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diff --git a/old/66786-0.txt b/old/66786-0.txt deleted file mode 100644 index 1100a78..0000000 --- a/old/66786-0.txt +++ /dev/null @@ -1,7285 +0,0 @@ -The Project Gutenberg eBook of A Text-Book of Horseshoeing, by Anton -Lungwitz - -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online at -www.gutenberg.org. If you are not located in the United States, you -will have to check the laws of the country where you are located before -using this eBook. - -Title: A Text-Book of Horseshoeing - for Horseshoers and Veterinarians - -Author: Anton Lungwitz - -Translator: John William Adams - -Release Date: November 21, 2021 [eBook #66786] - -Language: English - -Character set encoding: UTF-8 - -Produced by: Richard Hulse and the Online Distributed Proofreading Team at - https://www.pgdp.net (This file was produced from images - generously made available by The Internet Archive/American - Libraries.) - -*** START OF THE PROJECT GUTENBERG EBOOK A TEXT-BOOK OF HORSESHOEING *** - - - - -Transcriber’s Notes: - - Underscores “_” before and after a word or phrase indicate _italics_ - in the original text. - Equal signs “=” before and after a word or phrase indicate =bold= - in the original text. - Small capitals have been converted to SOLID capitals. - Illustrations have been moved so they do not break up paragraphs. - Typographical and punctuation errors have been silently corrected. - - - - - A TEXT-BOOK - OF - HORSESHOEING - - FOR - _Horseshoers and Veterinarians_ - - BY - A. LUNGWITZ - - FORMER MEMBER OF THE ROYAL SAXON VETERINARY COMMISSION, - LATE INSTRUCTOR IN THE THEORY AND PRACTICE OF HORSESHOEING, - AND DIRECTOR OF THE SHOEING SCHOOL OF THE - ROYAL VETERINARY COLLEGE IN DRESDEN, GERMANY - - AND - JOHN W. ADAMS - - PROFESSOR OF SURGERY AND OBSTETRICS, - AND LECTURER ON SHOEING IN THE VETERINARY SCHOOL, - UNIVERSITY OF PENNSYLVANIA - - _ELEVENTH EDITION_ - - _WITH TWO HUNDRED AND TWENTY-NINE ILLUSTRATIONS_ - - PHILADELPHIA & LONDON - J. B. LIPPINCOTT COMPANY - - Copyright, 1897, by J. B. LIPPINCOTT COMPANY. - Copyright, 1904, by J. B. LIPPINCOTT COMPANY. - Copyright, 1913, by J. B. LIPPINCOTT COMPANY. - - - - -PREFACE TO THE FIRST EDITION. - - -The inauguration of the law requiring horseshoers to be examined -emphasizes the need of a brief and easily understood text-book on -theoretical and practical horseshoeing. At the request of the _Royal -Veterinary Commission_, in charge of the Royal Veterinary School in -Dresden, and many interested individuals, I have attempted to meet -this need by condensing within the narrowest possible limits all that -is essential to the horseshoer in the practice of his profession. -The subject-matter has been cast into a logically arranged course of -instruction; all that is superfluous and is found only in exhaustive -treatises on shoeing has been omitted. - -In order to make this elementary text-book more easy to understand, -numerous instructive illustrations have been incorporated, which were -taken partly from “Der Fuss des Pferdes,” by Leisering & Hartmann, -fifth edition, Dresden, 1882; partly from the journal _Der Hufschmied_, -and partly from drawings made specially for this work. - -With the desire that this little book may find many friends and supply -them with valuable information, it is herewith given to the public. - - A. LUNGWITZ. - DRESDEN, September, 1884. - - - - -TRANSLATOR’S PREFACE. - - -During the past nine years in which it has been my privilege to teach -horseshoeing to students of veterinary medicine in the University of -Pennsylvania, and to classes of horseshoers under the auspices of the -Master Horseshoers’ National Protective Association of America, I -have been forcibly impressed with the urgent need of a text-book of -horseshoeing that is adapted to the needs of beginners. In my opinion, -such a work must present a detailed description of the anatomy and -physiology of the legs below the middle of the cannons, and must -emphasize in unmistakable terms the definite relations which exist -between certain well-defined forms of the hoof and certain well-defined -standing positions of the limb. Only on this sure foundation can a -thoroughly scientific system of shoeing be based. Furthermore, the -teachings must be eminently practical, logically arranged, as brief as -is consistent with clearness, easy of comprehension by persons who are -unfamiliar with technical language, profusely illustrated, and moderate -in price. - -Through the kindness of my respected friend and former teacher, -Professor A. Lungwitz, one of the highest authorities in all matters -pertaining to shoeing, and for many years a teacher in and the Director -of what I believe to be the best school of shoeing in the world, I am -enabled to present to the public this translation of his text-book -for students of shoeing. Written to meet requirements identical with -those existing today in the United States, and in scope and arrangement -exactly suited to both student and teacher, I am confident that it will -meet the favor that it merits. - - THE TRANSLATOR. - PHILADELPHIA, 1904. - - - - -PREFACE TO THE ELEVENTH EDITION. - - -Since the publication in 1904 of a translation of the tenth edition of -_Der Lehrmeister im Hufbeschlag_, Prof. Anton Lungwitz, the author, -having reached the age of retirement has withdrawn from the activities -of the _Royal Saxon Shoeing School_, and has expressed a desire that -the translator assume entire responsibility for future editions. - -To note the progress of farriery during the past ten years many -chapters have been revised, necessitating resetting, and sixty-nine new -illustrations have been added and many redrawn. It has seemed desirable -to discuss the effect of weight in the shoe in altering the flight of -the foot; to consider rubber pads so widely used in the United States, -and to direct attention to many innovations of more or less value, that -have appeared during recent years. - -In preparing this edition I have had the cordial co-operation of the -publishers, to whom I hereby express deepest gratitude. I wish also to -record my appreciation for the many suggestions and other aid given me -by Mr. Franz Enge, Chief Farrier of the shoeing shop of the Veterinary -Hospital, University of Pennsylvania. - - JOHN W. ADAMS. - UNIVERSITY OF PENNSYLVANIA, April, 1913. - - - - -CONTENTS. - - - PAGE - - INTRODUCTION 13 - The Object of Shoeing 13 - - PART I. - - CHAPTER I. - THE GROSS ANATOMY OF THE HORSE. - - BONES OF THE HEAD—BONES OF THE TRUNK 17 - THE SPINAL COLUMN—BONES OF THE THORAX 17-19 - BONES OF THE PELVIS—BONES OF THE LIMBS 19-21 - JOINTS—MUSCLES—TENDON SHEATHS 21-24 - - THE FOOT. - =A. The Bones of the Foot= 24 - The Cannon—The Long Pastern—The Sesamoid - Bones—The Short Pastern—The Pedal Bone— - The Navicular Bone 24-28 - =B. The Articulations of the Foot= 28 - I. THE FETLOCK-JOINT 28 - The Suspensory Ligament 29 - The Inferior Sesamoid Ligament 30 - II. THE CORONARY JOINT 31 - III. THE PEDAL ARTICULATION (COFFIN JOINT) 31 - =C. The Locomotory Organs of the Foot= 32 - The Anterior Extensor Tendon of the Phalanges— - The Perforatus Tendon—The Perforans Tendon 32-35 - =Mucous Bursæ and Tendon Sheaths= 35 - =Altering the Relative Tension of the Flexor Tendons - and Suspensory Ligament of the Fetlock-Joint= 36 - =D. The Elastic Parts of the Foot= 38 - The Lateral Cartilages—The Plantar Cushion 39, 40 - =E. The Blood-Vessels and Nerves= 41 - The Arteries of the Foot—The Veins of the Foot— - The Nerves of the Foot 41-44 - =F. The Protective Organs of the Foot= 44 - (_a_) THE HAIR-SKIN 44 - 1. The Epidermis 45 - 2. The Dermis 45 - 3. The Subcutaneous Tissue 45 - (_b_) THE HOOF-SKIN, OR PODODERM 45, 46 - 1. The Perioplic Band 47 - 2. The Coronary Band 47 - 3. The Fleshy Wall 48 - The Fleshy Leaves - (Podophyllous Tissue) 48, 49 - 4. The Velvety Tissue of the Sole 49 - 5. The Velvety Tissue of the Frog 49 - (_c_) THE HORN CAPSULE OR HOOF 50-53 - The Wall 50-53 - The Bars 51, 52 - The Layers of the Wall: - 1. The Periople. - 2. The Middle or Protective Layer. - 3. The Leafy Layer (Keraphyllous Layer) 53-55 - The Sole 55, 56 - The Frog 57, 58 - The Minute Structure of the Horn 58 - Hard and Soft Horn 59 - - CHAPTER II. - THE FOOT IN ITS RELATION TO THE ENTIRE LIMB. - =A. Standing Positions of the Limbs= 62 - (_a_) THE POSITIONS OF A FORE-LIMB VIEWED - FROM IN FRONT AND IN PROFILE 62-67 - (_b_) THE POSITIONS OF A HIND LIMB VIEWED - FROM BEHIND AND IN PROFILE 67-69 - =B. Forms of Feet, viewed from in Front, - from Behind, and in Profile= 69-72 - =C. Lines of Flight of Hoofs in Motion= 72-75 - =D. Influence of Weight upon Lines, - of Flight of Hoofs= 75, 76 - =E. Forms of Hoofs= 77 - The Hoof of the Regular Position—The Hoof of - the Base-Wide Position—The Hoof of the - Base-Narrow Position—Forms of Hind Hoofs— - The Wide and the Narrow Hoof—The - Characteristics of Healthy Hoofs 77-82 - =F. Growth of the Hoof and Wear of the - Hoof and Shoe= 82-86 - =G. Physiological Movements of the Hoof= 86-89 - - PART II. - - CHAPTER III. - SHOEING HEALTHY HOOFS. - =A. Examination of a Horse Preliminary - to Shoeing= 90 - =B. Raising and holding the Feet of the Horse - to be Shod= 92 - =C. Removing the Old Shoes= 97 - =D. Preparing the Hoof for the Shoe= 98 - =E. Preparing the Hoof for going Barefoot= 102 - =F. Making Shoes= 103 - The Podometer—Making Front Shoes—Making - Hind Shoes—General Characteristics of - Shoes—A Shoe with Heel-Calks—A Shoe - with Toe- and Heel-Calks—Special - Characteristics of Shoes 103-116 - =G. Choosing the Shoe= 116 - =H. Shaping and Fitting Shoes—General - Considerations= 117 - =Shaping and Fitting Shoes—Special - Considerations= 120 - =Fitting Shoes to Saddlers and Hunters= 122 - =Fitting Shoes to Runners= 123 - =Fitting Shoes to Trotters and Pacers= 124 - =Fitting Shoes to Heavy Draft-Horses= 125 - =I. Nailing the Shoe, Horseshoe-Nails= 128 - =K. Machine Shoes= 132 - =L. Rubber Pads= 135 - - CHAPTER IV. - SHOEING HORSES THAT FORGE AND INTERFERE. - =A. Forging—Cross-firing= 138, 140 - =B. Interfering= 142 - - CHAPTER V. - WINTER SHOEING. - 1. ICE-NAILS (FROST-NAILS) 146 - 2. SHARP TOE- AND HEEL-CALKS 146 - 3. SCREW-CALKS 148, 155 - 4. PEG HEEL-CALKS 150 - 5. PEG TOE-CALKS 152 - 6. REMOVABLE HEEL-CALKS, THAT DO NOT REQUIRE - SHARPENING 154 - - CHAPTER VI. - HOOF NURTURE. - =A. Care of Unshod Hoofs= 157 - =B. Care of Shod Hoofs= 159 - Greasing and Soaking the Hoof 159 - - PART III. - - CHAPTER VII. - GENERAL REMARKS CONCERNING THE SHOEING OF - DEFECTIVE HOOFS AND LAME HORSES. - GENERAL REMARKS 161-165 - CLASSIFICATION OF DISEASES OF THE HOOF 165 - - CHAPTER VIII. - INFLAMMATIONS OF THE PODODERM (PODODERMATITIS). - 1. NAILING 166 - 2. STREET-NAIL 170 - 3. CALK-WOUNDS OF THE CORONET 173 - 4. CORNS 174 - 5. INFLAMMATION OF THE HEELS 176 - 6. LAMINITIS (FOUNDER) 177 - 7. KERAPHYLLOCELE (HORN TUMOR) 181 - - CHAPTER IX. - DEFECTS OF THE HOOF. - =A. Changes of Form= 182 - 1. THE FLAT AND THE FULL HOOF 182 - 2. THE UPRIGHT OR STUMPY HOOF 184 - 3. THE CONTRACTED HOOF 185 - (_a_) The Contraction of Wide Hoofs 189 - (_b_) Contraction of the Sole 189 - 4. THE WRY HOOF 190 - 5. THE CROOKED HOOF 192 - 6. OSSIFICATION OF THE LATERAL CARTILAGE - (SIDE-BONE) 194 - =B. Disturbances of Continuity of Hoof= 195 - 1. CRACKS 195 - 2. CLEFTS 203 - 3. LOOSE WALL 204 - 4. HOLLOW WALL 205 - 5. THRUSH OF THE FROG 206 - - CHAPTER X. - SHOEING MULES, ASSES, AND OXEN. - 1. THE SHOEING OF MULES AND ASSES 207 - 2. THE SHOEING OF OXEN 207 - - - - -INTRODUCTION. - - -Horseshoeing is an industry which requires, in equal degree, knowledge -and skill. - -The word “horseshoeing” embraces various acts, especially preparing -the iron sole, the horseshoe; forming it and fitting it to the hoof, -whose ground-surface has been previously dressed in accordance with the -direction of the limb, and fastening it to the hoof by means of nails. - -Owing to the complicated structure of the hoof, success in the practice -of horseshoeing requires a knowledge of the anatomy and physiology of -the horse’s body in general and of the foot in particular. - -The object of shoeing is,— - - 1. To protect the hoof from excessive wear, and thus - render the horse continuously serviceable upon our - hard roads. - - 2. To prevent slipping and falling during the winter - season. - - 3. To so far remove the disadvantages of faulty - positions of the limbs that horses may render - good service, and, in some cases, - - 4. To cure or improve diseased or defective hoofs - or feet. - -Horseshoeing, though apparently simple, involves many difficulties, -owing to the fact that the hoof is not an unchanging body, but -varies much with respect to form, growth, quality, and elasticity. -Furthermore, there are such great differences in the character of -ground-surfaces and in the nature of horses’ work that shoeing which -is not performed with great ability and care induces disease and makes -horses lame. - -In view of these facts, a thorough training of the young horseshoer -in the principles and practice of his trade is not only greatly to be -desired, but is really essential to success; unreasoning work does -as much harm in this as in any other vocation. _A good common-school -education is necessary_ (more will do no harm). Further requisites -are a _healthy body_, not too tall, _liking for the work, aptness_, -an active, _reasoning mind, fearlessness, dexterity, a good eye for -proportion_, and, finally, _careful selection of a master-instructor_. -Theoretically educated, practically experienced and approved masters, -in whose shops all kinds of horses are shod, are to be preferred. - -During his term of apprenticeship the young apprentice should _learn -to make drawings of horseshoes, of tools of the trade_, and of hoofs -of various forms, and should also make _one or more model shoes as an -indication of his ability_. After completing his time he should seek a -position in a first-class shop, either at home or abroad. A visit to -foreign lands will widen one’s mental horizon and make him a broader, -abler man in every respect. Later, opportunity will be given to some -(in Germany) to join the cavalry, and thus acquire a good education -in shoeing under the patronage of the government. Finally, a course -of instruction in a school of horseshoeing will convert an already -practical and intelligent horseshoer into a thoughtful, capable, expert -workman. - -The scope of horseshoeing is by no means so narrow and insignificant -as it may appear, and since a knowledge of the anatomy and physiology -of the horse’s body in general, and of the foot in particular, is -necessary, it is evident that the schools of horseshoeing in which -one can get the best instruction are those in which there is not only -a regularly graded course of instruction, with demonstrations upon -dissected material and upon living horses, but also an abundance of -daily work at the forge and on the floor in the shoeing of horses. =A -course of four to six weeks is not sufficient.= - -Furthermore, it should be borne in mind that schools of horseshoeing -are not for the purpose of instructing young men in all matters which -pertain to the trade, but only in the making of shoes, the critical -examination and management of hoofs, and the rational and skilful -performance of shoeing. For this reason it is not advisable for young -men to attend a school of horseshoeing until they have at least -completed their apprenticeship. - - - - -HORSESHOEING. - - - - -PART I. - - - - -CHAPTER I. THE GROSS ANATOMY OF THE HORSE. - - -The supporting structure of the horse’s body is the =bony framework= or -skeleton (Fig. 1, page 18). We distinguish in the skeleton the bones of -the head, trunk, and limbs. - -The =bones of the head= are numerous and, excepting the lower jaw, are -solidly united with one another. In general, we distinguish in the head -only the upper and lower jaws (1 and 1′). Both form various cavities; -for example, the cranial cavity, in which the brain lies, the orbital -cavities (eye-sockets), the nasal passages, and the mouth. Besides, the -teeth are set in the jaws. - -The =trunk= comprises the bones of the spinal column, thorax, and -pelvis. - -The _spinal_ or _vertebral column_ (2 to 6), which bears the head at -its anterior end, is the chief support, of the entire skeleton. It -consists of from fifty-two to fifty-four single and irregular bones -called vertebræ, placed in the upper part of the median vertical plane -of the body. Each vertebra, with the exception of those of the tail -(coccygeal or caudal vertebræ), is traversed by a large opening called -the vertebral foramen. The vertebræ are placed end to end in a row, -and through them runs a continuous large canal called the _vertebral_ -or _spinal canal_, in which lies the spinal cord. The horse has seven -cervical, eighteen dorsal, six lumbar, five sacral, and sixteen to -eighteen caudal vertebræ. The sacral vertebræ are grown together to -form one piece called the sacrum. - -[Illustration: FIG. 1. - -SKELETON OF THE HORSE.—1, bones of the head; 1′, lower jaw; 2, cervical -vertebræ; 3, dorsal vertebræ; 4, lumbar vertebræ; 5, sacral vertebræ -(sacrum); 6, coccygeal vertebræ; 7, ribs; 8, sternum (breast-bone); -9, pelvis; 9′, ilium; 9″, ischium; 10, scapula (shoulder-blade); 11, -humerus; 12, radius; 13, ulna; 14, carpus (knee); 15, large metacarpal -bone (cannon); 16, rudimentary metacarpal bones (splint-bones); 17, os -suffraginis (long pastern); 18, os coronæ (short pastern); 19, os pedis -(hoof-bone); 20, sesamoid bones; 21, femur; 22, patella (knee-pan, -stifle); 23, tibia; 24, fibula; 25, tarsus, or hock; 26, large -metatarsal bone (cannon); 27, rudimentary metatarsals (splint-bones); -28, os suffraginis (long pastern); 29, os coronæ (short pastern); 30, -os pedis (hoof-bone, “coffin bone”); 31, sesamoid bones.] - -The _thorax_ is formed by the ribs and the breast-bone or sternum. -The horse has eighteen ribs on each side (7), and all articulate with -the dorsal vertebræ. The first eight pairs unite by their lower ends -directly to the sternum or breast-bone, and are therefore called _true -ribs_, while the last ten pairs are only indirectly attached to the -sternum, and are consequently called _false ribs_. The sternum (8) lies -between the forelegs, and helps to form the floor of the chest cavity. -The space enclosed by the bones of the thorax is called the thoracic, -pulmonary, or chest cavity, and contains the heart and lungs. The -_bones of the pelvis_ form a complete circle or girdle. The upper part, -called the ilium (9′), articulates on its inner side with the sacrum -(5), while its outer side is prolonged to form a prominent angle, which -is the support of the hip, and is called the “point of the hip.” The -posterior part of the pelvis is called the ischium (9″), and that part -lying between the ilium and the ischium and forming part of the floor -of the pelvis is called the pubis. - -The space between the thorax and the pelvis, bounded above by the -lumbar vertebræ and shut in below and on the sides by the skin and -muscular walls of the belly (abdomen), is called the _abdominal -cavity_. This cavity opens directly into the pelvic cavity, and -contains the stomach, intestines, liver, spleen, pancreas, kidneys, and -a part of the generative organs. The thoracic and abdominal cavities -are separated by a muscular partition, the _diaphragm_. - -The =bones of the limbs= may be likened to columns, upon which the body -rests; they articulate with one another at various angles, are tubular -in structure, and strong. - -The bones of the =fore-limbs= _do not articulate directly with the -bones of the trunk_, but are attached to the body by means of the skin -and muscles. From above to below we distinguish the following bones: - -1. The _scapula_, or shoulder-blade (10), a flat, triangular bone, -prolonged at its upper border by a flat, very elastic cartilage, called -the scapular cartilage. At its lower end the scapula articulates with— - -2. The upper end of the _humerus_ (11), forming the _shoulder-joint_ -(scapulo-humeral articulation). The humerus articulates at its lower -end with— - -3. The _radius_ (12) and the _ulna_ (13), to form the _elbow joint_. -These two bones are the basis of the _forearm_. The ulna, smaller and -weaker than the radius, lies behind and projects above it to form the -point of the elbow. The lower end of the radius articulates with— - -4. The _carpus_, or _knee_ (14), which comprises seven small, cubical -bones disposed in two horizontal rows, one above the other. The upper -row comprises four bones and the lower row three. The lower row rests -upon— - -5. The large metacarpal or _cannon bone_, and the two rudimentary -metacarpal or _splint-bones_. The lower end of the radius, the upper -ends of the metacarpal bones, and the small carpal bones together form -the carpal or _knee-joint_ (wrist of man). Of the metacarpals, the -middle one is the largest, longest, strongest, and most important, and -is called the _large metacarpal_, _cannon_, or _shin-bone_ (15). It -articulates at its lower end with the os suffraginis, or long pastern -(17), and with the two small sesamoid bones (20). On each side of -the upper part of its posterior surface lie the two long, slender -splint-bones (16). The inner splint-bone is sometimes affected with -bony thickenings (exostoses) called “splints.” - -6. The bones of the _phalanges_ (all bones below the cannon) will be -fully described in another place. - -The bones of the =hind limbs= articulate _directly_ with the pelvis at -the hip-joint. They are stronger than the bones of the anterior limbs. -We distinguish the following bones in the hind legs: - -1. The highest bone in the hind limb is the _femur_ (21). It is the -strongest bone in the entire body. It lies in an oblique direction -downward and forward, and at its lower end articulates with— - -2. The _patella_ (22), the _tibia_ (23), and the _fibula_ (24), to form -the _stifle-joint_ (knee of man). The patella plays over the anterior -surface of the lower end of the femur. The fibula is small, and lies -against the upper and outer side of the tibia. The latter at its lower -end articulates with— - -3. The bones of the tarsus, or _hock_ (25), which are six small, -irregular bones disposed in three rows, one above another. The _os -calcis_, or _heel-bone_, and the _astragalus_ are in the uppermost -row, and are the most important. The former projects above the true -hock-joint from behind, to form a long lever, the upper end of which -is called the “point of the hock,” and the latter articulates with the -tibia. The tarsal (hock) bones articulate below with— - -4. The _metatarsal bones_ (26 and 27), which are longer, and the cannon -narrower from side to side, than the corresponding metacarpal bones, -but are otherwise similar. - -5. The _phalanges_ of a hind limb (28 to 31) are also narrower than -those of a fore-limb, but are nearly alike in other respects. - -All the horse’s bones present small, but more or less distinct openings -(nutrient foramina) for the passage of blood-vessels and nerves. -Many bones possess roughened elevations and depressions, to which -ligaments, tendons, or muscles are attached. With the exception of -the os pedis, all bones are enveloped in a sort of “bone-skin” called -=periosteum=. The bones unite among themselves to form either _movable_ -or _immovable unions_. A movable union between two or more bones is -termed a “joint,” or =articulation=. The articulating ends of the -bones, presenting on one side a convex surface (head or condyle) and on -the other a corresponding concave surface (glenoid or cotyloid cavity), -are covered with elastic _articular cartilage_. The bones are bound -together by means of =ligaments=, which are tough, fibrous, cord-like, -or sheet-like structures. Ligaments are either (1) _capsular_ or (2) -_funicular_ (cord-like). Every articulation in the limbs possesses a -capsular ligament, and all, except the shoulder-joint, have several -funicular (cord-like) ligaments. The capsular ligaments are lined -upon their inner face with a delicate membrane (synovial membrane) -which secretes the _synovia_, or “joint-water,” whose function is to -lubricate the joint and prevent friction; they enclose the joint in -a sort of air-tight cuff or sack. The funicular ligaments are very -strong and often large, and are the chief means of union of the -bones. The immovable articulations are termed _sutures_; they are -found principally in the head. The mixed joints are found between the -bodies of the vertebræ, each two of which are united by an elastic -fibro-cartilage which, in the form of a pad, lies between them, and by -its elasticity allows of very slight movement, though the spinal column -as a whole can execute manifold and wide movements, as shown by the -neck and tail. - -Joints which permit motion in all directions are known as =free -joints=; such are the shoulder- and hip-joints (ball-and-socket -joints). Those which admit of motion in but two directions (flexion -and extension), and often to a very limited extent, are called -=hinge-joints=,—_e.g._, the elbow, hock, and fetlock. The joints -between the long and short pasterns and between the latter and the -pedal bone are imperfect hinge-joints, because they allow of some other -movements besides flexion and extension. The articulation between -the first and second cervical vertebræ (atlas and axis) is called a -=pivot-joint=. - -The skeleton represents a framework which closely approaches the -external form of the body, and by reason of its hardness and stiffness -furnishes a firm foundation for all other parts of the body. By -reason of the great variety of position and direction of the bones, -and of the fact that changes of position of each single part of this -complicated system of levers may result in the greatest variety of -bodily movements, we can readily understand how the horse is enabled -to move from place to place. Of course, the bones have no power of -themselves to move, but this power is possessed by other organs that -are attached to the bones. These organs are the =muscles=, and, owing -to their ability to contract and shorten themselves, and afterwards to -relax and allow themselves to be stretched out, they furnish the motive -power that is communicated to and moves the bones. - -[Illustration: FIG. 2. - -OUTER MUSCLES OF THE HORSE.—1, cervical trapezius; 2, dorsal trapezius; -3, mastoido-humeralis; 4, great dorsal muscle; 5, long abductor of -the arm; 6, long extensor of the forearm; 7, large extensor of the -forearm; 8, short extensor of the forearm; 9, sterno-trochinus (deep -pectoral); 10, sterno-aponeuroticus; 11, great serratus; 12, common -extensor of the metacarpus; 13, common extensor of the toe (anterior -extensor); 14, common extensor of the long pastern (lateral extensor); -15, oblique extensor of the metacarpus; 16, external flexor of the -metacarpus; 17, internal flexor of the metacarpus; 18, oblique -flexor of the metacarpus; 19, fascia lata; 20, superficial gluteus -(anterior portion); 21, middle gluteus; 22, superficial gluteus -(posterior portion); 23 and 24, femoral biceps; 25, semitendinosus; 26, -semimembranosus; 27, anterior extensor of the toe; 28, lateral extensor -of the toe; 29, perforans muscle (deep flexor of toe); 30, oblique -flexor of the phalanges; 31, perforatus tendon (superficial flexor of -phalanges); 32, Achilles tendon (ham-string).] - -The muscles of the body massed together are the red flesh which -we observe in every slaughtered animal. They are not, however, so -shapeless as they appear while in this condition; on the contrary, they -present well-arranged muscular layers of variable size, thickness, -length, and position. (See Fig. 2.) The muscles clothe the skeleton -externally, give the body its peculiar form, and, by their special -power of contraction, change the relative positions of the bones and -thus make it possible for the animal to move. For this reason, the -muscles are called the =active=, and the bones the =passive=, organs -of motion. By carefully examining a muscle it will be found to consist -of actual, minute, reddish, _muscular fibres_. As a rule, muscles -terminate in more or less strong, glistening, fibrous cords called -=tendons=, or fibrous sheets termed aponeuroses, by which they are -attached to the bones. In the limbs are muscles terminating in very -long tendons, which act as draw-lines upon the distant bones of the -foot (long and short pasterns and pedal bone) and set them in motion. -Such long tendons are enclosed in sheaths of thin, membranous tissue, -known as _tendon sheaths_. The inner surface of such a sheath is in -direct contact with the surface of the tendon, and secretes a thin -slippery fluid (synovia) which lubricates the tendon and facilitates -its gliding within the sheath. - -As long as the bones, articulations, muscles, and tendons of the limbs -remain healthy, just so long will the legs maintain their natural -direction and position. Frequently, however, this normal condition of -the limbs is gradually altered by disease of the bones, joints, and -tendons, and defects in the form and action of the lower parts of the -limbs arise that often require attention in shoeing. - - -THE FOOT. - - -A. The Bones of the Foot. - -Since the horse is useful to man only by reason of his movements, his -foot deserves the most careful attention. The horseshoer should be -familiar with all its parts. Fig. 3 shows the osseous framework of -the foot, consisting of the lower end of the cannon bone (_A_), the -long pastern (_B_), the two sesamoid bones (_C_), the short pastern -(_D_), and the pedal bone (_E_). The lower end of the cannon, or large -metacarpal bone (_A_) exhibits two convex articular surfaces (condyles) -separated by a median ridge running from before to behind, and all -covered by articular cartilage. On both the external and the internal -aspects of the lower end of the cannon are small uneven depressions in -which ligaments take their attachment. - -[Illustration: FIG. 3.] - -The condyles of the cannon articulate with the os suffraginis (long -pastern) and the two sesamoids (Figs. 3, _C_, and 4, _B_) in such a -manner that in the forefeet the cannon makes an angle with the long -pastern of from one hundred and thirty-five to one hundred and forty -degrees, and in the hind feet of from one hundred and forty to one -hundred and forty-five degrees. - -The =long pastern= (first phalanx) (Fig. 4, _A_) is about one-third the -length of the cannon; its upper and thicker end presents two condyloid -cavities (_a_) (glenoid cavities), separated by a median groove, which -exactly fit the condyles and ridge at the lower end of the cannon. -The lower end of the long pastern is smaller than the upper, and is -provided with two condyles, between which is a shallow groove (_e_). -The anterior face of the bone is smooth, rounded from side to side, and -blends into the lateral borders. The posterior face is flatter, and -shows a clearly marked triangle to which ligaments attach. - -The two =sesamoid bones= (Fig. 4, _B_) are small, and somewhat -pyramidal in shape, and, lying against the posterior part of the -condyles of the cannon bone, increase the articular surfaces at the -upper end of the long pastern. - -[Illustration: FIG. 4. - -Os suffraginis with both sesamoid bones in position, as in Fig. 3. _A_, -os suffraginis; _B_, sesamoid bones; _a_, upper joint-surface of long -pastern; _b_, joint-surface of sesamoid bones; _c_, roughened surface -at upper end; _d_, roughened surface at lower end, both for attachment -of ligaments; _e_, lower joint-surface.] - -The =short pastern= (second phalanx) (Figs. 5 and 6) lies under the -first phalanx and above the os pedis; it is somewhat cubical in -shape. Its upper articular surface (Fig. 5, _a_) presents two glenoid -cavities to correspond with the condyles of the first phalanx. The -lower articular surface (Fig. 5, _d_) resembles the lower end of the -first phalanx. The upper posterior border of this bone is prominent and -prolonged transversely (Fig. 6, _a_), to serve as a _supporting ledge_ -for the first phalanx, as a point of attachment for the perforatus -tendon, and as a gliding surface for the perforans tendon. - -[Illustration: FIG. 5. - -Short pastern (os coronæ) viewed in front and in profile: _a_, upper -joint-surface; _b_, anterior surface; _c_, lateral surface; _d_, lower -joint-surface.] - -[Illustration: FIG. 6. - -Short pastern seen from behind: _a_, smooth surface over which the -perforans tendon glides; _b_, lower joint-surface.] - -The lowest bone of the limb is the =third phalanx= or =os pedis= (Fig. -7). In form it is similar to the hoof. The _anterior or wall-surface_ -(_a_) is rough, like pumice stone. Above and in front is the _pyramidal -eminence_ to which the tendon of the anterior extensor of the phalanges -attaches. Behind, the bone extends backward to form the _inner_ and -_outer branches_ (_c, c_) or wings of the os pedis. The _upper_, -articular surface (_b_) slopes backward and downward. The _lower_, -solar or plantar surface (Fig. 8, _a_) is slightly concave, and -presents posteriorly a half-moon-shaped excavation, with a roughened -border called the _semilunar crest (c)_, to which the perforans tendon -attaches; just above this crest are two small holes (_e_) known as the -_plantar foramina_, through which the plantar arteries pass into the -bone. The surfaces of wall and sole come together in a sharp edge, -which is circular in its course. It is easy to tell whether a pedal -bone is from a fore or a hind limb; the os pedis of a hind leg has -a steeper and more pointed toe, and a more strongly concaved solar -surface than the same bone of a fore-leg. Not only is the outline of -the sharp inferior border of the os pedis of a _front foot more rounded -at the toe_, but when placed on a flat surface the _toe does not touch_ -by reason of being turned slightly upward, much as a shoe designed to -give a “rolling motion.” The os pedis of a _hind foot is narrower from -side to side_ (pointed), and _does not turn up at the toe_. - -[Illustration: FIG. 7. - -Os pedis seen in profile and in front; _a_, anterior face with -pyramidal eminence above; _b_, joint-surface; _c_, wings or branches -of hoof-bone; _d_, notch which, by the attachment of the lateral -cartilage, is converted into a foramen and leads to _e_, the preplantar -fissure.] - -[Illustration: FIG. 8. - -Lower surface of hoof-bone; _a_, anterior portion covered by the -velvety tissue of the sole; _b_, wing of the os pedis; _c_, semilunar -crest, to which the perforans tendon attaches; _d_, plantar fissure -leading to _e_, plantar foramen.] - -The right and left hoof-bones are also, as a rule, easily distinguished -by variations in the surfaces of wall and sole. The shape of the os -pedis corresponds to the form of the horny box or hoof, and therefore a -knowledge of this bone is absolutely necessary. - -The =navicular bone= (os naviculare, nut-bone, Figs. 9 and 10) is -an accessory or sesamoid bone to the os pedis. It is a small bone, -transversely elongated and situated behind and below the os pedis and -between the wings of the latter. It adds to the articular surface of -the pedal joint. Its under surface is smooth, and acts as a gliding -surface for the perforans tendon, which is quite wide at this point. - -[Illustration: FIG. 9.] - -[Illustration: FIG. 10. - -Fig. 9 represents the upper surface of the navicular bone; Fig. 10 the -lower surface of the same: _a_, anterior border; _b_, slight elevation -in middle of under surface.] - -The long axes of the three phalanges (os suffraginis, os coronæ, and os -pedis) should unite to form a straight line, when viewed either from -in front or from one side; that is, the direction of each of these -three bones should be the same as the common direction of the three -considered as a whole. - - In young colts both the long and short pasterns are - in three parts and the pedal bone in two parts, all - of which unite later in life to form their respective - single bones. - - In mules and asses the os pedis is comparatively - small and narrow. In cattle all three phalanges are - double, and split hoofs cover the divided os pedis. - - -B. The Articulations of the Foot. - -There are three articulations in the foot—namely, the fetlock, -coronary, and pedal joints. All are hinge-joints, the fetlock being a -perfect hinge-joint, and the other two imperfect hinge-joints. Each -has a _capsular ligament_, and also several _funicular_ or cord-like -_ligaments_ which are placed at the sides of (lateral ligaments), or -behind (on the side of flexion) the joints. - -I. The =fetlock= or =metacarpo-phalangeal articulation= is formed by -the condyles at the lower end of the cannon bone and the glenoid -cavities formed by the union of the articular surfaces of the sesamoids -and the upper end of the first phalanx. The following ligaments are -about this joint: - -[Illustration: FIG. 11.] - -1. _Two lateral ligaments_, an external and an internal (Fig. 11, _a_). - -2. _Two lateral sesamoid ligaments_ (_f_). - -3. An _intersesamoid ligament_ (Fig. 12, _b_), a thick, fibrous mass, -binding the sesamoid bones almost immovably together, extending above -them and presenting on its posterior face a smooth groove, in which -glide the flexor tendons of the phalanges (perforans and perforatus). - -4. The _suspensory ligament_ of the fetlock (Figs. 11, _c_, 12, _c_, -and 13, _c_, pages 29 and 30). This may also be called the superior -sesamoid ligament. It is a long and very powerful brace, originating -on the lower row of carpal bones (bones of the hock in the hind leg) -and on the upper end of the cannon between the heads of the two -splint-bones, and dividing at the lower third of the cannon into two -branches (_c_), which are attached one to each sesamoid bone. Below -these bones these two branches are prolonged obliquely downward and -forward on opposite sides of the long pastern to pass into the borders -of the anterior extensor tendon of the toe at about the middle of the -long pastern (Fig. 14, _b′_, page 32). - -[Illustration: FIG. 12.] - -[Illustration: FIG. 13. - -Fig. 11 shows a side view, and Figs. 12 and 13 a posterior view of the -phalangeal bones, with their articular ligaments. The lettering is the -same in all three figures: _a_, lateral ligament of fetlock-joint; _b_, -intersesamoid ligament; _c_, suspensory ligament of the fetlock; _d_, -median branch of inferior sesamoid ligament; _d′_, lateral branches -of inferior sesamoid ligament; _e_, deep inferior sesamoid ligament; -_f_, lateral sesamoid ligaments; _g_, inferior coronary ligaments; _h_, -superior coronary ligaments; _h′_, median coronary ligaments; _i_, -lateral pedal ligament; _k_, lateral coronary ligament and suspensory -ligament of the navicular bone; _l_, interosseous ligament.] - -5. The _inferior sesamoid ligament_ (Figs. 11, _d′_, 12, _d_, _d′_, -and 13, _d′_, _E_). This originates at the lowest part of the sesamoid -bones and intersesamoid ligament, and consists of _three parts_ or -branches. The _median branch_ (_d_) is the longest and strongest, and -takes its lower attachment in the middle of the fibro-cartilaginous lip -found on the upper border of the posterior face of the second phalanx. -The _two lateral branches_ (_d′_) approach each other as they descend, -and terminate on the sides of the roughened triangle on the posterior -face of the first phalanx. - -6. The _deep inferior sesamoid ligament_ (Fig. 13, _e_) is quite short, -and consists of a number of distinct, thin fibrous bands lying directly -against the bone and entirely covered by the median and lateral -inferior sesamoid ligaments. These fibrous bands cross one another in -passing from the sesamoids to the first phalanx. - -II. The =coronary joint= is the simplest of the three articulations of -the foot. The long pastern furnishes two condyles and the short pastern -two glenoid cavities. Besides a capsular ligament there are— - -1. _Two lateral coronary ligaments_ (_k_) and, - -2. _Six posterior coronary ligaments_,—namely, _two superior_ coronary -ligaments (_h_), _two median_ coronary ligaments (_h′_), and _two -inferior_ coronary ligaments (_g_). - -III. The =pedal articulation= (“coffin” joint) is an imperfect -hinge-joint, and is formed by the condyles at the lower end of the -short pastern and the two glenoid cavities in the united upper surfaces -of the pedal and navicular bones. Besides the _capsular ligament_ -(Figs. 12 and 13, _l_), which binds all three bones together, there are -the following accessory ligaments: - -1. _Two strong lateral ligaments_, an external and an internal (Fig. -11, _i_), whose posterior borders are lost in the lateral cartilages -which cover them. - -2. _Two lateral suspensory ligaments of the navicular bone_ (_k_). -They begin on the posterior border and ends of the navicular bone, -and terminate on the lower part of the anterior surface of the os -suffraginis, where they are lost in the lateral ligaments of the -coronary articulation. - -3. The _lateral ligaments_ of the lateral _cartilages_, _navicular -bone_, and _os pedis_. They are short, and unite the navicular bone -with the os pedis and lateral cartilages. - -Of the three phalangeal articulations, the pedal is the only one that -permits of any lateral movement; hence it is an imperfect hinge-joint. - - -C. The Locomotory Organs of the Foot. - -Though the muscles are the organs which produce motion, the horseshoer -need concern himself only with the tendons of those muscles which -extend and flex the phalanges. These tendons are either =extensors= or -=flexors=. The extensors lie on the _anterior face_ and the flexors on -the _posterior face_ of the phalanges. - -[Illustration: FIG. 14. - -Right forefoot viewed from in front and from the external side: _a_, -anterior extensor tendon of the toe; _b_, suspensory ligament of the -fetlock; _b′_, branch of the same passing forward and uniting with the -extensor tendon of the toe; _c_, extensor tendon of the os suffraginis -(absent in the hind leg), called the lateral extensor.] - -The _anterior extensor of the phalanges_ (Fig. 14, _a_) extends -the long and short pasterns and the hoof-bone; it is broad, and -made somewhat broader by receiving the branches of the suspensory -ligament (_b′_) that come from the sesamoid bones. It takes a firm -attachment on the pyramidal eminence of the os pedis. In the forefeet -the long pastern has a special extensor tendon (_c_), which is known -as the _lateral extensor_. When the muscles to which these tendons -are attached act,—that is, when they draw themselves together, or -_contract_, as we term this action,—the foot is carried forward -(extended). - -There are _two flexor tendons_ of the phalanges,—namely, the -_superficial_ (perforatus tendon) and the _deep_ (perforans tendon). - -[Illustration: FIG. 15. - -Right forefoot seen from behind: _a_, lower end of the perforans -tendon, cut through and hanging down, so that its anterior surface is -visible; _a′_, lower expanded end (plantar aponeurosis) of this tendon, -which attaches itself to the semilunar crest of the os pedis; _a″_, -shallow groove which receives the slight elevation on the under surface -of the navicular bone; _a‴_, piece of the perforans tendon enclosed -by the ring formed by the perforatus tendon; _b_, perforatus tendon -bent over backward so that its anterior surface is visible; _b′_, ring -of the perforatus tendon; _b″_, terminal branches of the same; the -perforans tendon passes through the space between these two branches; -_c_, navicular bone; _d_, suspensory ligament of the same; _e_, smooth -surface on the os coronæ over which the perforans tendon glides; _f_, -the smooth groove (sesamoid groove) on the posterior surface of the -intersesamoid ligament for the gliding of the perforans tendon; _g_, -body of the suspensory ligament of the fetlock; _g′_, terminal branches -of the same, attaching to the sesamoid bones.] - -1. The _superficial flexor_ or _perforatus tendon_ (Figs. 15, _b_, -and 16, _a_, _b_) lies behind, immediately under the skin, and covers -the deep flexor or perforans tendon. At the gliding surface between -the sesamoid bones (Fig. 15, _f_) it broadens, and forms a ring or -tube (Fig. 15, _b′_) through which the perforans tendon (_a‴_) passes, -while a short distance farther down it bifurcates, or divides into two -branches (Figs. 15, _b″_, and 16, _b_), which terminate, one on either -side, partly on the inferior lateral borders of the first phalanx -and partly on the fibro-cartilage of the second phalanx. It acts -simultaneously on the long and short pasterns. - -2. The _deep flexor_ or _perforans tendon_ (Figs. 15, _a_, and 16, -_c_) is cylindrical and stronger than the perforatus tendon; above -the fetlock-joint it lies between the perforatus and the suspensory -ligament of the fetlock. At the sesamoid bones it passes through the -ring formed by the perforatus tendon (Fig. 15, _b′_), then becomes -broad and double-edged, passes between the two terminal branches of the -perforatus, glides over the fibro-cartilage of the second phalanx and -over the inferior surface of the navicular bone, and finally ends on -the semilunar crest of the third phalanx. In common with the perforatus -tendon it flexes the foot. - -[Illustration: FIG. 16. - -Right forefoot seen from behind and a little from the external side: -_a_, perforatus tendon; _b_, terminal branches of the same; _c_, -perforans tendon; _d_, annular ligament which attaches to the sesamoid -bones: _d′_, the “x” ligament, which attaches by four branches to the -os suffraginis; _d″_, an upper branch of the same (the lower branches -are not shown in the figure); _e_, reinforcing sheath of the perforans -tendon, covering the under surface of the latter and attached by -its branches at _e′_ to the lower end of the os suffraginis; _f_, -suspensory ligament of the fetlock.] - -If at a point a few inches above the fetlock a limb be cut through -from behind, the knife will pass successively through the following -structures: skin, perforatus tendon, perforans tendon, suspensory -ligament, cannon bone, lateral extensor tendon, anterior extensor -tendon, and, lastly, the skin on the anterior surface of the limb. The -flexor tendons are frequently thickened and shortened by inflammation -due to injury, and as a result the foot is pulled backward and the hoof -gradually becomes more nearly upright,—_i.e._, stubby, steep-toed. -A knowledge of the normal condition of the tendons is, therefore, -absolutely necessary to the horseshoer. Both flexor tendons are -embraced and held in place by ligaments and fascia passing out from -the phalanges (Figs. 16, _d′_, and 24, _e_, _f_). The extensor and -flexor tendons essentially contribute to the strong union of the -phalangeal bones, and especially to the support and stability of the -fetlock-joint. The gliding of the tendons is made easy by the secretion -of a lubricating fluid, called synovia, from the inner surface of the -sheaths which surround them. In thin-skinned well-bred horses with -sound limbs one can not only distinctly feel the tendons through the -skin, but can see their outline. _When the tendons and bones are free -from all inflammatory thickenings, and the tendon sheaths are not -visibly distended, we say that the leg is “clean.”