Footnote 49: + + _These de Lyon_, 1901. + +Footnote 50: + + _Verein Freibürger Aerzte_, May, 1902. + +Footnote 51: + + _Arch. f. Wiss. u. Prak. Tierhk._, Vol. 36, 652, 1910, and Vol. 39, + 164, 1913. + +Footnote 52: + + _Vet. Med. Inaug. Diss. Giessen_, 1913. + +Footnote 53: + + _Traite d’ Anatomie Path._, 1883. + +Footnote 54: + + _Jour. Med. Res._, Vol. 24, 43, 1911. + +Footnote 55: + + _Publ. Jefferson Med. College_, Vol. 6, 1, 1915. + +Footnote 56: + + We have observed later, however, one case with very definite + degenerative arterial disease; it will be discussed under the + affections of the eye since the most definite and indeed only lasting + sign of trouble was amblyopia, the attack being ushered in by a + nondescript fit. + +Footnote 57: + + _Chemistry of the Proteins_, Mann. + +Footnote 58: + + _Ann. Inst. Past._, 1899, XIII, 558, and _Skandinavisches Arch. f. + Physiol._, 1904, XVI, 249. + +Footnote 59: + + _Skandinavisches Arch. für Physiologie_, Vol. 17, p. 211, 1905. + +Footnote 60: + + _Jour. Physiologie et Path._, Vol. 14, 108, 1912. + +Footnote 61: + + _Carnegie Institute Publication_, No. 203, p. 247, 1915. + +Footnote 62: + + _Jour. Biol. Chem._, Vol. 14, p. 59, 1913. + +Footnote 63: + + _Publication of the Jefferson Medical College and Hospital_, Vol. 6, + p. 1, 1915. + +Footnote 64: + + _These de Lyon_, 1901. + +Footnote 65: + + _Verein Freiburger Aerzte_, May 30, 1902. + +Footnote 66: + + _Vet. Med. Inaug. Diss. Giessen_, 1913. + +Footnote 67: + + _Chemistry of Food and Nutrition_, Macmillan, 1918. + +Footnote 68: + + Ohio Agricultural Experiment Station Bull., 295. + +Footnote 69: + + _Skandinavisches Archiv. f. Physiologie_, Vol. 17, p. 211, 1905. + +Footnote 70: + + _Bull._, 185, Experiment Station, U. S. Dept. Agriculture, 1907. + +Footnote 71: + + _Physiological and Pathological Chemistry_, Blakiston, 1902. + +Footnote 72: + + _Journ. Physiol._, 1912, XLIV, 425. + +Footnote 73: + + Die Vitamine und ihre Bedeutung für die Physiologie und Pathologie mit + besonderer Berücksichtigung der Avitaminoses, Wiesbaden, 1914. + +Footnote 74: + + _Newer Knowledge of Nutrition_, Macmillan, 1919. + +Footnote 75: + + _Bull._, 34, Bureau of Amer. Ethnology. + +Footnote 76: + + _Jahrhuch. Kinderheilk._, 1904, LIX, 175. + +Footnote 77: + + _Journ. Am. Med. Assoc._, 1917, LXVIII, 1516. + +Footnote 78: + + _Arch. Path. Anat._, 1897, CXLVIII, 523. + +Footnote 79: + + _Lancet_, London, March 12, 1910, 733. + +Footnote 80: + + _Lancet_, London, 1911, II, 1266. + +Footnote 81: + + _Bull._, Dept. of Agriculture, Dec. 13, 1915. + +Footnote 82: + + Bureau of Animal Industry, 1895–96, 172. + +Footnote 83: + + _Z. Hyg. u. Infektionskrankh._, 1913, LXXV, 334. + +Footnote 84: + + _Jour. Biol. Chem._, 1917, XXXI, 229. + +Footnote 85: + + _Jour. Infect. Dis._, 1916, XIX, 478. + +Footnote 86: + + _Jour. A.M.A._, 1922, 79, 2132. + +Footnote 87: + + _Pflüger’s Arch._, 1909 (129), 63. + +Footnote 88: + + _Chemical Pathology_, Philadelphia, 1918. + +Footnote 89: + + These