THE ARMY HORSE IN ACCIDENT AND DISEASE A MANUAL PREPARED FOR THE USE OF STUDENTS OF THE TRAINING SCHOOL FOR FARRIERS AND HORSESHOERS BY THE TRAINING SCHOOL INSTRUCTORS 1909 ' ^ < Webster Family Library of Veterinary Medicine Cummings School of Veterinary Medicine at Tufts University 200 Westboro Road North Grafton, MA 01536 TUFTS UNIVERSITY LIBRARIES 3 9090 014 529 70 i/Vebs Cumri Ms 200 V! \10f1h THE ARMY HORSE IN ACCIDENT AND DISEASE EDITION: 1909 A MANUAL PREPARED FOR THE USE OF STUDENTS OF THE TRAINING SCHOOL FOR FARRIERS AND HORSESHOERS BY THE TRAINING SCHOOL INSTRUCTORS MOUNTED SERVICE SCHOOL FORT RILEY, KANSAS MILITARY PUBLISHING CO. 42 BROADWAY New York PREFACE TO REVISED EDITION, 1906. This manual, as originally compiled l)y Alexander Plummer, D. V. S., veterinarian Fourth Cavalry, and Richard H. Power, V. S., veterinarian Artillery Corps, was pub- lished in 1903. In this edition the work has been revised by the compilers, assisted by Charles 11. Jewell, D. V. M., veterinarian, Thirteenth Cavalry, and Capt. Geo. H. Cameron, Fourth Cavalry, secretary. Matter from the companion text-book, '"The Army Horseshoer," has been substi- tuted in several places for that of the original. An original chapter on Tropical Diseases, by Veterinarian Jewell, and many illus- trations from photographs and drawings, have been added. Captain Cameron, in addition to his work on the revision of the text, made the original drawings and prepared the others for reproduction. His valuable assistance is here acknowledg(?d. The greater part oi the photographic work was done by First Lieut. S. B. Pearson, Ninth Cavalry. The arrangement of tlie text has been adapted to the course of practical instruction, and the language, as far as possible, to study by men who, as a rule, have had limited educational advantages. , School of Application for Cavalry and Field Artillery, Fort Kilt'!/, Kans., Decernhrr JO, 1905. PREFACE TO REVISED EDITION, 1909. In this edition- a few errors of plates and text have been corrected, and certain parts of the text have been rewritten as the result of the class room experience of the instructors, \'eterinarian Alexander Plummer, Fourth Cavalry, and Veterinarian Charles II. Jewell, Sixth Field Artillery (horse). A chapter on Age by the Teeth, compiled by the secretary, First Lieut. Robert M. Danford-, Fifth Field Artillery, has been added. Plate IX has been redrawn and Plate XIX, prepared by Capt. Geo. H. Cameron, P'ourth Cavalry, assistant comman- dant. Mounted Service School, Fort BUey, Kans., Jubj .W, 1909. 3 AUTHORITIES CONSULTED. BcEEAU OP Animal Industry: Special Report on Diseases of the Horse. Cadiot: a Treatise on Veterinary Therapeutics of the Domestic Animals. Chauvbau: Comparative Anatomy of Domesticated Animals. Dun: Veterinary Medicines, Their Actions and Uses. Fleming: Operative Veterinary Surgery. Friedburger and Frohner: Pathology and Therapeutics of the Domestic Animals. GouBAUx AND Barrier: The Exterior of the Horse. (Translation.) Law: Veterinary Medicine. Liautard: Manual of Veterinary Surgery. Moller: Operative Veterinary Surgery. (Translation.) Neumann: Parasites and Parasitic Diseases of the Domesticated Animals. Quitman : Notes on Veterinary Medicine. Smith: Veterinarj' Hygiene. Smith: A Manual of Veterinary Physiology. Strangeway: Veterinary Anatomy. Williams: Principles and Practice of Veterinary Medicine and Surgery. Winslow: Materia Medica. Wyman: Diagnosis of Lameness in the Horse. 4 CONTENTS, Chapter I.— Conformation and Points. Defects and Blemishes. II.— Stable Management of the Sick and Injured. III.— Anatomy. IV.— Administration of Medicines. Weights and Measures. v.— Wounds, Sprains, Bruises, Abrasions, and Abscesses. VI -Diseases of the Respiratory System and Influenza. VIL-DisEASES of the Digestive, Urinary, Nervous, and Lymphatic Systems. VIII.— Miscellaneous Diseases. IX.— Diseases of the Skin and Eye. X. — Diseases qf the Feet. XI. --Diseases of Bone and Detection of Lameness. XII. — Age by the Teeth. XIII.— Tropical Diseases. XIV.— Medicines, Their Actions and Uses. ^ LIST OF ILLUSTRATIONS. Frontispiece. — Attendance at operation. Plate I. — Points of the horse. II. — The horse in slings. III. — Skeleton of the horse. IV. — Muscles and tendons of the horse. V. — Respiratory apparatus. VI. — Digestive apparatus. VII.— Circulatory apparatus. VIII. — Section of the eye. IX. — Section of the hoof and pastern. X. — Fig. 1, Curb. Fig. 2, Bursal enlargement. Fig. 3, Sprain of the flexor tendons (bowed tendons). Fig. 4, Line firing. Fig. 5, Capped hock. XI.— Fig. 1, Fistulous withers. Fig. 2, Poll evil. XII. — Characteristic symptoms of spasmodic colic. XIII. — Lymphangitis. XIV. — Purpura hemorrhagica. XV.— Farcy. XVI.— Tetanus. XVII.— Grease. XVIII.— Fig. 1, Sidebone. Fig. 2, Ringbone. Fig. 3, Bone spavin. Fig. 4, Splint. XIX. — Longitudinal section and cross sections of lower incisor. XlXa. — Surra: characteristic swellings. XX. — Surra parasite. XXI. — Chronic epizootic lymphangitis (tropical). 6 ■¥ o Ph o pti P^ Ph K ^ -^ 3 c3 O H w W O W -^ .9 c J»j -« a c o <« 9 (Lt M a (v d o O Q fe fc Ph O PtH ■— I (M CO ■* ■* CO 05 O B W K O 02 H ;2; I— I o P^ 03 -Q tM o a Ph O hJ Q H P 3 o ^■-2 9 C M rt -T! 2 SR -S r^ 00 05 O t-H OO isj 4) O) & ^ i HqSf^feWfeWK:lG;z;p^'^p^;2; :;; rt :2 O fH 08 4J >? m t^ p:^ I— iwec-*io«c>t-~soo50i— 11— ic^coeo-^iocot^ THE ARMY HORSE IN ACCIDENT AND DISEASE. CHAPTER I. CONFORMATION AND POINTS— DEFECTS AND BLEMISHES. CONFORMATION AND POINTS. (Plate I.) The forehead should be broad and not bulging; the eyes full, clear, and prominent, with a mild expression, and not showing any of the white; the muzzle not too large, as a coarse, large muzzle indicates ill breeding; the nostrils large and open; the face straight; and the lower jaw with ample width between the two sides, for the develop- ment and play of the larynx (Adam's apple) and windpipe, and, in addition, to allow the head to be nicely bent on the neck. The ears should be of medium size, set well on the head and held erect. The parotid and submaxillary regions should be free from large glands and without any loose skin at the lower part of the throat. The neck should be of moderate length, clean and not too narrow at a point just in rear of the throat; a short, thick neck does not allow of free movement from side to side, and a long, slim neck is apt to be too pliable. A neck with concave upper border, known as "ewe neck" is unsightly. The jugular channel or furrow should be free from enlargements. The point of the shoulder should be well devel- oped. The point of the elbow should not be turned in, as the horse in that case is apt to turn his toes out; the opposite conformation results in the condition called "pigeontoed." The forearm should be long and muscular; the knee broad, and when looked at from the front, much wider than the limb above and below, but tapering off backward to a comparatively thin edge. A bending of the knee backward is called a "calf knee," and is very ob- jectionable. The opposite condition isJcnown as "knee sprung." The cannon should be of uniform size; if smaller just below the knee than elsewhere (a condition called "tied in"), weakness is to be expected. 10 THE ARMY HORSE IN ACCIDENT AND DISEASE. The fetlock joint should be of good size and clean; the pasterns of moderate length, and forming an angle of between 45 and 50 degrees with the ground or floor. The foot should be of moderate size; a flat foot or one too narrow at the heels is objectionable. The relative proportions of the shoulders and the exact shape de- sirable vary considerably in cavalry and artillery horses. Thus, when speed and activity are essential, as in the cavalry horse, the shoulder should be oblique (sloping), as this shape gives elasticity to the gait of the horse. For the artillery horse, working in harness, a more up- right shoulder bears the pressure of the collar more evenly, and when the collar is at right angle to the traces the horse exerts his strength to the greatest advantage. The front line of the shoulder must be clearly marked; an irregular surface or excessive muscular develop- ment in the region marked A (Plate I) prevents a = lose fit of the collar. The withers should not be thin and high, as this conformation will allow the saddle to slip too far forward and the pommel will rest upon the withers. The bars of the saddle will be forced against the shoulder blades, causing irritation and inflammation, and preventing free mo- tion of the shoulders; the constraint causes stumbling. On the other hand, the withers should not be low or thick, as the saddle is then apt to pinch them. The breast and chest should be of moderate width and have con- siderable depth; the narrow chest indicates weakness, and the wide, heavy chest is suitable for heavy-draft horses only. The capacity of the lungs is marked by the size of the chest at the girth, but the stamina will depend upon the length of the back ribs. The barrel should not be broad back of the cinch, as it would cause the cinch to slip forward and chafe the body just back of the point of the elbow. The opposite conformation would allow the saddle and cinch to sUp backward. The back should be short, with muscles well developed, and the upper lines of the back bending down a little be- hind the withers and then swelling out very gently to the junction of the loins, which can hardly be too broad and muscular. The last rib should be placed close to the point of the hip, as this is an indication of strength, and the horse is more easily kept in good condition than one having the opposite conformation. A slightly arched loin is essential to the power of carrying weight; the concave or "sway-back" is therefore a sign of weakness; the much arched or ' ' roach back ' ' is almost sure to give uneasy action from its want of elasticity. The hips should be broad, smooth, and muscular. The croup shouW be well rounded, should slope slightly downward and be of moderate length; both the straight, horizontal croup and DEFECTS AND BLEMISHES. 