_ - - -Mucous Bursæ and Tendon Sheaths. - -Accessory to the tendons, there are in the foot roundish, membranous -sacs (mucous bursæ) and membranous tubes (tendon sheaths). Both contain -a liquid resembling synovia (“joint-water”), which facilitates the -gliding of the tendons. These bursæ and sheaths are often distended to -form soft tumors, known as hygromata (“wind-puffs,” “wind-galls”). - -(_a_) =Mucous Bursæ.=—They lie beneath tendons at those places where -the tendons pass over bony prominences. - -1. The mucous bursa of the anterior extensor tendon of the toe is about -the size of a walnut, and lies between the tendon and the capsular -ligament of the fetlock-joint (Figs. 17, _g_, and 18, _e_). - -2. The mucous bursa of the extensor tendon of the long pastern (lateral -extensor) is somewhat smaller, and lies, likewise, beneath the tendon, -between it and the capsular ligament of the fetlock-joint (Fig. 17, -_h_). - -3. The mucous bursa of the navicular region lies between the under -surface (gliding surface) of the navicular bone and the flexor pedis -perforans tendon (deep flexor). Its width equals the length of the -navicular bone, and it extends upward and downward beyond the bone. -Above, it is separated from the sheath of the perforans tendon (“great -sesamoid sheath”) by a membranous partition; below, it passes to the -attachment of the perforans tendon to the semilunar crest of the os -pedis. - -(_b_) There is but one tendon sheath in the foot—the sheath common to -the two flexor tendons (great sesamoid sheath). It encloses the flexor -tendons from the middle third of the cannon down to the middle of the -short pastern, and is intimately united with the flexor pedis perforans -tendon (Fig. 17, _f_, _f′_, _f″_, _f‴_. Fig. 18, _d_, _d′_, _d″_, _d‴_). - -[Illustration: FIG. 17. - -Right forefoot seen from the external side; _f_, _f′_, _f″_, _f‴_, -great sesamoid sheath (tendon sheath); _g_, mucous bursa beneath -anterior extensor tendon of the toe; _h_, mucous bursa beneath extensor -tendon of long pastern; _i_, synovial distension of the fetlock-joint; -7, suspensory ligament; 9, cannon bone; 10, outer sesamoid bone; 12, -fetlock-joint; 13, lateral cartilage; 14, suspensory ligament of the -lateral cartilage. (Ellenberger in Leisering’s Atlas and Veterinary -Anatomy, Sisson, Saunders.)] - -[Illustration: FIG. 18. - -Right forefoot seen from the inner side; _d_, _d′_, _d″_, _d‴_, great -sesamoid sheath; _e_, mucous bursa beneath anterior extensor tendon of -the toe; _f_, synovial distension of fetlock-joint; 10, inner sesamoid -bone; 11, “x” ligament; 14, fetlock-joint; 15, lateral cartilage; 16, -suspensory ligament of lateral cartilage (Ellenberger in Leisering’s -Atlas and Veterinary Anatomy, Sisson, Saunders.)] - -Altering the Relative Tension of the Flexor Tendons and Suspensory -Ligament of the Fetlock-Joint. - -The body-weight imposed at the fetlock-joint is supported, in large -part, by the suspensory ligament; somewhat less weight is borne by the -perforans tendon, and a still smaller amount by the perforatus. The -coronary joint is supported chiefly by the perforatus, assisted by -the perforans. The pedal joint is pressed forward and upward by the -perforans tendon passing in a curve beneath the navicular bone. Each of -these three structures bears its normal proportion of the body-weight -when the three phalanges, as viewed from the side, form a continuous -straight line from the fetlock-joint to the ground. In such a case the -obliquity of the long pastern will be the same as that of the toe (see -Foot-Axis, p. 70). - -[Illustration: FIG. 19. - -Right forefoot viewed from the external side: _A_, os coronæ; _B_, os -pedis; _C_, external lateral cartilage; _a_, lateral pedal ligament; -_b_, ligament uniting the lateral cartilage with the os coronæ; _c_, -aponeurosis joining lateral cartilage and os pedis.] - -_Raising the toe_ by means of a tip, a full shoe with thinned branches -or a toe-calk, _or paring away the quarters_ will tilt the os pedis -backward, break the foot-axis backward in the pedal joint and to a less -extent in the coronary joint, and increase the tension of the perforans -tendon considerably and of the perforatus slightly. These tendons -tightening behind the fetlock-joint force it forward, causing the long -pastern to stand steeper, and taking some strain from the suspensory -ligament. Hence, _the perforans tendon is under greatest tension, and -the suspensory ligament under least tension, when the foot-axis is -broken strongly backward_. - -_Shortening the toe, or raising the quarters_ by heel-calks or -thickened branches, will tilt the os pedis forward, break the foot-axis -forward in the pedal joint, and will _greatly lessen the tension of the -perforans tendon_. The aggregate tension of perforans and perforatus -tendons being diminished, the fetlock sinks downward and backward, -the long pastern assumes a more nearly horizontal direction, and the -tension of the suspensory ligament is increased. Thus, _the perforans -tendon is under least tension, and the suspensory ligament under -greatest strain, when the foot-axis is broken strongly forward_. - - -D. The Elastic Parts of the Foot. - -[Illustration: FIG. 20. - -Os pedis and inner face of one lateral cartilage; _a_, toe of os pedis; -_a′_, pyramidal eminence to which the extensor tendon attaches; _a″_, -wing of pedal bone; _b_, lateral cartilage; _C_, points of attachment -of suspensory ligament of lateral cartilage; _d_, point of insertion -of ligament to the short pastern; _e_, point of insertion of ligaments -from navicular bone.] - -All bodies which under pressure or traction change their form, but -return again to their original shape as soon as the pressure or -traction ceases, are called _elastic_ or _springy_. Nearly all parts of -the horse’s foot, except the bones, possess more or less elasticity. -The _lateral cartilages_ and the _plantar cushion_ are elastic to a -high degree, but the _coronary band_, the _laminæ_, the _articular -cartilage_, and the horny box or _hoof_ are less elastic. This property -or characteristic is possessed by the respective parts of the foot in -accordance with their function, location, and structure. - -[Illustration: FIG. 21. - -Plantar cushion seen from below: _a_, base or bulb of the plantar -cushion; _b_, summit; _c_, median lacuna or cleft in which lies the -“frog-stay” of the horny frog.] - -[Illustration: FIG. 22. - -Plantar cushion seen from above: _a_, base (bulbs) of same; _b_, -summit; _c_, suspensory ligament of plantar cushion; _d_, place at -which the elastic ligament connecting the os suffraginis and the -lateral cartilage unites with the plantar cushion.] - -The =two lateral cartilages= (Figs. 19, _C_ and 20, _b_) are irregular, -quadrangular plates, attached to the wings of the os pedis, and -extending so far upward and backward that one can feel them yield -to pressure on the skin above the coronet, and can thus test their -elasticity. The perforans tendon and the plantar cushion lie between -the lateral cartilages, and on the sides and behind are partially -enclosed by them. The internal concave surface of the lateral cartilage -(Fig. 20) is attached to the plantar cushion, the os pedis, and the -navicular bone, and, like the external, slightly convex surface, is -covered with many blood-vessels (veins) Fig. 25, _B_. - -[Illustration: FIG. 23. - -Section lengthwise through middle of the plantar cushion: _a_, glome -(bulb) of heels; _b_, apex or point of fleshy frog; _c_, fibro fatty -tissue of plantar cushion; _d_, median cleft which receives the -frog-stay of the horny frog.] - -The =plantar cushion= (Figs. 21, 22, 23) is composed almost entirely -of yellow elastic and white fibrous tissues, with adipose (fat) cells -distributed throughout their substance. It is similar in form to the -horny frog, and lies between it and the perforans tendon (Fig. 24, -_a_). The bulbs are formed by the posterior thicker portion which lies -between the lateral cartilages and is divided into two parts by the -cleft or median lacuna (Figs. 21, _a_, and 23, _d_). The summit is -attached to the plantar face of the os pedis in front of the semilunar -crest, and the bulbs are attached to the lateral cartilages. It is -covered inferiorly by the velvety tissue of the frog (pododerm). - -[Illustration: FIG. 24. - -Right forefoot viewed from below, behind, and the external side. This -figure shows clearly the position of the plantar cushion. The external -lateral cartilage and the tissues covering the plantar cushion and -under surface of the os pedis (velvety tissue of the sole and fleshy -frog) have been removed: _a_, fleshy frog or plantar cushion; _a′_, -bulbs of plantar cushion; the remaining visible parts belong to the -so-called “fleshy frog;” _a″_, groove (median lacuna) in the lower -surface of the fleshy frog, in which lies the frog-stay of the horny -frog; _b_, suspensory ligament of the plantar cushion passing out of -the bulbs; _b′_, small elastic cords passing to the lateral cartilage; -_c_, elastic ligament coming from the lateral cartilage and uniting -with the suspensory ligament of the plantar cushion; _d_, small -tendinous cord beginning in the skin behind the fetlock-joint and -ending on the os suffraginis in common with _b_ and _c_; _e_, tendinous -reinforcing sheath of the perforans tendon; _f_, reinforcing stay of -the perforatus tendon; _g_, perforatus tendon; _h_, perforans tendon; -_i_, suspensory ligament of the fetlock; _k_, plantar surface of the os -pedis, to which the plantar cushion is joined by fibrous bands.] - - -E. The Blood-Vessels and Nerves. - -Vessels which carry blood from the heart to the tissues are called -=arteries=, while those which return the blood to the heart from the -tissues are called =veins=. Arteries and veins are connected by very -small, thread-like vessels called _capillaries_, which originate in the -smallest arteries and are so minute that they can not be seen without -the aid of a microscope. The capillaries penetrate the soft tissues in -every direction, and finally unite to form small veins. For our purpose -we need consider only the arteries and veins. - -The =arteries= carrying blood from the heart ramify and subdivide in -all parts of the body, and thus reach the foot. They are thick-walled, -very elastic tubes, =without valves=, and carry =bright-red= blood, -which flows in spurts, as can be seen when an artery is cut. If a -finger be pressed lightly over an artery lying near the surface, the -blood-wave can be felt as a light stroke (pulse). The character of -the pulse is important, because in inflammations of the pododerm or -horn-producing membrane of the foot we can ascertain by feeling that -the pulse is stronger than usual in the large arteries carrying blood -to the inflamed foot. - -On either side of the phalanges below the fetlock-joint there lies an -artery called the _digital artery_ (Fig. 25, _a_). The pulse can be -felt in it as it passes over the fetlock at _A_, Fig. 25. It gives off -the following collateral (side) branches: 1. The _artery of the first -phalanx_ (perpendicular artery), with anterior and posterior branches. -2. The _artery of the plantar cushion_, which supplies with blood the -plantar cushion, the velvety tissue of the sole and frog, the bar -portion of the coronary band, and the sensitive laminæ of the bars. 3. -The _coronary artery_, which carries blood to the coronary band, os -coronæ, ligaments of the coronary and pedal joints, flexor tendons, and -skin. - -The terminal branches of the digital arteries are the _preplantar_ and -_plantar ungual arteries_. The preplantar artery passes through the -notch in the wing of the os pedis, then along the preplantar fissure, -splitting up into many branches, which spread over and penetrate the -porous surface of the os pedis. The plantar artery courses along the -plantar fissure, enters the plantar foramen, and passes into the -semilunar sinus of the os pedis, where it unites with the terminal -branch of the opposite digital artery, forming the _semilunar arch_. - -[Illustration: FIG. 25. - -Side view of forefoot, showing blood-vessels and nerves: _a_, digital -artery; _b_, anterior artery of the os suffraginis; _d_, anterior -coronary artery, or circumflex artery of the coronet; _e_′, preplantar -ungual artery; _f′_, inferior communicating arteries passing out from -the semilunar artery of the os pedis, through minute holes just above -the lower border of the bone; they unite to form (_f″_) the circumflex -artery of the toe; _A_, digital vein; _B_, superficial venous plexus of -coronary band and lateral cartilage; _C_, podophyllous venous plexus; -_G_, circumflex vein of the toe; 1, plantar nerve; 2, anterior digital -branch of same; 3, posterior digital branch of same; 4, small cutaneous -branches of same.] - -After the arterial or pure blood passes through the capillaries it -is collected by the =veins=, to be returned to the heart; then it is -driven to the lungs for purification, and is again returned to the -heart, from whence it is pumped through the arteries to all parts of -the body. - -[Illustration: FIG. 26. - -Foot viewed from below and behind: _a_, digital arteries; _c_, arteries -of the plantar cushion; _f‴_, small branches of the semilunar artery -of the os pedis, which ramify in the velvety tissue of the sole; _A_, -digital vein; _B_, venous plexus of the heels or bulbs; _D_, solar -venous plexus; _G_, circumflex vein of the toe; 3, posterior digital -branch of the plantar nerve; 4, cutaneous branches of the same.] - -The veins are more numerous than the arteries; they have thinner walls, -and the larger ones are provided with =valves= that prevent the impure -blood from flowing backward. The veins carry impure or =dark-red= blood -towards the heart, and if one is opened the dark blood flows in a -steady stream; it does not spurt. The great number of veinlets in the -lower parts of the foot form a complex net-work (plexus) of vessels -which are in such manifold and close union with one another that -checking the flow of blood in one part does not seriously interfere -with the flowing of the blood towards the larger veins. The following -are the most important of these net-works of veins or venous plexuses: -(1) the _solar venous plexus_ (Fig. 26, _D_); (2) the _podophyllous -venous plexus_ (Fig. 25, _C_); (3) _superficial coronary venous -plexus_ (Fig. 25, _B_); (4) _bulbar venous plexus_ (Fig. 26, _B_). All -these plexuses of small veins contribute to form the _digital veins_ -(Figs. 25 and 26, _A_). - -=Nerves= are roundish white cords which come from the brain and spinal -cord; they generally accompany arteries. They divide and subdivide -into smaller and smaller branches till they become invisible to the -naked eye and are lost in the tissues. The nerves that are found in the -foot come from the spinal cord, and because the largest nerves of the -foot accompany the digital arteries they are called _digital nerves_ -(Fig. 25, 1). The branches ramify throughout all parts of the foot -except the horny box and the hair. Nerves, according to their use or -function, are classed as _motor_ and _sensory_. The motor nerves end in -muscles which they stimulate to action and control. The sensory nerves -terminate in the skin and in the soft tissues just under the horny box -or hoof (pododerm), and render these parts sensitive; that is, they -convey certain feelings, as, for example, the pain caused by bruising, -pricking, or close-nailing, to the brain and consciousness. - - -F. The Protective Organs of the Foot. - -The protective organs are the skin and the horny box or hoof. - -The _external skin_, or _hide_, covers the entire body; in the feet it -covers the bones, tendons, and ligaments, even passing in under the -hoof and directly covering the os pedis. This portion of the skin, -enclosed by the hoof and therefore invisible, is called the _pododerm_ -or foot-skin. In Germany it is called the _hoof-skin_ (huflederhaut), -because it is a continuation of the outer visible skin, and because -it secretes the hoof,—that is, the hoof is produced by it. That part -of the skin which is covered with hair is known as the external or -_hair-skin_. - -(_a_) =The hair-skin= (Fig. 27, _a_) consists of _three_ superposed -_layers_,—(1) the _external_ superficial layer, or _epidermis_; (2) the -_middle_ layer, _derm_ or leather-skin (so-called because leather is -made from it); (3) the _internal_ layer, or _subcutaneous connective -tissue_. - -1. The _external layer_, or _epidermis_, is composed merely of single -flattened, horn-like cells (scales) lying side by side and over one -another, and uniting to form one entire structure,—a thin, horn-like -layer, without blood-vessels or nerves. It extends over the entire -surface of the body, and protects the underlying, very sensitive middle -layer from external influences. The oldest cell-layers lie on the outer -surface, and are being continuously brushed off in patches or scales, -while new ones are constantly being formed on the outer surface of the -middle layer. - -2. The _middle layer_, _leather-skin_ or _dermis_, is composed of -solid, fibrous, and elastic tissues, and contains many blood-vessels, -small nerves, sweat-and oil-glands, and hair follicles from which the -hair grows. The hair upon the posterior surface of the fetlock-joint is -usually long and coarse, forming a tuft known as the “foot-lock,” which -encloses a horny spur, called the ergot. Common-bred horses have, as -a rule, larger and coarser footlocks than thoroughbreds. The derm or -leather-skin, which produces the hair and epiderm, is the thickest and -most important layer of the skin. - -3. _The inner layer, or subcutaneous tissue_, unites the middle layer -with the muscles, tendons, ligaments, bones, or other structures. It is -that loose fibrous mesh or net-work through which the butcher cuts in -removing the hide from the carcass. - -[Illustration: FIG. 27. - -Foot from which the horny capsule or hoof, has been removed by -prolonged soaking: _a_, skin; on the left the hair has been rubbed -away; _b_, perioplic band; _c_, coronary cushion; _d_, podophyllous -tissue (fleshy leaves); at the lower border of the figure can be seen -the minute thread-like processes or villi which grow down from the -lower end of each fleshy leaf.] - -(_b_) =The hoof-skin= (Figs. 27 and 28, _b_, _c_, _d_), or pododerm, -is completely enclosed by the hoof. Although it is only an extension of -the derm or middle layer of the hair-skin, it differs from the latter -in structure and relations. - -[Illustration: FIG. 28. - -Foot from which the near half of the horny wall and a greater part -of the so-called fleshy wall have been removed, in order to show the -relation of the lateral cartilage to adjacent structures: _a_, vertical -section of the skin prolonged downward through the pododerm (foot-skin) -to show clearly that the latter is but a continuation of the former; -_a′_, hairless place on the skin; _b_, perioplic band; _b′_, line -indicating the upper border of the same; _b″_, surface of section of -the periople, or perioplic horn-band; _c_, coronary cushion; _c′_, -(left) line which marks the upper border of the coronary cushion; -_c″_, section of wall at the toe; _d_, podophyllous tissue (sensitive -laminæ); _e_, horny sole; _f_, white line; _g_, horny frog; _h_, fleshy -frog; _i_, lateral cartilage.] - -In order to study the pododerm we should not wrench the hoof off with -violence, but should allow the foot to partially decompose by leaving -it for six to eight days at ordinary room temperature; it can then -be removed without injuring the pododerm. After the hoof has been -removed the entire pododerm presents a more or less dark-red color -(flesh-color), which is due to the great number of blood-vessels that -it contains. For this reason different parts of the pododerm have -received the prefix “fleshy,” as for example, fleshy wall, fleshy sole, -fleshy frog, etc. The pododerm is what the uninformed horseshoer calls -the “quick.” I will here remark that the three layers of the external -or hair-skin are represented in the foot; however, the epidermis is -in an entirely different form,—namely, the horny box or hoof. The -internal layer or subcutaneous tissue of the hair-skin is absent in -those parts of the foot where the pododerm covers the os pedis. There -remains, therefore, only the middle layer, derm, or _pododerm, which -secretes the hoof_, and which is the prolongation and representative -of the middle layer of the hair-skin. The pododerm is distinguished -from the derm of the hair-skin chiefly by the absence of hairs, oil- -and sweat-glands, and the presence on its outer surface of fleshy, -sensitive laminæ and small thread-like projections called villi. - -The pododerm consists of five different parts: the _perioplic band_, -the _coronary band_, the _sensitive laminæ_ (podophyllous tissue), the -_velvety tissue of the sole_, and the _velvety tissue of the fleshy -frog_. - -1. The _perioplic band_ (Fig. 28, _b_) is a narrow ridge, about -one-fifth to one-fourth of an inch wide, lying between the hair-skin -and the coronary band. Somewhat broader at the toe than on the sides, -it broadens out near the bulbs of the heels, over which it passes to -end in the velvety tissue of the fleshy frog. It is separated from -the coronary band by a narrow depression called the _coronary furrow_ -(Moeller). The surface of the perioplic band glistens faintly, and is -thickly studded with numerous thread-like projections called villi, -which are from one-twenty-fourth to one-twelfth of an inch in length. -=The perioplic band secretes the soft horn of the perioplic ring and -the perioplic or varnish-like outer layer of the wall.= - -2. The _coronary band_ (Fig. 27, _c_) lies between the perioplic band -and the sensitive laminæ or fleshy leaves. It presents a prominent -convex band or cushion about three-fourths of an inch wide, which -extends entirely around the foot from one bulb of the heel to the -other. In front it directly covers the anterior extensor tendon of the -toe, and at the sides the lateral surfaces of the os coronæ and the -upper part of the lateral cartilages, while farther back towards the -heels the lateral cartilages project considerably above both coronary -and perioplic bands. The coronary band is more convex (rounded) in -front than on the sides of the foot, and is flattened in the region -of the bulbs of the heels. Its surface is thickly covered with villi, -which are longer and stronger than those of the perioplic band. At the -bulbs of the heels the coronary band turns forward and inward along the -fleshy frog nearly to its summit. This portion of the coronary band -is from one-third to one-half an inch wide, and is called the _bar -portion of the coronary band_. It is also covered with villi, which are -directly continuous with those of the fleshy frog. =The coronary band -secretes the principal part (middle layer) of the horny wall of the -hoof, including the bar portion (bars) of the wall.= - -[Illustration: FIG. 29. - -Plantar surface of a foot deprived of its horny capsule by prolonged -maceration: _a_, laminæ of the bars; _b_, velvety tissue of the sole; -_c_, velvety tissue of the frog; _d_, median cleft of the fleshy -frog, into which the velvety tissue dips; _e_, bulbar portion of the -perioplic band, which passes insensibly into the velvety tissue of the -fleshy frog.] - -3. _The fleshy wall_, or _podophyllous tissue_ (Figs. 27, 28, _d_, -and 29, _a_), is all that portion of the pododerm on which there are -fleshy leaves. This leafy tissue covers the anterior surface of the -os pedis and the lower portion of the external surface of the lateral -cartilages. At the bulbs of the heels it turns inward at a sharp angle -and extends forward and inward, between the bar portion of the coronary -band and the posterior part of the velvety tissue of the sole, nearly -to the middle of the solar surface of the foot, to form the _laminæ -of the bars_ (Fig. 29, _a_). The fleshy wall and fleshy bars are not -covered with villi, but with numerous prominent, parallel, _fleshy -leaves_ placed close together, each of which runs in a straight line -downward and forward from the coronary band to the lower border of the -os pedis. Between the fleshy leaves are deep furrows in which, in a -foot which has not been deprived of its horny capsule, lie the horny or -insensitive leaves of the wall. The fleshy leaves (podophyllous laminæ) -are related to one another somewhat as the leaves of a book; their -posterior borders are attached to the body or basement membrane of the -fleshy wall, while their anterior borders and sides are free. At their -upper ends immediately below the coronary band the leaves are quite -narrow, but they gradually increase in width down to the middle, and -thereafter maintain that breadth to the lower border of the os pedis, -where they terminate in free, fleshy villi, which differ in no respect -from those of the fleshy sole. The number and length of the fleshy -leaves vary; in a medium-sized foot there are about five hundred, while -in a large foot there may be as many as six hundred. On the anterior -surface of the os pedis the leaves are thickest and longest; on the -sides and quarters they gradually decrease in length, while in the bar -region they are the shortest and gradually disappear near the anterior -ends of the bars. The width of the leaves decreases as they become -shorter. Viewed with the naked eye the leaves appear flat and smooth, -but under the microscope one can see on both sides of a fleshy leaf -numerous small, fleshy leaflets parallel to one another and extending -lengthwise with the larger leaf. The large ones are called _principal -leaves_, and the small ones are known as _collateral leaves_, or simply -as _leaflets_. - - =The fleshy leaves (podophyllous tissue) secrete - the horny leaves (keraphyllous tissue) and serve to - bind the horny wall to the pododerm. The strength - of this union is due largely to the dovetailing of - the horny leaves and their leaflets with the fleshy - leaves and their leaflets.= - -4. _The fleshy sole_ or _velvety tissue of the sole_ (Fig. 29, _b_) is -that part of the pododerm which covers all the under surface of the -foot except the plantar cushion, the bar laminæ, and the bar portion of -the coronary band. It is sometimes slate-colored or studded with black -spots, but is usually dark-red. It is thickly set with villi, which are -especially long and strong[1] near its periphery. =The fleshy sole= -covers the solar plexus, or net-work of veins, and =secretes the horny -sole=. - -[1] In order to see the length, thickness, and abundance of the villi -of the pododerm, place the foot deprived of its hoof in a clear glass -jar and cover it with water, renewing the latter until it is no longer -tinged with blood. - -5. _The velvety tissue of the frog_ (Fig. 29, _c_) covers the lower -surface of the plantar cushion, and in the region of the bulbs (_e_) -passes insensibly into the perioplic band. In comparison with the -fleshy sole, it has much finer and shorter villi and contains fewer -blood-vessels. =It secretes the soft, horny frog.= - -[Illustration: FIG. 30. - -Side view of hoof recently removed: _a_, the perioplic horn-band; it -is swollen from prolonged maceration in water; the upper border shows -adhering hairs; the inner surface (perioplic groove) presents many -minute openings; _a′_, the perioplic horn-band broadens in passing over -the bulb or glome of the heel, and is finally lost in the horny frog; -_a″_, section of wall removed. That part of hoof on the right of _b_ is -called the toe; between _b_ and _c_ is the side wall or “mamma,” and -between _c_ and _d_ the “quarter;” _e_, projecting horny frog; _f_, -coronary groove with numerous minute openings; _g_, keraphyllous layer -of the wall (horny leaves).] - -(_c_) =The horn capsule= or =hoof= (Fig. 30) is the entire mass made up -of the horn-cells secreted from the whole surface of the pododerm, and -next to the shoe is the organ with which the horseshoer has most to do. -The horn capsule or hoof is nothing more than a very thick epidermis -that protects the horse’s foot, just as a well-fitting shoe protects -the human foot. The hoof of a sound foot is so firmly united with the -underlying pododerm that only an extraordinary force can separate them. -In its normal condition the hoof exactly fits the soft structures -within it; hence it is evident that local or general contraction of the -hoof must produce pressure on the blood-vessels and nerve-endings of -the pododerm, disturb the circulation of the blood and the nutrition of -the foot, and cause pain. - -[Illustration: FIG. 31. - -Plantar surface of right fore-hoof: _a_, _a_, bearing-surface of the -toe; _a_, _b_, bearing-surface of the side walls or mammæ; _b, c_, -bearing-surface of the quarters; _d_, buttress, or angle formed by wall -and bar; _e_, bar; _f_, sole; _f′_, branches of the sole; _g_, white -line; it passes between the sole and bars and ends at _g′_; _h_, horny -frog; _i_, branches of the frog; _k_, heels, bulbs, or glomes of the -hoof; _l_, median lacuna of horny frog. Between the bars and the horny -frog lie the lateral lacunæ of the frog.] - -The hoof is divided into three principal parts, which are solidly -united in the healthy foot,—namely, the =wall=, the =sole=, and the -=frog=. That part of the hoof which is almost wholly visible when -the foot is on the ground (Fig. 30, _b_, _c_), and which protects -the foot in front and upon the sides, is known as the =wall=. In -position, course, direction, and arrangement of its parts it simulates -the different parts of the pododerm from which it is developed. It -extends from the edge of the hair just above the coronary band to the -ground; backward it gradually decreases in height (length), passes -around the bulbs of the heels, and turns forward and inward (Fig. 32, -_d_, _e_, and 34, _a_, _b_) to form the =bars=, which are finally -lost in the edge of the sole near the summit of the frog. It thus -forms at each heel an angle (Fig. 31, _d_, and 32, _d_) known as a -buttress, which encloses a branch of the horny sole. Externally the -wall is smooth, covered with the varnish-like periople, and presents -indistinct ring-like markings (Fig. 30). Its inner surface, on the -contrary, presents a great number of horn-leaves which are spoken of -collectively as the _keraphyllous tissue_ (Figs. 32, _g_, and 35, -_f_). The upper or =coronary border= of the wall is thin and flexible, -and on its inner aspect is the =coronary groove=, into which fits the -=coronary band= (Fig. 30, _f_). The lower border of the wall, called -the “=bearing-edge=” or _plantar border_ (Fig. 31, _a_), is the one to -which the horseshoe is fastened. By dividing a hoof from before to -behind along its median line, _outer_ and _inner_ halves or _walls_ are -produced, and by dividing the entire lower circumference of the wall -into five equal parts or sections, a =toe=, two =side walls or mammæ=, -and two =quarters= will be exhibited (Figs. 32 and 33). In order to -designate these regions of the hoof still more accurately, they are -spoken of as outer and inner toes, quarters, and heels. - -[Illustration: FIG. 32. - -Wall and bars seen from below: _a_, toe; _b_, side wall, or mamma; _c_, -quarter; _d_, buttress; _e_, bar; _g_, horn-leaves; _h_, space occupied -by the frog.] - -_The direction_ (slant) _and length of the wall_ vary in one and the -same hoof, as well as between fore and hind hoofs. The portion of the -wall of fore-hoofs is the most slanting,—that is, forms the most acute -angle with the surface of the ground,—and is also the longest. Towards -the quarters the wall gradually becomes very nearly vertical; in almost -all hoofs the posterior part of the quarters slants downward and inward -towards the median vertical antero-posterior plane of the foot. At the -same time the wall, in passing back from the toe to the heel, becomes -gradually shorter in such a manner that the heights of the toe, side -walls, and quarters are related to one another about as 3: 2: 1 in -front hoofs and as 4: 3: 2 in hind hoofs. The outer wall is, as a rule, -somewhat more slanting than the inner. Viewing a foot in profile, the -toe and heel should be parallel; that is, the line from the hair to the -ground at the toe should be parallel to the line from the hair to the -ground at the buttress. =All deviations of the wall from a straight -line= (outward or inward bendings) =are to be regarded as faults or -defects=. - -[Illustration: FIG. 33. - -A hoof in profile; _a_, toe (one half); _b_, side wall; _c_, quarter.] - -[Illustration: FIG. 34. - -Vertical section through the middle of a hoof, with horny frog removed, -to show the position of the bar: _a_, _b_, marks the line at which the -wall bends forward and inward towards the median line of the foot to -become the bar. Bar runs forward and passes imperceptibly into the sole -_c_; _a_, _a′_, the light shading shows the part of the bar that was in -contact with the horny frog.] - -The _thickness of the wall_ is also variable. In front hoofs the wall -is thickest at the toe, and becomes gradually thinner towards the -quarters, while in hind hoofs, there is very little difference in -the thickness of the wall of the toe, sides, and quarters. _The more -slanting half of the hoof is always the thicker_; thus, for example, -the outer wall of a base-wide foot is always longer and more oblique -than the inner wall, and is also thicker. According to Mayer, the -thickness of the wall at the toe varies from three- to five-eighths of -an inch, and at the quarters from two to three-eighths of an inch. -These measurements are dependent upon the size and breeding of the -horse. - -[Illustration: FIG. 35. - -The outer wall of the hoof has been removed by cutting vertically -through the middle of the toe, down to the upper surface of the sole, -then horizontally backward into the quarter, and, finally, upward -through the quarter: _a_, perioplic horn-band; _b_, coronary groove; it -turns inward and forward at _c_ to form the upper border of the bar; -_d_, surface of section of the wall at the toe; _d′_, at the quarter; -_e_, surface of horizontal section of the wall near its lower border; -_f_, keraphyllous layer of the wall; at _f′_ it turns forward and -inward to cover the bar; _f″_, horny leaves standing free and passing -insensibly into the white horn of the middle layer or true wall; _g_, -horny sole; _h_, white line; _i_, small horn-spur in middle of toe; -_k_, part of horny frog which is in intimate union with the upper edge -of the bar; _l_, frog-stay of horny frog; it divides the trough-like -depression of the upper surface of the frog into _m_, the two upper -channels of the frog.] - -The horn wall is composed of _three superposed layers_. These from -without to within are: (1) the =periople=, secreted by the perioplic -band. It is very thin, glistening, and varnish-like in appearance, and -covers the entire outer surface of the wall, except where it has been -removed by the rasp, and prevents rapid evaporation of moisture from -the horn. (2) The middle or =protective layer= (Fig. 35, _d_) is the -thickest, strongest, and most important of the three layers; it forms -the principal mass of the wall, and is developed or secreted by the -coronary band, which fits into the coronary groove. There are in the -coronary groove a great number of small, funnel-shaped openings into -which project the horn-producing villi or papillæ of the coronary band. -(3) The =inner layer= or =keraphyllous layer= (Fig. 35, _f_) consists -of prominent, parallel horn-leaves lying side by side over the entire -inner surface of the middle layer of the wall, and continuing beyond -the buttresses to the ends of the bars (Fig. 35, _f′_). This layer of -horn-leaves (keraphyllous layer) has in a general way about the same -shape and arrangement as the layer of fleshy leaves (podophyllous -layer) which secretes it; for the horn-leaves fit in with the fleshy -leaves in such a way that every fleshy leaf is embraced by two -horn-leaves, and every horn-leaf by two fleshy leaves (Fig. 36). The -keraphyllous layer and the horn of the inmost part of the middle or -protective layer are always white, even in pigmented (colored) hoofs. - -[Illustration: FIG. 36. - -Cross-section of keraphyllous and podophyllous laminæ (horny and fleshy -leaves): _a_, inmost part of the solid wall; the horn-tubes approach -very close to the horny leaves; _b_, body of the podophyllous membrane; -_c_, horny portion of a horn-leaf directly continuous with the middle -or principal layer of the wall; _c′_, a rudimentary horn-leaf that does -not reach the body of the podophyllous membrane; _c″_, cross-section -of horny leaves from the sides of which branch many secondary leaves -(leaflets) composed of soft (young) horn-cells. These soft cellular -horn-leaflets dovetail with the podophyllous or fleshy leaflets; -_d_, podophyllous laminæ extending from the body of the podophyllous -membrane; _d′_, podophyllous laminæ which have branched in their course -to the wall, and thus given rise to _c′_, rudimentary horn-leaves; -_d″_, cross-section of podophyllous leaflets extending from the -sides of the podophyllous leaves; each two such leaflets secrete a -keraphyllous leaflet between them; _e_, injected arterial vessels.] - -[Illustration: FIG. 37. - -Vertical section of the horny sole magnified: _a_, funnel-shaped -openings which contain the horn-producing villi of the fleshy sole; -they are of various sizes; _b_, horn-tubes; _c_, intertubular horn.] - -[Illustration: FIG. 38. - -Horny frog, with the posterior portion of the perioplic horn-band and -the periople which covers the quarters removed from the hoof as one -piece by maceration: _a_, trough-shaped depression of upper surface, -which is divided posteriorly into the two upper channels of the frog by -_b_, the frog-stay; _c_, part of the frog that is joined to the bar and -forms the lateral wall of the depression (channels) on upper surface -of frog; _d_, lateral surface of horny frog which, in its upper part, -adheres to the bar, but below, at _d′_, lies free; _e_, point or summit -of the frog; _f_, perioplic horn-band; _f′_, periople of the quarters.] - -The =horn sole= (Fig. 31, _f_, and Fig. 35, _g_) is secreted by the -velvety tissue of the sole. A sole from which the loose flakes of -old horn have been removed is about as thick as the wall. It covers -the under surface of the foot, and presents upon its upper surface a -convexity which exactly fits into the concavity on the under surface -of the os pedis. This upper surface is thickly covered by a multitude -of minute funnel-shaped openings for the reception of the villi of the -velvety tissue of the sole (Fig. 37). The lower surface of the sole -is more or less concave, rough, uneven, and often covered by loose -scales of dead horn. Behind, the sole presents a triangular opening -whose borders lie partly in contact with the horny frog and partly -with the bars. This opening or re-entering angle divides the sole into -a _body_ (Fig. 31, _f_) and two wings or _branches_ (Fig. 31, _f′_). -The outer border of the sole unites through the medium of the =white -line= with the lower part of the inner surface of the wall,—that is, -with the keraphyllous layer of the wall. This =white line= (Figs. 31, -_g_, and 35, _h_), of so much importance to the horseshoer, is formed -by the horn-leaves, and by those short plugs of tubular horn which -are secreted by the villi that are always found at the lower ends of -the fleshy leaves. The white line may be said to exist wherever the -horn-leaves can be discerned upon the plantar surface of the hoof. -It not only passes around the circumference of the sole from heel -to heel, but may be followed forward from the buttresses along the -bars almost to the summit of the frog. The horn of the white line is -soft, unpigmented (white), and possesses so very little resistance -(strength) that it is often found crumbling or even absent in places. -The visible part of the white line is usually of a grayish-black color, -owing to the working in from below of dirt and liquid manure, and to -staining by rust from the nails. =The white line is very important, -since it serves as the point from which we judge of the thickness of -the wall, and because the horseshoe nail should penetrate it.