botanical names are taken from Chestnut’s _Poisonous Plants of + America._ + +Footnote 90: + + _Textbook of Histology_, 1920. + +Footnote 91: + + _Zeitch. für Krebsforsch_, Vol. 15, p. 1. + +Footnote 92: + + _Proceed. Phila. Path. Soc._, 1910, and _Journal of Pathology and + Bacteriology_, Vol. XVII, 1912. + +Footnote 93: + + Figures in parentheses are numbers of animals with captivity known. + +Footnote 94: + + See Gould’s _Birds_, Vol. II, p. 83. + +Footnote 95: + + _Am. Jour. Med. Soc._, 1907, 133–769. + +Footnote 96: + + _Jour. Path. and Bact._, Vol. XVII, 1912. + +Footnote 97: + + Totals and percentages for class, including all members. + +Footnote 98: + + Grand Totals, all autopsies. + +Footnote 99: + + Totals used for analysis after deduction of cases insufficiently + described. + +Footnote 100: + + _Rev. de Med. Vet._ T. 89, p. 221. + +Footnote 101: + + White and Fox, _Archives of Internal Medicine_, 1909, Vol. IV, p. 517. + +Footnote 102: + + The temperature in the axilla is often .5°F. higher than by rectum, + but the difficulties of the axillary method render it impracticable. + +Footnote 103: + + A. E. Brown, _Proc. London Zool. Soc._, June, 1909, p. 81. + +Footnote 104: + + Simpson and Galbraith, _Trans. Royal Soc._, Edinburgh, XIV, p. 1, 65, + 1906. + +Footnote 105: + + This term will be used in the following pages to mention the organism + since by many persons it is better known than Nocardia and moreover + describes the form better. I believe genus Nocardia is the correct + nomenclature for reasons given on a subsequent page. + +Footnote 106: + + Those interested in the investigation of the cause of Blackhead are + referred to the recent literature by Tyzzer and by Smith, in the + _Jour. of Exp. Med._ and _Jour. of Med. Research_, 1918–1922. + +Footnote 107: + + There are certain exceptions to this, as with Nicoll’s (_Proc. Zool. + Soc. London_, 1912, p. 858) careful search for trematodes with sieves, + but this means a separate research, and is incompatible with the all- + round, general policies of present routine laboratory organization. + +Footnote 108: + + _Phila. Zool. Soc. Rep._, 1920, p. 28. + +Footnote 109: + + _Proc. Zool. Soc. London_, 1910, p. 134. + +Footnote 110: + + _Proc. Zool. Soc. London_, 1905, p. 252. + +Footnote 111: + + _Phila. Zool. Soc. Rep._, 1920, p. 29. + +Footnote 112: + + _Phila. Zool. Soc. Rep._, 1921, p. 31. + +Footnote 113: + + _Proc. Zool. Soc. London_, 1919, p. 15. + +Footnote 114: + + _Proc. Zool. Soc. London_, 1919, p. 15. + +Footnote 115: + + _Phila. Zool. Soc. Rep._, 1916–1921. + +Footnote 116: + + _Journal of Parasit._, June, 1921, p. 194. + +Footnote 117: + + _Proc. Zool. Soc. London_, 1910, p. 147. + +Footnote 118: + + Fantham, _Proc. Zool. Soc. London_, 1910, p. 672. + +Footnote 119: + + _Loc. cit._, 1911, p. 674. + +Footnote 120: + + _Loc. cit._, 1915, p. 87. + +Footnote 121: + + _Loc. cit._, 1910, p. 233. + +Footnote 122: + + _Loc. cit._, 1914, p. 222. + +Footnote 123: + + _Phila. Zool. Soc. Rep._, 1912, p. 