11 the drooping croup are unsightly; when the croup droops and also becomes narrow below the tail, the conformation is known as "goose rump " and is a sign of weakness. The dock should be large and muscular; the tail carried firmly and well away from the quarters. The quarter (thigh and buttock) and gaskin should be broad. The muscles of the two quarters should come close together, leaving no hollow below the anus; the widely separated conformation is an indication of a want of constitution. The hock should be of good size, but clean and flat, and with a good clean point standing clear of the joint. The two hocks should stand well apart, but not enough to give the horse the appearance of being "bow-legged." "Cow-hocked," so called, is when the hocks stand close together and the hind feet wide apart, with the toes turned out. If the hocks stand in, it will be noticed that the stifles stand out, and the reverse. "Straight hock" and "crooked hock" are terms used to express the shape of the hind leg as seen from the side; both shapes are objectionable. "Sickle hock" describes the curve which results from a crooked bock, a short cannon, and a sloping pastern. The cannon should be short, not tied in below the hock, and the line from the point of the hock to the back part of the fetlock should be straight. The fetlock when bent forward is an indication of weakness known as "cocked ankle." The hind fetlocks, pasterns, and feet should correspond to those of the fore extremity, but the pasterns are usually more upright. DEFECTS AND BLEMISHES. Defects and blemishes are those results of injuries (more or less severe) which show on the outside of the body. They are regarded as external diseases, and may be classed as follows: 1 . Diseases of bones. 2. Diseases of synovial membranes. 3. Diseases of muscles, tendons, ligaments, and skin. 4. Diseases of the foot. 1 . Diseases of hones. Bone spavin. — Location : Lower and inner part of the hock joint. Splints. — Location: Usually appearing on the inner side of the upper third of the front cannon ; occasionally found on the outer side of the upper third of the hind cannon. Sidebones (ossification of lateral cartilages). — Location: Sides of the foot just above the coronet. Ringbone. — Ix)cation: Between coronet and fetlock joint. 12 THE ARMY HORSE IN ACCIDENT AND DISEASE. 2. Diseases of synovial meTinbranes. Bog spavin. — Location: Front part of hock joint. Thorough-'pin. — Location: Upper and back part of hock joint. Wind puffs (windgalls) . — Location: On the sides of the tendons just above the fetlock joints. Other bursal enlargements (distended synovial sacs or pouches) may be found located on various parts of the legs, but no special name has been given to them. 3. Diseases of the muscles, tendons, ligaments, and sTcin. Poll mZ.-^Location : In the region of the poll. Fistulous withers. — Location: In the region of the withers. Sweeny (atrophy or wasting of the muscles). — Location: Usually in the shoulder or the hip. Brolcen knees. — Location: Front part of the kneejoint. Capped elbow. — Location : Point of the elbow. Capped ^oc^.— Location : Point of the hock. Curb. — Location: Lower and back part of the hock. Sprung Jcnees. — Location : Ejiees. Cocked ankles. — Location: Fetlock joints. Bowed tendons. — Location: Flexor tendons below the knee and hock. Breakdown. — Location: Sprain of the suspensory ligament. Saddle galls. — Location: On the saddle bed. Cinch galls. — Location: On the parts coming in contact with the cinch. Collar galls. — Location: On the parts coming in contact with the collar. J).. Diseases of the foot. Thrush. — Location: Frog. Canker. — Location : Frog and sole. Chronic laminitis. — Location : Sensitive laminae. Com. — Location: Between the wall and bar. False quarter and quarter crack. — Location: Quarters of the hoof. Quittor. — Location : Top of the coronet. Contracted heels. — Location: Heels. Toe cracks. \ j^^ation: At the toe of the hoof. Seedy toe. ) / CHAPTER II. STABLE MANAGEMENT OF THE SICK AND INJURED. CARE OF THE SICK. The sick horsiB should, if practicable, be immediately removed to a large, clean, light and well-ventilated box stall, free from drafts and located as far as possible from other horses. Clean bedding should be provided, and the stall kept free from manure and moisture. If such a stall can not be provided a double stall, with the kicking bar removed and ropes or bars placed across the front of it, will answer the purpose. If the patient is suffering from a febrile disease (fever) during the cold season of the year, paulins or horse covers can be hung up in such a nianner as to serve as a protection from drafts, care being taken to allow sufficient air to enter this improvised box stall. Such patients must be clothed according to the season of the year, the blanket drawn well forward on the neck and fastened in front, the legs, after hand-rubbing, bandaged with red flannels. The bandages should be changed several times daily, and the legs thoroughly rubbed to stimu- late circulation. Horses with diseases of the nervous system require to be kept absolutely quiet, and must be removed as far as possible from all noise. It is preferable that only one man be allowed to attend to their wants, as a change of attendants would very likely cause excite- ment and thus increase the severity of the disease. Animals suffering from debilitating diseases should be tempted with and fed any food that is rich in nourishment and easily digested. Salt should fre- quently be added. The food, etc., should be given only in such quantities as the animal will readily eat, and any portion left over should be at once removed, as food constantly placed before a sick animal will have a tendency to deprive it of all appetite. Food that is wet, such as bran mashes or steamed oats, will soon sour in warm weather and will get cold or may freeze during the winter; if eaten in these conditions it may cause diarrhea, colic, etc. Feed boxes, water buckets, and all parts of the stall must be kept clean and free 13 14 THE ARMY HORSE IN ACCIDENT AND DISEASE. from odor. The hay should be clean and bright, and only the best given to the sick animal. Pure water should be provided, and placed in such a position as to enable the animal to reach it without difficulty; a sick horse will frequently rinse the lips and mouth with water if given the opportunity, even when not thirsty. The water should be changed as often as necessary during the day to insure a pure and f resb supply at all times. A horse suffering from colic requires sufficient space, well bedded, to prevent injuring himself by rolling during a spasm of pain. A man should be constantly in attendance, as there is danger that the animal may become cast and be unable to get up without assistance. Undigested matter being the exciting cause in almost all cases of colicj food should be withheld for about twelve hours after all pain has disappeared, and then given only in small quantities during the next twenty-four hours, after which the ordinary ration may be re- sumed. A few swallows of pure water may be given at short intervals, but special care must be taken when the water is very cold. The pulse is the beating of the arteries, usually felt at the jaw (the submaxillary artery), and is an important guide in determining the physical condition of the animal; the normal pulsations are about 40 per minute. The count is best taken by placing the fore or middle finger transversely on the artery. The slightest excitement, when the horse is sick, will cause an alteration in the pulse; therefore the animal should be approached very quietly. A strong and full pulse is an indication of health. In the first stages of fever the pulse is full and bounding, after- wards becoming small and weak. A very slow pulse denotes disease or injury of the brain or spinal cord. An imperceptible pulse indi- cates the approach of death. At rest the healthy horse breathes from 13 to 15 times per minute. Difficult or rapid breathing is a prominent symptom of disease of the respiratory organs ; it may also be observed in some cases of flatulent colic. Abdominal breathing is the respiratory movement performed with the ribs fixed as much as possible, owing to pain or mechanical obstruction in the chest, and is a symptom of pleurisy and hydro- thorax (water in the chest). Irregular breathing is that condition where there is a want of harmonious correspondence between the inspiratory and expiratory movements, and is observed in the disease commonly known as "broken wind" or "heaves." The inspiratory movement in this affection is performed quickly and with jerky effort, while the expi- ratory movement is performed slowly and with a double action, more particularly of the abdominal muscles. Irregular breathing often becomes spasmodic or convulsive during the progress of the disease. The condition and color of the visible mucous membranes STABLE MANAGEMENT OF SICK AND INJURED. 