= - -[Illustration: FIG. 39. - -A horny frog cut vertically and lengthwise through its middle: _a_, -upper surface; _b_, frog-stay; _c_, median lacuna of frog, which at -_c′_, is overlaid with superposed layers of horn.] - -[Illustration: FIG. 40. - -Longitudinal section of the wall magnified. The dark stripes parallel -and close together are horn-tubes; the lighter surface between the -tubes represents the intertubular horn. Notice that the horn-tubes are -of various diameters. The space between _a_ and _b_ represents the -small tubes of the outer, darker horn of the principal (middle) layer -of the wall; the space between _b_ and _c_ the lighter, inner horn of -the wall; _c_, _d_, the horn separating the wall proper from the horny -leaves; _d_, _e_, the horny leaves (keraphyllous tissue), on which can -be seen fine, parallel, vertical stripes; in the horn-leaf at _f_, -_f′_, are seen fissures passing obliquely upward and outward towards -the wall.] - -=The Frog= (Figs. 31, _h_, 35, _k_, _l_, 38 and 39), secreted by the -velvety tissue covering the plantar cushion and presenting almost the -same form as the latter, lies as a wedge between the bars and between -the edges of the sole just in front of the bars, with both of which -structures it is intimately united. Its horn is _quite soft_ and _very -elastic_. The median lacuna or cleft of the frog (Fig. 31, _l_) -divides it into two branches (Fig. 31, _i_), which pass backward and -outward into the horny bulbs (Fig. 31, _k_). In front of the median -lacuna the two branches unite to form the _body_ of the frog (Fig. 31, -_h_), which ends in a point, designated the _point_, apex, or summit of -the frog. On the upper surface of the frog, directly over the median -cleft of the lower surface, there is a small projection called the -frog-stay (Figs. 35, _l_, 38 and 39, _b_), which fits into the median -cleft of the plantar cushion. Besides, the upper surface of the frog -shows many minute openings, similar to but smaller than those of the -sole and coronary groove, for the reception of villi. In unshod hoofs -the frog, sole, bars, and bearing-edge of the wall are on a level; that -is, the plantar surface of such hoofs is perfectly flat. - -[Illustration: FIG. 41. - -Cross-section of the wall, magnified: _a_, horn-tubes; _b_, -intertubular horn.] - -The _minute structure of the horn_ can scarcely be considered in detail -in an elementary treatise such as this is. However, a few of the most -important facts are as follows: - -If we carefully examine a transverse section of the horn of the wall -(Fig. 41), sole, or frog, we will see with the naked eye, though much -better with a magnifying glass, many minute points quite close to one -another, and greatly resembling the small openings which we have seen -in the coronary groove of the wall and on the upper surface of the -horny sole and frog. If, now, we examine a longitudinal section of the -wall (Fig. 40) or sole, we will see a number of fine, dark stripes -which are straight, parallel, quite close to one another, of different -widths, and which are separated by bands of lighter horn also of -different widths. A thin section or slice of the wall taken at right -angles to the direction of these dark lines (Fig. 41) shows us that the -minute points that are visible to the naked eye, when held up to the -light or moderately magnified, prove to be small openings (Fig. 41, -_a_). Since these openings, shown in Fig. 41, represent the dark lines -shown in Fig. 40, because an opening is found wherever there is a dark -line, _we must regard all dark lines seen in longitudinal sections of -wall, sole, and frog as hollow cylinders or tubes_, though they are not -always hollow, but are often filled with loosely adjusted, crumbling, -broken down horn-cells. The dark edges of the openings (_a_) consist of -thick layers of horn-cells (tube-walls). The entire structure is called -a =horn-tube=, and the lighter-colored masses of horn (Fig. 41, _b_) -between the tubes are known as =intertubular horn=. - - =With the exception of the horny leaves of the wall - and bars, all the horn of the hoof is composed of - horn-tubes and intertubular horn.= - -The horn-tubes of the wall, sole, and frog always run downward and -forward parallel to the direction of the wall at the toe,—that is, -in a direction parallel with the inclination of the hoof as a whole. -Although the wall, sole, and frog differ from one another considerably -with respect to the size and number of the horn-tubes, the quality -of the intertubular horn, and the thickness and strength of the -horn-cells, these differences are only of subordinate interest or -importance to the horseshoer; but he who desires to learn more of this -matter is referred to the work of Leisering & Hartmann, “Der Fuss des -Pferdes in Rücksicht auf Bau, Verrichtungen und Hufbeschlag,” eighth -edition, Dresden, 1893. This book also treats of the variations in the -quality of hoofs, which is very important for the practical horseshoer -to know. It, furthermore, considers the solidity and strength of the -horn of the different parts of the hoof. - -With respect to solidity, two kinds of horn are distinguished,—namely, -=hard= and =soft horn=. The periople, the white line, and the frog are -soft horn structures; the middle layer of the wall and the sole are -hard or solid horn. The wall, however, is somewhat harder and more -tenacious than the sole, for the latter passes off in more or less -large flakes (exfoliates) or crumbles away on its lower surface, at -least in shod feet, while no such spontaneous shortening occurs in the -wall. - -[Illustration: FIG. 42. - -Vertical section through middle of a forefoot, the skin and pododerm -being in red. (In the figure the direction of both long and short -pasterns, _B_ and _D_, is too nearly vertical—too steep). _A_, -metacarpal bone (cannon); _B_, os suffraginis (long pastern); -_C_, inner sesamoid bone (to render it visible a portion of the -intersesamoid ligament was removed); _D_, os coronæ (short pastern); -_E_, os pedis (foot-bone); _F_, navicular bone; _a_, extensor tendon; -_b_, suspensory ligament of the fetlock; _b′_, superficial inferior -sesamoid ligament; _c_, perforatus tendon or flexor of the os coronæ; -_c′_, ring passing forward from this tendon and encircling the -perforans tendon; _d_, perforans tendon; _e_, capsular ligament of -fetlock-joint; _f_, capsular ligament of coronary joint; _g_, _g′_, -capsular ligament of pedal joint; _h_, synovial sheath of the perforans -tendon; _i_, plantar cushion and fleshy frog; _i′_, bulbs or glomes -of plantar cushion; _i″_, indicates the lowest point reached by the -plantar cushion, which in the figure is hidden below by the frog-stay -of the horny frog; _k_, coronary band (red); _l_, podophyllous tissue -(red); _m_, velvety tissue of the sole (red); _n_, velvety tissue of -fleshy frog (red); _o_, wall; _p_, sole; _q_, frog; _q′_, the inner -half of the frog-stay which reposes in the median lacuna of the fleshy -frog; _s_, hair-skin (red).] - -Soft horn differs from hard horn in that its horn-cells never become -hard and horn-like. It is very elastic, absorbs water quickly, and as -readily dries out and becomes very hard and brittle and easily fissured -and chapped. With respect to _quality_, we distinguish good and bad -horn; the former is fine and tenacious (tough), the latter coarse and -either soft and crumbling or hard and brittle. If not dried out, all -horn is elastic, though soft horn is more elastic than hard. All horn -is a _poor conductor of heat_. - -The relative positions of the various parts of the foot are shown in -Fig. 42. - -Fig. 43 represents the exterior of a well-formed foot. - -[Illustration: FIG. 43. - -Right forefoot viewed from the side: _A_, lower end of the cannon; _B_, -fetlock-joint; _C_, long pastern; _D_, coronet; _E_, hoof; _F_, heel; -_F′_ inner heel; _G_, foot-lock covering the ergot.] - - - - -CHAPTER II. - -THE FOOT IN ITS RELATION TO THE ENTIRE LIMB. - - -[Illustration: FIG. 44. - -Normal (regular) position of fore-limbs.] - -As there are well-formed and badly formed bodies, so there are -well-formed and badly formed limbs and hoofs. The form of the hoof -depends upon the position of the limb. A straight limb of normal -direction possesses, as a rule, a regular hoof, while an oblique or -crooked limb is accompanied by an irregular or oblique hoof. Hence, -it is necessary, before discussing the various forms of the hoof, to -consider briefly the various positions that may be assumed by the -limbs. In this discussion we shall deal with the =living= horse. - - -A. Standing Positions of the Limbs. - -The position of a limb depends upon the varying lengths of its -component bones and the angles at which they meet one another. To judge -the standing position of a fore-limb one must stand _in front_ of the -horse; to judge a hind limb, stand _behind_ the horse; the backward -or forward deviations of both front and hind limbs are judged by -standing at the side. But a horse does not always move as his standing -position would lead one to suspect; standing and moving are different. -Therefore, in order to arrive at a proper judgment, one must observe -the limbs both at rest and in motion. - -(_a_) =The position of a limb viewed from in front= is normal or -straight (Fig. 44) when it stands vertical or perpendicular. A -plumb-line dropped from the point of the shoulder (middle of the -scapulo-humeral articulation) should pass down the middle line of the -limb, dividing it into inner and outer halves of equal width, and -meeting the ground at the middle of the toe. - -[Illustration: FIG. 45. Base-wide] - -[Illustration: FIG. 46. Toe-wide] - -[Illustration: FIG. 47. Toe-narrow (“pigeon-toed”)] - -In the _base-wide standing position_ (Fig. 45) the plumb-line falls to -the inner side of the limb; the limb extends obliquely downward and -outward. To this class belong also the _knee-narrow_ (knock-kneed) -_position_, in which the knees are too close together, while the feet -stand wide apart, and the _toe-wide position_ (splay-footed, Fig. 46) -in which the toes point obliquely forward and outward. In base-wide -positions either the entire limb extends downward and outward or the -foot alone is turned outward. - -The _base-narrow position_ is frequently observed in horses with -very wide breasts. The limbs run downward and inward, a plumb-line -dropped from the point of the shoulder falling to the outer side of -the leg and foot. A special form of the base-narrow position is the -_toe-narrow_ or _pigeon-toed position_ (Fig. 47). In some instances the -legs are straight and perpendicular down to the fetlock, while from -there to the ground the phalanges incline obliquely inward. Another -form is the _knee-wide_ or _bandy-legged position_, in which the knees -are placed too far apart, while the cannons and phalanges incline -downward and inward. - -[Illustration: FIG. 48. Normal (regular) fore-limb in profile.] - -[Illustration: FIG. 49. Normal (regular) hind-limb in profile.] - -[Illustration: FIG. 50. Camped in front.] - -[Illustration: FIG. 51. Calf-kneed.] - -[Illustration: FIG. 52. Acute-angled foot (low-jointed).] - -=The position of a fore-limb viewed in profile= is regular or normal -(Fig. 48) when a perpendicular line dropped from the tuberosity of -the acromian spine (point of union of the upper and middle thirds of -the scapula or shoulder-blade) divides the leg from the elbow to the -fetlock into anterior and posterior halves of equal width, and touches -the ground immediately back of the bulbs of the heel. A perpendicular -line dropped from the point of union of the middle and lower thirds of -the scapula (shoulder-blade) will cut the humerus into halves, and meet -the ground between the toe and the heel.[2] The _foot-axis_ (line of -direction of the three phalanges) and the wall at the toe form an angle -of from forty-five to fifty degrees with the horizontal ground-surface. - -[2] =In station of rest=, the normal position of a fore-leg, as seen -from the side, is somewhat different. The _station of rest_ is the -position that is maintained with the least possible muscular effort. -With gradual muscular relaxation the head and neck sink to a point -somewhat below the line of the back, the top of the shoulder-blade -sinks a little, and the shoulder and elbow joints move forward till -the centre of the elbow joint is directly above the ground-surface of -the hoof. Therefore, when a horse _at rest_ stands firmly on all four -feet, _the fore-leg_ viewed from the side, _has a normal_ (regular) -_direction, when a perpendicular line dropped from the tuberosity of -the acromian spine passes through the middle of the elbow joint and -meets the ground near the middle of the hoof_. - -From this normal or regular standing position, there are _deviations -forward_ as well as _backward_. - -=Forward Deviations.=—“_Standing in front_” or “_camped in front_” -(Fig. 50) is that position in which the entire leg from the body to -the ground is placed too far forward. _Sheep-kneed_ (Fig. 51) is that -position in which the forward deviation is from the knee downward, -the knee being placed too far under the body. “_Weak-jointed_,” -“_low-jointed_,” or “_acute-angled_” (Fig. 52) is that position in -which the limbs are perpendicular and straight down as far as the -fetlock-joint, but the feet are placed too far in front. - -[Illustration: FIG. 53. Standing under.] - -[Illustration: FIG. 54. Knee-sprung.] - -=Backward Deviations.=—_Standing under in front_ (Fig. 53) is that -deviation in which the entire leg from the elbow down is placed back -of the perpendicular line and, therefore, too far under the body. -When this deviation affects only the cannon bone, the horse stands -bent forward at the knees,—a condition known as “_goat-kneed_,” -“_buck-kneed_,” “_over in the knees_,” or, more commonly, -“_knee-sprung_” (Fig. 54). When the backward deviation is only from the -fetlock down, the animal is said to stand _upright_ or “_straight in -the fetlock_.” - -[Illustration: FIG. 55. Normal (regular) position viewed from behind.] - -[Illustration: FIG. 56. Base-wide (cow-hocked).] - -[Illustration: FIG. 57. Base-narrow.] - -[Illustration: FIG. 58. Base-narrow position of hind limbs -(bandy-legged).] - -(_b_) =A hind leg viewed from behind= is said to be _regular_ or -_straight_ (Fig. 55) when a perpendicular line dropped from the -tuberosity of the ischium (see Fig. 1, 9″) divides the entire limb into -inner and outer halves of equal width and touches the ground opposite -the median lacuna of the frog. =Seen from the side=, this line just -touches the point of the hock and, passing down at some distance from -the flexor tendons, meets the ground considerably back of the heels. -A perpendicular line dropped from the hip-joint should pass through -the foot, meeting the ground half-way between the point of the toe and -the heel (Fig. 49). There are base-wide, base-narrow, toe-wide, and -toe-narrow deviations in the hind limbs as in the fore-limbs. - -The hind limbs are _base-wide_ when they, either as a whole or in part, -deviate outward from the normal. The “_cow-hocked_“ position (Fig. 56) -is an example of the base-wide; in this case the points of the hocks -are too close and turn towards each other, while the feet are widely -separated and the toes turned outward. _Base-narrow_ is that position -of the hind legs in which either the entire leg deviates to the inner -side of the perpendicular (Fig. 57), or the leg is about perpendicular -down as far as the hock, but below this joint runs downward and inward -(Fig. 58). In this latter case the hocks may be too far apart, the leg -is bent outward at the hock and the animal is termed “_bandy-legged_,” -“_bow-legged_.” - -=Viewing a hind limb from the side=, it may be observed to deviate -either forward or backward from the normal. Among forward deviations -is the so-called “_sabre-leg_“ or “_sickle-hock_“ (Fig. 59), in which -the hock-joint is too much flexed, the foot placed too far forward -under the body, and the fetlock too slanting. In the position known as -“_camped behind_” (Fig. 60) the leg is behind the body and the pastern -is too upright, too nearly vertical. - -It is possible for each limb of the same horse to assume a different -direction. It more often happens that if the fore-limbs are base-wide -the hind limbs are base-narrow, or _vice_ _versa_. While there are some -other deviations that differ somewhat from those already described, -they are of less importance to the horseshoer. - -[Illustration: FIG. 59. Sabre-legged or sickle-hocked.] - -[Illustration: FIG. 60. Camped behind.] - - -B. Forms of Feet. Viewed from in Front, from Behind, and in Profile. - -In all the various positions of the limbs we find the feet in one of -the following _three forms_, or very closely approaching one of them. -By means of a proper knowledge of these three forms, the judging of the -form, flight of the foot in travelling, and preparation of the hoof -for the shoe, as well as the choice of the length of the shoe, are -regulated, facilitated, and simplified. - -Whether a horse’s feet be observed from _in front_ or from _behind_, -their form corresponds to, or at least resembles, either that of the -=regular= position (Figs. 61 and 62), the =base-wide= or toe-wide -position (Figs. 63 and 64), or the =base-narrow= or toe-narrow position -(Figs. 65 and 66). - -By the _direction_ of the =foot-axis=—that is, an imaginary line -passing through the long axis of the three phalangeal bones (Figs. 61, -65, 67, 68 and 69)—we determine whether or not the hoof and pastern -stand in proper mutual relation. - -[Illustration: FIG. 61.] - -[Illustration: FIG. 62. - -A pair of front feet of regular position viewed from in front and from -behind.] - -In the regular standing position (Figs. 61 and 62) the foot-axis runs -straight downward and forward, in the base-wide position (Figs. 63 and -64) it runs obliquely downward and outward, and in the base-narrow -position (Figs. 65 and 66) it runs obliquely downward and inward. - -[Illustration: FIG. 63.] - -[Illustration: FIG. 64. - -A pair of feet of the base-wide (toe-wide) position seen from in front -and from behind.] - -_Viewing the foot from the side_, we distinguish the =regular= -(normal) position (Fig. 68), and designate all forward deviations as -=acute-angled= (long toe and low heel, Fig. 67), and all deviations -backward from the regular position as =upright= (short toe and high -heel, Fig. 69), steep-toed, or stumpy. - -[Illustration: FIG. 65.] - -[Illustration: FIG. 66. - -A pair of feet of the base-narrow (toe-narrow) position seen from in -front and from behind.] - -When the body-weight is uniformly distributed over all four limbs, the -foot-axis should be _straight_ (Figs. 67 and 69), not “broken” (bent); -=the long pastern, wall at the toe, and foot-axis should have the same -slant=. - -[Illustration: FIG. 67. An acute-angled hoof.] - -[Illustration: FIG. 68. A normal-angled hoof.] - -[Illustration: FIG. 69. An upright (“stumpy”) hoof.] - -[Illustration: FIG. 70. The “bear-foot.”] - -A peculiar form of foot is the so-called _bear-foot_ (Fig. 70), in -which the foot-axis, viewed from the side, is broken strongly forward -at the coronet. The wall at the toe stands much steeper than the long -pastern and is more or less convex; in other words, a low-jointed, -sloping pastern is attached to an upright hoof. Such a foot is -sometimes improperly called a “club-foot.” - - -C. Lines of Flight of Hoofs in Motion. - -If we observe horses moving unrestrained over level ground, we will -notice differences in the carriage of the feet. =Viewed from in front, -or from behind=, in the _regular standing position_ of the limbs the -hoofs are carried forward in a _straight direction_, that is, in a -line parallel with the median line of the body (Fig. 71). The toes -likewise point straight forward; the hoofs alight properly (flat) on -the ground. If the horse stands _base-wide_, the hoof is carried in a -circle; from its position, which is behind and well out from the median -line, the hoof passes first forward and inward until it is close to -the supporting leg, and then outward to the ground (Fig. 72), where -the shock is received principally upon the outer toe. The toes point -either directly forward, as in the regular standing position (Fig. 72), -or forward and outward as in the toe-wide position (Fig. 73). In the -toe-wide position the hoof in its flight may cross the median line. - -Exactly the reverse is true of the horse that stands _base-narrow_; -in this case the hoof is moved in a circle whose convexity is -outward,—that is, the hoof from its position behind, and close to the -median line, is carried forward and outward and then inward to the -ground (Figs. 74 and 75). - -=Viewed from the side=, the line of flight of a hoof is determined -largely by the obliquity (slant) of the foot-axis. - -[Illustration: FIG. 71] - -[Illustration: FIG. 72.] - -[Illustration: FIG. 73.] - -[Illustration: FIG. 74.] - -[Illustration: FIG. 75.] - -1. With a straight foot-axis of _normal slant_ (45°-50°, Fig. 76, _A_), -the hoof follows the arc of a circle and reaches its highest point when -directly above the supporting hoof, _i.e._, when half-way in the stride. - -2. With a straight, but _acute-angled_ foot-axis (less than 45°, Fig. -76, _B_), the hoof rises rapidly, reaches its highest point before -it has completed the first half of the stride, _i.e._, before it has -passed the supporting hoof, and descending gradually in a long curve -alights easily on the ground. - -3. With a straight, but upright foot-axis (55° or more, Fig. 76, _C_), -the hoof rises slowly, reaches its highest point in front of the -supporting hoof, from which point it descends rapidly. The gait is -“choppy,” and in the saddle-horse unpleasant for the rider. _The length -and the height of the stride are greatest in acute-angled feet; least -in upright feet._ Furthermore, length and height of stride are in a -measure dependent on breeding, training, condition of the legs (whether -stiffened by use or disease), length of the hoof and the weight of the -shoe. - -[Illustration: FIG. 76. - -Flight of the hoof as seen from the side: _A_, flight of a regular -hoof; _B_, flight of an acute-angled hoof; _C_, flight of an upright -hoof.] - -Many deviations in the line of flight of hoofs and in the manner in -which they are set to the ground occur; for example, horses heavily -burdened or pulling heavy loads, and, therefore, not having free use -of their limbs, project their limbs irregularly and meet the ground -first with the toe; however, careful observation will detect the -presence of one or the other of these lines of flight of the foot. -Irregular carriage of the feet renders a horse unsuitable for general -purposes only when it is very pronounced, in which case certain -troublesome conditions, such as interfering and disease of joints, are -of frequent occurrence. - - -D. The Influence of Weight in the Shoe or Otherwise Attached to the -Hoof, in Altering the Flight of the Hoof. - -There is nothing mysterious in the effect of weight upon the flight -of the feet. On the contrary, the lines of flight are determined (as -shown in pages 72-74, Figs. 71-76), _first_, by the relation of the -transverse axes of the hinge-joints of the leg and foot to the line of -progression (median line); _second_, by the length and obliquity of the -hoof and pastern; _third_, by the height and length of stride which is -natural to each individual. - -_Weight induces higher action and a longer stride._ Inertia increases -with the weight. A heavy shoe cannot be snatched from the ground as -quickly as a light one, but when moving forward at a given velocity its -greater momentum (momentum = mass (wt) × velocity: m = wt × v) carries -the foot farther forward then does the lighter shoe. Thus, the heavier -shoe, or weight attached to the hoof, lengthens the stride at both -ends. The farther from the centre of rotation of the scapula the weight -is placed, _i.e._, the nearer to the toe it is placed, the greater the -muscular effort required to start it and to stop it. - -_Height of action_, though largely the result of breeding, temperament, -and the exhilaration that accompanies perfect health and entire -absence of muscular fatigue, is to a certain extent influenced by the -_inclination of the pastern and toe to the cannon_. _The acute-angled -foot_, in the folding of the leg during the first half of the stride, -moves through a longer arc of a circle whose centre is the fetlock -joint than does the normal or the upright foot; rises more rapidly -and to a higher point. (See Fig. 76, _B_.) When the momentum of a foot -moving rapidly and abruptly upward is increased by weight the result is -extreme and even exaggerated flexion of all joints of the leg, and by -allowing the hoof to grow long the flexion is still further increased. -In the show ring, harness horses with fair natural action may be made -to “climb” by shoes weighing from thirty to sixty ounces upon hoofs -an inch or more longer than normal. The leverage of a heavy shoe on -a long hoof is excessive, fatiguing and most injurious to ligament, -tendon and muscle. The action, while high, is _labored_, _pounding_ and -_altogether inelegant_. - -[Illustration: FIG. 77. - -A 40 oz. right front shoe (hoof-surface) to increase knee-action in a -high acting harness horse. For show-purposes only.] - -[Illustration: FIG. 78. - -The same seen from the ground-surface in profile: _a_, bevel from inner -border of the web to outer border; _b_, ends of the branches of full -thickness from outer to inner border.] - -In the training of trotters weight is often used _to increase the -length of the stride_, or to cause a _higher folding of a front foot_, -in order to prevent “scalping“ or “speedy-cut.“ As soon as the new gait -becomes a fixed habit the weight should be gradually lessened. _Weight -is carried with less fatigue at a trot_ then at a pace, or at a gallop. -It therefore steadies a trotter that is inclined to pace, or “break” -into a run. The increased momentum of the weighted hoof makes for -rhythm of movement, and increases the difficulty of skipping, dwelling, -or mixing gaits. - -In the _base-wide_ (toe-wide) and _base-narrow_ (toe-narrow) _standing -positions_, the flight of the hoofs, as seen from in front or behind, -is not straight forward, _i.e._, parallel to the line of progression -of the body, but in _arcs of circles_. (See Figs. 72-75, p. 73.) In -these cases, increasing the weight of the hoofs, by increasing the -momentum, must of necessity increase the tendency of the hoofs to move -off at a tangent to the curves which they describe. In other words, -_weight increases the centrifugal force_ of a body moving in a curve. -The _outward swing_ of the hoofs of a base-narrow horse (paddling), and -the _inward swing_ of a base-wide horse (interfering), are made _more -pronounced by adding weight to any part of the hoof_. _The centrifugal -force is greatest_ in base-wide feet when the weight is on the medial, -or inner side of the hoof; in base-narrow feet when it is on the -lateral or outer side. - -A side weight, or side weight shoe is often of service in a cross -firing pacer. This animal usually stands base-narrow (toe-narrow) -behind, and in motion his hind hoofs describe a curve at first forward -and outward and then inward till contact is made with the diagonal hoof -or leg. The added weight (placed on the outer side) by increasing the -centrifugal force carries the hoof just enough farther from the centre -around which the hoof swings to prevent contact. (See cross-firing, p. -138.) - -Finally, it must not be forgotten that _weight is always weight_; that -it _cuts speed_ and _devours endurance_. - - -E. Forms of Hoofs. - -_A front hoof of the regular standing position_ (Fig. 79). The inner -and outer walls differ but little in direction and thickness. The outer -wall is a little thicker and somewhat more slanting than the inner (see -Figs. 61 and 62), and its outer circumference describes a larger arc of -a circle,—that is, is more curved, as can be seen both at its plantar -border and at the coronet. The length of the quarter in relation to the -length or height of the side wall and toe is about as 1: 2: 3. The toe -forms an angle with the ground of forty-five to fifty degrees (see Fig. -68). The direction of the wall at the toe, viewed from the side, should -be parallel with the direction of the long pastern. - -[Illustration: FIG. 79. - -Right fore-hoof of the regular position: _a_, side wall; _b_, quarter; -_c_, beginning of the bar; _d_, buttress; _e_, middle of the bar; -_f_, body of the sole; _f′_, branches of sole; _g_, white line; _g′_, -apparent end of the bar; _h_, body of the frog; _i_, branch of the -frog; _k_, bulbs (glomes) of the heel; _l_, middle cleft of frog; _m_, -lateral cleft of frog.] - -_A hoof of the base-wide position_ (Fig. 80) _is always awry_, because -the outer wall is naturally somewhat longer and decidedly more slanting -then the inner (see Figs. 63 and 64). The plantar border of the outer -wall describes a large arc, whose sharpest curvature is where the side -wall passes into the quarter. The plantar border of the inner wall is -straighter (less curved); the outer half of the ground-surface (sole) -of the hoof is, therefore, wider than the inner. So long as the hoof -is healthy, both branches of the frog are equally developed. The -wryness of the hoof depends upon the direction of the limb; therefore, -a base-wide hoof should be regarded as a _normally wry hoof_, to -distinguish it from hoofs which are wry from disease. - -_A hoof of the toe-wide position_ (Fig. 81) is distinguished from the -preceding by the bending or curvature of the plantar border of the -outer toe and inner quarter being often decidedly less pronounced than -on the inner toe and outer quarter; therefore, two short curves and two -long curves lie opposite each other; in other words, the inner toe and -outer quarter, lying opposite each other, are sharply curved, while the -outer toe and inner quarter, lying opposite each other, are much less -sharply bent or curved. The toes are turned out. The feet are not set -down flat upon the ground, but meet it with the outer toe. - -[Illustration: FIG. 80. Right fore-hoof of the base-wide position.] - -[Illustration: FIG. 81. Right fore-hoof of the toe-wide position.] - -_A hoof of the base-narrow position is normally wry_, but never so -pronounced as a hoof of the base-wide position. The inner wall is -but little, more oblique than the outer, the difference being most -noticeable at the quarters (Figs. 65 and 66). The curve of the plantar -border of the wall is similar to that of a regular hoof, except that -the inner side wall and quarter are a little more sharply curved in a -base-narrow hoof. Occasionally the outer quarter is somewhat drawn in -under the foot. - -This form of hoof is most distinctly marked in animals that stand -toe-narrow or are bandy-legged. - -As to the _forms of the hind hoofs_, what has been said concerning the -influence of position of the limbs upon the shape of the front feet -will apply equally well to them. The hind hoof (Fig. 82) is not round -at the toe, but somewhat pointed or oval. It greatest width is between -the middle and posterior thirds of the sole. It usually has a strongly -concave sole and a somewhat steeper toe than the fore-hoof; viewed from -the side, the angle of the toe with the ground in the regular standing -position is from fifty to fifty-five degrees. - -[Illustration: FIG. 82. - -Right hind hoof of the regular position: _a_, side wall; _b_, beginning -of the quarter; _c_, beginning of the bar; _d_, buttress; _e_, middle -of bar; _f_, body of the sole; _f′_, branch of sole; _g_, white line -of the toe; _g′_, white line of the bar; _h_, body of the frog; _i_, -branch of the frog; _k_, bulbs of heel; _l_, middle cleft of frog; _m_, -lateral cleft of frog.] - -Finally, we also distinguish _wide_ and _narrow_ hoofs; they are -not dependent upon the position of the limbs, but upon the race and -breeding of the animal. - -_The wide hoof_ (Fig. 83) is almost round upon its plantar surface. -Its wall runs quite oblique to the ground. The sole is but moderately -concave, and the frog is strong and well developed. _The narrow hoof_ -(Fig. 84) is rather elliptical, with steep side walls, strongly concaved -sole, and small, undeveloped frog. The horn of the narrow hoof is fine -and tough; of the wide hoof, usually coarse. The wide hoof may readily -become flat. Narrow hoofs are either the result of breeding or premature -shoeing. - -In enumerating the preceding forms of the hoof we have by no means -referred to all the forms in which the hoof may be found; on the -contrary, hoofs vary in shape and quality to such an extent that among -a hundred horses no two hoofs can be found which are exactly alike. In -fact, the same variety exists as in the faces of people, and we know -that we can recall in succession even many more faces without finding -two that are exactly alike. This explains the manifold differences in -horse’s shoes with respect to size, form and other qualities. - -[Illustration: FIG. 83. Wide fore-hoof.] - -[Illustration: FIG. 84. Narrow fore-hoof.] - -Suppose now a hoof is before us; it is first necessary to know whether -or not it is =healthy=. Unfortunately, a perfectly healthy hoof is -not so easy to find as one may think. We recognize a sound hoof by -the following marks: Seen from in front or from the side, the course -of the wall from the coronet to the ground, in the direction of the -horn-tubes, is straight,—that is, bent neither in nor out. A straight -edge, placed upon the wall in the direction of the horn-tubes, touches -at every point. The wall must show neither longitudinal nor transverse -cracks or fissures. If there be rings, their position and course are -important. Rings which pass around the entire circumference of the -wall parallel to the coronet indicate nothing more than disturbances -of nutrition of the hoof; _but the hoof cannot pass for sound_ -when the rings have any other position and direction than the one -mentioned, or if the rings upon any part of the wall are more marked -than elsewhere, even though they may be parallel to the coronary band. -Marked ring-building upon the hoofs of horses which have regular -feeding, grooming, and work indicates a weak hoof. Viewed from the -ground-surface and from behind, the bulbs of the heels should be well -rounded, strongly developed, and not displaced. The concave sole should -show no separation along the white line. The frog should be strong, -well developed, and have symmetrical branches and a broad, shallow, dry -median lacuna. The lateral lacunæ of the frog should be clean and not -too narrow. The bars should pass in a straight direction forward and -inward towards the point of the frog. Any bending outward of the bars -towards the branches of the sole indicates the beginning of a narrowing -of the space occupied by the frog,—that is, contraction of the heels. -The horn of the branches of the sole in the buttresses and in their -proximity should show no red staining. The lateral cartilages should be -elastic. No part of the foot should be weakened at the cost of other -parts. By firm union of all strong parts the strength and vigor of the -hoof is in no sense disturbed. _If one desires to ascertain the exact -form and state of health of the hoof, it must never be inspected and -judged alone, but in connection with the entire limb._ - - -F. Growth of the Hoof and Wear of the Hoof and Shoe. - -All parts of the horn of the hoof grow downward and forward, the -material for this growth being furnished by the remarkably large -quantity of blood which flows to the pododerm. The growth of the hoof -is regulated by the nerves. - -As a rule, the hoof grows =uniformly=,—that is, one section of the wall -grows just as rapidly as another. A visible indication of growth is the -increase in height and width of the hoof from colthood to maturity. - -The _rapidity of growth_ of the wall varies, amounting in a month to -from one-sixth to one-half of an inch. The average monthly growth in -both shod and unshod horses of both sexes is, according to my own -experiments, one-third of an inch. Hind hoofs grow faster than front -hoofs, and unshod faster than shod. The hoofs of stallions grow more -slowly than those of mares and geldings. - -Abundant =exercise=, proper grooming (flexibility and moistness of -the horn), regular dressing of the wall, and =running barefoot= from -time to time =favor growth=; while little or no exercise, dryness, and -excessive length of the hoof hinder growth. - -The time required for the horn to grow from the coronet to the ground -is, therefore, equally variable, and is, moreover, dependent upon the -height (length of toe) of the hoof. At the toe the horn grows down in -from eleven to thirteen months, at the mammæ or sides in from six to -eight months, and at the quarters in from three to five months. The -time required for the renewal of the entire hoof we term the _period of -hoof renewal_. If, for example, we know exactly the rapidity of horn -growth in a given case, we can estimate without difficulty the length -of the “period of hoof renewal,” as well for the entire hoof as for -each individual section of the wall. The duration of many diseases of -the hoof (cracks, clefts, partial bendings of the wall, contractions, -etc.) can be foretold with relative certainty only by knowing the -period of hoof renewal. - -_Irregular growth_ sometimes takes place. The chief cause of this is -usually an improper distribution of the body-weight over the hoof,—that -is, an unbalanced foot. Wry hoofs of faulty positions of the limbs are -often exposed to this evil; a faulty preparation of the hoof (dressing) -for the shoe, as well as neglect of the colt’s hoofs, is in the -majority of cases directly responsible for this condition. - -If in the shortening of the wall a part is from ignorance left too -long, or one-half of the hoof shortened too much in relation to the -other half, the foot will be unbalanced. The horse will then touch the -ground first with the section of wall which has been left too high, -and will continue to do so until this long section has been reduced to -its proper level (length) by the increased wear which will take place -at this point. In unshod hoofs this levelling process takes place -rapidly; such, however, is not the case in shod hoofs, for here the -shoe prevents rapid wear, and, indeed this levelling process is often -rendered impossible through the welding of high steel calks to the -shoe. If this fault in trimming be repeated at the next and subsequent -shoeings, and if the faulty relation of the ground-surface of the hoof -to the direction of the foot-axis remain during several months, the -portion of wall left too high will grow more rapidly, the walls will -lose their natural straight direction and become bent. If, for example, -the outer wall has been left too long during a considerable period of -time, a crooked hoof results (Fig. 85) in which the rings are placed -closer together upon the low (concave) side than upon the high (convex) -side. If for a long time the toe is excessively long, it will become -bent; or if this fault affects excessively high quarters they will -contract either just under the coronary band or will curl forward and -inward at their lower borders. These examples are sufficient to show -both the importance of the manner in which a horse places his foot to -the ground and its influence upon the loading, growth, and form of the -hoof. - -[Illustration: FIG. 85. - -Crooked (right) fore-hoof.] - - -Wear of the Shoe and of the Hoof upon the Shoe. - -The wear of the shoe is caused much less by the weight of the animal’s -body than by the rubbing which takes place between the shoe and the -earth whenever the foot is placed to the ground and lifted. - -The wear of the shoe which occurs when the foot is placed on the ground -is termed “=grounding wear=,” and that which occurs while the foot is -being lifted from the ground is termed “=swinging-off wear=.