40. + +Footnote 124: + + _Proc. Zool. Soc. London_, 1914, p. 140. + +Footnote 125: + + _Jour. Parasit._, June, 1921, Vol. VII, p. 198. + +Footnote 126: + + This figure and a number of others in the tables do not correspond + with those in other sections of this book because certain injured, + decomposed and newly arrived animals were available and accepted for + my purposes, but were objectionable for the general medical statistics + and therefore excluded. + +Footnote 127: + + For foot note see page 630. + +Footnote 128: + + For foot note see page 630. + +Footnote 129: + + Not generically diagnosed. + +Footnote 130: + + _Proc. Acad. Nat. Sci. Phila._, March, 1913, p. 127. + +Footnote 131: + + _Proc. Zool. Soc. London_, 1912, p. 858. + +Footnote 132: + + _Proc. Acad. Nat. Sci. Phila._, 1913, p. 133. + +Footnote 133: + + _Proc. Roy. Soc. N. So. Wales_, Sydney, Vol. 27, pp. 86–90, 1893. + +Footnote 134: + + _Proc. U. S. Nat. Mus._, Wash., D. C., Vol. 50, 1916, p. 31. + +Footnote 135: + + _Proc. Zool. Soc. London_, 1911, p. 674. + +Footnote 136: + + _Indian Med. Gaz._, June, 1913, p. 217. + +Footnote 137: + + _Jour. Trop. Med. Etc., London_, 1913, XVI, p. 334. + +Footnote 138: + + _Am. Med. Phila._, V. 6 (16), 1903, p. 611. + +Footnote 139: + + Eichhorn and Gallagher, _Jour. Inf. Dis._, XIX, No. 3, Sept., 1916, p. + 395. + +Footnote 140: + + Macfie, _Ann. Trop. Med. and Parasit._, 1915, 9, p. 507. + +Footnote 141: + + _Arch. f. Protistenk_, Jena, V. 26 (2), 22, July, p. 241. + +Footnote 142: + + _Jour. Parasit._, Sept., 1915, V. 2, pp. 37–45. + +Footnote 143: + + _Proc. Zool. Soc. London_, 1919, p. 14. + +Footnote 144: + + _Jour. Parasit._, Dec., 1916, V. 3, pp. 82–89. + +Footnote 145: + + _Proc. Zool. Soc. London_, 1909, p. 335. + +Footnote 146: + + _Loc. cit._, 1912, p. 236. + +Footnote 147: + + _Loc. cit._, 1912, p. 576. + +Footnote 148: + + The exact taxonomic position could not be stated,-probably an ameba. + +Footnote 149: + + _Proc. Zool. Soc. London_, 1910, p. 134. + +Footnote 150: + + Weidman (F. D.), “Dermatoses of Monkeys,” _Arch. Derm. and Syph._, + Chicago, March, 1923, p. 289. + +Footnote 151: + + Railliet Traite de Zool. Med. et Agric. Paris—Asselin et Houzeau, + 1895, p. 659. + +Footnote 152: + + Megnin, Les Parasites Articules, 1895, Masson et Cie, Paris. + +Footnote 153: + + Quoted by Jensen (V.), _Hospitalstidende_, Copenhagen, 1922, 65, No. + 28, p. 457. + +Footnote 154: + + Centr. f. Bakt. u. Parasitk., (etc.), Jena 1—Abt. V. 35 (1), 5, 1903, + orig. p. 89. + +Footnote 155: + + _Phila. Zool. Soc. Rep._, 1917, p. 36. + +------------------------------------------------------------------------ + + + + + TRANSCRIBER’S NOTES + + + ● Typos fixed; non-standard spelling and dialect retained. + ● Used numbers for footnotes, placing them all at the end of the last + chapter. + ● Enclosed italics font in _underscores_. + ● Subscripts are shown using an underscore (_) with curly braces { }, + as in H_{2}O. + + + +*** END OF THE PROJECT GUTENBERG EBOOK 76817 *** |