15 should be closely observed ; as will be learned in detail later, they are an important guide in determining the physical condition of the animal. The normal temperature of the horse in the internal part which is most easily accessible, the rectum, may be estimated at from 99° to 101° F. In ver}'^ young animals the temperature is commonly about 101°, but in very old ones it has been known to be as low as 96° F. The temperature of the external parts of the body becomes lower according to their distance from the heart, and liable to much vr.riation from the state of the surrounding atmosphere. Fever is an elevation of temperature. The production of animal heat is due to certain chemical and vital changes which are continually taking place in the body ; these changes consist in the absorption of oxygen by the capillaries in the lungs, and the combination of that oxygen with the carbon and hydrogen derived (first) from the disintegration of animal tissues and (second) from cer- tain elements of the food which have not been converted into tissue. This combination with oxygen, or oxidation, not only takes place in the blood, which may be looked upon as a fluid tissue, but in the tissue cells also, in all parts of the body, the animal heat being main- tained by the natural changes which are essential to a healthy condition. As previously stated, oxygen is absorbed from the air by the capil- laries of the lungs in respiration (breathing). Expired air is found to have lost about 10 per cent of the oxygen contained in pure air, and to have accumulated a like aniount of a combination of carbon and oxygen, called carbonic acid gas. If we imagine the animal breathing and rebreathing the same air, it can be seen that the oxygen, so necessary for the purification of the blood, would soon diminish to a dangerous degree. Hence, we realize the importance of a large supply of air to draw on and the necessity of good ventilation. At each inspiration the horse draws about 250 cubic inches of air into the lungs, and he therefore requires about 2 cubic feet per minute, or 120 per hour. It is customary, in building ordinary stables, to allow 1,600 cubic feet of air space (over twelve hours' supply) for each animal, and to provide means of admitting fresh air without causing drafts. In infirmary stables the allowance is increased to 1,900 cubic feet. Without good air the blood is imperfectly purified, the vitality of the animal is lessened, he is more susceptible to disease, and will suc- cumb more easily when attacked; consequently horses should never be kept in the vicinity of a marsh, the air from which contains an excess of carbonic acid gas and a diminished supply of the necessary oxygen. 16 THE ARMY HOBSE IN ACCIDENT AND DISEASE. ^CARE OF THE INJURED, ■P If the horse is seriously injured and stands with difficulty, he should be placed in slings (Plate II) to partially support the weight of the body. The slings must be properly adjusted, fitting closely behind the elbows in such a manner as to support the weight of the body on the chest and not on the abdomen. This position is maintained by the use of the breast piece and breeching, which prevent the shifting of the sling. A single stall, having a level floor, free from bedding, is more suitable than one allowing more motion to the animal. If the horse is but slightly injured, there is no necessity of placing him in slings. An ordinary stall with a level floor is all that is re- quired. After the injury has been dressed he should be allowed to stand without being disturbed. If very lame, and movement is painful, the more quiet he is kept the more quickly will recovery take place. Absolute rest and perfect quietude are two very essential things, and when secured they will hasten the process of recovery with- out inflicting unnecessary pain upon the animal. In some surgical cases it is necessary to restrain the animal so that he can not injure himself by rubbing or biting the affected parts. This can be accom- plished by tying up the head or by the application of side lines. Bandages may be applied to the legs of animals for different purposes : First, to give support to the blood vessels and synovial bursae; sec- ond, to dry and warm the legs; third, to support packs used in apply- ing hot and cold lotions; and fourth, when conditions are favorable, to check haemorrhages. WATER SUPPLY. However harmless impure water may have been to animals in a wild state, the more we subject them to an artificial existence the more we remove them from the immunity they may have possessed against common causes of disease and the greater liability is there for the development of diseases which originally may never have existed. In other words, the domesticated animal should always have pure water; when the vitality is further reduced by sickness the necessity of absolute purity is even more imperative. CHAPTER III. ANATOMY. Anatomy is a description of the structures that make up the body. THE SKELETON. (Plate III.)' The skeleton is the framework for the support of the softer struc tures, and is composed of 216 bones (exclusive of the teeth) of various sizes and forms. Flat bones, such as the skull, ribs, and scapula, are found covering vital organs ; long bones are found principally in the extremities, for the support of the body. The spinal column is composed of bones of very irregular shape, which are divided into five groups according to their location, and are known as vertehrsp. Commencing at the back of the head, the first seven are called tlie cervical vertebrae, or bones of the neck; of these the first is called atlas, the second axis; the next eighteen are called the dorsal vertebras, forming the main part of the back; the next six, the lumbar vertebrae, form the loins; the croup or sacrum is. com- posed of five bones, which in the adult animal are united together as one bone; and following this are found the coccygeal or tail bones, numbering from thirteen to twenty. All vertebrae have irregular projections of varying length, called spinous processes; these are named, according to location, dorsal, cervical, etc. ; the third to sixth dorsal spinous processes (often called dorsal spines) are very long and form the withers. The ribs are eighteen on each side, attached above to the dorsal vertebrae. The first eight (true or fixed ribs) are attached below, by cartilage, to the sternum or breastbone; the remaining ten (false or floating ribs) are attached by cartilage to one another and indirectly to the sternum ; they form the walls of the chest and serve as a pro- tection for the heart, lungs, and large blood vessels. 17 18 THE AKMY HORSE IN ACCIDENT AND DISEASE. a a -2 Co' ^ CI. flo ,1a TT^ I* • — -^- -f— ^^ r^ »-' 3 -— "^ "73 ^ ''-' (- B-^"rii^ jiDot:"^'^ S.a c o-^- oOi-HSoQOl-'PHPHPHi-iKaiOO t-i C^' ^ N c -^' ^" -^ ^ --; > -^ «-. -^ c S — ■ '^ • o +^ - g >.ai 00^. cl p^cs»n "^^^ r-i-^ C300C3 ^ ^ ^ cS r^ rs C V a. .=2. a s ?= G Si,^ S «i _r a i=i i ^o^^j-dPHScsoo^S^oseo^^ ANATOMY. 19 The skull, containing cavities (or chambers), is composed of irregularly shaped flat bones, the most important of which is the cranium, or brainpan, occupied by the brain and communicating with the bony canal (containing the spinal cord), which passes through the center of the cervical, dorsal, lumbar, sacral, and some- times the first two or three coccygeal vertebrae. The orbital cavities (containing the eyes) communicate with the brain by narrow pas- sages, through one of wliich the optic nerve passes. On each side, below the eye, are two closed cavities known as the superior (upper) and inferior (lower) maxillary sinuses; in the lower third of the skull are found the nasal chambers extending from the nostrils backward to the pharynx, arid separated by a thin partition of bone and cartilage, called the septum nasi; the floor of these chambers forms the roof of the mouth. From the orbital cavities the skull gradually becomes narrower and terminates a short distance below the nostrils in the premaxilla, which contains the six upper incisor teeth; these six, with the corresponding teeth in the lower jaw, form the anterior (front) boundary of the mouth, which extends back to the pharynx. On the upper portion of the back of the mouth cavity are found six molar or grinder teeth on each side ; that portion of the jaw between them and the incisors is called the interdental spa^e. Situated on each side near the incisor teeth in this space are found, in the male, and rarely in the female, the tushes or canine teeth. The inferior maxilla or lower jaw is composed of two segments firmly united in front and spreading backward somewhat in the form of a letter V. Each branch, at the end, turns upward and is united to the skull proper in a movable joint. The branches of the jaw include- a space appropriately called the maxillary space. Located in the united or front part of