“ When a -horse travels normally, both kinds of wear are nearly alike, but are -very distinct when the paces are abnormal, especially when there is -faulty direction of the limbs. While in the majority of horses whose -limbs have been stiffened by age and overwork both kinds of wear are -most marked at the toe of the shoe, we see relatively fewer cases of -“grounding wear” at the ends of the branches (as in laminitis); on the -contrary, we =always= notice “swinging-off wear” at the toe of the -shoe. It is worthy of notice that length of stride has much to do with -the wear. We observe that with shortening of the stride both kinds of -wear occur at the toe of the shoe, and this is rapidly worn away, as -is the case with horses which are fretful and prance under the rider, -draw heavy loads, or from any other cause, as disease or infirmity, are -obliged to shorten their steps. With increase of length of stride the -wear of the shoe becomes more uniform. - -[Illustration: FIG. 86. - -A normal-angled foot with straight foot-axis. The shoe shows uniform -wear.] - -[Illustration: FIG. 87. - -An upright foot with foot-axis broken forward by reason of too high -quarters. The shoe shows “grounding“ wear at ends of branches, and -“swinging-off“ wear at toe.] - -[Illustration: FIG. 88. - -A hoof with foot-axis broken backward by reason of surplus horn at the -toe. The shoe shows excessive “grounding“ and “swinging-off” wear at -the toe.] - -The _position_ and _form of the shoe_ have a marked influence upon its -wear; =at the place where the shoe is too far under the hoof= either -as a result of shifting or of having been nailed on crooked, or where -the outer branch has not the necessary width, or does not form a -sufficiently large curve, =the wear will be increased=. - -Also the relative length of side walls, or of toe and heels, influences -rapidity of wear of the shoe. If through ignorance or carelessness one -side wall be left too long, the branch beneath will meet the ground -before other parts of the shoe and will wear faster (see Figs. 87, 88 -and 89). - -_The wear of the hoof upon the shoe_ occurs as a result of the -movements of the quarters. Visible indications of this are the brightly -polished, often sunken places upon the bearing-surface of the ends -of the branches, showing that scouring occurs between the horn and -the iron. Shoes which show brightly polished places in their anterior -halves have been loose. The wear of the quarters upon the shoe is not -always uniform, but is usually greater on the inner than on the outer -quarter, especially in base-wide feet. The degree of this wear of the -hoof may be from nothing to one-fourth of an inch or more from one -shoeing to the next. Finally, we should remember that this usually -invisible scouring away of the hoof gradually causes the nails at the -quarters to become loose, and that this is more clearly marked in the -front than in the hind hoofs. - - -G. Physiological Movements of the Hoof. (Mechanism of the Hoof.) - -These movements comprise all those changes of position within and of -the hoof which are brought about by alternately weighting and relieving -the foot, and which are manifest as changes of form of the hoof. The -following changes in form of the hoof are most marked at the time -that the hoof bears greatest weight,—that is, _simultaneous_ with the -greatest descent of the fetlock-joint. - - 1. A lateral expansion over the entire region of the - quarters, occurring simultaneously at the coronary - and plantar borders. This expansion is small, and in - general varies between one-fiftieth and one-twelfth - of an inch. - - 2. A narrowing of the anterior half of the hoof - measured at the coronary border. - - 3. A decrease in height of the hoof, with a slight - sinking of the heels. - - 4. A flattening (sinking) of the sole, especially in - its branches. - -These changes of form are much more pronounced in the half of the hoof -that bears the greater weight. - -[Illustration: FIG. 89. - -Transverse vertical section through the middle of a right fore shod -hoof of base-wide form, viewed from behind. The outer wall having been -insufficiently lowered has caused increased wear of the underlying -branch of the shoe: _a_, wear of inner branch (beneath the relatively -short wall); _b_, greater wear of outer branch beneath the relatively -long wall; _c_, the horn between the dotted line and the shoe -represents the surplus length of this outer wall.] - -A hoof while supporting the body-weight has a different form, and -the tissues enclosed within it a different position, than when not -bearing weight. Since loading and unloading of the foot are continually -alternating, the relations of internal pressure even in the standing -animal are continuously changing, so that, strictly speaking, the hoof -is never at rest. - -The changes in form take place in the following order: the body-weight -falls from above upon the os coronæ, os pedis, and navicular bone, and -at the moment that the foot is placed upon the ground is transmitted -through the sensitive laminæ and horny laminæ to the wall. At the -instant that the fetlock reaches its lowest point the os pedis bears -the greatest weight. Under the body-weight the latter yields, and with -the navicular bone sinks downward and backward. At the same time the -upper posterior portion of the os coronæ (Fig. 90, _A_) passes backward -and downward between the lateral cartilages (_a_), which project above -the upper border of the wall, and presses the perforans tendon down -upon the plantar cushion. The plantar cushion being compressed from -above, and being unable to expand downward, is correspondingly squeezed -out towards the sides and crowded against the lateral cartilages, and -they, yielding, press against and push before them the wall at the -quarters. The resistance of the earth acts upon the plantar surface -of the hoof, and especially upon the frog, and it, widening, crowds -the bars apart, and in this manner contributes to the expansion of the -quarters, especially at their plantar border (see Fig. 90). The horny -sole under the descent and pressure of the os pedis sinks a little—that -is, the arch of the sole becomes somewhat flattened. All these changes -are much more marked upon _sound unshod_ hoofs, because in them the -resistance of the earth upon the sole and frog is pronounced and -complete. These changes in form are more marked in front feet than in -hind. In defective and diseased hoofs it may happen that at the moment -of greatest weight-bearing, instead of an expansion a contraction may -occur at the plantar border of the quarters. - -[Illustration: FIG. 90. - -Vertical, transverse section of a foot seen from behind: _A_, os -coronæ; _B_, os navicularis; _C_, os pedis; _a_, lateral cartilage; -_b_, anterior portion of fleshy frog; _c_, section of perforans tendon; -_d_, suspensory ligament of the navicular bone; _l_, wall; _m_, sole; -_n_, white line; _o_, frog.] - -Three highly elastic organs there are which play the chief part in -these movements,—namely, the lateral cartilages, the plantar cushion, -and the horny frog. Besides these structures, indeed, all the remaining -parts of the horn capsule, especially its coronary border, possess more -or less elasticity, and contribute to the above-mentioned changes of -form. - -In order to maintain the elastic tissues of the foot in their proper -activity, regular and _abundant exercise_, with protection against -drying out of the hoof, are absolutely necessary, because the movements -of the different structures within the foot and the changes of form -that occur at each step are indispensable in preserving the health of -the hoof. Long-continued rest in the stable, drying out of the hoof, -and shoeing decrease or alter the physiological movements of the foot, -and these lead under certain conditions to foot diseases, with which -the majority of horse owners are entirely unacquainted. - -As an outward, visible indication of the mobility of the quarters upon -the shoe we may point to the conspicuous, brightly polished, and often -sunken spots, or grooves, upon the ends of the branches. They are -produced partly by an in-and-out motion of the walls at the quarters, -and partly by a forward and backward gliding of the quarters upon the -shoe. - -_The benefits of these physiological movements_ within the hoof are -manifold: - - 1. Through them shock is dispersed and the body - protected from the evil consequences of concussion - or shock. - - 2. These movements increase the elasticity of the - entire limb, and in this way contribute much to - a light and elegant gait. - - 3. They maintain a lively circulation of blood in the - vessels of the pododerm, and this insures a rapid - growth of horn. - -Since it is a generally accepted fact that shoeing interferes with -the physiological movements of the hoof, alters them, indeed, almost -suppresses them, and that all these movements are spontaneous and -natural only in sound _unshod_ hoofs, we are justified in regarding -shoeing as a _necessary evil_. However, it is indispensable if we -wish to render horses serviceable upon hard artificial roads. If, in -shoeing, consideration be given to the structure and functions of the -hoof, and particularly to the hoof-surface of the shoe, the ends of the -branches being provided with a smooth, level bearing-surface, which -allows free play to the elastic horn capsule, in so far as this is not -hindered by the nails we need have no fear of subsequent disease of the -hoofs, provided the horse is used with reason and receives proper care. - - - - -PART II. - - - - -CHAPTER III. - -SHOEING HEALTHY HOOFS. - - -A. Examination of a Horse Preliminary to Shoeing. - -An examination should be made while the animal is =at rest=, and -afterwards while =in motion=. The object of the examination is to gain -accurate knowledge of the direction and movements of the limbs, of the -form and character of the feet and hoofs, of the manner in which the -foot reaches and leaves the ground, of the form, length, position, and -wear of the shoe, and distribution of the nail-holes, in order that -at the next and subsequent shoeings all ascertained peculiarities of -hoof-form may be kept in mind and all discovered faults of shoeing -corrected. - -The examination is best conducted in the following order: The horse -should first be led at a walk in a straight line from the observer over -as level a surface as possible, then turned about and brought back, -that the examiner may notice the direction of the limbs and the manner -in which the hoofs are moved and set to the ground. While the animal -is moving away the observer notices particularly the hind limbs, and -as it comes towards him he examines the fore-limbs. Then a few steps -at a trot will not only show whether or not the animal is lame, but -will often remove all doubt in those cases in which, while the animal -was walking, the examiner was unable to make up his mind as to which -was the predominating position of the limb. The problem presented is, -therefore, to determine whether or not the direction of the limbs, -the lines of flight of the hoofs, and the manner in which they are -set down and picked up are regular. If there are deviations from the -normal they will fall either into the base-wide and toe-wide group -or into the base-narrow and toe-narrow group. When clear upon these -points the horse is allowed to stand quietly, and the observer, placing -himself in front, examines the foot more closely, fixes the direction -of the foot-axis clearly in his mind, marks also the form and character -of the hoofs and the position of the coronets, as far as these parts -can be inspected from in front. At the same time each hoof should be -closely inspected to determine whether the slant of both quarters -corresponds to the direction of the long pastern, and whether the -course of the wall from the coronet to the plantar border is straight -or bent in or out (contraction, fulness). Walls curved from above to -below always indicate an unnatural height of some section of the wall -and a displacement of the base of support of the foot. In order to -gain accurate and complete knowledge of the position of the limbs, -the flight of the hoofs, and the manner of setting the foot to the -ground, the horse must frequently be moved back and forth many times, -especially when the standing position is somewhat irregular and the -hoofs are of different shapes. - -At this point begins the examination of the position of the limbs, and -the form of the feet and hoofs, in profile. After casting a glance over -the entire body, so as to gain an idea of the animal’s weight, height, -and length, the attention is turned to the position and direction of -the limbs and hoofs. The eye should particularly note whether the form -of the hoof corresponds to the position of the limb, and, furthermore, -whether the slant of the pastern is the same as that of the wall at the -toe,—that is, whether the foot-axis is straight or broken; also whether -the toes and quarters are parallel, for the toe is sometimes bulging -(convex) or hollowed out (concave) between the coronet and plantar -border, and the quarters are frequently contracted and drawn or shoved -under the foot (weak quarters). If the wall present rings the observer -should note their position with reference to one another and to the -coronet, and also their extent, and, furthermore, should determine -whether or not they cross one another (thrush of the frog). At the same -time he should notice the length of the shoes. - -Next, the feet should be raised and the examiner should notice the -width of the hoof, the arching of the sole, the character of the frog, -the position of the bulbs of the heel, as well as the presence of any -cracks or clefts in the wall. Then the old shoes should be examined as -to their age, form, the distribution and direction of their nail-holes -(“punching”), position, and wear. With respect to the form of the -old shoe, one should observe whether or not it corresponds to the -form of the hoof. The same careful examination should be made of the -number and distribution of the nail-holes. As regards the position -of the shoe, one must first ascertain whether it completely covers -the bearing-surface of the wall, and whether the shoe extends beyond -the wall at any point and has caused interfering or given rise to -irregular wear. Finally, the wear of the shoe should be observed, and -the following points borne in mind: _One-sided wear, uneven setting -down of the feet, and an unnatural course of the wall are often found -together_, especially when uneven wearing of the shoe has existed for -a long time,—that is, during several shoeings. As a rule, in such a -case the more worn branch of the shoe is too near the centre of the -foot, and the opposite branch too far from the centre (too “full”); in -other words, the base of support (shoe) has been shifted too far in the -direction of the less worn branch. Moreover, increased wear of a part -of a shoe is an indication that the section of the wall above it is too -high (too long) (Fig. 89), or that the wall upon the opposite side of -the foot is too low (short). The twisting movement of many hind feet -should, from physiological reasons, not be hindered by shoeing. - - -B. Raising and Holding the Feet of the Horse to be Shod. - -This can always be done without much trouble if the horse has been -accustomed to it from early colthood. Certain rules governing the -manner of taking hold of the feet, and of afterwards manipulating them, -are of value. - -A shoer should =never grasp a foot suddenly=, or with both hands. The -horse should first be prepared for this act. First see that the horse -stands in such a position that he can bear his weight comfortably upon -three legs. This is well worth noticing, and if the horse does not -voluntarily assume such an easy position, move him gently until his -feet are well under his body. - -If the shoer, for example, wishes to raise the left fore foot for -inspection, he stands on the left side facing the animal, speaks -quietly to him, places the palm of the right hand flat upon the -animal’s shoulder, and, at the same time, with the left hand strokes -the limb downward to the cannon and seizes the cannon _from in front_. -With the right hand he now gently presses the horse towards the -opposite side, and the foot becoming loose as the weight is shifted -upon the other leg, he lifts it from the ground. The right hand now -grasps the pastern from the inside followed by the left hand upon the -inside and the right hand on the outside; then, turning partly to the -right, the holder supports the horse’s leg upon his left leg, in which -position he should always stand as quietly and firmly as possible. If, -now, the shoer desires to have both hands free to work upon the hoof, -he grasps the toe with the left hand in such a manner that the toe -rests firmly in the palm while the four fingers are closely applied to -the wall of the toe, takes a half step toward the rear, passes the hoof -behind his left knee into his right hand which has been passed backward -between his knees to receive it, and drawing the hoof forward outward -and upward supports it firmly on his two knees,—the legs just above the -knees being applied tightly against the pastern. The forefoot should -not be raised higher than the knee (carpus), nor the hind foot higher -than the hock, nor either foot be drawn too far backward. The correct -standing position of the shoer or floorman while holding a front foot -is shown in Fig. 91. Shortness of stature (5′-5′.6″) is desirable in a -floorman. - -In lifting the _left hind foot_ the animal should be gently stroked -back as far as the angle of the hip, against which the left hand is -placed for support, while the right hand strokes the limb down to the -middle of the cannon, which it grasps _from behind_. While the left -hand presses the animal’s weight over towards the right side, the right -hand loosens the foot and carries it forward and outward from the body -so that the limb is bent at the hock. The holder then turns his body -towards the right, brings his left leg against the anterior surface of -the fetlock-joint, and carries the foot backward, at which time his -left arm passes over the horse’s croup and above and to the inner side -of the hock. Finally, both hands encompass the long pastern. - -[Illustration: FIG. 91. Proper position for holding a front foot.] - -If the right feet are to be raised, the process is simply reversed. - -In raising the feet no unnecessary pain should be inflicted by -pinching, squeezing, or lifting a limb too high. The wise shoer avoids -all unnecessary clamor and disturbance; quiet, rapid, painless methods -avail much more. In dealing with _young_ horses the feet should not be -kept lifted too long; let them down from time to time. In _old_ and -_stiff_ horses the feet should not be lifted too high, especially in -the beginning of the shoeing. - -[Illustration: FIG. 92. The Martin horse rack (modified).] - -_Vicious_ horses must often be severely handled. Watch the play of the -ears and eyes continually, and immediately punish every exhibition of -temper either by jerking the halter or bridle vigorously, or by loud -commands. If this does not avail, then if soft ground is at hand make -the horse back as rapidly as possible for some time over this soft -surface; it is very disagreeable and tiresome to him. To raise a hind -foot we may knot a strong, broad, soft, plaited band (side-line) into -the tail, loop it about the fetlock of the hind foot, and hold the -end. This often renders valuable service. The holder seizes the band -close to the fetlock, draws the foot forward under the body, and then -holds it as above described. The use of such a band compels the horse -to carry a part of his own weight, and at the same time hinders him -from kicking. Before attempting to place this rope or band about the -fetlock, the front foot on the same side should be raised. - -The various sorts of twitches are objectionable, and their use should -not be allowed unless some painful hoof operation is to be done. The -application of the tourniquet, or “Spanish windlass,” to the hind leg -is equally objectionable. - -Those horses which resist our attempts to shoe them we do not -immediately cast or place in the stocks, but first have a quiet, -trustworthy man hold them by the bridle-reins and attempt by gentle -words and soft caresses to win their attention and confidence. - -_Ticklish_ horses must be taken hold of boldly, for light touches of -the hand are to such animals much more unpleasant than energetic, rough -handling. Many ticklish horses allow their feet to be raised when they -are grasped suddenly without any preparatory movements. - - -C. Removing the Old Shoes. - -If a horse’s hoofs are healthy, all the shoes may be taken off at the -same time, but there are certain diseases of the hoof in which this -should not be done. - -The rule to follow in removing every shoe is to _draw it cautiously_, -not wrench it away with violence. Hoofs which are dirty should first -be cleansed, preferably with a stiff brush. Next, the clinches should -be _carefully_ lifted by means of a rather dull clinch cutter (Fig. -93), _without injuring the horn_ of the wall. In order, now, that the -nails may be removed singly, the shoe must be slightly lifted. This may -be done in one of two ways. The shoer may use a pair of pincers (Fig. -94), with broad bills which will encompass the branch of the shoe and -come well together underneath it. The handles of the pincers are then -moved _in the direction of the branches_ of the shoe. The second method -consists in raising the branches of the shoe by driving the nail-cutter -from behind between the shoe and hoof and using it as a lever or pry to -loosen the shoe. - -[Illustration: FIG. 93. Clinch cutter and punch.] - -[Illustration: FIG. 94. Pincers.] - -Violent and excessive twisting of the hoof and straining of ligaments -may easily occur, but the smith should guard against them by supporting -the hoof with the left hand or with the leg just above the knee, while -loosening the shoe. - - -D. Preparing the Hoof for the Shoe. - -This preparation is usually termed paring, trimming, or dressing. It is -a most important step in the process of shoeing, and its object is to -shorten the hoof, which has grown too long under the projection of the -shoe, and prepare it to receive the new shoe. The instruments needed -for this work are the rasp and the hoof-knife (Fig. 95); upon large and -hard hoofs a pair of sharp nippers (Fig. 96), or a sharp =hewing knife, -with broad handle and perfectly flat, smooth sides=, may be used, since -these instruments will considerably facilitate and hasten the work. - -[Illustration: FIG. 95. German hoof set with detachable hook blades. -(W. M. Kunde, Dresden): _a_, _a_, hoof blades; _b_, pus searcher; _c_, -scalpel.] - -After the shoer has carefully examined the hoofs in the manner -described upon pages 90, 91, and 92, and has fixed in mind the relation -of the height of the hoofs to the size and weight of the body, he -cleanses the hoof and removes all stubs of old nails. At the same time -he should be asking himself _if_, _where_, and _how much_ horn is to be -removed. In all cases all loosely attached fragments of horn are to be -removed, for example, chips of horn produced by repeated bending and -stretching of the lower border of the wall. The sole is then freed from -all flakes of dead horn. The shoer then runs the rasp around the outer -border of the wall and breaks it off to the depth to which he thinks it -should be shortened, and then =cuts the wall down to its union with the -sole, so that at least one-eighth of an inch of the edge of the sole -lies in the same level as the bearing-surface of the wall=. Finally, -the wall, white line, and outer margin of the sole, forming the -“bearing-surface,” must be rasped until they are perfectly horizontal, -except that at the toe of fore-hoofs this bearing-surface may be rasped -slightly upward (rolled toe). - -In dressing the hoof the =branches= of the frog should always be left -prominent enough to project beyond the bearing-surface of the quarters -about the thickness of an ordinary flat shoe. If it be weakened by -paring, it is deprived of its activity, shrinks, and the hoof becomes -narrow to a corresponding degree. The frog should, therefore, be -_trimmed_ only when it is really _too prominent_. However, loose and -diseased particles of horn may be trimmed away when it is affected with -thrush. - -[Illustration: FIG 96. Nippers.] - -The _bars_ should be spared and never =shortened= except when too long. -Their union with the wall at the quarters must in no case be weakened, -and never cut through (opening up the heels). They should be left as -high as the wall at the quarters, or only a little less, while the -branches of the sole should lie about one-eighth of an inch lower. - -The _buttress_ (angle formed by the union of wall and bar) requires -special attention. In healthy unshod hoofs the bars run backward and -outward in a straight line from the anterior third of the frog. In shod -hoofs, however, it happens that the buttresses gradually lengthen, curl -inward, and press upon the branches of the frog, causing the latter to -shrink. In such cases the indication is to remove these prolongations -of horn from the buttresses so as to restore to the bars their normal -direction. - -=The sharp edge of the plantar border of the wall should be broken -away with a rasp until the relative thickness of the wall equals its -absolute thickness.= (Fig. 97). However, in healthy hoofs, that is, -in those whose _walls are straight from the coronet to the ground_, -the outer surface of the wall should =never= _be rasped_. The only -exceptions to this rule are those cases in which there is an outward -bending of the lower edge of the wall, most frequent on the inner side -wall and quarter. - -[Illustration: FIG. 97. Longitudinal (vertical) section of the wall at -the toe: _a c_ is the absolute, and _a b_ the relative thickness of the -wall. With _a_ as the centre, and the line _a c_ as a radius, a circle -is drawn; the corner of horn in front of this circle and indicated by -dotted lines is to be removed with the rasp.] - -With respect to the inclination of the ground-surface of the hoof to -the direction of the foot-axis, as viewed from in front, the following -facts are established: - -In the _regular_ standing position of the limbs (seen from in front) -the plantar surface of a hoof is at right angles to the foot-axis, and -the outer and inner walls are of equal heights. - -In the _base-wide_ position of the limbs the plantar hoof-surface is -more or less inclined to the foot-axis, usually to a very small degree, -and the outer wall is somewhat higher (longer) and more slanting than -the inner. - -In the _base-narrow_ position of the limbs the plantar hoof-surface is -more or less inclined to the direction of the foot-axis, usually quite -considerably, and the inner wall is somewhat higher than the outer. - -The foot is observed from the side in order to determine the proper -relation of the length of the toe to the height of the quarters. - -[Illustration: FIG. 98. An untrimmed hoof with an excess of horn (_a_) -at the toe which breaks the foot-axis backward.] - -[Illustration: FIG. 99. An untrimmed hoof with an excess of horn (_b_) -at the heels, which breaks the foot-axis forward.] - -[Illustration: FIG. 100. Hoof dressed and foot-axis straightened -by removing excess of horn below dotted lines in the two preceding -illustrations.] - -In this also the foot-axis is our guide. If this axis is as it should -be, the wall at the toe and the long pastern will have the =same slant= -(Figs. 67, 68 and 69). If the hoof has become too long under the -protection of the shoe, this will be shown by the foot-axis being no -longer a straight line, but broken backward at the coronet (Fig. 98); -that is, the hoof in comparison with the fetlock will be too slanting. -By shortening the toe more than the quarters this faulty relation will -be corrected (Fig. 100) and the foot restored to its proper slant. If -the quarters are too long (too high) in comparison with the length of -the toe, the foot-axis will be broken forward at the coronet (Fig. 99), -and the hoof will be too upright. By shortening the quarters more than -the toe the foot-axis may be made straight. =The plantar surface of the -hoof is therefore correct (balanced) when the horse places the foot -flat upon the ground in travelling=, and when the lines bounding the -hoof, viewed from in front, from behind, and in profile, correspond to -the direction of the three phalanges (foot-axis). - -Finally, this fact should be emphasized, that in changing from flat -shoes to those with calks, or the reverse, the hoofs must first be -dressed in accordance, so that the foot axes will remain straight, and -the feet be set always flat to the ground when the new shoes are on. -Each hoof, when ready for the new shoe, should be let down and the -horse allowed to stand upon it while it is again carefully examined -and closely compared with the opposite hoof. Only after such close -inspection has proved the dressing to be faultless can the hoof be -considered as properly prepared and ready for the shoe. _The two front -hoofs and the two hind hoofs, when the legs are in the same position, -should not only be of equal size, but also in proper relation to the -size and weight of the body_. - - -E. Preparing the Hoof for going Barefoot. - -This becomes necessary when the nature of the ground and the kind of -service required of the horse render shoeing unnecessary. However, -to go barefoot the hoof must have =plenty of horn=. After removing -the shoes the =frog should be pared down nearly to the level of the -wall=, and the sharp outer edge of the wall well =rounded off= with the -rasp, in some cases as far as the white line, otherwise large pieces -of the wall will readily break away. Hoofs with very slanting walls -must be more strongly rounded off than upright hoofs. Going barefoot -strengthens the hoofs. From time to time the condition of these -shoeless hoofs should be ascertained by inspection, and any growing -fault in shape or direction of the horn immediately corrected. It quite -frequently happens that the sharp edge of the wall must be repeatedly -rounded, especially on very oblique walls (outer half of base-wide -hoofs), and the quarters may require frequent shortening, because they -are not always worn away as fast as the horn at the toe. - - -F. Making Shoes.[3] - -Besides good, tough iron for the shoe, we need an anvil with a round -horn and a small hole at one end, a round-headed turning-hammer, a -round sledge, a stamping hammer, a pritchel of good steel, and, if -a fullered shoe is to be made, a round fuller. Bodily activity and, -above all else, a good eye for measurement are not only desirable, but -necessary. A shoe should be made thoughtfully, but yet quickly enough -to make the most of the heat. - -[3] On a shoe we distinguish an _outer_ and an _inner branch_. The -anterior portion, formed by the union of the two branches, is called -the _toe_. The upper surface, upon which the hoof rests, is called the -_hoof-surface_, and the under surface, which is in contact with the -ground, the _ground-surface_. That portion of the hoof-surface which is -in direct contact with the lower border of the wall, the white line, -and a narrow margin of the sole is termed the _bearing-surface_, and -when necessary “concaving” (seating) extends from this to the inner -border of the shoe. On the ground-surface is seen the “fullering” or -“crease.” - -=The iron= of which horseshoes are made is derived from the natural -iron ore. Iron used for technical purposes is not chemically pure. -Pure iron is rather too soft, and is therefore mixed with different -substances, mostly with “carbon,” the most important ingredient of our -fuel. Of course, the iron contains a very small quantity of carbon (0.5 -to 5 per cent.). When iron contains more than 2.2 per cent. of carbon -it is hard, brittle, and more easily melted, and is known as crude -iron, or raw iron, because it is derived from the raw product,—black -ore. The melted crude iron is called _cast iron_. Iron is ductile when -it contains less than 2.2 per cent. of carbon, and is then called -forge iron, or _wrought iron_. Wrought iron is fusible only at a high -temperature. Only weldable iron containing less than 1.6 per cent. of -carbon is suitable for general use. Of this iron we distinguish two -sorts,—steel and wrought iron. A larger percentage of carbon is found -in steel than in wrought iron. Steel is hard, can be tempered, and may -be called tempered wrought iron. In order to temper or harden steel, -bring it to a cherry-red heat, and then cool it suddenly by dipping it -in cold water or wet sand. The tempered steel can again be softened as -desired by heating and slowly cooling. By heating to a high temperature -in a forge wrought iron will become doughy, and may then be intimately -united (welded) with another piece at the same temperature by pressure -or hammering. This property is called weld-ability; it is of great -importance in making horseshoes. The heating of iron until it reaches -the welding stage is called getting a “heat.” The act of welding -wrought iron with steel is called “steeling.” - -[Illustration: FIG. 101. Fuller.] - -[Illustration: FIG. 102. Hammer-punch.] - -[Illustration: FIG. 103. Pritchel.] - -Regarding =the tools=, the following hints are sufficient: - -The _anvil_ should have a level, smooth, flat steel face. - -Likewise, the round head and flat face of both _turning-hammer_ and -_sledge_ should be smooth. - -On the _fullering-hammer_ (Fig. 101) the left side is flat, the right -side convex, and the cutting edge has slightly rounded corners. - -The _hardy_, _fullering-hammer_, and _cold chisel_ should be flawless -on the edge. - -The _punch_ (Fig. 102), used to make the nail-holes in the shoe, has -a dull point, which should correspond in size with the head of the -horseshoe-nail and have slightly rounded corners. - -The _pritchel_ (Fig. 103) should not taper to a point, but should end -in a rectangular surface whose length is twice its width, in order to -punch iron through the shoe under the blow of the hammer. - - -Making the Shoe. - -To make a flat shoe, take the length of the hoof from the point of -the toe to the buttress and the greatest width of the hoof; these two -measurements, when added together, give the length of the bar for the -shoe. The bar should be of such width and thickness as will require the -least amount of working. For a bar-shoe or a shoe with heel-calks the -bar must be correspondingly longer. - -Should we wish to preserve the exact outline of the plantar border of -the wall, we may advantageously use such a _podometer_ as is shown in -Fig. 104. This consists of a perforated sheet-iron plate one-sixteenth -to one-twelfth of an inch thick. This is laid upon the hoof, and the -outline of the wall marked upon it with chalk. - -If necessary, the hoof may be set on a piece of smooth, stiff wrapping -paper or card-board, and the outline of the wall closely traced with a -lead pencil. - -[Illustration: FIG. 104. Podometer.] - -To make a =front shoe= (Figs. 107 and 108), heat the bar white-hot -just beyond its middle, place the head of the sledge hammer across -one end of the face of the anvil, hold the unheated end of the bar -on the head of the sledge,—the heated end resting on the face of the -anvil, and bend the bar into a half-circle with the round head of the -turning-hammer. (The outer branch of all shoes is made first; in making -pairs the right shoe is made first.) The extreme end of the heated -bar is drawn out to the desired width and thickness with the sledge. -The bent branch is then placed obliquely across the heel of the horn -of the anvil, is turned over toward the right till it rests upon an -edge, and is then bevelled diamond-shaped from the toe to the end of -the branch. [The edge in contact with the horn is the inner edge of -the right branch (outer branch) of the right shoe; the edge beaten -down by the hammer is the outer edge of the outer branch.] The branch -is then flattened on the anvil because in the bending the outer edge -has been stretched and thinned, while the iron of the inner edge has -been crowded together (back-set) and thickened. In flattening, the shoe -should be left a trifle thinner on the inner edge. The branch is again -placed over the horn, and gone over lightly with the flat head of the -turning-hammer and brought to a proper shape. It is now to be concaved -with or without the help of the sledge, or the concaving may be -omitted. The concaving should end about three-fourths of an inch from -the end of the branch. Now turn the branch and fuller it, or fuller -it first and concave afterwards. The fuller should be set in about -one-twelfth of an inch from the edge for small shoes, somewhat more for -large shoes, and led from the end of the branch towards the toe, twice -being necessary to make the fullering of sufficient depth. Next, stamp -the holes, punch them through with the pritchel, run over the surfaces, -go over the outer edge of the shoe upon the horn, and, finally, hammer -the bearing-surface smooth and horizontal. The left branch is made in -the same way, except that it is turned to the left and the fullering -carried from the toe to the heel. =Any ordinary shoe can and should be -completed in the rough in two heats.= One pair of shoes requires from -eight to fifteen minutes. - -The =hind shoe= (Fig. 116) is made in like manner, but the branches are -not bent in a circle but given that form shown in Fig. 106. Concaving -is not necessary; it is sufficient merely to round the inner edge of -the web. - -[Illustration: FIG. 105. The curvature of a branch of a front shoe.] - -[Illustration: FIG. 106. The curvature of a branch of a hind shoe.] - -Since in bending the shoe, and especially the toe of a hind shoe, the -inner edge is crowded together (back-set) and thickened to the same -extent that the outer edge is stretched and thinned, we must remember -to do away with these inequalities of thickness and strain by hammering -the shoe smooth. - - -Peculiarities of the Shoe. - -They are dependent upon the structure, direction, and position of the -leg and hoof, as well as upon the horse’s service and the nature of the -ground. Since the shoe is an artificial base of support, and since a -proper surface of support is of the greatest importance in preserving -the soundness of the feet and legs, careful attention must be given to -this matter. Naturally shoes designed for the various forms of hoofs -must present equally great and equally numerous differences of form, as -well as other peculiarities. - -=General Properties.= 1. =Form.=—A form corresponding to the shape of -the hoof is indispensable in every shoe. Front and hind and right and -left shoes should be sharply defined and easily distinguishable. _Front -shoes_ must, above all else, be circular _round cut the toe_. _Hind -shoes_, on the contrary, should be _round pointed at the toe_, yet not -too much so, but as in Fig. 116. - -2. =Width.=—All shoes should be wider webbed (more covered) at the toe -than at the ends of the branches. The medium width should be about -twice the thickness of the wall. - -[Illustration: FIG. 107. Right front shoe, ground-surface.] - -[Illustration: FIG. 108. Right front shoe, hoof-surface: _a_, -bearing-surface; _b_, concaving, or “seating.”] - -3. =Thickness.=—Each shoe should, in general terms, be so thick that -it need not be renewed under four weeks. Lungwitz found that the -average required thickness is about seven-sixteenths of an inch. Of -course, this thickness must be diminished or increased according to the -rapidity of wear of the shoe. _Shoes without calks should be of uniform -thickness_, unless there are special reasons for making them otherwise. - -4. =Length.=—For draft-horses they should be long enough to reach the -bulbs of the heel, otherwise shorter, though in other respects they may -differ (see “special properties”), but should in all cases completely -cover the bearing-surface of the hoof. - -5. =Surfaces.=—That part of the hoof-surface of the shoe which is in -contact with the hoof (bearing-surface of the shoe, Fig. 109, _a_) -should be horizontal and wide enough to cover the wall, the white line, -and from a twelfth to an eighth of an inch of the outer edge of the -sole. Shoes for large hoofs require a broader bearing-surface than -those for small hoofs. The concaving, or “seating” (Fig. 109, _b_), -should be made deeper or shallower, according to the nature of the -sole. _Shoes for hoofs with strongly arched_ (very concave) _soles, do -not require any concaving_ (hind hoofs, narrow fore-hoofs). _The object -of concaving is to prevent pressure of the shoe upon the horny sole -except at its margin._ - -[Illustration: FIG. 109. Transverse section of a branch of a front -shoe: _a_, bearing-surface; _b_, concaving; _c_, fullering, or -“crease”; _d_, nail-hole.] - -The ground-surface of the shoe should be flat and _perfectly -horizontal_, except at the toe, which may be turned upward (rolled toe, -“rolling motion”). - -6. =Borders.=—The _outer border_ should usually be moderately -_base-narrow_,—that is, the circumference of the ground-surface of the -shoe should be less than the circumference of its hoof-surface; in -other words, the entire outer border of the shoe should be bevelled -under the foot. Shoes made base-narrow are not so easily loosened, and -materially assist in preventing interfering. The _inner border_ should -be moderately rounded. - -[Illustration: FIG. 110. (_a_) correct and (_b_) incorrect fullering.] - -7. =The “Fullering”= (Fig. 109, _c_).—In depth it should be about -two-thirds the thickness of the shoe, of uniform width, and “clean.” A -fullering is not absolutely necessary, but it makes the shoe lighter -in proportion to its size, facilitates a uniform placing of the -nail-holes, renders the ground-surface somewhat rough, and, because it -is rather difficult to make, increases the workman’s skill. - -[Illustration: FIG. 111. Swiss military shoe, hoof-surface.] - -[Illustration: FIG. 112. Swiss military shoe, ground-surface.] - -8. =Nail-Holes= (Fig. 109, _d_).—=The importance of the nail-holes=, -as regards their _character_, _number_, _distribution_, _depth_, and -_direction_, =cannot be over-estimated=, because by the nails which -are driven through them the stability of the shoe upon the hoof should -be maintained without injuring the sensitive structures, splitting the -horny wall, or immoderately interfering with the elasticity of the -foot. Each nail-hole should taper uniformly from the ground to the -hoof-surface (funnel-shaped). For a medium-weight shoe six nail-holes -are sufficient, while for all heavy shoes, especially those with -toe- and heel-calks, eight are indicated; however, it should by no -means be said that every nail-hole should contain a nail. Hind shoes -usually require one more nail-hole than front shoes, yet seldom more -than eight. In front shoes the nail-holes should be placed in the -anterior half of the shoe (Figs. 107 and 108), while in hind shoes -they are to be placed in the anterior two-thirds of the shoe (Fig. -116), and in both cases so distributed that the toe shall be without -nail-holes, except in those shoes in which it may be desirable to -omit the nail-holes in an entire branch (Fig. 153). =The depth of -the nail-holes=—that is, their distance from the outer edge of the -shoe—will depend always upon the thickness of the wall, and =should -equal the absolute= (real) =thickness of the wall= (Fig. 97). It is -evident, therefore, that all nail-holes should not be placed at the -same depth (for thickness of the wall, see p. 53). - -The =direction= in which the nail-holes should pass through the shoe -depends upon the obliquity of the wall. The nail-holes around the toe, -as a rule, should incline somewhat inward, the holes at the sides less -so, while those at the quarters should be punched straight,—that is, -should pass perpendicularly through the shoe. - -Both front and hind shoes for army horses in time of war and manœuvres -should be so punched that one or two nails may be placed in the -posterior half of the shoe (Figs. 111 and 112). - -[Illustration: FIG. 113. Form of clips: _a_, correct; _b_, indifferent; -_c_, faulty.] - -9. =Clips= (Fig. 113) are _half-circular, leaf-like ears_ drawn upward -from the outer edge of the shoe. They should be strong and without flaw -at the base, and somewhat =higher and thicker= upon hind than upon -front shoes. Their height on flat shoes should equal the thickness -of the shoe, while on shoes with leather soles, or with toe- and -heel-calks they should be somewhat higher. - -According to their position we distinguish toe- and side-clips. They -secure the shoe against shifting; therefore, as a rule, every shoe -should have a toe-clip. A side-clip should always be drawn up on that -branch of the shoe which first meets the ground in locomotion. - -=A Shoe with Heel-Calks.=—All shoes with heel-calks designed for -healthy hoofs should be so made and applied that they will disturb the -normal setting down of the foot as little as possible, that the wear of -the shoe will take place uniformly, and slipping be diminished. The toe -of the shoe must, therefore, be left somewhat thicker than the branches -just in front of the heel-calks. Moreover, every front shoe with -heel-calks must be relatively long, and be provided with considerable -rolling motion at the toe; that is, the shoe should be turned up at the -toe, the bending beginning near the inner edge of the web. The three- -or four-cornered, somewhat conical heel-calks with rounded corners -should not be higher than the thickness of the shoe. With reference to -the direction of the ends of the branches, we should see to it that -they do not rise excessively, but that they assume as near as possible -a horizontal direction in passing back to the heels (see Fig. 115). - -[Illustration: FIG. 114. Shoe without calks, with perfectly -level hoof- and ground-surfaces, and with roll at the toe (flat, -rolling motion shoe).] - -[Illustration: FIG. 115. Shoe with heel-calks for a front hoof.] - -=A Shoe with Toe- and Heel-Calks.=—Such a shoe should be of uniform -thickness from end to end, and should have a toe-calk and two -heel-calks that are somewhat stronger and longer than the heel-calks -of a shoe which has no toe-calk. If to a shoe of uniform thickness, on -which the heel-calks are somewhat higher than those already described, -a piece of steel (Fig. 116, _b_) of the height of the heel-calks is -welded at the toe, we have a shoe with toe- and heel-calks. The toe-calk -should never he higher than the heel-calks. There are three principal -kinds of toe-calks,—namely: - -1. _The Sharp Toe-Calk._—A bar of toe-steel of proper width and -thickness for the toe-calk is thrust with the shoe into the fire. When -the end of the bar is cherry-red in color it is withdrawn, laid across -the straight hardy, and cut nearly through at a point a calk-length -from the end. Bar and shoe are then brought to a welding heat, the -calk quickly and securely welded across the toe of the shoe, the bar -wrenched away, the calk gone over again with the hammer, when it is -immediately beaten out to a sharp edge from the anterior face, either -over the far edge of the anvil, or in a foot-vise. The posterior face -of a sharp toe-calk should be perpendicular to the ground-surface of -the shoe. Machine-made toe-calks, sharp, half-sharp and blunt, provided -with a sharp spud at one or both ends, are in general use. Their use -requires two heats, and the sharp calk is blunted in the welding. - -[Illustration: FIG. 116. Right hind shoe with toe- and heel-calks: _a_, -heel-calks; _b_, toe-calk; _c_, greatest width of the base of support -(_i.e._, contact with the ground) of this shoe when _without_ toe- and -heel-calks; _d_, the greatest, and _e_, the least width of the base of -support of this shoe with calks.] - -2. _The Blunt Toe-Calk._—It is a rather long rectangular piece of -toe-steel, straight, or curved to conform to the toe of the shoe. -The shoe-surface and the ground-surface of the calk are of equal -dimensions. It should be welded on in one heat. - -3. _The Half-Sharp Toe-Calk_ (Coffin-Lid Toe-Calk).—It resembles the -blunt calk, except that the surface of the calk that is applied to the -shoe is somewhat broader and longer than the surface that comes in -contact with the ground. It is welded on in one heat. The first and -third kinds are most suitable for winter. - -Since heel-and toe-calks raise the hoof far from the ground and -prevent all pressure upon the frog, they diminish the elasticity of -the hoof and injure it. They are injurious also to the joints, because -they furnish a base of support which is essentially smaller than that -afforded by a flat shoe (Fig. 116). However, they are indispensable for -heavy draft purposes on _slippery_ roads and in winter. Upon all other -roads and in summer they are superfluous, at least upon front hoofs, -especially as they do not wholly prevent slipping. - -=Special Properties.=—The many different forms of hoofs require a great -variety of shoes. Following are the special peculiarities of each of -the chief classes of shoes. - -1. _Shoe for a Regular Hoof._—Outer edge: moderately base-narrow -(bevelled under) all around. Distribution and direction of the -nail-holes: regular. Length: longer than the hoof by the thickness of -the shoe (see Figs. 121 and 122). - -2. _Shoe for an Acute-Angled Hoof._—Outer edge: strongly base-narrow -around the toe, but gradually becoming perpendicular towards the ends -of the branches. Punching: regular, except that the nail-holes at the -toe must incline inward somewhat more than usual. Length: rather longer -than the preceding shoe (see Fig. 123). - -3. _Shoe for an Upright_ (stumpy) _Hoof_.—Outer edge: perpendicular -at the toe; but if the hoof is very steep, then base-wide at the -toe,—_i.e._, bevelled downward and outward. Punching: last nail should -be placed just beyond the middle of the shoe. Direction of the holes: -perpendicular. Length: short; at most, one-eighth of an inch longer -than the hoof. In the case of a “bear-foot” (see Fig. 70) the shoe -should be long. - -4. _Shoe for a Base-Wide Hoof._—Outer edge; the outer branch should be -moderately base-narrow,—_i.e._, bevelled downward and inward, the inner -branch perpendicular. Punching: upon the outer branch the holes should -extend well back, while upon the inner branch they are to be crowded -forward towards the toe (see Fig. 117). Length will depend upon the -obliquity of the hoof as seen in profile (see 1, 2, and 3). - -5. _Shoe for a Base-Narrow Hoof._—Outer edge: the outer branch either -perpendicular or base-wide, the inner branch strongly base-narrow. -Punching: the nail-holes in the outer branch should be crowded towards -the toe and, under certain conditions, punched deeper than the wall is -thick, on account of the greater width of this branch; in the inner -branch the nail-holes are to be distributed back to the quarter and -punched light (see Fig. 118). Length will depend upon the obliquity of -the hoof. The outer branch should be about one-fourth of an inch longer -than the inner. - -[Illustration: FIG. 117. A right front shoe for a base-wide (toe-wide) -hoof. The inner branch should be about one-fourth of an inch longer -than the outer.] - -[Illustration: FIG. 118. A right front shoe for a base-narrow -(toe-narrow) hoof. The outer branch is wider and one-fourth of an inch -longer than the inner.] - -6. _Shoe for a Wide Hoof._—Somewhat wider webbed (more covered) than -usual. Outer edge: bevelled under the foot all around (base-narrow). -Punching: nail-holes carried back into the posterior half of the shoe -(see Fig. 119). Length will depend upon the obliquity of the hoof. - -7. _Shoe for a Narrow Hoof._—Outer edge: moderately bevelled under the -foot at the toe (base-narrow), elsewhere perpendicular. Distribution of -the nail-holes: regular. Direction of the nail-holes: perpendicular and -towards the quarters, inclining somewhat outward. The holes about the -toe incline somewhat inward. Length will depend upon the obliquity of -the hoof. Concaving unnecessary (see Fig. 120). - -[Illustration: FIG. 119. Flat shoe for a round hoof (right front).] - -[Illustration: FIG. 120. A left front shoe for a narrow hoof. The -concaving is unnecessary.] - -The forms of shoes described in paragraphs 2 to 7 differ from that -described in paragraph 1, but are necessary in order to lessen the -injurious consequences of irregular loading (unbalancing) of the feet, -and of unfavorable bases of support of the body-weight. - - -G. Choosing the Shoe. - -The choice of the shoe for a given horse is not at all difficult after -we have carefully considered his weight, the nature of his work, his -standing position, gait, the form of his hoofs, and quality of the -horn, bearing in mind the general and peculiar properties of shoes. -As a rule, we choose a shoe that is longer than the hoof, because the -latter grows and carries the shoe forward with it, and because the -quarters gradually become lowered by rubbing and wearing away upon -the branches of the shoe. The =length= of the shoe is of especial -importance. For horses employed for slow, heavy draft purposes the -shoe supplied with heel-and toe-calks should extend backward far -enough to support the bulbs of the heels. On the contrary, horses used -at a trot or gallop, as coach-and saddle-horses, require shorter shoes -(see Fig. 124). - -The _weight_ of the shoe should be so adjusted to the demands of the -horse’s work, the condition of the legs (whether used up with work -or not), and the nature of the ground that the shoeing will last _at -least a month_. Hard roads and a heavy, clumsy gait require strong, -durable shoes, which, under some conditions, are to be rendered still -more durable by welding in steel. For moderate service upon soft roads -we should use light shoes. Running horses require unusually thin and -narrow shoes of steel (see Figs. 125-128). - - -H. Shaping and Fitting Shoes. General Considerations. - -This is one of the most important parts of horseshoeing. Its object is -to so fashion or shape the shoe which has been chosen for a particular -hoof that its circumference will exactly correspond to the lower -circumference of the previously prepared hoof, and its bearing-surface -will fit air-tight to the bearing-surface of the hoof. At this time all -defects in the surfaces of hoof and shoe and in the nail-holes must be -remedied, the clips drawn up, and the shoe made to fit perfectly. The -bearing-surface of the shoe, especially at the ends of the branches, -must be kept =horizontal=[4] and smooth, and its width regulated by -the width of the bearing-surface of the hoof (see page 99). Perfectly -_uniform heating_ is absolutely indispensable in shaping the shoe, -because an irregularly heated shoe twists or becomes distorted at the -warm places. Every shoe should be straight, and when held before the -eye one branch should exactly cover the other. A flat shoe laid upon -a level surface should touch at all parts of its ground-surface; the -only exception to this is the shoe with a rolled toe (rolling motion), -in which the toe is turned upward. A shoe is termed “_trough-shaped_” -when only the inner edge of the web rests upon the flat surface. It is -faulty, disturbs the stability of the foot, and shifts the weight of -the body too much upon the quarters. - -[4] The horizontal bearing-surface is in accordance with nature, -because the changes of form of the hoof which take place at the plantar -border of the wall, on burdening and unburdening the foot, should not -be interfered with. A horizontal bearing-surface best fulfils this -requirement. - - -[Illustration: FIG. 121. - -Shod fore-hoof viewed in profile to show the “roll” at the toe.] - -To front shoes we give a =rolled toe= (Fig. 121, rolling motion), by -which we mean a more or less pronounced upward turn of the toe of the -shoe. Ordinarily, the toe begins to turn up at the middle of the web, -and should be elevated about one-half the thickness of the iron. The -rolled toe corresponds to the natural wear of front hoofs, facilitates -the “breaking over” of the feet, and insures a uniform wear of the -shoe (see Fig. 86). The shoe is made moderately hot and placed on the -foot with the toe-clip against the wall exactly in front of the point -of the frog. The scorched horn should be repeatedly removed with the -rasp until a perfect-fitting bed has been made upon the bearing-surface -of the hoof. From the bearing-surface of the shoe to the inner border -of the web the iron must be free from the sole around its entire -circumference. The horn sole should not be burnt, because the velvety -tissue of the sole lies immediately above it. In the region of the -nail-holes the outer borders of shoe and wall should correspond. =The -nail-holes must under all conditions cover the white line.= From the -last nail-hale back to the ends of the branches, for hoofs of the -regular standing position of the limbs, the shoe should gradually widen -until it projects at each quarter from a sixteenth to an eighth of -an inch beyond the edge of the wall. The posterior half of the shoe -should, therefore, be somewhat wider than the hoof. The effect of -this will be to prolong the usefulness of the shoes. With respect to -the _width of the branches_, an exception arises in the case of _hind -shoes_, in which the inner branch, with few exceptions, should closely -follow the border of the wall; this will prevent interfering and -tearing off the shoe by the opposite foot. - -[Illustration: FIG. 122. Left fore-hoof of normal position shod.] - -Between the ends of the branches and the frog there should be enough -room, with few exceptions, to pass a foot-pick. - -In order to judge of the width of a shoe which has been fitted to -the hoof, it is of advantage to seize the hoof in the left hand and, -extending it towards the ground, to observe from behind and above the -outer border of the shoe and the surfaces of the wall. - -_Furthermore, the most important rule is that the shoe should always -have the form of the foot, so long as the form of the hoof remains -unaltered. In all hoofs that have already undergone change of form we -must strive to give the shoe that form which the hoof had before it -underwent change._ Such treatment will not only do the hoof no injury, -but, on the contrary, is of advantage to it, as it is well known that -in time the hoof will acquire the form of the shoe. - - -Shaping and Fitting Shoes. Special Considerations. - -(_a_) _A shoe for a hoof of the regular form fits properly_ when the -outer border of the shoe in the region of the nail-holes closely -follows the outer edge of the wall, but from the last nail-hole to -the end of each branch extends beyond the wall from a sixteenth to an -eighth of an inch, the shoe is straight, lies firmly and air-tight -upon the bearing-surface of the hoof, the nail-holes fall exactly upon -the white line, and there is sufficient space between the frog and the -branches of the shoe for the passage of a foot-pick. The branches must -be of equal length. - -While in fitting a shoe to a hoof of regular form we need pay attention -only to the form of the hoof, _it is very different when we come to -shape and fit shoes to hoofs of irregular forms_. _In these cases we -must consider not only the form of the hoof, but the position of the -limbs and the distribution of weight in the hoof_, because =where the -most weight falls the surface of support of the foot must be widened, -and where least weight falls= (=on the opposite side=) =the surface of -support must be narrowed=. In this manner the improper distribution of -weight within the hoof (an unbalanced foot) is regulated,—that is, is -evenly distributed over the surface of support. The manner in which -this is accomplished in the various forms of hoofs is as follows: - -(_b_) _An acute-angled hoof_ requires the shoe described in paragraph -2, page 114. The branches must be long, because more of the weight -falls in the posterior half of the foot, and long branches extend the -surface of support backward, while the surface of support in front is -to be diminished by making the toe of the shoe base-narrow, either -by turning it up or by bevelling it in under the foot. A shoe for an -acute-angled hoof fits when it is otherwise related to the hoof as is -described in paragraph _a_, above. - -(_c_) _An upright or stumpy hoof_ presents exactly reverse conditions -with respect to the distribution of weight within the hoof, and -is treated in an exactly opposite manner. The surface of support -should be increased at the toe and diminished at the quarters. This -is accomplished by a shoe possessing the peculiarities described in -paragraph 3, page 114, whose nail-holes are directed either straight or -slightly outward. - -(_d_) _A base-wide hoof_ requires the surface of support to be widened -upon the inner side of the foot and narrowed upon the outer side, -because the inner half of the foot hears the more weight. A shoe having -the peculiarities described in paragraph 4, page 114, accomplishes this -end. - -(_e_) _The base-narrow hoof_ is just the reverse of the preceding, and -requires a shoe whose peculiarities are described in paragraph 5, page -114. While in the normal standing position of the limbs, viewed from in -front, the ends of the branches of the shoe should be equally distant -from the middle of the median lacuna of the frog, this is not so in -the base-wide and base-narrow positions. In the base-wide position -the outer and in the base-narrow position the inner branch should be -somewhat farther from the median lacuna than the branch of the opposite -side. - -[Illustration: FIG. 123. - -The three principal forms of hoofs shod with flat shoes.] - -(_f_) _The wide hoof_ has too large a surface of support, and, -therefore, the shoe designed for it should possess the peculiarities -enumerated in paragraph 6, page 115. - -(_g_) _The narrow hoof_ has already too narrow a base of support, -and must not be made smaller; therefore, the shoe should not have a -base-narrow but a perpendicular outer border, as described in paragraph -7, page 115. - - -Shoeing Saddlers and Hunters. - -_The shoes for saddlers_ (Park Hacks) should be light, short, and -fitted snug to prevent forging, interfering and pulling of the -shoes. The hoof-surface should cover the wall, white line and at -least one-fourth of an inch of the margin of the sole. An average -width of one inch is desirable. Both front and hind shoes should be -fullered and concaved on the ground-surface (convex iron). =The Front -Shoe=:—_Length_, should not project beyond the buttress more than -one-eighth of an inch. _Width_, an inch at the middle on the branches, -somewhat more at the toe, and less at the ends of the branches. -_Bevelling_, outer border, base-narrow all around. The ends of the -branches, and the heel-calks, in case they are used, are bevelled -strongly downward and forward under the foot. The toe is rolled from -the inner edge of the web, and provided with a strong central clip. Six -nails are sufficient (see Fig. 124). - -[Illustration: FIG. 124. - -A right front shoe with forging calks; suitable for a saddle-horse, or -hunter (convex iron).] - -=The Hind Shoe=:—_Length_, the shoe may project from one-fourth to -three-eighths of an inch behind the buttresses. The toe should be well -rounded and somewhat blunt so that the horn of the toe will project -beyond the shoe an amount equal to one-half the thickness of the -wall. _Width_, somewhat less than the front shoe. The branches are of -equal thickness, and should carry heel-calks whose height equals the -thickness of the shoe. To guard against interfering the inside calk may -be omitted and the inner branch thickened, fitted snug and bevelled -strongly base-narrow. Clips are to be placed at inner and outer toes. -Seven nails are sufficient. - -_The shoes for hunters_ do not differ materially from those suitable -for Park Hacks. The hunter’s shoes are somewhat lighter, and to guard -against injury to the feet by over-reaching and interfering, and -against the shoes being pulled by stiff mire and by treading, the shoes -must represent merely a prolongation of the hoofs, _i.e._, must be no -longer and no wider than the hoofs themselves. =The front shoe= of -narrow, convex iron is rolled at the toe and has a central toe-clip. -Forging heel-calks are advisable. - -=The hind shoe= is set back at the toe, carries inner and outer toe -clips, an outer heel-calk and an inner interfering branch. Seven nails. - - -Shoeing Runners. - -Racing plates are intended solely to prevent excessive wear and -breaking away of the wall, and to insure a secure foothold upon the -ground. The shoes are made as light as possible, but they must not be -so narrow and thin that they will bend or break. They are therefore -made of steel, wide enough to cover the bearing-surface of the wall, -white line, and an eighth of an inch of the sole. The ground-surface -is divided into two sharp edge’s by a deep, clean, fullering continued -entirely around the shoe. heel-calks are of no advantage. Front and -hind shoes carry six nails. The last nails are well back in the -quarters to prevent the spreading or bending of the light shoe. Front -shoes are provided with central toe-clips; hind shoes carry inner and -outer toe-clips and are set slightly under at the toe (see Figs. 125, -126, 127, 128). An _average weight_ running plate for a medium-sized -hoof is _three to four ounces_. - -[Illustration: FIG. 125. A fore running plate, hoof-surface.] - -[Illustration: FIG. 126. A fore running plate, ground-surface.] - -[Illustration: FIG. 127. A hind running plate, hoof-surface.] - -[Illustration: FIG. 128. A hind running plate, ground-surface.] - - -Shoeing Trotters and Pacers. - -The shoes worn while the trotter or pacer is in training are somewhat -heavier than those worn while racing. Training shoes will average 40 -ounces to the set, while trotting and pacing plates weigh from 16 to -28 ounces to the set. Of the six fastest trotters during the last year -(1912) the average weight of the front shoes was 6⅚ ounces, of the -hind shoes 4 ounces. Of the seven swiftest pacers of the same year the -front shoes averaged 5½ ounces, and the hind shoes 3⅝ ounces. In short, -_extreme speed at running, pacing or trotting demands as light a shoe -as can be made, which will at the same time furnish a bearing for wall, -white line and a narrow rim of the sole_. - -In style of shoes there is no marked difference between trotters -and pacers—except in the hind shoes of pacers that cross-fire (see -“cross-firing,” p. 140). Open shoes predominate. Bar-shoes are used, -not to give frog pressure, but to stiffen and prevent spreading of -the shoe, when after a few days’ wear it becomes thin at the toe. The -average trotting and pacing plate is so thin that it would be weakened -by fullering, so most of them are stamped (punched). Six nails are -sufficient. Clips are seldom needed. - -Pacers usually require a low circular grab or “rim” at the toe. This is -set flush with the outer border, is about one-eighth of an inch high -and is brazed on. Trotting plates are usually without toe-calks, though -many are fullered across the toe (corrugated) to furnish a grip upon -the ground. - -On both trotting and pacing shoes the heel-calks should be low and -sharp and should run straight forward so as not to retard the forward -glide of the foot as it is set to earth heel first. The heel-calk -serves chiefly to prevent the lateral twist of the foot as the horse -takes the sharp turns of the track. - -Freak shoes, toe-weights, side-weights, excessive length of hoof or -toe, and other unscientific appliances and methods of shoeing speed -horses are being gradually eliminated, and today the fastest are -dressed and shod in accordance with the principles enunciated in this -book. - - -Fitting Shoes to Heavy Draft-Horses. - -What has been previously said concerning shoeing holds good here; -however, the conditions of shoeing are somewhat different in heavy -horses, and particularly with respect to hoofs which, without being -clearly diseased, have been injured by shoeing. The entire operation -requires more circumspection, because it is more difficult. In many -cases one will find that the width that has been advised for the -outer branch of the shoe at the quarter is not sufficient. Indeed, -if a horse has wry feet, and there is unequal distribution of weight -within the hoof, and we attempt in shoeing it to follow to the letter -the directions given on preceding pages, we would be apt to favor the -perpetuation of the defect. In such cases the slant of the wall at the -quarters is of the greatest practical value to us in estimating the -proper width for the shoe at this point. - -[Illustration: FIG. 129. Left hind shoe with a broad, base-wide outer -branch for draft-horses that stand markedly base-narrow (close behind).] - -When uniform setting down of the hoof and uniform wear of the shoe are -desired, every point in the coronary band in the posterior half of the -foot must receive support by the shoe. This applies particularly to the -outer halves of hoofs that are extremely base-narrow. If, for example, -the coronet of the outer quarter projects beyond the plantar border -of the quarter, the outer branch of the shoe from the last nail-hole -back must be kept so wide (full) that an imaginary perpendicular line -dropped from the coronary band will just touch the outer border of the -shoe. The inner branch, on the contrary, should follow the edge of the -wall as closely as possible. Furthermore, the new shoe should be given -more curve,—that is, made wider and fitted more full where the old shoe -shows greatest wear. _The principal thought should be to set the shoe, -which should always be regarded as the base of support of the hoof, -farther towards the more strongly worn side._ Such a practice renders -superfluous the wide-spread and popular custom of bending outward the -outer quarter and heel-calk of hind shoes. From the manner in which a -horse travels and the wear of the old shoe, we estimate the distance -that the branches of the shoe should be set from the middle line of -the hoof. If in following out this plan the bearing-surface of the -outer quarter of the wall is not completely covered, the quarter will -be pinched and squeezed inward; this should be prevented by a broader -branch punched so deeply that the holes will fall upon the white line -(Fig. 129). - -When the shoer has satisfied himself that the shoe fulfils every -requirement and fits perfectly, it is to be cooled, the holes opened -with an oiled pritchel, and the shoe brightened with a file. In filing, -all sharp edges should be removed. If a shoe is to be filed upon the -outer border, to give it a neater appearance, the filing should be done -_lengthways of the shoe_, and _not crossways_; of course, the shoe must -not be bent by being improperly clamped in the vise. - -It indicates much greater skill in making and fitting shoes when they -look clean and finished with little or no filing. - - In the preceding remarks I have insisted upon a - horizontal bearing-surface for all shoes, with the - single exception of shoes provided with the rolled - toe (rolling motion). As far as I can judge from the - literature of shoeing, and from what I have seen - with my own eyes in many countries, this is the most - wide-spread practice. In Germany, on the other hand, - there is another method, followed in the military - shoeing shops, _which consists in placing the - bearing-surface of the shoe as nearly as possible - at right angles to the slant of the wall_. - According to this method the bearing-surface of - the shoe, depending upon the direction of the wall - (viewed from in front, from behind, and from the - side), should incline more or less, now backward, - now inward, now horizontal, and now outward. Shoes - for wide hoofs are given a bearing-surface which - inclines inward, while for narrow hoofs the shoes - have a horizontal bearing-surface. Shoes for wry - hoofs have a bearing-surface which inclines downward - and inward for the slanting wall, and for the steeper - wall a horizontal bearing-surface, which towards the - end of the branch may incline slightly downward and - outward. Besides, the bearing-surface of the ends of - the branches, viewed from the side, has a backward - and downward inclination. This method is practicable - =only in part=. - - -I. Nailing the Shoe. - -This is that act of horseshoeing by which the shoe is fastened to the -hoof by special nails called hoof-nails or horseshoe-nails, which are -driven through the shoe and horny wall. - -At present there are hand-made and machine-made horseshoe-nails. Both -kinds should be made of the best wrought iron. The nails must be -slender, wedge-shaped, and twice as wide as they are thick. Thickness -and length must be in proper relation to each other. We should never -choose a nail which is longer than is absolutely necessary to hold the -shoe; six to eight sizes are sufficient for all purposes. - -The rough nails (hand-made), before being used, must undergo a special -shaping to prepare them to pass through the wall easily and in the -desired direction. This preparation is called _shaping and bevelling_. -In doing this we should see to it that the nails are made smooth, and -even, but are not hammered harder than is absolutely necessary, because -the lighter one can hammer the nails the better they will be. - -[Illustration: FIG. 130. Hand-made horseshoe-nails, natural size, for -fullered shoes (1, not bevelled).] - -Furthermore, we must give the nail that form which will insure its -passing through the horn _straight_ and _not in a curve_; with this -object in view, the nail is to be slightly curved so that the side -which is turned towards the frog in driving (inside) will be a little -concave, the opposite side convex (Figs. 130, 3, and 131, No. 10), -since it is known that a straight nail always passes through the horn -in a curve, and not only does not long remain tight, but is quite -likely to _press upon and injure the soft tissues_ of the foot. (See -also, Nailing.) - -At the point of the nail the _bevel_ is to be so placed that it will -form a short one-sided wedge with the slanting side directed =from -within to without= (Figs. 130, 3, and 131, _d_). A short bevel is -suitable for nails that are to be driven low, while a long bevel makes -it possible to drive them high. _The bevel should never form a hook; -it must always be straight, should be sharp but not thin, and under no -conditions incomplete_ (defective). - -[Illustration: FIG. 131. Machine-made horseshoe-nails (natural size) -with a low, wide head for a fullered shoe. The last nail is shown from -one border; the others from the inner face: _a_, head; _b_, neck; _c_, -shank; _d_, bevel; _e_, point; _f_, inner face; _g_, outer face.] - -Machine-made nails, smooth, polished, bevelled, and ready for use, are, -for many reasons, to be preferred to hand-made nails, though the latter -are rather tougher (see Fig. 131). - -Before the shoe is nailed on it should be cooled and again carefully -examined by a competent shoer, who should then place it upon the -hoof, where it should be critically observed to see whether it really -fulfils every requirement of a properly-fitting shoe. Afterwards, the -least fault or defect must be remedied, and then the work of _nailing_ -it begins. By nailing, the shoe is firmly and durably fastened to the -hoof, in doing which the horn of the wall is spared so far as possible, -the elasticity of the hoof borne always in mind, and wounding of the -pododerm entirely avoided. =The nails must in all cases penetrate the -white line= and pass through the wall in such a straight direction -that they will appear neither too high nor too low upon its outer -surface. In the first case there is considerable danger of pricking or -close-nailing, and in the latter the nail-holes will tear out easily -when the nails are being clinched. - -[Illustration: FIG. 132. - -Driving hammer.] - -In driving a nail, it should be held in the fingers as long as possible -in the direction in which it is desired that it shall pass through -the horn. A nail should be driven cautiously, with attention to its -_sinking and sound_, and yet with enough force so that at each stroke -it will penetrate from one-fifth to one-fourth of an inch. The power -required at each stroke will depend upon the hardness of the horn and -the size of the nail. Fearless driving and timorous tapping should not -be allowed. - -Nails, which at a depth of five-eighths of an inch are still going -soft, or which bend and give a dull sound, or cause pain, should be -immediately withdrawn. - -According to the size of the horse and his hoofs the nails should be -driven from five-eighths to an inch and five-eighths high, and as -_even_ as possible. As soon as a nail is driven its point should be -=immediately= bent down towards the shoe in order to prevent injuries. -The heads of all the nails should then be gone over with a hammer and -driven down solidly into the nail-holes, the hoof being meanwhile -supported in the left hand. Pincers are then held under the bent nails -and they are more sharply bent by _light_ blows upon the nail-heads. -The points of the nails are now nipped off near the hoof, the horn -which has been thrown out just below the clinches by bending the nails -down is removed with rasp or gouge, and the ends of the nails bent down -still more, but not quite flush with the wall. This operation is called -“clinching.” A clinching-block or a pair of ordinary blacksmith’s -pincers is then placed under the end of the nail, now called a clinch, -and by light blows (in doing this the nail must not bend within the -wall) upon the head the clinch is turned closer to the surface of the -wall; finally, with the front edge of the nail-hammer the clinch is -hammered down flush with the wall. On the inner half of the wall the -clinches should not be felt on stroking the wall with the fingers. The -small amount of horn that projects beyond the shoe around the toe may -be carefully rasped away in the direction in which the wall slants, but -_never higher than the clinches_; finally, the sharp lower edge of the -wall is to be removed by carrying the corner of the rasp around between -the shoe and the horn. - -A clinch is sufficiently long when it equals the width of the nail at -that point. - -It is of advantage to use a shoeing-bock or foot-stool in clinching -the nails on the front hoofs. The hind hoofs may be clinched in the -hands. Then the horse should be led out and again moved in order to -see whether or not the new shoeing has actually accomplished what was -desired. Finally, the entire hoof should be given a thin layer of -hoof-salve. - - -K. Horseshoes More or Less Deficient in the Desirable Qualities -Described on Pages 107-116. - - -Machine Shoes. - -1. _Machine Shoes of Wrought Iron._—They are half-finished and -finished. Though machine shoes with few exceptions show no distinction -between front and hind, or left and right, with correct punching for -these different feet, but usually present one form in different sizes, -yet, unfortunately, they are in high favor with horseshoers, because -they may be used for both summer and winter and for bar-shoes. - -[Illustration: FIG. 133. - -A machine-made (drop-forged) front shoe, ground-surface.] - -[Illustration: FIG. 134. A machine-made toe-weight front shoe for a -harness horse, showing ground-surface. Punching good.] - -For these reasons we cannot approve of machine shoes. - -2. _Finished Cast Shoes._—They are of four kinds,—ordinary cast shoes, -cast shoes with rope buffer, cast shoes with fiber buffer, and cast -shoes fenestrated to hold a rubber buffer. Ordinary cast shoes of -correct form and proper punching designed by Grossbauer, of Vienna, are -sold by Hannes’ Sons, of that city. - -[Illustration: FIG. 135.] - -[Illustration: FIG. 136.] - -[Illustration: FIG. 137. - -Machine-made (drop-forged) multi-calk fore shoe. _A_, ground-surface; -_B_, hoof-surface; _C_, profile.] - -[Illustration: FIG. 138.] - -[Illustration: FIG. 139.] - -[Illustration: FIG. 140. - -Machine-made (drop-forged) multi-calk hind shoe. _A_, ground-surface; -_B_, hoof-surface; _C_, profile.] - -_Rope Shoes._—These shoes have a groove on the ground-surface, in -which rests a tarred rope, which greatly diminishes slipping on smooth -pavement. For this reason alone they are extensively used in the large -cities of Germany. Since the open rope shoe, when half worn out, will -warp, the bar rope shoe is more satisfactory and more extensively used -(Figs. 141-144). - -[Illustration: FIG. 141. Bar rope shoe with bar bent forward.] - -[Illustration: FIG. 142. The same with bar bent backward.] - -[Illustration: FIG. 143. The same with beak-formed bar.] - -[Illustration: FIG. 144. An open rope shoe.] - -Before fitting the shoe the rope must be removed. After the nails are -driven it is laid in the groove and hammered into place. Rope shoes can -seldom be fitted properly to hoofs other than those which are healthy -and of regular shape. - -_Fiber Shoes._—These have a groove on the ground-surface into which -layers of linen fiber belting have been tightly pressed. The fiber -cannot be removed, and therefore the shoes cannot be heated, but -must be fitted cold. The nail-holes are placed between the fiber and -the outer border of the shoe, and are punched too light. The bearing -surface of the shoe is unsupported, so that when the shoe is half worn -out, it warps. There is no distinction between rights and lefts. - -_Rubber shoes_ have all the defects of fiber shoes, and one more. -The hoof-surface is covered with canvas, which under normal and -acute-angled hoofs wears through under the quarters and leads to -loosening of the last nails. - - -L. Rubber Pads. - -The increasing use of asphalt, tarvia and other hard, smooth and -slippery materials for surfacing city streets and country highways has -not only made travelling in flat and even in calked shoes precarious, -but has aggravated all those injuries produced by concussion. - -To prevent slipping and the injurious effects of concussion a great -many shoes have been devised, in which are incorporated such materials -as hemp rope, linen fibre, papier maché, cork, wood, bast, felt and -rubber, but all fail in greater or lesser degree to meet practical -requirements. - -Rubber, though the most expensive of these materials, is the most -resilient and takes the best grip on smooth pavement. A pad of rubber, -wide enough to cover the branches of the frog alone, or the branches of -the frog and the buttresses of the hoof, firmly cemented to a leather -sole, constitutes the modern rubber pad (Figs. 145, 146, 147). - -[Illustration: FIG. 145. A light driving pad, gummed and stitched to a -leather sole; seen from the ground-surface and in profile. Used with a -seven-to ten-ounce short shoe. _a_, stitching; _b_, rubber bar under -buttress and frog; _c_, leather sole.] - -The frog- and buttress-pad used with a short shoe is to be preferred to -the earlier frog pad which takes a full shoe. - -_The advantages of rubber pads are_: - -1. They prevent slipping upon asphalt and other smooth, dry surfaces. - -2. They diminish concussion, and are valuable in the prevention and -treatment of sore heels, dry and moist corns, bruised sole, and -incipient side-bone. - -[Illustration: FIG. 146. Air-cushion pad, seen from ground surface and -in profile. Suitable for light harness horses.] - -[Illustration: FIG. 147. A heavy bar-pad suitable for heavy harness and -draft-horses on pavement. The short shoe may carry a toe-calk of medium -height.] - -3. They give frog pressure, develop the frog and tend to prevent -contraction of the quarters and those lesions which may follow -contraction, as corns, cracks of bars and quarters, laminitis of the -quarters and thrush. - -_A rubber pad should not be used_: - -1. In contraction of one or both quarters, when the frog is too much -shrunken to bear upon the pad. - -2. In lameness from well developed side-bones. - -3. In navicular bursitis (“navicular disease”). - -4. In thrush, or canker of frog or sole. - -Rubber pads, light, medium and heavy, are made in all sizes and are -suitable for all classes of horses, from the light roadster to the -heavy draft type. The short shoe with which they are used reaches -the middle of the quarters. The pad surface (upper surface) of the -ends of the branches should be bevelled to conform to the pad, and to -hold it firmly against the frog and buttresses. The thickness of the -shoe should equal two-thirds the thickness of the pad, so that when -fitted one-third of the thickness of the pad shall project below the -ground-surface of the shoe. The shoe should be provided with a strong -toe-clip. With the heavy, thick pad of a draft-horse a low toe-calk may -be used, but heel-calks should never be put on a short shoe. Pads are -seldom necessary on the hind feet. - - - - -CHAPTER IV. - -SHOEING HORSES THAT FORGE AND INTERFERE. - - -A. Forging. - -Forging is that defect of the horse’s gait by reason of which, at a -trot, he strikes the ends of the branches or the under surface of the -front shoe with the toe of the hind shoe or hoof of the same side. -Forging in a pacer is termed “cross-firing” and consists in striking -the inner quarter, or the under surface of the inner branch of a front -shoe with the toe of the diagonal hind shoe or hoof. - -Forging is unpleasant to hear and dangerous to the horse. It is liable -to wound the heels of the forefeet, damages the toes or the coronet of -the hind hoofs, and often pulls off the front shoes. - -[Illustration: FIG. 148. Right front shoe with concave ground-surface -(“convex iron”) to prevent “forging.”] - -[Illustration: FIG. 149. Right hind shoe with lateral toe-clips to -prevent “clicking” and the various injuries due to forging.] - -_Causes._—1. Faulty conformation; for example, horses that stand -considerably higher at the croup than at the withers; horses with -long legs and short bodies; horses that “stand under” in front and -behind. 