this bone are the inferior incisors and canine teeth, and, in the branches, the inferior molars, which corre- spond to those of the upper jaw. The space between the molars and incisors is the same as that in the upper jaw. The front leg is composed of the following bones, named in order from above downward: Scapula, shoulder blade; humerus, bone of the arm; radius, bone of the forearm, and ulna, bone of the elbow (radius and ulna are united in one bone) ; carpus, knee bones (seven small bones) ; large metacarpal, cannon bone ; two small metacarpals, splint bones (the three metacarpal bones are joined together, forming the metacarpus); two sesamoids, pulley bones; os suffraginis, upper pastern bone; os corona, lower pastern bone; os pedis, coffin bone, and OS navicularis, shuttle bone. The scapula is extended by means of a thin plate of gristle, called the " caHilage of prolongation," which offers additional attachment for the muscles of the body. 20 THE ARMY HORSE IN ACCIDENT AND DISEASE. The pelvis is composed of two segments. In each segment are three united, irregularly shaped, flat bones, namely, ilium, ischium, and pubis (haunch bones). The ischium and pubis bones are also united in pairs, forming the floor of the pelvic cavity occupied by the bladder and rectum. The two ilium bones or branches are triangular in shape. The outer angle in each case is the point of the hip. The two inner angles are close to each other, and together form the point of the croup. Just below this point each branch is attached to the sacrum by ligaments. That portion of the ilium extending back to the hip joint is called the "shaft." The hind leg is composed of the following bones: Femur, thigh bone ; tihia, leg bone ; fibula, accessory leg bone ; patella, stifle bone ; tarsus, hock (made up of six small bones; named calcaneum, astrag- alus, cuneiform raagnum, medium and parvum, and cuboid) ; large metatarsal, cannon bone; two STnall metatarsals, sphnt bones. Below the cannon, the bones have the same name as in the fore leg. JOINTS. A joint is a movable union between two or more bones. Covering the adjacent surfaces in the joint is a thin and very smooth layer of a jjeculiar kind of cartilage called articular cartilage. A lubricating fluid, synovia, joint oil, is required to reduce the amount of friction; this fluid is secreted or formed by the synovial membrane and the latter is confined and protected by the capsular ligament which com- pletely surrounds the joint. Outside of the capsular ligament are binding hgaments holding the bones in position. The joints of the fore leg are as follows: Shoulder joint, formed by the lower end of the scapula and the head of the humerus; elhow joint, by the radius, ulna, and humerus; knee-joint, by the radius, seven small bones (carpals), and the upper end of the metacarpals; fetlock joint, by the large cannon, upper pastern bone, and the two sesamoids; pastern joint, by the upper and lower pastern bones; coffin joint, by the lower pastern, cofRn bone, and shuttle bone. The following joints make up the articulation of the hind leg: Hip joint, formed by the socket of the pelvis and the head of the femur ; stifle joint, by the lower end of the femur, head of the tibia, and the patella ; hock joint, by the lower end of the tibia, six small bones (tarsals), and the upper ends of the metatarsals. The fet- lock, pastern, and cofiin joints correspond to those of the fore limb. LIGAMENTS. Ligaments are, generally speaking, strong bands of white fibrous inelastic tissue. Their principal use is to firmly bind joints together, thereby preventing vibration and diminishing friction. ANATOMY. 21 The suspensory ligament should be carefully studied on account of the numerous accidents to which it is liable. It is a long, strong hand of fibrous tissue originating in the back part of the lower bones of the knee and in the upper part of the cannon bone; it occupies tlio space between the splint bones and passes down immediately l)ehind the cannon bone, lying between it and the tendon (sinew) of the jlexor pedis perforans: it bifurcates (divides into two) oppo- site the lower third of the cannon bone and becomes attached to the sesamoids, whence the parts pass forward and downward, joining the tendon of the extensor pedis just above the pastern joint. It is thin and comparatively weak near the knee, but as it approaches the fetlock joint it almost equals the back tendons in substance, and its size and wiriness to the touch may be taken as some test of the power of any particular leg to resist a breakdown. The suspensory ligament of the hind leg corresponds in every particular to that of the fore leg. The calcaneo-cuboid ligament stretches from the posterior (back) border of the calcaneum to the posterior part of the cuboid, ending on the head of the external (outer) splint bone. A sprain of this ligament is known as a ^'curh." Capsidar ligaments, as we have seen, are pouch-shaped, are found around joints, and are intended to protect the lubricating apparatus inside. Some ligaments are made up almost entirely of yellow tissue, which is elastic. The ligamentum nuchse, neck ligament, is an impor- tant example. It occupies the space in front of the dorsal spines, above the cervical vertebra?, and is attached to the top of the skull. In this position it separates the neck muscles of the right side from those of the left. The object of elasticity in this ligament is to permit of great freedom in the motion of the head, although sup- porting its great weight in proper position. MUSCLES AND TENDONS. (Plate IV.) The muscles are divided into voluntary and involuntary mus- cles; the former being under the direct control of the will, as, for example, the muscles of the neck, legs, tail, etc. ; and the latter acting independently of the animal's will, as, for example, the heart, intes- tinal muscles, etc. The muscles form about one-half of the entire weight of the body. With regard to their form they are divided into long, wide, and short. Long muscles are generally found in the limbs; wide mus- cles are stretched beneath the skin or around the great cavities of the trunk, and short muscles are found chiefly around the irregularly shaped bones. 22 THE ARMY HORSE IN ACCIDENT AND DISEASE. Tendons are whitej round or flattened cords affixed to the ex- tremities of long muscles, attaching them to other structures, but themselves neither stretching nor contracting. -^ All leg muscles are long muscles. Extends are those that have the power of straightening the \\mh',jlexors, of bending the limb. The extensor 'pedis is the principal extensor of the fore leg; it originates at the lower extremity of the humerus, and its fleshy por- tion continues to the lower third of the radius; at this point it be- comes tendinous, and, passing down over the knee, continues along the front of the leg and becomes attached to the upper and front part of the os pedis. Action, to extend the leg. The extensor suffraginis has its origin from the external head and outer border of the radius and from the side of the ulna ; it is inserted (attached) to the upper and front part of the os suffraginis. Action, to extend the foot. The extensor metacarpi magnus has its origin from the lower and external surface of the humerus, passes down the front of the radius and kneejoint, and is attached to the upper end of the large meta- carpal bone. Action, to extend the metacarpus. The jlexor hracliii has its origin from the lower end of the scapula, near the shoulder joint, and passes down in front of that joint and the humerus and becomes attached to the upper front part of the radius. Action, to flex the elbow joint and extend the shoulder. The- jlexor pedis perforatus originates from the inner and lower part of the humerus; it passes down the back part of the leg, becoming tendinous just above the carpus; behind the pastern it bifurcates, forming a ring for the passage of the tendon of the perforans and becomes attached to the sides of the os coronas. Action, to bend or flex the knee, fetlock, and pastern. The jlexor pedis perjorans originates with the perforatus ; its fleshy portion passes down and is attached to the back part of the radius; its tendinous portion, beginning at the knee, passes down the leg between the cannon bone and the tendon of the perforatus, over the back of the fetlock, through the arch formed by the division of the tendon of the perforatus, and is attached to the under surface of the OS pedis. Action, to flex the knee and all joints below. The extensor pedis of the hind leg originates from the lower and front part of the femur; its fleshy portion extends downward along the front surface of the tibia to the hock, where it becomes tendinous; passing thence down the front of the leg it is attached in the same manner as the extensor pedis of the front leg. Action, to extend the leg and flex the hock. The peroneus has its origin from the e^temai hgament of the stifle and from the outer part of the fibula, and is attached to the tendon ANATOMY. 