2. Using horses on heavy ground, unskilful driving, allowing -a long-necked, heavy-headed horse to carry his head too low; riding -without holding a horse to his work by feeling his mouth and pressing -the knees against his sides. 3. Fatigue frequently leads to forging, -even in horses that are well built and properly shod. It may also occur -in the act of vaulting over an obstacle. 4. Poor shoeing, especially -too long toes upon the front and hind hoofs, and too long front shoes. - -The aim of the shoer should be to facilitate the quick and easy -“breaking over” of the =front foot=, so that it may get away before -it is overtaken by the hind foot. The toe of the front hoof should be -fairly short and rolled; the quarters spared. The front shoe should be -light, rolled at the toe and =no longer and no wider= than the hoof. -The ends of the branches of a flat shoe, and also the heel-calks, in -case they are needed to elevate a heel that is too low, should be -bevelled from the hoof-surface of the shoe downward and forward under -the foot. Such short heel-calks, bevelled to prevent forging, are -called “forging calks.” If the horse continues to forge between the -branches and against the ground-surface of the shoe, concaving this -surface will prove advantageous (convex iron). The form of the front -shoes of horses that forge should represent merely a prolongation of -the hoof. - -The “breaking over” of the =hind foot= should be delayed by sparing -the toe and lowering the quarters, but not sufficiently to break the -foot-axis too far backward. The hind shoe is to be squared at the toe -and the lower edge of the shoe in the region of the toe well rounded; -instead of a toe-clip, two side-clips are to be drawn up and the shoe -so fitted that at least three-fourths of the thickness of the wall of -the toe, with the edge well rounded, will extend forward beyond the -shoe. Should the toe of the hoof be short it may be raised either by a -low toe-calk set one-fourth of an inch back from the edge of the shoe, -or by thinning the shoe from the toe to the ends of the branches. The -branches of a flat hind shoe should extend somewhat farther back of -the buttresses than under normal conditions, to trail upon the ground -just before the hoof alights, and acting as a brake, to bring the hoof -to earth (Fig. 150). - -[Illustration: FIG. 150. Hind shoe with swelled toe to slow the -breaking over. Often efficient when the hoof is too short at the toe: -_a_, long branches to trail and bring the foot to earth; _b_, outer toe -clip; _c_, toe squared and set under to prevent injury to front hoof, -and to deaden the sound of forging.] - -“Cross-firing” is most apt to occur and is most dangerous at extreme -speed. Then, when the inner branch of the hind shoe strikes the inner -heel, quarter or shoe of the diagonal front foot, both feet are in the -air,—the fore foot is approaching the middle of its stride, while the -offending hind foot is in the last third of its flight. The standing -position that favors cross-firing is the base-wide (toe-wide) in front, -and the base-narrow (toe-narrow) behind. With this direction of limbs -the flight of the fore feet is forward and inward during the first -half of their stride, while the flight of the hind feet is forward and -inward during the second half of their stride (see Figs. 72, 73, 75). - -The problem is, therefore, so to pare and shoe a base-wide fore foot -that it will break over nearer the centre of the toe and thus execute -less of an inward swing during the first half of its stride, and to so -pare and shoe a base-narrow hind foot that it will break over nearer -the centre of the toe and thus execute less of an inward swing during -the second half of its stride. Neither a toe-wide nor a toe-narrow -foot can be made to break over the exact centre of the toe, and yet it -is possible by dressing the hoof and by shoeing to shift the breaking -over point nearer to the centre of the toe, and by doing so, to alter -slightly the lines of flight of the feet. - -Dressing and shoeing the front foot: =The hoof= should be relatively -low from the middle of the toe around to and including the _outer_ -buttress. If the inner half of the wall is deficient in length it must -be raised above the outer half by applying a shoe which is thinner in -its outer than in its inner branch. The inner toe should be left long. - -[Illustration: FIG. 151. - -Left hind hoof of a toe-narrow pacer, shod to prevent cross-firing: -_a_, dotted line indicating outer border of the hoof; _b_, long bent -outer branch; _c_, short, thin inner branch; _d_, inner wall extending -beyond the shoe; _f_, line from which inner branch is feather-edged. -The shoe is of even thickness from _b_ to _f_ at inner toe; but from -latter point to _c_ diminishes to a feather edge.] - -[Illustration: FIG. 152. - -Front view of hoof and shoe depicted in Fig. 151: _a_, outer branch -fitted very full and bevelled base-wide; _b_, inner branch diminishing -in thickness from inner toe _c_, to its termination at the inner -quarter. Designed to favor “breaking over” near centre of the toe, and -to widen the gait.] - -=The shoe= should be light, without heel-calks, but may carry a low, -curved grab (“grab,” is a low, straight or curved, toe-or heel-calk on -a racing plate) running from the second inner toe nail to the centre -of the toe. _The inner branch_ is to be fitted flush with the wall -from the centre of the toe back to the quarter, back of which point -it gradually extends beyond the wall, _i.e._, is fitted full; and -terminates well back of the buttress. _This inner branch_ should be -from one-fourth to three-eighths of an inch longer than the outer -branch. _The long inner branch, full at the quarter, is desirable, but -must be covered by a quarter-boot, which a cross-firer should always -wear._ - -_The outer branch_ should be fitted snug and terminate at the buttress. -From the centre of the toe to the end of the branch the ground-surface -should be bevelled from the inner edge of the web to a knife-edge at -the outer border. - -Dressing and shoeing the hind foot: =The hoof= should be relatively -low from the centre of the toe around to and including the _inner_ -buttress. If the outer half of the hoof is deficient in length, it must -be raised above the inner half by applying a shoe with a thin inner -branch. The inner branch may terminate in a knife-edge midway between -toe and heel (Figs. 151 and 152). - -_The inner branch_ is to be fitted snug from the centre of the toe to -its end, and its ground-surface should be bevelled from the inner edge -of the web to a knife-edge at the outer border. - -_The outer branch_ is to be fitted very full from the outside toe to -the end. This branch should extend well behind the buttress, and in -well-marked base-narrow hoofs should be turned outward in order to -support the overhanging coronet of the quarter. The outer border should -be bevelled base-wide, and the nail-holes punched coarse, _i.e._, far -in from the outer border (Figs. 151 and 152). The outer branch may -carry a small heel-calk. - - -B. Interfering. - -A horse “interferes” when a hoof in motion strikes the opposite -supporting leg. Interfering is apt to produce injuries, either of the -coronary band of the inner half of the foot or of the fetlock-joint, or -(in fore-limbs) of the cannon, even as high up as the knee. Lameness -frequently accompanies such injuries. - -_The causes of interfering_ lie either in the _shoeing_ (of the foot -that strikes, as well as of the foot which is struck), in the _position -of the limbs_, or in the _use_ of the animal. Horses that have the -correct standing position do not interfere when they are properly shod; -base-wide horses interfere sometimes; horses base-narrow down to the -fetlock and toe-wide below that point interfere very frequently. Traces -of unequal length, weariness, and shoeing at too long intervals favor -interfering. - -In attempting to lessen or remove interfering, the horse must be most -carefully examined with respect to the position of his limbs, his gait, -and his shoeing, in the manner described on pages 90 to 92. - -[Illustration: FIG. 153. - -A right front shoe with nailless and narrow inner branch for a -base-wide hoof. Suitable for horses that strike anywhere from inner toe -back to the quarter.] - -If the cause is found to be the twisted position of a shoe, too wide -hoofs, raised clinches, etc., nothing need be done further than to -correct the shoeing; but if a faulty position of the limbs is the -cause, we must ascertain the exact part of the hoof that does the -striking, diminish the size of the hoof at that point, regulate the -entire plantar surface of the hoof, make the shoe straight along -the region that strikes,—that is, without curve,—and so fit it to -the foot that one-third of the thickness of the wall will extend -beyond the shoe. Where interfering is so pronounced as to produce -serious injuries, we use a shoe with no nails in the inner branch -(“dropped-crease” shoe) (Figs. 153, 156, 157). - -[Illustration: FIG. 154. - -Left hind shoe with interfering branch (ground-surface), for -base-narrow standing position.] - -[Illustration: FIG. 155. The same (hoof-surface).] - -[Illustration: FIG. 156. - -Left hind interfering shoe without nail-holes in inner branch -(“dropped-crease” shoe): _a_, side-clip.] - -[Illustration: FIG. 157. - -Right hind shoe for toe-cutters. The dotted lines indicate the distance -that the wall projects beyond the shoe: _a_, side-clip.] - -The so-called _interfering shoes_ (Figs. 154 and 155) are worthy -of recommendation only for hoofs of the base-narrow position. The -interfering branch, whose greater thickness raises the inner wall, -which is often too low, is to be so shaped and directed that the hoof -will project somewhat beyond it. _This interfering branch must be -made and shaped in accordance with each individual case._ The holes -in the interfering branch should be punched somewhat finer (nearer -the edge) than usual. Interfering shoes in which the nail-holes, with -the exception of the inner toe nail-hole, are placed in the outer -branch, are called “_dropped-crease interfering shoes_” (Fig. 156). -Such shoes are not recommended for hind hoofs that are decidedly -toe-wide (toe-cutters); in such cases better results will be obtained -by using a shoe, either with or without heel-calks, whose inner branch -is straight and without nails along the striking region, and is fitted -wide (full) at the quarter. The inner branch should be from one-fourth -to three-eighths of an inch longer than the outer. The inner heel-calk -should be higher than the outer, and the end of the outer branch should -be as base-narrow as it can be made (fitted close) (Fig. 157). In order -to prevent shifting of an interfering shoe, a side-clip should be drawn -up on the outer branch (_a_). - -There is no manner of shoeing that will prevent interfering which is -caused by improper harnessing, crooked hitching, or weariness. The -simpler and the _lighter_ the shoes the less will horses interfere. - - - - -CHAPTER V. - -WINTER SHOEING. - - -All shoes whose ground-surface is provided with contrivances to prevent -slipping upon snow and ice are called winter shoes. - -[Illustration: FIG. 158. An ice-nail, frost-nail.] - -These various contrivances are produced by several processes called -“methods of sharpening.” All methods may be gathered into two -groups,—namely, _practical_ sharp-shoeing and _impractical_. Only the -first will be considered. - -The durability of sharpened shoes depends partly upon whether they -are made of steel or iron, and partly upon the nature of the ground -in winter. If the ground is continuously covered with a thick layer -of snow, whatever method of sharpening is followed, the shoes =stay -sharp=; if, however, the winter is open, changeable, with more bare ice -than snow, no method of sharpening, whatever it may be, will last long; -the shoes will =not stay sharp=. - -For these reasons no method of sharpening which fulfils all conditions -satisfactorily has yet been discovered. - -The simplest and at the same time the least durable method of -sharpening is: 1. That by means of =ice-nails= or =frost-nails= (Fig. -158). One or two nails are drawn from each branch of the shoe and -replaced with ice-nails. - -2. =Sharp Toe- and Heel-Calks.=—The outer calk is split and a small -steel wedge welded in. It is then laid upon the edge of the anvil, -indented and sharpened from within to without in such a manner that -the calk shall be thin from the branch to the ground, and the outer -surface shall be in the same vertical plane as the outer edge. If a -calk is narrow from its base to its end, and at the same time without -flaw, it does not need a sharp cutting edge. The inner calk should -never be sharpened except the ground be very slippery. The cutting edge -of this inner calk stands at right angles to the length of the branch, -and its outer corner should then be rounded to prevent its injuring the -opposite foot (Figs. 159, 160). - -[Illustration: FIG. 159.] - -[Illustration: FIG. 160. - -Outer and inner heel-calks sharpened.] - -For horses used for heavy draft purposes a toe-calk is welded to the -shoe and sharpened. For this purpose we use only steel (toe-steel), -which is easily welded to the shoe and remains firm. Toe-calks and -steeled heel-calks are tempered, in order, as much as possible, to -lengthen their period of durability. This method of sharpening is the -oldest and most wide-spread, and is employed on the shoes of all horses -of which we require more than light service. - -[Illustration: FIG. 161. - -Left fore-hoof sharp-shod: _a_, toe-calk bevelled from in front; -_b_, outer heel-calk directed lengthwise with the branch; _c_, inner -heel-calk, half sharp and directed transversely to direction of the -branch.] - -Hoofs are easily damaged or even ruined by frequently repeated -sharpening of the shoes, because every time this is done the shoes must -be removed and replaced. - -3. =Shoeing with Screw Heel-Calks.=—Any ordinary flat shoe not too thin -and narrow at the ends of the branches can be changed to a shoe with -screw heel-calks by punching holes in the ends of the branches and -cutting a thread in them. - -[Illustration: FIG. 162. - -Ground-surface of the end of a branch of shoe, showing (_a_) hole and -counter-sinking for a screw-calk (one-half natural size).] - -The screw heel-calk holes are made either by punching or boring. The -punching is done by means of an almost cylindrical hammer-punch, -afterwards finishing the holes by driving through them a round punch -which tapers from the middle towards both ends. On the ground-surface -of the shoe the hole is moderately counter-sunk (Fig. 162, _a_), so -that after the thread has been cut and the calk screwed into place the -shoulder of the latter will rest on the counter-sinking. - -At present nearly all screw-calks are made by machinery, either of iron -or toe-steel. The former is too soft and therefore not sufficiently -durable; the latter, however, is quite durable when the calk is -properly hardened (tempered) by heating to a cherry-red, sticking -the head of the calk as far as the tap into a bed of moist sand, and -allowing it to slowly cool. - -The chief requirements of a good screw-calk are, further, a =clean, -deep=, but not too coarse =thread=, and but _one size of thread and tap -for all calks_, so that every calk will fit in every shoe. A calk whose -tap measures one half-inch (12.7 millimetres) (Whitworth) in diameter -is sufficient for the heaviest shoes. The tap which is used to cut -the thread in the holes for the screw-calks must be about ¹/₁₂₅ of an -inch thicker than the head of the calk. In the German army the calks -have a tap fifteen thirty-seconds of an inch in diameter. The coachman -should be given four calks (sharp and blunt) for each shoe, and a -small screw-calk key for placing and removing them. Screw toe-calks -are also used, yet they require special security to prevent their -becoming loose. Experimentation with the screw toe-calks, though not -yet entirely satisfactory, cannot be said to have ended. - -The advantages of shoes provided with good screw heel-calks are so -manifold that they deserve marked preference over shoes sharpened -by the ordinary methods. The common objections urged against -screw-calks,—namely, that they loosen and are lost, or break off, are -not worthy of serious consideration, since these evils are merely the -result of unskilful workmanship and poor material. _Shoes with screw -heel-calks are the best shoes for winter, especially for horses that -have to work hard and continuously._ - -[Illustration: FIG. 163. Sharp screw-calks with Whitworth thread -(half-inch, natural size).] - -[Illustration: FIG. 164. Whitworth tap (half-inch, half natural size).] - -Balling with snow is prevented by using shoes narrow in the web and -concave upon the ground-surface (convex iron), and thoroughly oiling -the sole and frog. Sole-pads of felt, leather, or straw serve the -same purpose. Balling with snow is _best_ prevented by a rubber -sole-and-frog pad, or by a “stopping” of a patent hoof cement known in -Germany as “huflederkitt.” - -4. =Shoeing with Peg-Calks.=—The calks are merely stuck into the -calk-holes, hence their name. Round and square peg-calks are used, but -the former are better than the latter. - -The inventor of round peg-calks is Judson, an American. The shoes -differ in no respect from the ordinary flat shoes. It is necessary that -the tap of the calk have a moderately conical form, and exactly fit -into the calk-hole of the shoe. The taper of the calk-tap is correct -if for every ten thirty-seconds of an inch in length it increases or -diminishes one-thirty-second of an inch in diameter (equal to one inch -in every ten inches of length). - -[Illustration: FIG. 165. Sharp peg-calk (cog): _a_, the tap; _b_, the -head.] - -[Illustration: FIG. 166. Blunt peg-calk: _a_, the tap; _b_, the head.] - -[Illustration: FIG. 167. Lower part of the reamer.] - -Although the calk-holes may be punched in a hot shoe, yet boring and -reaming them is much better, because by this method a more perfect fit -can be secured. For this purpose we require a drill (a spiral drill is -the best) whose diameter is exactly the same as that of the small end -of the calk-tap (Figs. 165, _c_, and 166, _c_). After the shoe has been -fitted to the hoof, the provisional holes are drilled and afterwards -reamed out from the ground-surface of the shoe with the reamer shown in -Fig. 167. Since the tap of the reamer corresponds exactly in size to -the tap of the calk, it is evident that the latter must exactly fit and -be tight. The wire edge that is raised around the hole is removed with -a file, and the edge then smoothed by introducing the reamer a second -time. The calks are made of rolled round steel, which has the thickness -of the tap-end of the calk. For this purpose we require a calk-mould or -matrix, in which one or more holes have been finished with a reamer. -A piece of rod steel is heated at the end for a distance nearly twice -the length of the calk, is swaged, thrust into the matrix, then broken -off, and back-set. This will give a blunt peg-calk. If a sharp calk is -desired, the upper part of the head of the calk is sharpened in the -ordinary manner, although this is accomplished most easily by using a -pair of tongs with short jaws that are hollowed upon the inside for -seizing the tap of the calk. - -Before the shoes are nailed on, the normal punch should be oiled and -driven into the calk-holes, and the calks passed into the holes to see -that they fit perfectly. - -The calks are driven into place =after= the shoes are nailed to the -hoofs. A light blow is sufficient to fasten a calk, yet a necessary -precaution is first to remove every trace of oil from the calks and -calk-holes. The first calk driven into place must be held with the hand -while the second is being driven, otherwise it will either spring from -the calk-hole or be loosened so that it will soon afterwards be lost. - -To remove such a calk we strike its head from different sides with a -hammer, stone, or other hard object until it becomes loose, when a -rather hard blow upon the shoe causes it to spring out. Calks which -have worn down are seized by a pair of sharp nippers and loosened by -blows upon the shoe. Since a calk which is firm soon rusts and is then -very difficult to remove, it is recommended that all calks be removed -every night. - -The =advantages= of peg-calks over screw-calks are: 1. They do not -break off. 2. They are easier to make and simpler to use. 3. They are -=cheaper=. - -=Disadvantages.=—1. Peg-calks are sometimes lost, even when properly -made and most carefully introduced. This evil happens much less -frequently when the calks are put in by the maker (horseshoer) than -when they are stuck in by the coachman, attendant, rider, or other -person. When calks are lost on the way from the shop, it is usually due -to some fault in the calk-holes or in the calks, although when the feet -are balled with snow the calks are easily lost, because they do not -then touch the ground. - -2. The removal of the calks often involves many difficulties, since -they are apt to rust into place if not removed daily, and when worn -down so far that they cannot be grasped with the pincers are almost -impossible to remove. By hammering upon the calks and shoe many horses -are rendered not only restive, but sensitive in the feet. - -3. If horses are used without the calks, a wire edge forms around the -hole on the bottom of the shoe, which interferes with the placing of -the calk and lessens its security. - -The =hollow peg-calk= (Fig. 168), made by Branscheid & Philippi, of -Remscheid, has considerable merit. It holds exceedingly well, and is -very durable. It is furnished in three sizes,—Nos. 12, 13, and 14,—of -twenty-seven, thirty-one, and thirty-four millimetres length, and -twelve, thirteen, and fourteen millimetres diameter at the end of the -tap. - -A punch is furnished which, when driven up to its head in the holes of -the heated shoe, insures a proper width and shape of the hole and an -accurately fitting calk. - -[Illustration: FIG. 168. Hollow-spring peg-calk, No. 12.] - -[Illustration: FIG. 169. Peg-puller.] - -The calks may be removed by an extractor (Fig. 169) having at one end -a thread which is screwed into a corresponding thread on the inside -of the hollow calk, when by a few hammer blows on the shoe the calk -loosens. To prevent the calk becoming choked with dirt, a piece of cork -is thrust into the hollow. It may be easily removed by means of the -corkscrew at the other end of the extractor. - -5. =Shoeing with Peg Toe-Calks.=—These are an invention of considerable -worth, especially for heavy draft in hilly country. They render better -service on hind than on front shoes. - -Peg toe-calks with a single tap are simpler and preferable to those -with two taps. Every known contrivance to prevent the occasional loss -of the peg toe-calk is impractical. - -The shoe for a peg toe-calk should be of good tough material and -without a flaw. The toe of the shoe should be about one-twelfth to -one-tenth of an inch thicker than the branches. - -The hole for the peg toe-calk, whatsoever its shape may be, must be -smooth and uniform, with clean, true corners. Semi-circular holes -should present the convex side towards the toe. - -Before punching, draw up the toe-clip. A punch-plate with a good-sized -hole, and a tap which will fit into the square hole in the anvil will -facilitate the work. The punch-plate when in position should be flush -with the front edge of the anvil. Place the toe of the shoe, hoof -surface upward, over the hole of the punch-plate, and drive a hole with -a punch-hammer which is perceptibly thinner than the model punch. Now -turn the shoe over, punch back from the ground-surface, and then file -away the wire edge which the punch has raised on the ground-surface. -Next, take a hand-punch, the end of which should just enter the hole, -punch through from the ground-surface, and correct any bulging by -dressing lightly over the horn of the anvil. Finally, use the model -punch to give the hole the exact size and smoothness. - -Should the hole in the toe of the shoe enlarge in time, as sometimes -occurs, then back-set when necessary on removing the shoe. Backsetting -is easiest with the half-round hole, because the curved side, being -turned forward, runs approximately parallel to the outer border of the -toe of the shoe. - -[Illustration: FIG. 170. Cross-section of different forms of peg -toe-calk taps.] - -A good serviceable peg toe-calk must possess the following -characteristics: - - 1. The tap must be of such shape as not to turn; - therefore, not round. - - 2. The tap must be cone-shaped, and diminish in - diameter about one-thirty-second of an inch for each - one-fourth of an inch of its length from base to - apex. If the tap has less taper it will enlarge the - hole in the shoe till the head of the calk comes into - contact with the shoe, when the calk will loosen and - drop out. - - 3. The tap must be full-formed and smooth. - - 4. It must fit air-tight in the toe, and a single - hammer-blow should be sufficient to fix it securely. - - 5. The =head= of the toe-calk =must not rest - on the shoe=; a space of one-sixteenth of an inch - should intervene. - -While a shoer of average mechanical ability can make a faultless peg -toe-calk, it is not profitable to do so while good machine-made calks -are to be had very cheap. - -[Illustration: FIG. 171. Chisel toe-calk. (Doring.) No. 1 from the firm -of Branscheid & Philippi, of Remscheid.] - -[Illustration: FIG. 172. Shovel toe-calk.] - -[Illustration: FIG. 173. Peg toe-calk shoeing after Fisher-Renker, of -Dresden.] - -[Illustration: FIG. 174. Peg-calk (shovel-calk) after -Kunze-Klotzsche-Königswald, of Dresden.] - -The best forms in use are the quadrangular heads, with oval, half-round -(Figs. 171 and 172), and with two taps (Figs. 173 and 174). - -In several European countries the peg toe-calks with half-round tap and -with two round taps are in use. To make good peg toe-calk shoes and fit -the calks properly requires =more than ordinary knowledge and skill=. -Poor work does much harm. Therefore, work carefully and get well paid -for it. - -6. =Removable Heel-Calks that do not Require Sharpening.=—The -undeniable fact that all chisel-shaped or pyramid-shaped sharp calks -become dull in time, and must then either be sharpened or replaced -by new calks, renders shoeing not only costly, but injurious to the -hoofs and annoying to the owner. This drawback is most pronounced in -large cities, where the snow never lies long upon the streets, and the -horse just sharp-shod is soon obliged to travel upon bare pavements. -Attempts have been made to lessen this annoyance by the use of calks -that do _not require sharpening_, and yet which will prevent slipping -even after they have been used for a long time upon bare pavements. -It cannot be denied that such calks have considerable value, and, -except when the ground is covered with ice, many of these calks render -excellent service. Just as the ordinary sharp calks are satisfactory -and very durable outside of the large cities, so now for the first -time a few of these recently invented sharp calks seem to be worthy of -recommendation for city use. The following are the best: - -[Illustration: FIG. 175. Screw-calk with H-formed cross-section.] - -[Illustration: FIG. 176. Screw-calk with +-formed cross-section.] - - 1. Screw-calks and peg-calks with H-shaped - cross-section (Fig. 175). - - 2. Screw-calks with +-shaped cross-section (Fig. 176). - - 3. Screw- and peg-calks with O-shaped cross-section (Fig. 176). - - 4. Screw- and peg-calks with S-shaped cross-section. - - 5. Angle-calks (Fig. 177). - - 6. Screw- and peg-calks with rubber foot-pad. - - 7. Screw-calks with Y star-shaped cross-section (Fig. 178). - - 8. Hollow wedge-calks (Fig. 179). - - 9. Perforated screw-calks (Fig. 180). - -[Illustration: FIG. 177. Corner calk.] - -[Illustration: FIG. 178. Star calk.] - -[Illustration: FIG. 179. Hollow calk.] - -[Illustration: FIG. 180. Perforated calk.] - -There is no doubt that the grip that these calks take upon the ground -and their durability depend upon the diameter and the arrangement of -their surfaces of friction. From all experiments made thus far it is -shown that those calks which have narrow and comparatively few surfaces -of friction are the least durable. - -[Illustration: FIG. 181. Universal screw-calk key with tap.] - -[Illustration: FIG. 182. Felber’s hand-vise to secure the hoof from -twisting while changing the screw-calks.] - -To introduce and remove the calks we use a calk key or wrench. For the -shop, the ordinary fork key (Fig. 181), the jaws of which are tempered, -is recommended. It fits all calks. - - - - -CHAPTER VI. - -HOOF NURTURE. - - -Hoof nurture comprises all those measures which are employed to keep -hoofs healthy, elastic, and serviceable. - - -A. Care of Unshod Hoofs. - -The care of the hoofs of colts is of special importance. _Abundant -exercise_ upon dry ground which is not too stony is most beneficial. -Such exercise will cause the hoofs to wear gradually, and it will only -be necessary from time to time to observe whether the wear is taking -place uniformly, and if not, to correct the uneven wear with the rasp. - -[Illustration: FIG. 183. - -Twisted left front long pastern of colt, viewed from the upper -articular surface. The lower end has been twisted toward the left: _a_, -transverse axis of lower articular surface; _b_, transverse axis of the -upper articular surface.] - -If colts are reared in the stable, the horn continuing to grow down -does not undergo sufficient wear, and changes in form of the hoof, -and even permanent distortions of the bones of the foot gradually -occur. The wall becomes too long and bends or sometimes separates from -the sole and keraphyllous layer. Weak quarters bend (curl) inward -and encroach upon the space occupied by the frog (contracted feet of -colts). The toe becomes too long, and this gives rise to too steep a -position of the pastern and causes an insecure and diffident gait; -therefore the hoofs must be shortened from time to time. The in-curved -quarters should be removed with the hoof-knife, and the outer edge -of the plantar border of the wall well rounded with the rasp. In the -base-wide and base-narrow standing positions the outer and inner walls -respectively become relatively long and induce the colt to assume a -still more abnormal position. The young and pliant pasterns may thus -become permanently twisted and distorted (see Figs. 183 and 184). In a -hoof that is becoming awry, restoring to the wall its proper level with -relation to the position of the limb will not only be invaluable in -ultimately producing a good hoof, but will improve the faulty position -of the limb. In exceptional cases, where the plantar border of some -section of the wall gives evidence of too rapid wear, the application -of a tip or of a half-shoe may be of benefit. Furthermore, we should -attempt to secure greater cleanliness by frequently and thoroughly -washing the hoofs and bedding with plenty of good straw. - -[Illustration: FIG. 184. - -Left front long pastern of a colt showing compression shortening of -outer half: _a_, transverse axis of upper articulation; _b_, transverse -axis of coronary joint, not parallel to upper axis.] - -Too early shoeing of young horses is very injurious; it hinders the -development of the hoofs, and, furthermore, young horses when shod are -frequently seriously overworked and prematurely ruined. Moderate work -in the fields does not injure young horses, but for such service they -do not require shoes. - -The unshod hoofs of older horses should be periodically rounded with a -rasp and the length of the walls regulated when, by reason of a lack of -exercise, proper wear has not taken place. - - -B. Care of Shod Hoofs. - -Shod hoofs are exposed to many more injuries than are unshod hoofs, -because shoeing itself, although absolutely necessary to render horses -continuously serviceable upon hard streets, is injurious to the hoof, -since it to a greater or less extent prevents the physiological -movements of the different parts of the foot, interferes with the -circulation of the blood in the foot, slows the growth of the horn, and -brings about a gradual shrinking of the entire hoof. - -In addition, there are the injurious consequences of stabulation. These -are _prevention of free movement_, _uncleanliness_ due to bad floors -and filthy bedding,—as, for example, peat moss and soiled straw,—and -_dryness_. - -Continuous standing always contributes to contraction of the hoofs, -and this evil is greatly favored by dryness, which more particularly -affects the front hoofs. The hind hoofs receive sufficient moisture -from the animal’s manure. Poor floors, particularly those that are -uneven, tire the limbs. Accumulation of manure and the _careless_ use -of stationary sole-pads induce thrush of the frog. - -The object of hoof nurture is to lessen or entirely remove all these -injurious consequences of shoeing and stabulation. It comprises, -therefore, not only the proper shortening of the hoofs every five to -six weeks, but careful attention to _cleanliness and moisture_. Both -are insured by dry straw and daily picking out and washing the hoofs. -Such measures will prevent thrush in the hind feet. If front hoofs -are washed once a day, sufficient moisture will penetrate the horn to -give it that degree of suppleness (elasticity) which is possessed by -an unshod hoof, and which contributes to a proper expansion of the -hoof when the body-weight is placed upon it. _In order to prevent a -hoof from again drying out_, the entire hoof should receive a thorough -application of an oil or ointment (hoof-salve). _The object of greasing -the horn is to prevent evaporation of the moisture that has penetrated -the horn._ Specially compounded hoof-salves are not necessary. Melted -horse-grease, pork-fat, or any other fat that is not rancid is -sufficient. Cosmoline is an excellent hoof-salve. - -_Abundant_ but not excessive _exercise_ is more necessary than -anything else to the preservation of the health of the hoof. It aids -the circulation of blood within the foot, and, therefore, the growth -of the horn. Horses which perform hard, regular work have, as a rule, -better hoofs than those which stand the greater part of the time in the -stable. Poulticing hoofs with clay, bran, linseed-meal, or white-rock, -or standing them in water is unnecessary if they have had proper care, -but will sometimes be of benefit when the hoofs have been neglected, -and especially so for front hoofs. The latter are more exposed to -drying influences, and the shoes prevent the moistening process by -keeping the hoofs partially or completely removed from contact with the -earth. _Oiling alone is not sufficient to soften horn_, but must always -be preceded by permeation of the horn with water. =Oiling without first -cleansing the hoof is useless, because this soon produces a greasy -crust underneath which the horn is crisp and brittle.= - -The surest sign of cleanliness of a hoof is the appearance of the -natural color of the horn, the latter appearing translucent even after -the hoof-ointment has been applied; therefore, blackened hoof-ointments -should not be used. When hoofs are exposed to too much moisture (muddy -roads, melting snow, etc.) an addition of wax or common yellow rosin to -the hoof-ointment is recommended to prevent too great softening of the -horn. _No hoof-ointment has any direct influence upon the growth of the -horn._ - -Inasmuch as it is a fact that the very best shoeing injures the hoof, -it is advisable to allow horses to go barefoot whenever it is possible. -This applies especially to horses that from any cause are thrown out -of service, presupposing, of course, that the nature of the hoofs will -allow them to go barefoot. - - - - -PART III. - - - - -CHAPTER VII. - -GENERAL REMARKS CONCERNING THE SHOEING OF DEFECTIVE HOOFS AND LAME -HORSES. - - -The boundary between health and disease of the hoof is difficult to -determine, especially when we have to deal with minor defects of -structure or shape of the hoof. Ordinarily, we first consider a hoof -diseased when it causes lameness. However, we know that diseases of the -hoof may exist without lameness. Therefore, a hoof should be regarded -as diseased or defective when the nature of the horn, the form of the -hoof, or the parts enclosed by it, deviate from what we consider as -normal or healthy (see page 81), whether the service of the animal is -influenced by it or not. - -Front hoofs become diseased or defective more readily than hind -hoofs, because they bear greater weight, have more slanting walls, -and are more exposed to drying influences. =All normally wry hoofs -and acute-angled hoofs become more readily diseased than regular and -upright (stumpy) hoofs.= - -The _indications_ of the various diseases of the hoof are discussed -in the following chapters. We shall in this chapter undertake only -a brief general discussion of _inflammation of the pododerm_. This -inflammation, known as =pododermatitis=, always manifests itself by -_lameness_ and, under closer examination of the foot, by _increased -warmth_, _pain_, and _stronger pulsation of the digital_ and _plantar -arteries_. The pain produces either a _timid, shortened_ (sore) _gait_, -or well-marked _lameness_, especially upon _hard_ ground. Increased -sensitiveness of the pododerm is detected by compression of the hoof -with the pincers (hoof-testers), or with greater certainty by lightly -tapping the hoof. The increased warmth of a part or of the entire -hoof is detected by feeling with the hand. Intense pain and greatly -increased warmth, with a moderate, diffuse swelling of the soft parts -between the hoof and fetlock-joint, indicate suppuration within the -hoof. - -_The examination_ of horses lame in the feet must always be cautious -and searching, and should begin with the moving and judging of the -horse as already described on page 90. The faults detected in the hoof -or in the shoeing, the pain and increased warmth of the hoof, will not -leave us in doubt as to whether the animal is lame in the hoof or not. -However, should there be a doubt, we must carefully examine all the -joints and tendons of the foot and, if necessary, of the limb above, -and observe the animal’s manner of travelling at a walk and at a trot, -on soft and on hard ground, in a straight line and in a circle. - -The =removal of the shoe= should be performed with =greatest caution=. -Under certain conditions the second shoe should not be removed until -the first has been replaced. The same caution must be observed in -paring the hoof, which is to be regarded as a part of the examination -of the hoof. The paring of a hoof for this purpose often differs -somewhat from the preparation of a sound hoof for the shoe, and while -it is necessary because it frequently furnishes the first trustworthy -indication of the trouble, it must be done with circumspection and -intelligence. - -The _causes_ of diseases of the hoof are very numerous, for many -external influences act injuriously upon the hoof. In addition to -too great dryness, want of care (neglected shoeing), and premature, -unreasonable, cruel use of the horse, should be mentioned particularly -_injudicious dressing of the hoof and direct and indirect faults in -the shoeing_. The pododerm, shut in between the hard os pedis and the -stiff, unyielding horn capsule, is frequently exposed to bruising -and other injuries, from which arise most of the defects of the hoof -itself. All these things lead, under certain conditions, to lameness. - -[Illustration: FIG. 185. Bar-shoe for right foot.] - -_Treatment._—First of all, the discovered causes should be removed, -or, if this is not possible, as is frequently the case, they should be -ameliorated. Very often the lameness may be removed by proper shoeing, -a change in the animal’s work, and better care of the hoof. When there -is intense inflammation within the foot, the shoe should be removed -for a few days. When the inflammation is moderate and confined to a -small area, it is usually sufficient to alter the shoeing by regulating -unnatural relations of height in the different parts of the wall, and -by removing all superfluous horn from the wall and sole (to a less -degree from the frog), partly for the purpose of rendering the horn -capsule more yielding, and partly to make the poultices which are used -more effective. The shoe is then to be so applied that the diseased -region will be _relieved of the body-weight_, and will remain free -from all pressure from the shoe. This can be done partly by making -the underlying branch of the shoe somewhat wider and longer than the -other, and partly by cutting down the bearing-edge of the wall where -this is possible without weakening it too much, otherwise by concaving -or beating down the upper surface of the shoe. By reason of the fact -that the posterior half of the hoof is the seat of most diseases of -the hoof, it is to be recommended that the nail-holes in shoes used -in these diseases be placed as far as possible in the anterior half -of the shoe, and in some special cases distributed evenly around the -toe. Among shoes suitable for diseased hoofs the bar-shoe (Fig. 185) -holds the first place, because it renders superfluous many other shoes -specially designed for various diseases of the hoof. It is made like -an ordinary flat shoe, except that it requires a somewhat longer piece -of iron; the ends of the branches are bent inward over a dull corner -of the anvil, bevelled, laid one over the other, and welded together -to form the bar. The width and thickness of the bar should be the same -as of the rest of the shoe, and its frog-surface should be slightly -concave. - -The _bar-shoe is valuable, because_ it protects from pressure diseased -sections of the wall which have been laid free, allows part of the -body-weight to be borne by the frog, and restores normal activity to -the disturbed physiological movements of the foot. By using it we can -either gain a more extensive bearing-surface for the hoof, or can make -it easier for the surface that bears the weight to do the work. If on -account of _weakness_ of the bearing-surface of the hoof, or from any -other cause, we wish to distribute the body-weight over the entire -plantar surface of the foot with the exception of the painful region, -we add a _leather sole_ to the bar-shoe. - -In this case it is necessary to place holes in the ends of the branches -of the shoe, so that we may rivet the leather firmly to the shoe with -small nails. The shoe should be made somewhat wider than the hoof, -and the clips somewhat higher than usual. After fitting the shoe the -grooves for the clips are cut in the leather, the latter is riveted -to the shoe, and all leather projecting beyond the outer edge of the -shoe is trimmed away. The lacunæ of the frog and other concavities of -the sole are then thickly smeared with wood-tar and afterwards filled -up with oakum to such a degree that the packing will bear some of -the body-weight when the shoe and leather sole are in position. This -packing is of great importance, because it prevents the filtering in -from behind of sand and slime, preserves the toughness and pliability -of the horn, breaks shock, and produces a gradual expansion of the -posterior half of the hoof. Before nailing the shoe to the foot the -leather sole should be soaked in water. - - -Classification of Diseases of the Hoof. - - -INFLAMMATIONS OF THE PODODERM. - -1, Nailing (pricking and close-nailing); 2, street-nail; 3, -calk-wounds; 4, corns (bruised sole); 5, bruised heels; 6, laminitis -(founder); 7, keraphyllocele (tumor of horny leaves). - - -DEFECTS OF THE HORN CAPSULE AND LATERAL CARTILAGES. - -(_a_) Changes of form: 1, flat hoof and full hoof (dropped sole); 2, -upright hoof (stumpy or stubby hoof); 3, contracted hoof; 4, wry hoof; -5, crooked hoof; 6, ossification of the lateral cartilage (side-bone). - -(_b_) Disturbances of continuity of the horn capsule: 1, cracks; 2, -clefts; 3, loose wall; 4, hollow wall; 5, thrush. - - - - -CHAPTER VIII. - -INFLAMMATIONS OF THE PODODERM (PODODERMATITIS). - - -1. Nailing. - -Wounds of the velvety tissue of the sole or of the podophyllous tissue -of the wall, caused by nails which have been driven into the hoof for -the purpose of fastening the shoe, are usually termed “nailing.” - -We distinguish _direct_ and _indirect_ nailing; the former is noticed -_immediately_, the latter _later_. - -In =direct= nailing the nail passes directly into the pododerm (velvety -tissue of the sole, podophyllous tissue); the wound produced may vary -from a simple puncture of the pododerm to chipping of the border of the -os pedis, and is =always accompanied by bleeding=, even though it may -not always be noticed. - -In =indirect= nailing the nail does not pass entirely through the horn -capsule, but very close to the sensitive tissues, and crowds the soft -horn inward against them. This inward bulging presses upon the pododerm -and causes inflammation and lameness, which may not manifest themselves -for several days. - -_Symptoms._—The first symptom of direct nailing is =instant pain= -indicated by flinching or a jerking of the limb, showing that the nail -has taken a wrong course, and then a more or less profuse hemorrhage. -Usually the blood flows from the nail-hole, or the nail when withdrawn -may merely show a bloodstain at its point; however, internal bleeding -may occur without any external manifestations. The symptoms of indirect -nailing are entirely different. In this case _pain does not arise -immediately_, but later, sometimes as soon as the horse attempts to -bear his weight upon the shod foot. In the latter case, on holding up -the opposite foot the animal sways backward and throws his weight -upon the holder, or becomes restless. As a rule, the consequences -of indirect nailing are first manifested after two or three days, -infrequently from the eighth to the fourteenth day, as inflammation -within the hoof and lameness, at which time a careful examination -will usually reveal increased warmth of the hoof, pain upon pressure -with the hoof-testers and on tapping the hoof lightly, some swelling -of the entire foot, increased pulsation of the digital arteries, and -unwillingness of the animal to place all or perhaps any of its weight -upon the foot. - -_Suspicion of nailing_ should be entertained if the shoeing be recent, -the hoof appear too small in relation to the body-weight, the walls -have been thinned by rasping or have been broken away, or if the nails -have been driven too high or very irregularly. - -_Causes._—The most common causes are mistakes in shoeing. In the -majority of cases the cause is a disregard of the rule that the =nails -should penetrate the white line= (see pages 118, 119 and 130, heavy -type). 