28 m 5 S on C |i g c3 Im t v2 s S^ •c i-i 3 S »-i (1 O !0 Q. (1) a. 1-2 on '5 3 maxi nemiu pedis O' 0) ft 3 a s S § I fe o a o § ki -S -2 X X o X S ,2 ^ S^ ^ ^ X EoOP^PMP^faW «5 O CO oi d r-t c^ CO p4 »< -^ Tj. ai A O W W w B fe o ^^ i' ^ 1. o 1 P-i 6 -a sc X '"* a 4) 3 -S >. .i^ ft QQ 0) *s Ui (i ft O o a 0) o XI c 0) 9 fl r^ O a "^ o 2 iJiiS^'xxift 24 THE ARMY HORSE IN ACCIDENT AND DISEASE, of the extensor pedis a short distance below the hock. Action, to assist the extensor pedis. The tendon of the peroneus is cut in the operation for string halt. The jlexor metatarsi is divided into two portions — a muscular and a tendinous. The tendinous part is a strong pearl-white cord, situ- ated between the muscular portion and the extensor pedis. It com- mences at the lower extremity of the femur, and terminates in two branches — a large one inserted in front of the upper extremity of the cannon bone and a small one deviating outward to reach the front surface of the cuboid bone. The fleshy portion originates on the front face of the tibia and is ins^ted by two tendons, one in the head of the large metatarsal bone, the other in the small cuneiform on the inner side of the hock. Action, to flex the hock. The jlexor 'pedis perforatus of the hind leg originates at the back and lower part of the femur. Its fleshy portion extends about halfway down the tibia, then becomes tendinous, and passes over the point of the hock, continues down the back of the leg, and is attached in the same manner as the perforatus of the front leg. Action, to extend the hock and to flex the fetlock and pastern. The gastrocneinius extemus has a double origin at the lower and back part of the femur and is attached to the point of the hock. At the back part of the leg the tendon of this muscle becomes closely associated with the tendon of the flexor pedis perforatus, the two forming the tendon of Achilles, or hamstring. The flexor pedis perforans of the hind leg originates at the upper and back portion of the tibia. Above the hock it becomes tendinous and passing down over the inner and back side of the hock is at- tached to the OS pedis in the same maimer as the perforans of the front limb. Action, to extend the hock and to flex the joints below. Wide muscles are attached to other structures by broad bands of strong white tissue instead of by tendons. The panniculus camosus (fly shaker) is a wide flat muscle situated on the inner surface of the skin and covering most of the neck, sides of the chest, and belly. Action, to shake the skin. The principal muscles of the back, loins, and haunches are the longissimus dorsi, gluteus extemus, gluteus maximus, and gluteus intemus. The longissimus dorsi is situated on the upper part of the back and loins, and is the largest and most powerful muscle in the body, occup3nng the space on either side of the dorsal and lumbar spines. Is broad and fleshy at its origin in the loins and becomes narrower as it proceeds forward. It is attached to the front part of the pelvis (ilium), first two bones of the sacrum, all of the lumbar and dorsal vertebrae, the external surface of the last fifteen or sixteen ribs, and to the last three or four cervical vertebrae. Action: It is brought ANATOMY. 25 p5 ^_ W Pm -< . e • • • lO lO =o t^ oo 02 tc P 3 H ,a <1 a tf o -*5 > Ph > ^ o -< S ^ c4 >H CS -kj o a> a o (I o 3 o (4 J3 H M tc rC "o fl -t; ll -^ 00 OJ P5 o 2 a M 0) 1— 1 aT Ph 3 ^ J O a !=1 be a a 01 P5 o OD 01 "a f "cu OQ 01 ^ "2 I* *^ W cc rt Ph H^ c/2 o^ 2 ;d ^ ^ iS; TS .S- ;5 &. q3 S ^ a c4 CO JS ■ ^ *? eS O 0^ fl >< o S --" ?n ^ fi -r -« nS fl cS 03 o ja cS Cu S ^ H Pi 1-; W H CO -^ lO 'US t- c« 26 THE ARMY HORSE IN ACCIDENT AND DISEASE. powerful!}^ into play in kicking or rearing; it elevates the hind or fore quarters, according as the fore or hind limbs are on the ground. Acting on one side only, it bends the back and loins laterally. Gluteus extemus is a V-shaped muscle situated on the upper and outer part of the haunch. It originates on the front part of the ilium and at the second and third sacral spines. Inser- tion, to the upper and outer part of the femur. Action, to draw the thigh outward. Gluteus maximus is a very large muscle, originating in the lumbar region; it is attached to the ilium and sacrum and is inserted en the upper and outer portion of the femur. Action, to extend the femur on the pelvis, and when the posterior limbs are fixed, to assist in rearing. Gluteus intemus is situated underneath the gluteus maximus and above the hip joint. It originates from the shaft (lower angle) of the ilium and is inserted by a tendon to the upper part of the femur. Action, to draw the leg outward and rotate it inward. THE RESPIRATORY SYSTEM. (Plate V.) The organs of respiration are the nostrils, nasal chambers, 'pharynx, larynx, trachea, bronchi, bronchial tubes, and air cells. AH of these organs, except the air cells, are lined with a soft tissue called mucous membrane; where organs open to the external surface the mucous membrane and the skin are continuous. The nostrils are two oblong openings (right and left) situated in the front part of the muzzle. The nasal chambers extend from the nostrils to the pharynx and are separated from each other by the cartilaginous septum nasi; each chamber is divided by the turbimded bone into three passages, all lined with a delicate rose-colored mucous membrane, called the Schneiderian membrane, which is continuous with the skin of the nostrils. The pharynx is a muscular, membranous cavity, common to the digestive and respiratory canals, somewhat cylindrical in form, and extending back to the larynx and the esophagus. The larynx (commonly known as "Adam's apple") is a complex musculo-cartilaginous box, situated in the back part of the maxillary space, and at the front part of the trachea or windpipe. It gives pas- sage to air and at the same time is the organ of voice. The front extremity opens into the pharynx and the posterior into the trachea; the front opening is guarded by a valve called the epiglottis or " pot- lid," which closes mechanically in the act of swallowing and thus prevents the passage of food or water into the trachea and lungs. ANATOMY. 27 The trachea, or windpipe, is a cylindrical, flexible tube con- sisting of a series of incomplete cartilaginous rings, numbering from forty to fifty, according to the length of the neck. It succeeds the larynx, runs down the neck, enters the thorax or chest, and terminates at the base of the heart where it branches into the right and left bronchi, which enter the lungs and subdivide into branches termed bronchial tubes. These, becoming gradually smaller as they divide, finally tenninate in air cells. The entire ramification, when isolated, has the appearance of a tree, the trachea being the trunk, the bronchi and bronchial tubes the branches, and the air cells the leaves. These structures are accompanied throughout by arteries, veins, and nerves. The thorax, or chest, is formed by the ribs, sternum, the bodies of the dorsal vertebrae, the muscles between the ribs (intercostal), and the diaphragm. It contains the lungs, heart, large blood vessels, the trachea, esophagus, and a nmnber of nerves. The thorax is lined by two serous membranes, the right and left pleura, each pleura lining one-half the thorax and enveloping the structures contained therein. A serous membrane is a thin glistening structure atid lines a closed cavity. The lungs, the essential organs of respiration, are light, spongy Gleans of a conical shape, situated in the thoracic cavity. (Healthy lungs float in water.) The diaphragm or midriff is the muscular partition which separates the thorax from the abdominal cavity or belly. DIGESTIVE ORGANS. (Plate VI.) The digestive organs consist of the mouth, pharynx, esophagus, stomach, intestines, and anus, all lined with mucous membrane. Together they form the alimentary canal through which the ahmen- tary matter (food) is subjected to the special actions which adapt it to the purpose of nutrition. The mouth is an iriegular cavity, containing the organs of taste and the instruments of mastication (chewing or grinding). It is situated between the jaws, its long diameter following that of the head, and is pierced by two openings— the anterior, for the introduc- tion of food, and the posterior, through which the food passes into the pharynx. It is bounded in front by the lips and laterally by the cheeks ; the roof is formed by the hard palate; the floor is occupied by the tongue, while the rear boundary is the soft palate. Opening into the mouth are ducts leading from the salivary glands: the parotid, submaxillary, and sublingual glands. The mucous mem- brane covers the whole free surface of the mouth and its accessories 28 THE ARMY HORSE IN ACCIDENT AND DISEASE. except the teeth. The lips are the organs of touch as well as of j»(- Jiension (picking up). The soft palate is a curtain suspended between the mouth and the pharynx, attached above to the palatini arch (the back j)art of th<^ hard palate); the lower border is free antl rests on the floor of the pharynx. Owing to the great size of this curtain, the horse is unable to breathe through his mouth. The tongue is a movable muscular organ, situated on the floor of the mouth between the branches of the lower jaw. It is the special organ of taste and at the same time assists in mastication. The pharynx has been previously described. The esophagus, or gullet, is a muscular tube connecting the })harynx to tlie stomach. The stomach is a ])ear-shaped organ situated in the abdominal cavity, close to the cHaphragm. Its internal, or mucous, coat is divided into right and left portions, the left is the cuticular portion and is continuous with the mucous membrane of the esophagus, which it resembles in structure antl appearance, being of a pale white color. The right jiortion, the mUous, or true digestive coat, is rethUsh in color, soft, v^ry vascular (filled with blood vessels) and velvety looking; it c Ah o Ph to <; s a > 0) 1 X H 02 o P- »— ( 3 a a ■ c fcc »-i O) M ::^ -^ a> fcc y 03 * •^ s 8d a p2 hJ »-) O 00 fi( 00 oj o 1-H c^ 02 2 t^ S fin W Q 02 OO r-i (m' CO ■<»< »0 CO 30 THE ARMY HORSE IN ACCIDENT AND DISEASE. 17 ounces. Its function is to secrete pancreatic fluid, which is poured into the small intestine. The spleen is situated on the left side of the stomach. It is pointed at the lower end and gradually widens as it extends up to the region of the left kidney. The spleen is of a reddish-gray color and in the healthy horse weighs from 2 to 4 pounds. In disease, however, it may reach an enormous size. The function of the spleen is not positively known, but it is believed that this organ acts as a storehouse for the supply of blood to the stomach during digestion and that it effects some change in the blood, many authorities claiming that it forms the white blood cor- puscles. (See "Blood.") The abdominal cavity is a large, somewhat oval cavity, bounded above by the muscles of the ba»ck, below by the abdominal muscles, and in front by the diaphragm; behind it is continuous with the pelvic cavity. The cavity is lined throughout by a serous membrane called the peritoneum. PHYSIOLOGY OF DIGESTION. By physiology is meant a description of the functions or uses of certain structures. The physiology of digestion describes the func- tions of parts of the digestive apparatus. Food, as it passes through the digestive or alimentary canal, is sub- jected to a series of mechanical and chemical agencies by which it is, in greater or less part, digested and worked up -to a condition in which it can be absorbed by the appropriate vessels, and, while this portion is taken up by the circulation, the effete (worthless) remain- der passes on and is discharged. The food is taken into the mouth by the lips {preTiension) , where it is ground up (mastication), and is mixed with saliva. Saliva, secreted by the salivary glands in different parts of the head, acts chemically upon the starchy components (parts) of the food and con verts them into sugar, which is more readily absorbed. This step is called insalivation. The next step, deglutition or swallowing, is mechanically per- formed by the tongue, pharynx, and esophagus. When the food reaches the stomach it is subjected to the next step, maceration, a mechanical rolling, mixing, and soaking with the gastric juice. During maceration the gastric juice acts chemically upon other components (nitrogenous parts), rendering them absorb- able. Food in the condition in which it leaves the stomach is called chyme. In the small intestines the villi take up the absorbable parts already prepared, and the remaining nourishing parts are imme- ANATOMY. 31 diately subjected to the chemical action of the bile aiul j)niu'reatic fluid. Chyme, acted upon by these juices, becomes ch/le. Passinoj through the - . »-i ^ y "S i s s s I § I s a 2 *^ > o = ■ ° in ° ^^ >. 'oT ^ ^ o ricl cle e). !S s . S i2 .y « c ht aur arteri veins OS >■ 0) ;3 "rt M -^ -^ ao >> j>> >-i ^— ' '-^ , a o o S ?? t ^ a a ■c a 03 C3 « 0) ,^ ^ Q} 0) aj '^_ pu d^ fl o Oj m w K << o 1-5 rH (>j CO CO -^ lO CD t-I oi 34 THE ARMY HORSE IN ACCIDENT AND DISEASE. color. The dark impure blood is then collected through the small veins into the larger veins and thence into the right auricle from which it started. This round or circuit, which is constantly going on, gives rise to the name circulation. It has been stated that arteries convey the blood away from the heart and that veins return it. In supplying the body, arteries carry pure blood and veins carry impure blood. When, however, the impure blood is sent to the lungs for purification, it is conveyed in an artery and the pure blood returns in a vein. These two important exceptions must be carefully noted. Arterial ramijication. The large artery given off from the l^ft ventricle of the heart is the common aorta, which passes upward and forward for 2 or 3 inches and divides into the anterior aorta and the posterior aorta, supplying, respectively, the fore and hind portions of the body. The anterior aorta is very short (1 or 2 inches), passes upward and forward under the trachea and between the lungs, and divides into the right and left brachial arteries, each supplying blood to one of the fore limbs and its neighboring muscles. The right brachial artery gives off a large branch, called the com- mon carotid. There is no corresponding branch of the left brachial. The common carotid is short and immediately divides into two branches, right and left carotids, which pass up the neck, at first under the trachea and then on either side; they follow the trachea to the throat, where they divide into branches, supplying the head. The brachial arteries continue toward the front part of the thorax, winding around the first ribs, and divide into branches, supplying the fore limbs. The main branch of each is here named the humeral artery. The humeral artery descends along the inner side of the humeiois, and just above the elbow joint divides into the anterior and posterior radial arteries. The anterior radial descends over the front surface of the elbow joint, passes down in front of the radius, and approaches the knee below the extensor pedis muscle, where it divides into numerous branches, supplying blood to the surrounding tissues. The posterior radial is a continuation of the humeral artery, passing down the inner side of the fore leg, inclining back and dividing at the lower end of the radius into the large and small metacarpal arteries. The small metacarpal passes outward from the inner and back i)art of the knee and, running downward, supplies nourishment to the surrounding tissues. The large metacarpal is a continuation of the posterior radial. It runs down the back of the knee, in company with the flexor tendon; above the fetlock it passes between the ANATOMY. 35 tendon and the suspensory liji^ament, dividing into the external and internal digital arteries, which supply the foot. The study of the digital arteries will be taken up later, when the student has a more extended knowledge of the bones and of the elastic and sensitive structures of the foot. We will now return to the posterior aorta. The posterior aorta is larger and longer than the anterior. It begins at about the level of the fourth dorsal vertebra, passes upward and backward, and reaches the left side of the spine just below the sixth or seventh dorsal verte- bra. It then passes straight back into the abdominal cavity and terminates in the lumbar region below the last lumbar vertebra. During its passage to this point it gives off branches to the muscles of the ribs, to the lungs for their nourishment, to the abdominal organs, and to the muscles of the loins. Below the last lumbar vertebra it divides into four branches, the right and left external and internal iliacs, which supply blood to the hind extremities. The internal iliacs are short thick trunks which soon break up into several branches to the muscles of the hind quarters. The external iliacs, with their continuations, are the main arteries of the hind legs. Each, as previously stated, begins below the last lumbar vertebra, curves obliquely outward and downward, giving off branches, and, near the head of the femur, receives the name of femoral artery. The femoral artery is the artery of the thigh. Just above the back of the stifle joint it divides into two branches, the anterior and pos- terior tibial, the latter supplying the back part of the gaskin and hock with nourishment, while the former winds forward between the tibia and fibula to the fore part of the leg, gaining it midway between the stifle and the hock. At the hock it passes obUquely outward, cross- ing the joint, and becomes the great metatarsal artery at the upper and outer part of the metatarsus. The great metatarsal passes under the small splint bone and gains the back part of the cannon, then, passing down the leg, it divides just below the fork of the suspensory Hgament into two branches, the external and internal digitals, which will be studied later. The involuntary muscles of the heart receive their blood supply from two small arteries, right and left coronary, which branch off at the beginning of the common aorta. Veins. Veins are usually found accompanying the arteries of the body and bearing similar names; there are several important exceptions, three of which will be here noted, namely, the anterior vena cava, jugular, and posterior vena cava. The anterior vena cava is the large, short vein, formed by numerous branches, returning the blood from the head, the neck, the fore leg. 36 THE AEMY HORSE IN ACCIDENT AND DISEASE. and part of the chest. It is located in the front pait of tlie thorax, below the trachea, and between the right and left pleuras, and empties into the right auricle. The jugular veins (right and left) are the largest branches