1, using badly-punched shoes; 2, excessive paring and shortening -of the hoof; 3, weakening of the lower border of the wall by excessive -rasping away of the outside (Fig. 187, _c_); 4, mistakes in fitting -the shoe, especially applying shoes that are too narrow, letting the -toe-clips too deep into the horn, by which the nail-holes near the toe, -instead of falling upon the white line, are carried back upon the edge -of the sole, or using shoes in which the nail-holes are too wide or -improperly directed; 5, using nails that are split, incomplete, badly -formed and bevelled, and too large; 6, starting nails too deep or with -the bevel on the outside, or drawing them too tight. As occasional -causes may be mentioned: 7, old nail-stubs in the horn; 8, walls -that are very thin or broken away; 9, a soft, crumbling wall, which -alters the sound and feeling of the nail as it is driven, and makes it -difficult to judge of its course; 10, restlessness of the animal while -being shod. - -_Examination._—Press with the hoof-testers upon the sole and clinches; -tap lightly upon the clinches. If these acts cause pain, there can be -little doubt that the nail is responsible for the damage. Remove the -shoe by drawing each nail separately and carefully. Examine the nails -with reference to their direction and size, as well as to staining -with blood, blood-serum, or pus. Immediately after removing the shoe, -look for the point of entrance of each nail into the hoof, and if a -nail-hole be found upon the edge of the sole (Fig. 187, _b_) instead -of in the white line, it is highly probable that the nail which passed -in at that place pressed upon the sensitive tissues of the foot. Every -nail-hole should then be searched by passing a clean new nail into it -and pressing its point towards the soft tissues at various depths; any -indication of pain caused by this act is pretty sure proof of nailing. -It stands to reason that the character of the nail-holes in the shoe -should be closely examined. - -[Illustration: FIG. 186. - -Cross-section of a shod hoof, the hoof-skin or pododerm being in red: -_a_, indirect nailing where backsetting has been overdone and has bent -the nail; _b_, nail properly placed and of correct shape.] - -[Illustration: FIG. 187. - -Front hoof deficient in horn: _a_, right position of the nail-holes in -the white line; _b_, faulty position inside of the white line; _c_, -wall weakened by excessive rasping.] - -_Treatment._—When the foot has sustained an ordinary simple prick with -a nail, the latter should be left out and the hole well filled with -wax. As a rule, no serious results follow. In severe direct nailing -the entire shoeing should be most carefully examined, and only after -everything is found to be right, and the shoe fits in such a manner -that the nails can only penetrate the wall from the white line, can it -be regarded as correct. The offending nail-hole is then to be closed -with wax. According to the intensity of the wound we may expect a more -or less pronounced inflammation of the pododerm, and this is to be -combated by resting the animal and cooling the foot. - -If the wound is clean and recent, enlarging the opening in the horn by -cutting and boring can have no reasonable object; the wound by such an -act will not be made smaller, but larger. - -Frequently, however, the wound is not observed or suspected until the -pain has become very intense (indirect nailing, nail-pressure); in -such cases the offending nail when withdrawn is apt to be covered with -pus or a dark, thin, ill-smelling liquid. In such a case the liquid, -whatever its nature may be, must be given free escape. In order to -accomplish this it is entirely sufficient to cut away a section of -the wall from the nail-hole outward, not greater than the width of -the little finger, and then to assist in the discharge of the pus -by placing the foot in a warm bath; it is entirely wrong, in fact, -reprehensible, to remove all horn of the wall and sole which has been -loosened from the soft parts by the suppurative process. After the -escape of the inflammatory fluids, the wall and sole will form the -best-fitting and most suitable protective dressing for the diseased -region until it has secreted new horn. If, after removal of the nail -and pus, the pain does not diminish, warm disinfecting baths of one to -two parts of creolin, or the same amount of lysol, to one hundred parts -of water at a temperature of about 90° F. will be of especial benefit; -they will not only soften the horn, but by their moisture and warmth -will directly diminish the pain and have a healing influence upon the -suppurating surfaces. The warm baths must actually _be warm and be kept -warm_. Antiseptic solutions at room temperature are much less efficient. - -If the pain has not been very pronounced, or if it has been greatly -alleviated by two or three warm baths, then, as a rule, it is -sufficient to put a few drops of creolin upon the inflamed surface, and -to close the opening with oakum (carbolized oakum or carbolized cotton -is better). - -The horse which has been nailed will be again perfectly serviceable -after a few days if shod with a shoe which does =not press= upon the -inflamed region. _The shoe does not press when it rests only upon the -bearing-edge of the wall, when the white line and the edge of the sole -are entirely free of the shoe, and no nails are driven in the immediate -vicinity of the wound._ - - Even though, as we have seen, nailing in the great - majority of cases is not particularly serious to - the horse and owner, yet we should never forget - that tetanus (lockjaw), a disease which is nearly - always fatal to horses, may follow. Nailing, however - insignificant it may seem, may under conditions lead - to the death of the horse. - - -2. Street-Nail. - -The _condition_ caused by accidental injury of the sensitive structures -covered by the horny sole, such as the velvety tissue of the sole and -frog, plantar cushion, perforans tendon, navicular bone, os pedis, or -the pedal articulation, by sharp objects, especially nails, is called -“penetrating street-nail,” or simply “street-nail.” The resistance of -the ground to the weight of the body drives these penetrating objects -through the sole or frog into the foot. - -Hind hoofs are more often affected than fore-hoofs. A favorite point of -entrance is the lateral lacuna of the frog. Street-nail is favored by -excessive thinning of the sole and frog. - -_Symptoms._—The symptoms are, as a rule, sudden pain followed by -lameness. The first assistance is usually sought in the shoeing shop. -If the cause of lameness be found to be a penetrating nail, piece of -glass, or other pointed foreign body, it must be _carefully drawn out_, -in doing which we should remove the _entire object_, not allowing -pieces to break off and remain in the wound. Since it is always -important to know in what direction and how deep the foreign body has -penetrated, in order to be able to estimate the gravity of the wound, -it is advisable in all cases to preserve the penetrating body, that it -may be shown to the veterinarian, in case his services are required. - -[Illustration: FIG. 188. Shod hind foot, with splint dressing.] - -In slight injuries to the velvety tissue of the sole or frog, -accompanied with moderate pain, it is of no benefit to enlarge the -opening, though the horn of the sole or frog should be thinned for -the space of an inch or more around the wound, followed by cooling -applications. Deep, penetrating wounds accompanied with intense pain -require the attention of a veterinarian. - -Often some form of dressing is necessary, and this is usually held in -place by a special shoe. For slight injuries, such _splint-dressings_ -as are shown in Figs. 188 and 189 are sufficient. Whether such a -dressing be applied to the front or hind feet, the shoe should be _well -concaved_ upon the hoof-surface. The dressing is held in place by thin -splints of tough wood, which are firmly wedged between the shoe and -hoof. - -[Illustration: FIG. 189. A practical “splint shoe” for hospital use.] - -In those rare cases in which it is necessary to maintain continuous -pressure upon the seat of the wound, and to protect the entire -plantar surface of the hoof, a _covered shoe_ (Figs. 190 and 191) is -recommended. This shoe is provided with a sheet-iron cover, having at -the toe a spur which fits into a corresponding hole in the toe of the -shoe, and fastened at the heels by means of screw heel-calks. - - -3. Calk-Wounds of the Coronet. - -All tread-wounds of the coronet, caused by the calks of the opposite -shoe, by the shoes of other horses, or by forging, are known as calk -wounds, or simply as “calking.” The injury itself is either a bruise -or a bruised wound, followed by inflammation of the coronary cushion -and an interruption in the formation of horn at that point. It occurs -most often in winter from sharp calks, especially on the hind feet. The -common seat of the injury is the coronet of the toe and inner side of -the foot. - -[Illustration: FIG. 190.] - -[Illustration: FIG. 191. - -Shoe with cover-plate for street-nail treatment; suitable where -pressure-dressing is desired: _a_, hole in the bottom of the toe-calk -for reception of spur, _b_, of cover-plate; _c_, holes for reception of -screw-calks, _d_, which fasten the cover-plate to the shoe.] - -The inflammation terminates either in resolution—that is, passes -gradually away, leaving the tissues apparently normal—or in -suppuration. The perioplic horn-band, which is usually loosened from -the perioplic band by the injury, does not again unite. For this -reason, and because of the interruption in the formation of horn at the -seat of injury, there results a transverse depression or cleft in the -wall. - -The shoeing has to deal only with the lameness that may be present as -a result of the calking. The section of the wall containing the lesion -should be shortened, so that it will not press upon the shoe. Serious -calk-wounds, as a rule, require treatment by a veterinarian. - - -4. Corns (Bruised Sole). - -The expression “corns” is applied to nearly all bruises of the pododerm -of the posterior half of the foot, with the exception of the frog, -which are apparent to the eye as yellowish, reddish, or bluish-red -discolorations of the horn of the sole and white line. - -The surface of the pododerm (fleshy leaves and villi) is chiefly -involved, and almost without exception there is rupture of small -blood-vessels and an outpouring of blood between the pododerm -and the horn. The blood penetrates the horn-tubes and causes the -above-mentioned staining. By subsequent growth of horn these stained -patches are carried downward, and are finally uncovered and brought to -sight in paring the hoof. - -The seat of corns is either on the fleshy leaves of the quarters, or on -the velvety tissue of the sole in the angle between the wall and the -bar, or on the fleshy leaves of the bars. Thus we distinguish _corns of -the wall, sole, and bars_. - -Corns affect chiefly the front hoofs, and more often the inner half -than the outer. Unshod feet are seldom affected. - -According to the intensity of the lesions we distinguish: - -1. _Dry Corns._—The red-stained horn is dry, and there is seldom -lameness. - -2. _Suppurating Corns._—They are the result of intense bruising -followed by inflammation. The pus is either thin and dark grayish -in color, denoting a superficial inflammation of the pododerm, or -yellowish and thick, denoting a deep inflammation of the pododerm. In -the latter case a veterinarian should be called. Lameness is usually -pronounced. - -3. _Chronic Corns._—In this case there is vivid discoloration of horn -in all possible hues. The horn is either soft, moist, and lardy, or -crumbling, cracked, and at times bloody. The inner surface of the -horn capsule has lost its normal character, and is covered with horny -swellings or nodules (Fig. 192, _a_). Sometimes the wing of the os -pedis on that side has become morbidly enlarged and loosened. A short, -cautious gait alternates with well-marked lameness; the latter appears -whenever the shoe presses too firmly on the corn, or when the hoof -becomes too dry. - -[Illustration: FIG. 192. - -Inner aspect of a quarter of a hoof, showing changes in the horn-leaves -due to chronic corns: _a_, horny tumor resulting from the disease.] - -_The causes_, aside from the form and quality of the hoofs and the -position of the limbs, lie in injudicious dressing of the hoof and -in faulty shoes. Too much trimming of wide and flat hoofs, excessive -weakening of the quarters, sole, bars, and frog of all other hoofs, -while the toe is usually left too long, are the usual causes. -Shortening one quarter too much in relation to the other, so that the -foot is unbalanced and the lower side overloaded, is a frequent cause. -Hollowing the sole and bars excessively and unnecessary thinning of the -branches of the sole in the search for corns are also causes. - -Among faulty shoes we may mention those not level on the hoof-surface, -trough-shaped, too short in the branches, shoes which do not completely -cover the bearing-surface of the hoof, or whose bearing-surface at -the ends of the branches is directed downward and inward so that the -quarters are squeezed together when the weight is put on the foot. -Insufficient concaving of the shoe is often an exciting cause of corns -in flat feet and in those with dropped soles. A well-formed shoe -which does not rest firmly upon the hoof, or which has been shifted -as a result of careless nailing, may as readily cause bruising of the -quarters as neglected shoeing. The latter causes, as a rule, corns of -the sole. It is very rarely that corns are caused by stones fastened -between the frog and branches of the shoe or in unshod hoofs by pebbles -becoming wedged in the white line. - -_Dryness_ is particularly injurious to the hoofs, and is in the highest -degree favorable to the production of corns. It renders the hoof stiff -and inelastic, and first manifests itself by a short, cautious (sore) -gait when the horse is first put to work. - -_Treatment._—First, removal of the causes, by restoring the proper form -to the hoof through shortening a toe which is too long (especially apt -to be the case in acute-angled hoofs), cutting down quarters which are -too high, and carefully removing all dead horn from the branches of the -sole, especially in acute-angled hoofs. - -Deeply digging out a small area of blood-stained horn is injurious. -It is much better to thin the horn of the entire branch of the sole -uniformly, in doing which we should avoid wounding the velvety tissue -of the sole or drawing blood. - -The proper shoe is the =bar-shoe=, except when both cartilages are -ossified. The pressure should not be taken from the quarters unless -they are sore. - -When there is a _suppurating corn_, the shoe should be left off several -days. A _chronic corn_ should be protected continuously from pressure -by the shoe. This is accomplished by using a bar-shoe with leather -sole. _A three-quarter shoe is not sufficient to properly protect a -hoof affected with a chronic corn, if the animal must perform exacting -labor on hard roads._ - -The care of the hoof consists in keeping it cool, moderately moist, and -pliant. - - -5. Inflammation of the Heels. - -Inflammation of the bulbs of the plantar cushion (heels) is usually -caused by such external influences as bruising. It occurs in both shod -and unshod feet. The symptoms are: increased warmth, pain and swelling, -sometimes infiltration of the tissues with blood, accompanied by a -short, cautious gait, or, if only one foot is affected, by well-marked -lameness. - -The _most frequent causes_ are: going barefoot upon hard (frozen), -uneven ground; shoeing hoofs having low heels with flat shoes that are -too short; sometimes too much frog pressure by the bar of a bar-shoe; -forging and grabbing. - -The treatment first indicated is a cooling application in the form of -an ice-poultice, or a soaking in cold water. Later, astringent (drying) -applications are of benefit, especially if the perioplic horn-ring -has partially loosened from the bulbs of the heels; for example, a -weak solution in water of sulphate of copper (1 to 20), followed by -the application of a shoe with heel-calks, which is quite long in the -branches and _which must not press upon the wall of the quarters_. - - -6. Laminitis (Founder). - -By this name we designate a peculiar inflammation of the pododerm at -the toe. It arises suddenly in well-nourished and apparently healthy -horses, following excessive work or long-continued rest in the stable, -and frequently leads to a decided change of form of the hoof. - -The disease is always accompanied with intense pain. It most often -affects both front feet, more rarely all four feet, or only one foot. -In the first case the two front feet are planted far in advance of -the body, and the hind feet well forward under the belly. When all -four feet are affected, travelling is exceedingly difficult, often -impossible; in this case there is nearly always a high fever over the -entire body. - -The seat of the disease is in the fleshy leaves about the toe, more -rarely upon the side walls and quarters. Depending upon the intensity -of the inflammation, the fleshy leaves are more or less loosened -from the horny leaves, as a result of which there is a change of -position of the os pedis, with a simultaneous sinking of the coronet -at the toe. This produces a change of form of the hoof. The quarters -become higher. Rings form upon the wall, and their course is quite -characteristic of the disease. At the toe these rings are quite close -to one another, but as they pass back towards the quarters they -gradually separate from one another and recede from the coronary band -(Figs. 193, 194, and 195). - - -[Illustration: FIG. 193. - -Vertical longitudinal section of a foot altered by chronic laminitis: -_a_, hollow wall at toe thrust forward; _b_, leafy layer much thickened -and crumbling (“seedy-toe”); _c_, dotted line showing limit to which -the toe may be rasped away in shoeing; _d_, dropped sole; _e_, atrophy -of lower sharp edge of os pedis; _g_, dotted line indicating the height -of the perioplic band; _h_, foot axis.] - -The wall at the toe is sunken just under the coronet; its lower part, -on the contrary, is thrust forward. _Later, the white line becomes -pathologically widened._ The horn of the white line is dry, crumbling, -and easily broken down, so that a break in continuity (crack) is apt to -occur between the wall and sole, and lead to the formation of a _hollow -wall_ (“seedy-toe”). Where the inflammation is moderate and is not -repeated, healing usually takes place and the horn grows down regularly -and in normal direction from the coronet. However, a rather brittle -condition of the horn remains permanently. If, on the contrary, the -inflammation was very severe or repeated several times, the horny sole -becomes flat just in front of the point of the frog as a result of the -sinking of the os pedis, or it may even drop below the level of the -wall (full hoof, dropped sole). Indeed, it even happens at times that -the toe of the os pedis perforates the horny sole just in front of the -point of the frog. The wall at the toe, which was previously but little -altered in form, is now thrust prominently forward. - -[Illustration: FIG. 194. Foundered foot (chronic laminitis), before -dressing.] - -[Illustration: FIG. 195. - -Foundered foot, dressed and shod. The dotted lines indicate its form -before being dressed,—_i.e._, as shown in Fig. 194.] - -The inflammation of the pododerm may under certain conditions and by -skilful veterinary treatment be removed, so that the characteristic -changes of form and quality of the hoof will not occur. But if this is -not accomplished, as is often the case, the disease will be obstinate, -and permanent morbid changes of the horn capsule take place. - -[Illustration: FIG. 196. - -A hoof altered by chronic laminitis; shod with an open flat shoe: _a_, -wall at the toe does not bear on the shoe; _b_, clip at the end of the -branch to oppose the tendency of the shoe to slip forward when half -worn out.] - -A horse in such a condition can be used, but the gait will be short -and stiff. The hoofs are shuffled forward and set heels first to the -ground, a manner of travelling that rapidly wears away the branches of -the shoe. - -In dressing a foundered hoof the outer circumference of the sole is -the guide. The thick projecting wall at the toe may be removed with -the rasp without injuring the foot. The sole should be spared, but the -quarters should be lowered to improve the setting of the foot to the -ground. - -The choice of the shoe will depend upon the shape and nature of the -sole. If this is still concave, an ordinary shoe may be used. If, -however, the sole is flat or dropped, it must be protected by an open -shoe with a broad web, or with a bar-shoe (Fig. 197), which is of -especial value when the bearing-edge of the wall is weak or broken away. - -[Illustration: FIG. 197. - -A well-covered (wide-webbed) bar-shoe, with two lateral toe-clips and -an end-clip, for a foundered foot.] - -[Illustration: FIG. 198. An open shoe for a foundered foot with a -dropped sole.] - -As long as there is pain on pressure about the toe there should be no -toe-clip, but two side-clips. The wall between these clips should be -lowered a tenth to an eighth of an inch to prevent pressure of the shoe -upon the sensitive tissues of the toe (Fig. 195). The nails should be -as small as possible and placed well back towards the quarters. No nail -should be driven in the wall at the toe when there is separation of -sole and wall at the toe (hollow wall, seedy-toe). - -The shoes of horses affected with founder often work forward as a -result of the animals travelling upon their heels. To prevent this -evil, clips may be raised at the ends of the branches of an open shoe, -or one clip in the middle of the bar, in case a bar-shoe is used (Fig. -197). - - -7. Keraphyllocele (Horn Tumor). - -A keraphyllocele is a more or less sharply bounded horn tumor -projecting from the inner surface of the wall. - -[Illustration: FIG. 199. - -A section of wall at the toe showing a Keraphyllocele (horn-leaf -tumor): _a_, coronary border; _b_, plantar border; _c_, body of tumor; -_d_, base of tumor presenting funnel-shaped opening discharging pus.] - -Its occurrence is rare. Its favorite seat is at the toe. It rarely -causes lameness. It can only be diagnosed with certainty when it -extends downward to the lower border of the wall. In this case there -may be seen a half-moon-shaped thickening of the white line which -rounds inward upon the edge of the sole, and is of a waxen color. -Frequently the horn at this place crumbles away, leaving a more or less -dark-colored cavity from which there sometimes escapes a small quantity -of dark-grayish pus. - -_Causes._—Chronic inflammation of the podophyllous tissue, resulting -from compression or bruising. Keraphyllocele frequently follows a -complete toe-crack of long duration, or a deep calk-wound at the -coronet. - -_Prognosis._—Unfavorable, whether there is lameness or not. If there -is no lameness it is very apt to arise later, and if lameness is -already present it can only be removed by an operation, which should be -performed by a veterinarian. A return of the lameness following hard -work at a trot upon hard roads is always to be feared. - -_Shoeing._—An ordinary shoe well concaved underneath the inflamed -region, which should be relieved of all pressure.[5] - -[5] Should lameness persist, it will be necessary to remove a strip of -the wall from the plantar border to the coronet in order to remove the -horn tumor. The fleshy leaves which have secreted the tumor must be -extirpated and the surface of the os pedis well scraped, or the growth -will return. - - - - -CHAPTER IX. - -DEFECTS OF THE HOOF. - - -A. Changes of Form. - -1. THE FLAT AND THE FULL HOOF (DROPPED SOLE). - -(_a_) _Flat Hoof._—A flat hoof is one whose toe and side walls are -_inclined very obliquely_ to the ground-surface, and whose sole is _on -a level_ with the bearing-surface of the wall. - -It exists most often in horses bred in low-lying, marshy countries. - -Frequently the frog is well developed, and projects considerably beyond -the level of the wall. The branches of the sole sink perceptibly under -the weight of the body, much more than in better-formed hoofs. - -[Illustration: FIG. 200. - -Cross-section of a shod flat foot: _a_, sufficiently high -bearing-edge of wall, and a horizontal bearing-surface on the shoe; -_b_, insufficient height of bearing-edge of wall, and therefore a -corresponding downward and inward inclination of the bearing-surface of -the shoe.] - -_Preparing the Hoof for the Shoe._—The rule is to =spare= the plantar -surface of the foot. After removing from the sole what little loose -horn there may be, level the usually deficient bearing-surface of the -wall with the rasp. The outer border of the wall, especially at the -toe, should be rounded off rather more strongly than usual, because the -toe requires and will bear considerable shortening. Outward bendings of -the lower border of the wall should be removed as far as it is -practicable to do so. - -The shoe, which should be rather wider in the web and thicker than -usual, should have its bearing-surface shaped to correspond to the -bearing-surface of the wall; that is, if the bearing-surface of the -wall is below the margin of the sole (the sole of the foot being -uppermost), then the bearing-surface of the shoe should incline -downward and inward (Fig. 200, _b_). The bearing-surface of the -branches, however, must always remain horizontal. The shoe always -requires deep concaving, especially along the inner branch of the sole. -If the quarters are weak, the walls defective, or there are corns, -cracks, loose walls, or other diseases of the hoof, a =bar-shoe= should -be selected. - -(_b_) _Full Hoof_ (Dropped Sole).—A full hoof is one whose sole instead -of being concave is convex,—that is, bulges beyond the bearing-surface -of the wall. It either arises gradually from a flat hoof or is the -result of laminitis (founder). In full hoofs the lower surface of the -os pedis is of the same shape as the horny sole. - -_The preparation of a full hoof_ for the shoe consists merely in -removing all loose horn. In case the dropping of the sole is very -pronounced, the bearing-surface of the wall should be built up -artificially with Defay’s hoof cement. The shoe should be light, but -broad in the web, and furnished with a more or less deep concaving, -which extends from the inner edge of the web to the outer edge of the -shoe, and corresponds in shape to the bulging of the sole. By reason of -the deficiency of the wall, the =bar-shoe= deserves the preference over -an open shoe. It is frequently necessary to apply toe- and heel-calks -to remove the hoof from contact with the ground. The nails should he -thinner and longer than usual, and a more secure position of the shoe -may be secured without injury to the hoof by drawing up two side-clips. - -Flat and full hoofs are =incurable=. Shoeing is of benefit only in -rendering such horses serviceable. Soles that are soft and sensitive -should he smeared with crude turpentine or pine-tar, though unusual -sensitiveness calls for a leather sole. Horses with full hoofs -should not be driven faster than a walk over hard roads. During -long-continued spells of wet weather softening of these hoofs should -be prevented by smearing the soles with a hoof-ointment containing -resin. - - -2. THE UPRIGHT OR STUMPY HOOF. - -The upright or stumpy hoof is that form in which the quarters, with -relation to the toe, are too long (too high). The wall at the toe -stands very steep, in some cases perpendicular, and is strongly worn -away by standing and travelling. - -[Illustration: FIG. 201. Upright or stumpy hoof, shod with a “tip.”] - -[Illustration: FIG. 202. Beaked shoe for stilt-foot.] - -_Causes._—1. The upright hoof is peculiar to the “standing under” -position (Fig. 53, page 66) and to the so-called bear-foot (Fig. 70, -page 72). - -2. It arises also as a result of all those alterations in the direction -of the limbs which tend to remove the quarters from contact with the -ground (contraction of the flexor tendons, spavin,—Fig. 202). - -3. It may arise gradually from neglect of the hoofs of horses running -barefoot. - -4. It may arise from excessive shortening of the toe in relation to the -quarters. - -_Shoeing._—The forms of hoofs mentioned in class 1 should be left -as they are. The hoofs that fall under class 2 should be dressed -and shod until a more natural setting down of the foot is secured. -This is brought about by sparing the quarters, and applying a shoe -with thickened branches or with heel-calks. Where the service of the -animal is exacting and upon hard streets, the toes, especially of -the hind shoes, may be made more durable by welding in steel plates. -Besides, the shoe should be moderately _base-wide_ around the toe,—that -is, should be bevelled downward and outward, should have a _strong -toe-clip_, and should be _quite concave at the toe_ and _rolled_. -(Figs. 203 and 204). Should the hoof tip forward whenever the weight is -thrown upon the limb, a shoe with a spur projecting from the centre of -the toe, and turning back and pressing upon the wall just underneath -the coronary band, will be of service (Fig. 202). - -[Illustration: FIG. 203.] - -[Illustration: FIG. 204. Shoe for stumpy hoofs, viewed from -ground-surface, hoof-surface, and in profile.] - -Only those upright hoofs which are the result of the causes mentioned -in 3 and 4 are to be dressed as ordinary hoofs, and if the service -required is not too exacting they should be shod with tips (Fig. 201), -or with shoes with thinned branches. - - -3. THE CONTRACTED HOOF. - -_A hoof which has deviated from its normal form in such a manner that -its posterior half, either in part or as a whole, is too narrow, is -a contracted hoof._ The walls of the quarters assume an abnormally -oblique direction downward and inward towards the median line of the -hoof. - -When contraction affects only one quarter, it is called _unilateral -contraction_, or abnormal wryness (Fig. 211). - -[Illustration: FIG. 205. - -A fore-hoof with bilateral contraction of the quarters: _a_, spur of -horn prolonged from the buttress, which compresses the frog; _b_, -narrow median lacuna of the frog.] - -The buttresses are usually very much prolonged and press upon the frog -and cause it to shrink. The bars no longer run in the natural straight -direction from the point of the frog backward and outward, but describe -a circle passing outward, backward, and inward. - -[Illustration: FIG. 206. - -_A_, Defay’s shoe for expanding the quarters of a hoof; _a_, clip -apposed to the buttress; _b_, slot sawed at the toe to weaken the shoe; -_B_, screw for expanding the Defay’s shoe.] - -Contraction affects front feet, especially those of the _acute-angled_ -form, more often than hind feet. In order to determine whether or not a -hoof is too narrow, we should always examine the frog and its lateral -lacunæ. If the frog is small and narrow, and the lateral lacunæ very -narrow and deep, there can be no doubt but that the hoof is too narrow -(contracted). - -_The causes_, aside from too little exercise, are chiefly errors in -shoeing, such as weakening the posterior half of the hoof, leaving -too long a toe, either neglecting to remove the spurs of horn which -grow from the buttresses and press upon the frog, or removing them -incompletely, and using shoes whose branches are either _too wide -apart_ or are inclined downward and inward, so that under the weight of -the body _the heels are squeezed together_ and contraction is favored. - -_Prevention and Treatment._—First, it should be borne in mind _that -whatever exercises moderate pressure upon the sole, frog, and bars -tends to expand the hoof_. The action and value of the various shoes, -frog-, and sole-pads, are measured by this rule. For this reason a -shoe with heel-calks is never advisable if an open flat shoe without -other means of relief can be used. Furthermore, since contraction is -the parent of nearly all diseases of the hoof (corns, quarter-cracks, -bar-cracks, thrush of the frog), we should use the greatest care to -=prevent= it by dressing the hoof as described on pages 98 to 103, -using flat shoes with a =horizontal bearing-surface for the quarters=, -giving =abundant exercise, preventing drying out of the horn=, and -allowing the animal to go barefoot whenever possible. _Where the -contraction is but slight_ the foregoing rules will be found sufficient. - -_In very pronounced contraction, where the hoof is not acute-angled, -an expansive shoe_ with clips raised at the ends of the branches to -press against the buttresses may prove very advantageous; but under -no conditions should violence be used in expanding the heels with the -expanding-screw. This is an act of extreme delicacy, and should be -performed only by experienced veterinarians. - -_In very pronounced contraction of one or both quarters of hoofs of -every degree of obliquity_ we may obtain a continuous expansive action -by the use of one of the numerous V-shaped springs, of which the -_Chadwick spring_ is the best (Fig. 207 and 208). After levelling the -wall and thinning the branches of the sole, the points of the spring -are set against the =buttresses=, the apex of the spring moved to -and fro till the points have bored well into the horn, when the apex -is laid against the sole at the toe, the sole filled with tar and -oakum and covered by a leather sole, and a bar-shoe applied. If the -contraction be less pronounced, or if the frog be much shrunken we may -place a Chadwick spring beneath a rubber bar-pad with a short shoe. The -spring may be stiffened from shoeing to shoeing, first by introducing -the ferrule at the apex of the spring and later by shifting the ferrule -toward the shoulder (Figs. 207, _b_, and 208, _b_). - -[Illustration: FIG. 207. - -The Chadwick spring for expanding contracted quarters: _a_, apex of -spring; _b_, ferrule to stiffen the spring; _c_, point which is buried -in a buttress of the hoof.] - -[Illustration: FIG. 208. - -A fore-hoof showing a Chadwick spring in proper position: _a_, Chadwick -spring; _b_, ferrule to stiffen spring as desired; _c_, uncompressed -spring before it has been engaged against the buttresses; _d_, -buttresses in which points of spring are buried.] - -For contracted hoofs of the _acute-angled form_ we use the bar-shoe, -and if there are other diseases of the hoof present, or if we wish a -more rapid and continuous expansive action, we use also a leather sole -with foot-packing with or without a buttress spring. A foul frog should -be properly cleansed, and then disinfected with pine-tar thinned with -alcohol or crude wood-vinegar (pyroligneous acid). - -Further curative measures are: turning the horse out without shoes -(expensive and seldom practicable); applying tips; using shoes the -bearing-surface of whose branches inclines downward and outward -(unilateral contraction requires but one branch to be so constructed); -hoof-pads of rubber (Figs. 145, 146, and 147), straw, rope, cork, -hoof cement, etc. Special forms of contraction are distinguished, and -are as follows: - -(_a_) _The Contraction of Wide Hoofs._—This contraction is manifest -as a concavity or groove in the wall just below the coronet, usually -at the quarters, though sometimes extending entirely around the foot -parallel to the coronary band (Fig. 209). Pain is produced in the -contracted area by lightly tapping the horn, but not by moderate -pressure with the hoof-testers. - -[Illustration: FIG. 209. - -Wide fore-hoof with “coronary contraction”: (_a_) broad shallow groove -in each quarter, and disappearing toward the toe.] - -Green horses with wide hoofs, just from the pasture, are particularly -liable to this form of contraction. As a rule, the lameness does not -disappear completely until the wall has assumed its natural, straight -direction by growing down properly from the coronary band. - -In dressing the hoof and applying the _bar-shoe_, care must be taken -that the lower border of the wall underneath the painful area is -lowered so much that it will not receive direct pressure from the shoe. - -(_b_) _Contraction of the Sole._—This is accompanied by an unnatural -direction of the wall. Instead of the wall being straight from the -coronet to the shoe, it describes a curve whose convexity is outward -(keg-shaped, claw-shaped when seen from the side) (Fig. 210). The hoof -seems constricted (tied in) at the coronet and at its plantar border, -the sole is abnormally concave (arched), and the plantar surface of -the hoof is considerably shortened from toe to heel. It happens in -both shod and unshod horses, with otherwise strong hoofs, but is quite -rare. It is occasionally associated with navicular bursitis (“navicular -disease”). - -_Causes._—Principally dryness, too little exercise, and shoes without -horizontal bearing-surface. - -[Illustration: FIG. 210. - -A fore-hoof with a contracted sole, properly shod: _a_, toe convex -in profile; _b_, shoe fitted full all around, and “bearing-surface” -inclining outward; _c_, outer border bevelled base-wide.] - -The treatment is correspondingly simple: The shoes should be flat, -fitted full all around to coax the wall out at every point, and the -outer border bevelled base-wide, so as to furnish a base of support -that is wider and longer than the hoof. In moderate contraction of the -sole, the bearing-surface of the shoe should be perfectly horizontal, -but if the contraction be very pronounced, the entire bearing-surface -should incline downward and outward (even at the toe). No toe-or -side-clip should be used. The shoe should be reset every two weeks; the -sole kept so thin by paring that it will spring under thumb pressure, -and kept moist by washing, tubbing or “stopping,” and the animal given -moderate exercise daily. - -_In all forms of contraction of the hoof abundant exercise and the -maintenance of the natural pliancy of the horn by daily moistening -(washing) with water are absolutely necessary for successful treatment._ - - -4. THE WRY HOOF. - -If one side wall and quarter is steep, and the other very slanting -or oblique, we term