of the anterior vena cava and collect the blood from the head and neighbor- ing parts. Just below and back of the lower jaw they approach the carotid arteries and run down the neck in their company. Each jugular is outside of the corresponding carotid and the two are sepa- rated by a thin muscle. The jugular veins in their descent follow grooves at the side of the neck (jugular furrows), and at first are close to the surface and easily felt; they soon take a deeper course, running beneath the panniculus carnosus muscle. They enter the front part of the thorax, where they empty into the anterior vena cava just in front of the heart. The posterior vena cava is the main vein returning the blood from the hind parts and from the abdominal and pelvic organs. It corre- sponds to the posterior aorta, which, as has been seen, is the main artery carrying the blood to these parts. This vein is formed at the front part of the pelvis and runs forward under the lumbar vertebra, accompanying the posterior aorta, which is at its left. When it reaches the upper border of the liver it inclines downward and passes through a notch or fissure of that organ. Thence it passes through the diaphragm into the thoracic cavity; here it follows a groove on the upper surface of the right lung and then enters the right auricle of the heart. The important veins of the foot will be discussed later. ANATOMY AND PHYSIOLOGY OF THE LYMPHATIC SYSTEM. The lymphatic or absorbent system resembles the system of blood veins with which it is connected. The main part of the system col- lects surplus lymph (to be described later) and returns it to the blood ; a smaller part has the same fimction, but, in addition, absorbs and collects chyle and adds it to the blood. When the blood in its circuit reaches the capillaries the serum. oozes through their thin walls into the minute spaces in the surround- ing tissues and there receives the name of lymph. This colorless fluid bathes and nourishes the tissues and takes up worn-out material. The spaces in the tissues assemble into minute, delicate, and trans- parent vessels (lymphatics), which are remarkable for their knotted appearance, due to numerous valves. The vessels join and increase in size, like veins, and through them flows the surplus lymph with its collected waste material. The vessels of the right fore extremity, the right side of the head, neck, and thorax, form tubes uniting in a main trunk, called the right lymphatic vein, which leads into the anterior vena cava; the ANATOMY. 87 vcssols from the rciiiaiiKlcr of the hod}' unite in a trunk called the thoracic duct, which begins in the lumbar region, passes forward beneath the lumbar and dorsal vertebrae, and empties into the anterijr vena cava just in front of the heart. Each of the villi of the intestines contains a minute vessel culled a lacteal, which absorbs chyle and receives its name from the lacteal or milky appearance of that fluid. These vesesis of the smaller lym- phatic system unite and form larger tubes which empty into th(» receptaculitm chyli (chyle reservoir), which is a part of the thoracic duct of the larger system. It will thus be seen that the lymph with its waste material and the chyle with its nutrient material are mixed and poured into the impure blood. The lymph and chyle are taken up into the serum and the waste material is thrown off from the circulating blood by t he lungs, skin, and kidnej's. Lymph, therefore, makes a circuit very much as blood does. To simi)liiy the explanation of the s^'^stem, the lymphatic glands have not been mentioned. Glands are organs, the function of which is to separate certain substances from the blood, which are either to be used in the animal's system or to be thrown off as waste material. The lymphatic glands are so placed that the lymphatic vessels pass through them in their course toward the main trimks. These glands act as filters and remove an}' infective material from the Ij^mph and also supply lymph corpuscles, which are identical with the white corpuscles of the blood. When the glands are situated near diseased structures, an amount of infected material lodges in the glands, greater than can be over- come by the lymph corpuscles, and, in consequence, inflammation and swelling of the glands result. ANATOMY OF THE NERVOUS SYSTEM. A nerve consists of a bundle of tubular fibers, held together by dense connective tissue; the nerve fibers form a conducting appara- tus, to convey impulses of sensation and to transmit impulses of motion. The nervous system is divided into two minor systems, the cerebro- spinal, which is to a considerable extent influenced by the will of the animal, and the sympathetic, which is not directly influenced by the will. In the first the center is made up of two portions, the brain and the spinal cord. The brain is situated in the cranial cavity; the spinal cord is elongated and continuous with the brain and is situated in th.e canal of the vertebral column. 38 THE ARMY HORSE IN ACCIDENT AND DISEASE. The communicating portion of this system consists of the cerebro- spinal nerves, which leave the brain and spinal cord in symmetrical paii's, and are distributed to the voluntary muscles, to the organs of common sensation, and to those of special sense. The sympathetic system consists of a double chain of ganglia (small brains), extending from the head to the coccyx, one chain along each side of the spine, and the two chains connected by nerve cords. The ganglia are also connected to branches of the cerebro- spinal nerves, thus uniting the two systems. The nerves of the sym- pathetic system are distributed to the involuntary muscles, mucous membranes, internal organs, and blood vessels, ANATOMY OF THE EYE. (Plate Vm.) The eye is the organ of sight and is situated in the orbital cavity. It is spherical in shape and is filled with fluid. The front portion, PLATE Vni. Section of the eye. e, Comea; e, eyelids; /, fluid; t, Iris; I, crystalline lens; o, optic nerve; p, pupil; r, retina. called the comea, is perfectly clear and admits the light to the back part of the eye, where it strikes the retina, an expansion of the optic nerve; through this nerve impressions are conveyed to the brain. The colored portion or iris, situated behind the cornea, acts as a cur- tain, regulating the amount of light admitted through the central opening, which is called the pupil. The crystalline lens is a small transparent body situated immediately behind the pupil; it is thick in the center and tapers toward the edges. Its function is to draw the rays of light to a focus on the retina. When the lens is diseased and no light can pass through, the animal is said to have a cataract. The eyelids are two movable curtains, superior and inferior, which protect the eye. The memhrana nictitans, or accessory eyelid (haw), is situated near the inner angle between the lids and the eyeball. ANATOMY. 89 Tliis membrane acts like a linger in the removal of foreign bodies from the eye. The conjunctiva is a continuous mucous membrane covering the cornea and haw and lining the eyelids. The fluid between the lens and the cornea (called "aqueous") is watery, while that between the lens and the retina (called "vitreous") is thicker and like the white of a raw egg. The outer covering (seen when the animal shows the white of the eye) is a fibrous tissue called the sclerotic coat. Between it and the retina, is a delicate, dark colored tissue containing the blood vessels and known as the choroid coat. ANATOMY OF THE SKIN. The skin consists primarily of two parts: The outer, nonvascular layer, called the cuticle or epidermis, and the deep vascular layer, called the corium, dermis, or true skin. The epidermis is a scaly covering. The true skin or dermis lies immediately under the epidermis, is much thicker, and contains the roots of the hair, the sweat glands, and the sebaceous glands. Sweat glands are simple tubes extending from the deeper layers of the skin to the surface of the body and pouring out perspiration, which carries with it certain waste materials from the system. The evaporation of sweat cools the body and assists in regulating its tem- perature. Sebaceous glands secrete an oily fluid. On parts of the skin which are subjected to much friction these glands pour their oil directly upon the outer surface, as in the sheath, the back of the pastern joints, etc. Usually, however, the glands open into the hair follicles or sacs, and the oily secretion gives gloss to the hair, prevents it becoming dry and brittle, and keeps the surrounding skin soft and supple. ANATOMY AND PHYSIOLOGY OF THE FOOT. (Plate IX.) The horse's foot is composed of three parts, viz: The bony frame- work or skeleton, completed by certain elastic structures of cartilage and fat; the layer of highl}^ sensitive flesh (quick), which covers the framework; and the box or case of horn, called the hoof, which incloses and protects the above-mentioned structures. Bones of the foot. The bones of the pastern region and foot form a column extending downward from the fetlock into the hoof, and, as previously stated, are named as follows: Os suffraginis (long pastern bone), os coronse (short pastern bone), os pedis (coffin bone), and os navicularis (shuttle bone). 40 THE AKMY HOESE IN ACCIDENT AND DISEASE. 