such a hoof a “wry hoof.” Such a hoof divided -in the middle line presents two very _dissimilar_ halves. There are -three classes of wry hoofs: 1, normal wry hoofs (see Figs. 63-66); -2, pathological wry hoofs, or hoofs contracted in one quarter (see -contracted hoofs); 3, wry hoofs which are the result of improper -shortening of the wall and of neglect in horses running barefoot. - -Only the second and third classes of wry hoofs require especial -attention. First, the more oblique wall must be cut down, and the steep -wall spared,—a procedure which differs essentially from that employed -in treating the first class, but is, nevertheless, entirely warranted, -because these second and third kinds of wry hoofs do not correspond to -the direction of the limb. - -[Illustration: FIG. 211. - -A wry right front foot of the base-wide class, viewed from behind. The -bar-shoe is fitted full along the contracted inner quarter, and snug -on the outside. The inner branch of the frog rests upon the bar of the -shoe; the outer branch is free. The inner quarter from the last nail -back to the frog is free of the shoe.] - -In order to take weight from the steep wall, we use with advantage -a _bar-shoe_, which should be longer and wider than the hoof on its -contracted side. In other words, enlarge the base of support by making -the branch of the shoe broader. If an entire side wall and quarter -is contracted the branch of the shoe beneath must be broad, the -border bevelled base-wide, and the branch punched so deeply that the -nail-holes will fall upon the white line. - -In old work-horses any sort of shoe may be used, though a flat shoe -serves the purpose best. If a hoof is wry from faulty paring, and we -cannot at once completely restore the proper relative slant of the two -walls by paring alone, we may use a shoe with a thicker branch for the -half of the hoof which is too low (too steep). - -In colts such wry hoofs can often be cured only by shoeing. The shoe -employed for this purpose is so made that the branch underneath the -steep (contracted) wall is quite thick, but gradually thins away around -the toe to the end of the other branch. In strongly marked cases the -thin branch may end at the middle of the side wall (a three-quarter -shoe). This method of shoeing shifts the body-weight upon the slanting -wall and restores the foot to its proper shape in from two to four -shoeings. - -_Causes._—Unequal distribution of the weight in the inner and outer -halves of the foot, in conjunction with excessive cutting down or -wear of the steeper wall. All faults in shoeing which tend to produce -contraction of the heels aid in the formation of a wry foot, especially -when these faults directly affect the steep wall. Neglect of the colt’s -hoofs during the first years of life frequently lays the basis for wry -foot in later years. All wry feet are more susceptible to disease than -others. - -The amount or degree of wryness varies considerably. In a moderately -developed case the steep wall (usually the inner) will be drawn in -at the plantar border of the quarter, presenting a convex surface -between this border and the coronet, and the adjacent branch of the -frog will be more or less shrunken. In extreme cases the slanting wall -(usually the outer) will also be involved and bent in the opposite -direction,—_i.e._, will be concave (dished) between coronet and lower -border (crooked hoof). - -_Prognosis._—When the degree of wryness corresponds to the slant of the -foot-axis and the old shoe shows nearly uniform wear, the defect is not -directly injurious. In very pronounced “wryness,” however, with thin, -bent walls, a number of associated lesions, such as corns and cracks, -may be present and render the animal unfit for service upon paved or -macadam roads. - - -5. THE CROOKED HOOF. - -A crooked hoof (Fig. 212) is one whose walls (viewed from in front or -behind) do not pass in a straight, natural direction from the coronet -to the ground, but are bent in such a manner that the bearing-surface -of the wall in relation to the foot-axis lies either too far out or in. - -It may occur on any foot, but is seldom strongly marked. - -_Causes._—The causes are either long-continued leaving of one-half of -the wall too high, or the use of shoes shaped for normal feet upon -hoofs of the base-wide position. - -[Illustration: FIG. 212. - -A crooked right fore-hoof of the base-wide position: _a_, convex wall, -too high; _b_, concave wall, too low; _c d_ shows how much of the outer -wall must be removed with the hoof-knife; _f_, superfluous horn to be -removed gradually with the rasp; _c e_ and _g h_ indicate the position -of the shoe with relation to the hoof.] - -The principal part of the treatment is the proper dressing of the hoof. -The wall which is bent out at the middle and drawn in at the plantar -border is, as a rule, too high and too near the centre of the foot -(too narrow); the opposite wall, on the contrary, is too low and too -far from the centre of the foot (too wide). This explains the manner -in which the hoof should be cut down and rasped. The shoe must be laid -out as far as possible towards the side which is too high and narrow. -A straight edge placed against the high wall touches it only at its -middle. The distance of this line from the lower edge of the wall shows -us how far the surface of support—namely, the shoe—should be set out -beyond the horn. If the straight edge be placed against the opposite -wall, it will touch only at the coronet and at the plantar border, -showing that the wall is concave. The distance of the middle of this -wall from the straight edge shows us how much too wide this half of -the wall is at its plantar border, and how much of the outer surface -of the wall at its plantar border should be removed with the rasp. -The restoration of a crooked hoof to its normal form requires several -shoeings. - - -6. OSSIFICATION OF THE LATERAL CARTILAGE (SIDE-BONE). - -The ossification of a lateral cartilage (Fig. 213) consists in a change -of the cartilage into bone. Heavy horses are more frequently affected -than lighter ones. It most often involves the outer cartilages of the -forefeet, seldom both cartilages. Side-bones always interfere with the -physiological movements of the foot, and may, indeed, entirely suppress -them. - -[Illustration: FIG. 213. - -A left fore os pedis viewed in profile, showing ossification of the -external lateral cartilage: _a_, dotted line shows normal line of -union of cartilage with wing of os pedis; _b_, ossified portion (“side -bone”). The unossified cartilage has been removed by maceration.] - -The disease can only be diagnosed with certainty after the upper part -of the cartilage has ossified. The coronet is then rather prominent -(bulging), and feels hard. The gait is short, and cautious, and -well-marked lameness often follows severe work. As _causes_, may -be mentioned predisposition in heavy lymphatic horses, and violent -concussion or shock due to fast work upon hard roads. The disease is -_incurable_. - -A special method of shoeing is only necessary when the outer cartilage -is ossified and the quarter upon that side is contracted. After -removing the old shoe, whose outer branch is, as a rule, more worn away -than the inner, the outer wall will always be found too high, due to -the fact that there has been little or no expansion and contraction -in this quarter and, therefore, little or no wear of the horn against -the shoe. The hoof is therefore wry,—on the outside too high, and on -the inside too low. This shows us how the foot should be dressed so -as to obtain a proper base of support and a uniform wear of the shoe. -The most suitable shoe is a _flat shoe_, whose outer branch must be -wider than the inner. It is so applied that the inner branch follows -the edge of the wall closely, while the outer branch must be full -and at the quarter must extend beyond the wall far enough to touch a -perpendicular line dropped from the coronet (Fig. 215). The shoe must, -therefore, be punched deep (coarse) on the outer branch and fine on -the inner. A side-clip must be placed on the outer branch, because in -time the outer half of the hoof will again be too high. _Bar-shoes and -rubber pads are injurious when both cartilages are ossified_, but may -be used when there is partial ossification of _but one cartilage_, -especially if corns are present. - -[Illustration: FIG. 214. Right fore-hoof whose form has changed as a -result of ossification of the external lateral cartilage.] - -[Illustration: FIG. 215. Shoe with broad outer branch, for the hoof -shown in the preceding cut.] - - -B. Disturbances of Continuity of the Hoof. - - -1. CRACKS. - -Interruptions of continuity of the wall extending in the direction of -the horn-tubes are known as cracks or seams. They have, according to -their location, degree, and extent, not only various names, but also a -varying significance. - -_Occurrence._—On the inner side of front hoofs, especially of horses -that stand base-wide; on hind hoofs, usually at the toe. - -[Illustration: _Fig. 216._ - -Hoof exhibiting a coronary crack, a plantar or low crack, and a -complete deep crack, the latter with a nail ready to be clinched.] - -_Classification._—According to location we distinguish toe-cracks, -side-cracks, quarter-cracks, and bar-cracks. Those cracks which affect -only the upper border of the hoof are called _coronary cracks_; those -which are limited to the lower border of the hoof are sometimes -designated _low cracks_ (plantar cracks); while those which are -continuous from one border to the other are called _complete cracks_. -If the crack passes through the entire thickness of the wall to the -sensitive tissues underneath, it is called a _deep_ or _penetrating -crack_, in contradistinction to the _superficial crack_ (Fig. 216). - -_Causes._—There are many. Besides wounds of the coronet, everything -that impairs the elasticity of the horn, weakens the hoof, and causes -an overloading of one-half of the hoof. Furthermore, great dryness and -excessive work on hard streets. - -_Prognosis._—This will depend upon the age, kind, and location of the -crack. A _low crack is without significance_ unless it is the remnant -of an old coronary crack which has grown down. _Coronary cracks_, on -the contrary, _are more serious_ because of the lameness which often -accompanies them, and especially on account of the long duration of the -healing process. - -The borders of the crack =never= grow together, and healing can only -take place through healthy, unbroken horn growing down from the -coronary band. - -(_a_) _Treatment of Coronary and Bar-Cracks._—If practicable, allow the -affected horse to go barefoot; otherwise, the use of the =bar-shoe= -for _all cracks_ is advised, because it will continuously protect the -diseased section of wall from pressure by the shoe. If there are -present still other diseases of the hoof (corns, contraction, flat or -full hoof), the addition of a leather sole with packing will be most -beneficial, not only in favoring the healing of the crack, but also in -improving the form of the hoof and in favoring the cure of the other -lesions. In all coronary cracks it is of advantage to assist healing -by fastening or immobilizing the borders of the crack by one of the -following methods: - -1. By rivets (nails), which pass across the crack through holes -previously drilled in the horn (Fig. 217). - -2. By clamps or hooks, which by means of special pincers are forced -into pockets previously burnt into the horn on opposite sides of the -crack (Fig. 219, B). - -3. By a thin iron plate placed across the crack and secured by small -screws, such as are used in wood (Figs. 220, 221). - -4. By means of a bandage to last one shoeing. - -=Toe-crack= occurs most often in draught horses and most frequently -in the hind feet. In shod hoofs it starts at the coronary border, and -unless proper treatment is instituted soon reaches the plantar border. -Long toes and low quarters and excessive dryness of the horn are -predisposing causes. The exciting cause is usually forward pressure -of the upper end of the short pastern against the thin upper edge of -the wall of the toe. In the last part of the phase of contact of hoof -with ground the pasterns are upright, or may even incline downward -and backward (foot-axis broken strongly backward), the short pastern -presses the coronary band firmly against the upper thin edge of the -toe, when if brittle through dryness it is unable to stretch and tears -asunder. Thus, under the effort of starting a heavy load, when a horse -with all four legs flexed has risen upon the points of his toes, a -short quick slip followed by a catch, will frequently start a crack at -the coronet. - -The hoof should be so dressed and shod that the foot-axis shall be -straight when seen from the side. In hind feet it is admissible to -break the foot-axis slightly forward. Therefore, shorten the toe and -spare the quarters. If the latter are deficient in length, raise them -by swelling the branches or by low heel-calks. - -[Illustration: FIG. 217. - -Toe-crack immobilized by lateral toe-clips: _a_, bearing-surface left -free from pressure; _b_, heads of the rivets (nails) driven through -holes previously drilled.] - -The shoe may be open, or a bar-shoe, or a short shoe with a rubber -frog- and buttress-pad. Whatever expands the quarters closes a -toe-crack. The Defay’s shoe (Fig. 206), or the Chadwick spring beneath -a rubber pad, or beneath a bar-shoe with leather sole, if the frog -be much shrunken, will be of service. The shoe should fit air-tight, -except for an inch or so on both sides of the crack. Two lateral -toe-clips (Fig. 217) are drawn up, and the wall between these clips is -cut down from a twelfth to an eighth of an inch. - -[Illustration: FIG. 218. - -Spiral drill for boring the hole into which a round wire nail is driven -to fasten a toe-crack: (_a_) three sided point of drill (similar to the -point of a stilet of a cæcal trocar).] - -After the shoe has been nailed on tight the toe-crack should be -immobilized. The best method is by buried nails. Slots are burned or -cut on opposite sides at a distance of an inch from the crack. With a -spiral drill (see Fig. 218) bore a hole from a slot at right angles to -the crack. Make a similar hole on the opposite side. Make the holes -continuous by introducing a straight hot wire. The rivet may be an -ordinary round wire nail which has been softened by bringing it to a -yellow heat and allowing it to cool slowly. It is driven through and -the ends firmly clinched. Such a nail is easily placed, need not press -upon fleshy leaves, can not be stripped off or lost, and holds fast. -The horse should stand on the foot while the rivet is being clinched. -Two are sufficient for a complete crack (Fig. 217). - -[Illustration: FIG. 219. - -_A_, Vachette burning iron for making the two slots to receive the -ends of the hook; _b_, shoulder; _B_, Vachette hook; _C_, pincers for -forcing the hook into the wall.] - -A more rapid, though less efficient method of immobilizing a toe-or a -quarter-crack is by the use of the Vachette hook. A special apparatus -is required (see Fig. 219). The burning iron (Fig. 219, _A_) is brought -to a yellow heat, its end applied to the wall so that the two ears are -on opposite sides and equidistant from the crack, when it is pressed -firmly till the shoulder (Fig. 219, _b_) touches the surface of the -wall. A Vachette hook, the distance between the points of which equals -the distance between the ears of the firing iron, is seized by the -special pincers (_C_), pressed into the slots burned to receive it, and -is then driven into the horn by compressing the pincers. At the toe -these hooks are frequently stripped off by the heels of the opposite -shoe (in hind feet). Free application of hoof ointment, and maceration -of the horn by melting snow or mud tends to loosen them so that they -often drop out. - -An efficient method of fastening either a toe-or a quarter-crack -is by using a metal plate one-sixteenth (¹/₁₆″) of an inch thick, -provided with four to eight holes for the reception of screws four- to -five-sixteenths of an inch long. The plate is heated, bent to conform -to the curvature of the wall and pressed against the horn till it -burns a bed for itself, when it is screwed fast. It will not loosen -(see Fig. 220, _b_). In every complete crack of the wall the growing -down of coherent horn is favored by thinning the horn for an inch on -both sides of the crack directly over the coronary band (see Fig. 221, -_a_), so that any gliding movement between the sides of the crack below -can not be transmitted through the thinned area to the crack in the -velvety tissue of the coronary band. Cutting a “V” at the coronet acts -similarly, but is less efficient. - -[Illustration: Fig. 220. - -Hoof with coronary quarter-crack, shod with a bar-shoe. The part of the -quarter relieved of pressure _a_, is indicated by the dotted lines; -_b_, iron plate secured by small wood screws ⁴/₁₆-⁵/₁₆ of an inch in -length.] - -[Illustration: FIG. 221. - -Hoof with complete quarter-crack, shod with a bar-shoe: _a_, area -thinned almost to the pododerm; _b_, ¹/₁₆ inch metal plate secured by -screw ⁵/₁₆ of an inch long; _c_, quarter relieved of pressure from -bottom of crack to a perpendicular dropped from top of crack.] - -=Quarter-crack= is usually associated with contraction of the heels. It -occurs on the inner quarter of base-wide (toe-wide) hoofs, and rarely -in the outer quarter of base-narrow hoofs. For quarter-cracks we use a -bar-shoe and determine the extent of the wall to be laid free in the -following manner: We imagine the crack to be prolonged in the direction -of the horn-tubes to the plantar border, and drop a perpendicular line -from the upper end of the crack to the plantar border. That part of the -plantar border lying between these two points is then to be lowered -sufficiently to prevent pressure from the shoe until the next shoeing -(Figs. 220, _a_, and 221, _c_). - -This method should be followed even when the perpendicular line falls -behind the buttress. - -The crack may be immobilized by the metal plate, or by narrow ticking -bandage or adhesive tape wound a half dozen times around the hoof, in -conjunction with a bar-shoe, Chadwick spring, leather sole and tar and -oakum sole-packing. - -In dressing the hoof, the side containing the crack should be spared, -the opposite side lowered, the object being to shift the weight and -consequent expansion into the sound quarter. When the affected quarter -is deficient in length the branch of the shoe beneath should be made -thicker, even to the extent of causing it to ground in advance of the -opposite branch. - -Next to shoeing, rubber hoof-pads render good service, because through -them a part of the body-weight is distributed over the sole and frog. -They assist in widening the hoof, and lessen shock when the foot is set -to the ground. These are all matters which favor the growing down of -unbroken horn. - -When the crack gaps widely, and the frog is small and deep in the foot -_a shoe with bar-clips_ (Defay’s shoe), or a Chadwick spring, with -bar-shoe and leather sole may be used. It is not impossible, indeed, -to obtain a cure by using an ordinary open flat shoe, though much will -depend upon the other lesions that may be present, the nature of the -hoof, and the service required of the animal. - -If the edges of the crack are irregular and overlapping, they should be -carefully thinned away. Thinning the horn on both sides of the crack -over the coronary band, preventing drying out of the horn, and frequent -applications of carbolized oil to the coronet favor growth of undivided -horn and guard against a renewal of the crack. - -If in the beginning of the disease there is inflammation and lameness, -cooling poultices should be used for several days. When there is no -lameness, the horse may be used for slow draft purposes. _Coach-and -saddle-horses should be kept from fast work until sound horn has grown -down at least one-half of an inch from the coronet._ - -_Bar-cracks_ are usually the result of changes of position of the -quarters, and are just as frequently brought about by contraction as -by leaving the quarters too high. We see them almost entirely upon the -fore-hoofs. They seldom occur alone, but are usually accompanied by -corns. When the crack extends to the pododerm there is a superficial -inflammation of the pododerm and lameness. When treatment is not -promptly begun the inflammation extends to the deeper layers of the -pododerm, or, indeed, even to the plantar cushion, and gives rise to -swelling of the bulb of the heel upon that side and to a well-marked -lameness, which requires treatment by a competent veterinarian. - -Ordinarily a bar-crack is only found by a close examination of the -hoof after the shoe has been removed. In paring the hoof the crack -usually appears as a dark streak, sometimes as a bloody fissure; not -infrequently grayish hoof-pus is discovered in the depths of the crack. - -The treatment must be directed towards favoring the growth of a -continuous (unbroken) bar. This is accomplished by completely removing -the edges of the crack, paring the horn of the vicinity very thin, and -preventing the least pressure upon the wall of this quarter by the -shoe, by lowering this quarter with the rasp and applying a =bar-shoe= -with leather sole. - -Following the removal of the edges of the crack there often appears, -especially in stumpy hoofs, a deep groove; if the bottom of this groove -is moist, we should pack it with oakum wet with a five per cent. -solution of creolin or carbolic acid, and cover the oakum with wax -(grafting-wax). The cracks will return if the exciting causes cannot be -completely removed. - -(_b_) _Treatment of Low Cracks (Plantar Cracks)._—These cracks, -occurring principally upon the hoofs of unshod horses, are the result -of excessive stretching and bending of the lower border of the wall. -Insufficient rounding of the wall with the rasp is largely responsible -for them. An exciting cause in shod horses is the use of too large -nails in shoes that are punched too fine. - -Every coronary crack becomes in time a low or plantar crack, and this -has an important bearing upon the prognosis, because a renewal of the -coronary crack will be followed by a low crack. - -In order to remove these cracks it is sufficient merely to shoe the -horse. Upon shod horses they may be prevented by using properly punched -shoes and thin nails. The lower border of the wall near the crack -should be relieved of pressure by cutting out a half-moon-shaped piece -of horn. To prevent the crack from extending farther upward we may burn -a transverse slot at the upper end of the crack, in as far as the leafy -layer of the wall, or cut such a slot with a small hoof-knife. - - -2. CLEFTS. - -An interruption of continuity of the wall, at right angles to the -direction of the horn-tubes, is called a _cleft_. - -Clefts may occur at any part of the wall; yet they occur most often -upon the inner toe and inner side, as a result of injury from sharp, -improperly placed heel-calks (see page 173). However, suppurating -corns, or other suppurative processes situated at the coronet or which -find their point of escape at the coronet, may from time to time lead -to separations of continuity and the formation of horn-clefts. - -[Illustration: FIG. 222. Hoof with clefts of the toe and side wall.] - -Horn-clefts, though the result of lesions which are often very -injurious and interfere with the use of the horse, are of themselves -not an evil which can be abolished or healed by shoeing, although, in -many cases, proper shoeing would have prevented them. A horn-cleft is -not a matter for consideration by the shoer until it has grown down so -far that it comes within the region of the nails. - -In order not to disfigure the hoof unnecessarily, the horn below the -cleft should be kept in place as long as possible by shortening the -wall at that point, to remove shoe-pressure, and by driving no nails -into it. If, however, the horn is loose and about to come away, it -should be removed and the defect filled with Defay’s patent horn-cement. - - -3. LOOSE WALL. - -Separation of the wall from the sole _in the white line_ is called -loose wall (Fig. 223, _a_). - -_Occurrence._—Frequent on the fore-hoofs of shod and unshod horses, -and oftener upon the inner than upon the outer side. More rare on hind -hoofs. Common-bred horses with wide and flat feet are predisposed to -this trouble. - -We distinguish _superficial_ and _deep loose wall_; only the latter -requires the shoer’s attention, because it leads to lameness. - -_Causes._—Walls which are very oblique (slanting); outward bendings of -the plantar border of the wall; burning the horn with hot shoes; -dryness; neglected shoeing; excessive softening of the horn with -poultices, particularly of cow-dung; carelessness in preparing the -bearing-surfaces of hoof and shoe in shoeing; uneven fitting of the -shoe. - -_Treatment._—It aims to remove the lameness and to favor growth of -coherent horn. In the first place the removal of the exciting causes, -followed by proper shortening of the wall. We should apply a shoe whose -bearing-surface _inclines slightly downward and inward_, is perfectly -smooth, and wide enough to cover the wall, white line, and outer border -of the sole; the iron should be only moderately warm. Where there is -lameness we use a leather sole with packing, or a =bar-shoe=. The loose -wall should be freed from shoe-pressure only when it does not extend -far along the white line. When the separation is extensive the loose -wall should not be lowered. The crack should be filled with wood-tar, -crude turpentine, or soft grafting-wax. - -If a loose wall occur upon the foot of a horse while running barefoot, -all separated horn should be removed; if, on account of the nature of -the ground, this seems to be impracticable, the hoof must be shod. - -_Care of the Hoof._—Shoe at least every four to five weeks. Preserve -the pliancy and toughness of the horn by judicious moistening. - - -4. HOLLOW WALL. - -A _hollow wall is one in which a separation has occurred between the -middle layer of the wall and the keraphyllous layer_. This crack or -separation always extends in the direction of the layers of the wall -(Fig. 223, _b_). - -[Illustration: FIG. 223. An imaginary transverse vertical section of a -hoof showing (_a_) loose wall and (_b_) hollow wall.] - -_Occurrence._—Quite rare. - -We should suspect a hollow wall when a part of the wall _rounds out -prominently beyond the rest_, and gives forth a hollow (resonant) sound -when struck. The white line presents a crack, yet we should hesitate to -form a conclusion as to the extent of the separation from the extent of -the crack along the white line, since the latter may be considerably -smaller. The separation extends higher up the wall than in the case of -loose wall, frequently to the coronet. The cavity is usually filled -with crumbling, disintegrated horn. - -Hollow wall is not often accompanied by pain. Lameness may arise, -however, if the hollow section of wall assists in bearing the -body-weight, and if the animal does fast work upon paved streets. - -_Causes._—Mechanical influences resulting in chronic inflammation of -fleshy leaves. - -_Treatment._—A cure is possible, but requires considerable time. In -shoeing, which should always aim to _relieve pressure_ from the hollow -section of wall, we cleanse the cavity and fill it with oakum and tar, -crude turpentine, or wax. Where the separation is very extensive we use -a _bar-shoe_. - -The time required for complete cure of hollow and loose walls will -depend upon the height of the separation (see growth of the hoof, page -82). - - -5. THRUSH OF THE FROG. - -When the horny frog is ragged and fissured, and an ill-smelling, -dark-colored liquid collects in the lacunæ of the frog, it is affected -with thrush. When thrush exists uninterruptedly for several months the -perioplic band is irritated and forms rings of periople which assume an -irregular course and cross the rings of the middle layer of the wall -(Fig. 224). - -[Illustration: FIG. 224. Hoof with irregular superficial rings -resulting from thrush of the frog.] - -The _causes_: uncleanliness, =too little exercise= in fresh air, -excessive paring of the frog, and the use of shoes with calks by which -the frog is permanently removed from the ground. - -The _consequences_ are, besides contraction of the hoof, soreness in -travelling, a shortening of the step, and, occasionally, well-marked -lameness. - -_Treatment._—Removal of all greasy horn from the frog, and of the -prominent overgrown angles of the buttresses (see page 100), thorough -washing of the frog once or twice daily with a 5 per cent. creolin or -carbolic solution, =abundant exercise=, and shoes without calks. - - - - -CHAPTER X. - -SHOEING MULES, ASSES, AND OXEN. - - -1. The shoeing of mules and asses is, as in the case of horses, a -necessity if these animals are to be used for draft or saddle purposes -on hard streets. The structure and characteristics of the hoofs of -these animals are quite similar to those of the horse, differing -chiefly in the form and thickness of the wall. The mule hoof is long -and narrow and round at the toe, the sole is well arched, and the side -walls are rather steep (Fig. 225). In the ass the narrowness of hoof -is still more pronounced, the wall is relatively =thick=, the frog is -particularly well developed in its branches, and therefore the hoof is -relatively wide in the region of the quarters. The horn of both mule -and ass is tough. - -The shoes differ from those of the horse in no other respect than that -they should be lighter and narrower. Four nail-holes are sufficient for -an ass’ shoe, and five to six for a mule’s. - -On account of the hardness and toughness of the walls, we use nails -that are short but strong in the shank; nails with weak shanks are apt -to bend in driving. - -[Illustration: FIG. 225. A mule’s hoof. (Plantar surface).] - -[Illustration: FIG. 226. A shod ox-claw.] - -2. _The shoeing of oxen_ is essentially different from that of horses, -because the foot of the ox is cloven (split), the long pastern, short -pastern, and hoof-bone are double, so that, instead of one hoof or -claw, there are two upon each foot, distinguished as outer and inner. -Each claw consists of wall, sole, and bulbs; the frog is absent. The -wall is considerably thinner than that of the horse’s hoof, the sole is -thin, and the bulbs are low. For these reasons the shoe designed for a -claw must be thin, but wide. - -The holes must be punched fine and the nails be quite short and strong. -On each shoe a long tongue should be made on the inner edge near the -toe, and so directed that it can be turned upward and outward to -embrace the toe of the claw. A small clip raised on the outer toe of -each shoe will increase its stability. In some parts of Saxony the -shoes are so made that the tongue of each shoe begins in the rear -third of its inner edge and runs forward, upward, and outward, closely -embracing the wall of the toe. The smaller clip is drawn up on the -outer edge of the shoe close to the toe. These shoes are more difficult -to make, but when applied sit more firmly and remain fast longer than -all others. Machine-made ox shoes (Fig. 227) have no clip at the inner -toe, and are frequently pulled and lost. For this reason they are -inferior to hand-made shoes. An undivided shoe (the so-called “closed -claw-shoe”) is unsuitable for oxen, because it deprives both claws of -their natural, free movements. However, such a shoe is of advantage -for heavy draft over hard and very rough roads, because it lessens the -liability of the fetlock and coronary joints and the cleft of the claws -to strains. - -[Illustration: FIG. 227. - -Pair of machine-made ox shoes, viewed from the ground-surface and in -profile; _a_, toe-calk; _b_, heel-calks.] - -Great difficulty is often encountered in holding the feet during the -operation of shoeing. It is necessary to fasten the head securely -against a tree, post, or wall. A front foot may be raised and held -by passing a slip-noose in the end of a rope or side-line around the -fetlock and carrying the line over the withers to the opposite side, -where it is held by an assistant. A hind limb may be controlled by -passing a round pole in front of the hock of the leg to be raised, -and, with a man at each end of the pole, carrying the limb backward -and upward, in which position it is held; or the limb may be bent and -controlled by tightening a twitch or tourniquet upon the leg just above -the hock (Fig. 228). Oxen that continue to resist may sometimes be -quieted by light blows of a short stick upon the base of the horns. In -parts of the country where many oxen are shod stocks are in common use. - -[Illustration: FIG. 228. Hind foot raised by means of a round pole.] - -Very satisfactory stocks have been designed by Gutenaecker, of Munich -(Fig. 229). The four corner-posts (_a_, _a_, _b_, _b_) are eight -inches square and eight feet long, of which three feet four inches -are solidly implanted in the ground. They are united by side- and -cross-bars (_c_, _c_, _d_). In front of the corner-posts (_a_, _a_) -and in the middle line stands a head-post (_e_) of the same dimensions -as the corner-posts, provided with a slot four inches wide and twenty -inches long beginning three feet from the ground. In this slot is -a pulley-wheel (_i_), and below it a windlass (_k_) for winding up -the rope which is tied around the base of the animal’s horns. The -corner-posts are provided with a slot (_n_) three inches wide and -three inches deep, within which are placed two movable side-bars (_o_, -_p_), which can be set at desired heights and fastened by iron pins. -Between the front and rear corner-posts of the right-hand side is an -eight-sided roller with a ratchet and click at one end, and having on -one of the sides six iron hooks, to which a girth is attached. On the -opposite side of the stocks, at the same height, is a stationary bar -(_f_) with six hooks (_g_, _g_) on the outer side. The belly girth is -six feet long, six inches wide, and terminates at both ends in several -strong cords two feet four inches long with iron rings at their ends. -Between the front corner-posts are a neck-yoke (_h_) and a breast-bar -which slide in the slots (_m_) and may be fixed at desired heights -by iron pins. On the rear face of each rear corner-post is an iron -bracket (_s_) one foot and a half long, with a ring (_t_) six inches in -diameter, through which passes a round pole padded in the middle and -kept in place by two iron pins. Above each bracket is a hook (_u_) to -which the end of the breeching attaches. - -[Illustration: FIG. 229. - -Gutenäcker’s stocks for oxen: _a_, front corner-posts; _b_, rear -corner-posts; _c_, _d_, connecting bars; _e_, head-post; _f_, bar -for holding belly girth; _g_, hooks for girth; _h_, neck-yoke; _i_, -pulley-wheel; _k_, windlass with ratchet and click; _m_, slot for -neck-yoke and breast-bar; _n_, slot for movable side-bars; _o_, _p_, -side-bars; _r_, hook for fetlock strap; _s_, iron bracket; _t_, iron -ring for rear cross pole; _u_, hooks for breeching.] - -Before an animal is brought into the stocks the neck-yoke is raised, -the breast-bar lowered, and the girth left hanging from the hooks on -the stationary bar. The ox is then led into the stocks and the rope -which is tied around the base of the horns is carried over the pulley -(_i_), fastened to the hook on the roller (_k_), and wound up till the -head is tight against the head-post. The yoke and breast-bar are then -placed in position and fastened, the breeching hung on the hooks (_u_), -and the belly girth attached to the hooks on the roller, so that, if -need be, it can be shortened till it bears the animal’s entire weight. - -To control a front foot a slip-noose is placed about the fetlock and -the limb is raised and lashed to the side-bar, the rope passing finally -to the hook (_r_). To control a hind foot a slip-noose is placed -about the fetlock, the foot carried upward and backward over the rear -cross-bar, and, with the front surface of the fetlock-joint resting -against the padding of the bar, the limb is firmly secured by wrapping -the line several times about the limb and bar. - -When no stocks are at hand, we may use an ordinary farm wagon or a -truck wagon. Tie the ox with his head forward between the front and -hind wheels. Fasten the large end of a binding pole to the spokes of -the front wheel and let it rest on the hub. Swing the pole close to the -ox and induce him to step over it with one hind leg, then raise the -rear end of the pole, and with it the leg and so much of the animal’s -hind quarters that the inner hind leg standing close to the wagon rests -but lightly upon the ground. The binding pole may then be slung with -a rope from the rack of the wagon or other stationary object and the -outer limb held in the usual manner. By following this method a shoer -with one assistant can easily and safely control the most refractory -oxen. - - - - -INDEX - - - Apprentice, 14 - Arteries, 41 - Articulations, 21 - - Balanced hoof, 101 - Balling with snow, 149 - Bar-shoe, uses of, 164 - Bare foot, preparing the hoof, 102 - Bars, 51 - dressing, 99 - Base-narrow position, 63, 68 - Base-wide position, 63, 68 - Beaked shoe, 184 - Bear-foot, 72 - Bearing-surface of shoes, 117, 127 - Blood-vessels, 41 - Bow-legged position, 64 - Buttress, 100 - - Calf-kneed, 66 - Calk-wound, 173 - Camped behind, 68 - in front, 66 - Cannon bone, 20, 21 - Carpus, 20 - Cartilages, lateral, 39 - Cast iron, 103 - shoes, 132 - Chadwick spring, 187 - Clefts, 203 - Clinch cutter, 97 - Clinching, 131 - Clips, 111 - Close-nailing, burning, 166 - Contracted hoof, 185 - sole, 190 - Corn, chronic, 175 - dry, 174 - suppurating, 174 - Corns, 174 - treatment, 176 - Coronary band, 47 - joint, 31 - ligaments, 31 - Cover-plate shoe, 173 - Cow-hocked, 68 - Cracks, 195 - coronary and bar, 196, 202 - plantar, 202 - Crest, semilunar, 27 - Crooked hoof, 192 - Cross-firing, 140 - - Defay’s shoe, 187 - Diseases of hoof, 165 - Dressing the hoof, 98 - Driving the shoe, 130 - Drop-forged shoes, 132 - Dropped sole, 178, 182, 183 - - Elastic parts of foot, 38 - Examination before shoeing, 90 - - Feet, forms of, 69 - Femur, 20 - Fetlock, ligaments of, 29 - joint, 28 - Fiber shoes, 134 - Fibula, 20 - Flat hoof, 182 - Fleshy frog, 49 - sole, 49 - wall, 48 - Flight of hoofs, 72, 75 - Foot, articulations of, 28 - bones of, 24 - Foot-axis, 70 - relation to sole, 100 - straight and broken, 101 - Forging, 138 - Founder, 177 - dressing hoof, 179 - shoeing, 180 - Frog, 57 - dressing, 99 - Front shoe, making, 105 - Frost-nails, 146 - Full hoof, 183 - Fullering, 109 - hammer, 104 - - Gathered nail, 170 - - Hair-skin, 44 - Head, bones of, 17 - Heavy draught horses, shoeing, 125 - Heel-calks, 112 - always sharp, 154 - Heels, inflammation of, 176 - Hind shoe, making, 107 - Hock, 21 - Hollow wall, 205 - Hoof, 50 - benefits of movements within, 89 - crooked, 84 - growth of, 82 - healthy, 81 - irregular growth, 83 - knife, 98 - ointments, 159, 160 - physiological movements of, 86 - wear against shoe, 86 - wear of, 82 - Hoof-skin, 45 - Hoofs, care of unshod, 157 - Hoofs, forms of, 77, 80 - of colts, care of, 157 - Horn, minute structure of, 58 - qualities of, 59 - tumor, 181 - Horseshoeing, object of, 13 - schools, 15 - Horseshoer, requisites of, 14 - Humerus, 19 - Hunters, shoeing, 123 - - Interfering, 142 - Iron for horseshoes, 103 - - Joints, free, hinge, and pivot, 22 - - Keraphyllocele, 181 - Knee-sprung, 67 - - Laminitis, 177 - Leather sole, 164 - Ligaments, 21 - Limbs, standing positions, 62 - Loose wall, 204 - Low-jointed, 66 - - Mucous bursæ, 35 - Mule shoes, 207 - Muscles, 22 - - Nail-holes, 110 - Nailing, 166 - causes of, 167 - examination and treatment, 167, 168 - Nails, 128 - Navicular bone, 28 - Nerves, 44 - Nippers, 99 - Normal position, 62, 64, 67, 69 - - Os pedis, 26 - Ox shoes, 208 - Oxen, securing feet, 209 - - Pacers, shoeing, 124 - Pads, rubber, 135 - Pastern, long, 25 - short, 26 - Patella, 20 - Pedal joint, 31 - ligaments, 31 - Peg-calks, 150 - Peg toe-calks, 152 - Pelvis, 19 - Periople, 53 - Perioplic band, 47 - Periosteum, 21 - Pigeon-toed position, 64 - Pincers, 97 - Plantar cushion, 40 - Pododerm, 45 - Pododermatitis, symptoms of, 161 - treatment of, 163 - Podophyllous tissue, 48 - Podometer, 105 - Pricking, direct nailing, 166 - Pritchel, 105 - Protective organs of foot, 44 - Punch, 105 - - Quarter-crack, 200 - Quarters, contraction of, 186 - - Radius, 20 - Raising feet in shoeing, 92 - Removing shoes, 97 - Rolled toe, 118 - Rope shoes, 133 - Rubber shoes, 134 - Runners, 123 - - Saddle-horses, shoeing, 122 - Scapula, 19 - Screw heel-calks, 148 - Seedy-toe, 178 - Sesamoid bones, 25 - ligaments, 29-31 - Sharp toe- and heel-calks, 146 - Shod hoofs, care of, 159 - Shoe, choosing the, 116 - for acute-angled hoof, 114, 120 - for base-narrow hoof, 114, 121 - for base-wide hoof, 114, 121 - for narrow hoof, 115, 121 - for regular hoof, 114, 120 - for stumpy hoof, 114, 120 - for wide hoof, 115, 121 - parts of, 103 - wear of, 84 - weight of, 116 - Shoeing defective hoofs, 161 - Shoes, fitting, 118 - general properties, 107 - machine, 132 - making, 103, 105 - nailing, 128 - removing old, 97 - shaping and fitting, 117, 120 - special properties, 114 - Sickle-hock, 68 - Side-bone, 194 - Sole, 55 - contraction of, 189 - Spinal column, 17 - Splint-bones, 20 - shoe, 172 - Standing under, 66 - Station of rest, 65 - Steel, 103 - Stocks, for horses, 95 - for oxen, 209 - Stifle-joint, 20 - Stilt-foot, 184 - Street-nail, 170 - Stride, height of, 75 - length of, 75 - Stumpy hoof, 184 - Suspensory ligament, 29 - altering tension of, 36-38 - Synovia, 21 - - Tendon, anterior extensor, 32 - deep flexor, 33 - lateral extensor, 32 - sheaths, 35 - superficial flexor, 33 - Tendons, 24 - Tension of tendon, altering, 36 - Thorax, 18 - Thrush, 206 - Tibia, 20 - Toe- and heel-calks, 112 - Toe-calk, blunt, 113 - half-sharp, 113 - sharp, 112 - Toe-crack, 197 - Tools for making shoes, 104 - Tread, 173 - Trotters, shoeing, 124 - Trunk, 17 - Tubbing and stopping, 159 - - Ulna, 20 - - Vachette hook, 199 - Veins, 43 - Velvety frog, 49 - sole, 49 - - Wall, 51 - dressing, 99 - height of, 52 - leafy layer, 53 - protective layer, 53 - slant of, 52 - thickness of, 53 - Weight, influence of, 75 - Weights, side and toe, 77 - White line, 56 - Wide hoofs, contraction of, 189 - Wry hoof, 193 - -*** END OF THE PROJECT GUTENBERG EBOOK A TEXT-BOOK OF HORSESHOEING *** - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the -United States without permission and without paying copyright -royalties. 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