2 .; 0) o OJ g C «*-! * 1^ OP ^ i> ;-] g .2 o "s e 'S 9 •- o W H GQ Q O O o 2 i ^ ^ ? s^ i I § . . S ^ Ci. & ;= S -^ ^p -a o • O rjrt,— .,-.i5fc,?" M X S I |.y .2 § ^ -S OOOOOfoOfUW PLATE IX Q- o X ANATOMY. 41 The OS sujfraginis is about ()iie-thii(l as long as the cannon bone (the bone extenciing from the knee or hock to the fetlock) and reaches from the fetlock joint above to the pastern joint below; its superior extremity shows a shallow cavity on each side, separated in the middle by a deep groove, and into this surface fits the lower end of the cannon bone. The inferior extremity is much smaller and nar- rower than the upper; on each side is a small convex surface, the two surfaces separated in the middle by a shallow groove. This extremity meets the upper end of the os coronse and forms the pastern joint. The OS coronse follows the direction of the os suffraginis downward and forward and lies between the pastern and coffin joints, its lower end being within the hoof. Its superior surface shows a shallow cavity on each side, with a ridge between them to fit the lower end of the os suffraginis. The lower surface of this bone shows a convex part on each side, sepa- rated by a groove, to fit the upper surface of the coffin bone in the coffin joint. The OS pedis is an irregular bone, situated within the hoof and is similar to it in shape. The anterior surface is known as the ipaU surface; it shows a num- ber of small openings, called foramina, for the passage of blood vessels and nerves, and is roughened to give attachment to the soft parts {sensitive laminse) covering it. At the top of this surface, in front, is a ridge called the pyramidal process, to which is attached the extensor pedis tendon. The lower surface, called the sole, is half-moon-shaped, concave and smooth, and is covered by the sensitive sole. The upper surface helps to form the coffin joint and is called the articular surface; it shows two shallow cavities, separated by a ridge. Just back of the articular surface is a small triangular surface to fit the navicular bone behind. Just back of the sole is a rough surface, to which is attached the flexor pedis perforans tendon; it is called the tendinous surface. On each side of this surface is a groove running forward and termi- nating in an opening, called the plantar foramen; an artery and a nerve enter the bone and a vein leaves it through this opening. On each side of the os pedis, extending backward, is a prolongation, called the wing. Each wing is divided by a notch and then by a groove, which runs forward on the outside of the bone ; an artery lies in the notch and groove. The OS navicularis is an irregular bone situated behind and below the OS coronse and bohind the os pedis, articulating with both bones. Its long axis is perpendicular to the axis of the foot. The extremi- ties of the bone are attached to the wings of the os pedis ; the inferior 42 THE ABMY HORSE IN ACCIDENT AND DISEASE. surface is covered with cartilage, which forms a smooth surface for the movements of the tendon of the flexor pedis perforans muscle. Elastic structures of the foot. All of the parts of the foot, except the bones, are more or less elastic or "springy" and yield when pressure is applied; but certain parts have a very high degree of elasticity, their special use being to over- come the effects of concussion or jar when the foot strikes the ground and to prevent injury, and these parts are referred to as the elastic structures of the foot. They are the lateral cartilages and plantar cushion, or fatty frog, as it is sometimes called. The lateral cartilages are thin plates of cartilage, one attached to the top of each wing of the os pedis, and extending backward and upward so far that their upper borders may be felt under the skin above the coronet at the heels. The plantar cushion is a very elastic wedge-shaped pad, which fills up the space between the two lateral cartilages on the sides, the sen- sitive frog below, and the flexor pedis perforans tendon above. The point or anterior part of the plantar cushion, extends foi-ward to the ridge which separates the sole from the tendinous surface of the OS pedis. The base is covered by the skin above the heels. Sensitive structures of the foot. Over the bones and elastic structures of the foot is found a com- plete coverifig of very sensitive flesh, and from each part of this cover- ing some part of the hoof is secreted or formed. The divisions of this layer of flesh are called the sensitive parts or structures of the foot. They are the coronary hand, sensitive laminse, sensitive sole, sensitive frog, and the coronary frog hand. The coronary hand is a thick convex band of tough flesh, about four- fifths of an inch wide, and extends entir.ely around the top of the hoof from one bulb of the heel to the other; in front it is attached to the extensor pedis tendon, and on the sides to ligaments of the coffin joint, to the lower end of the os coronse, and to the lateral cartilages. The surface of the coronary band is covered with small pointed projections or villi. The coronary band secretes or forms the principal part (middle layer) of the wall of the hoof. The sensitive laminx (fleshy leaves) cover and are fixmly attached to the anterior or wall surface of the os pedis and to the lower part of the outer surface of the lateral cartilages. These delicate leaves of the flesh dovetail into the homy laminse which they secrete and, with them, serve to fasten the wall of the hoof to the os pedis and to the lateral cartilages. The sensitive sole covers the sole surface of the os pedis, is covered with villi, and secretes the homy sole. ANATOMY. 43 The sensitive frog covers the lower face of the plantar cushion, and from its villi the horny frog is secreted. The coronary frog band or perioplic ring is a narrow band of flesh running around just above the coronary band and separated from it by a faint groove. From the fine villi on the surface of this ring the delicate fibers grow which form the periople. The hoof. The box or case of horn, called the hoof, which incloses and protects the other structures of the foot, is divided into three parts — wall, sole, And frog. In a healthy foot these parts are solidly united. The wall is the part seen when the foot is on the ground ; it extends from the edge of the hair to the ground and is divided into the toe, quarters, heels, and hars; it has an internal surface, an external surface, and an upper and a lower border. The toe is the front part of the wall. It is steeper in the hind foot than in the fore. The quarters extend backward from the toe to the heels. The hed or buttress is that part of the wall where it bends inward and forward, and the har is the division of the wall running from the heel to within about 1 inch of the point or apex of the frog. It lies between the homy sole and the frog. The external surface of the wall is covered by a thin varnish-like coat of fine horn, called the periople. The internal surface of the wall is covered by from 500 to 600 thin plates or leaves of horn, called the homy laminae. Between the homy laminae, which run parallel to each other and in a direction downward and forward, there are fissures into which dovetail the sensitive laminse, and this union, as previously stated, binds the wall of the hoof to the os pedis and lateral cartilages. The upper border of the wall shows a deep groove (coronary groove) into which fits the coronary band. The lower border is called the "bearing edge" (or "spread" in the unshod foot) and is the part to which the shoe is fitted. The homy sole is a thick plate of horn, somewhat half-moon-shaped, and has two surfaces and two borders. The upper surface is convex (round or bulging upward) and is in union with the sensitive sole from which the homy sole grows. The lower surface is concave or hollowed out and is covered with scales or crusts of dead horn, which gradually loosen and fall off. The outer border of the sole joins the inner part of the lower border of the wall by means of a ring of soft horn, called the white line. This mark or line is sometimes called the guide line, as it shows where the nail shoyld be started in shoeing. The inner border is a V-shaped notch and is in union with the bars, except at its narrow part where it joins the frog. 44 THE ABMY HOBSE IN ACCIDENT AND DISEASE. The horny sole protects the sensitive sole and does not, in a healthy foot, bear weight, except a very narrow border at the white line, an eighth or tenth of an inch in width. The homy frog is the wedge-shaped mass of horn filling up the tri- angular space between the bars. The lower face shows two prominent ridges, separated behind by a cavity, called the deft, and joining in front at the apex or point of the frog; these ridges terminate behind in the bulbs of the frog. Between the sides of the frog and the bars are two cavities, caUed the commissures. The upper surface of the horny frog is the exact reverse of the lower and shows in the middle a ridge of horn, called the frog stay, which assists in forming a firm union be- tween the homy and sensitive frog. The homy frog serves to break the jar or concussion by acting as a cushion or pad; it protects the sensitive frog and prevents the foot from slipping. Structure of horn. The hom of the hoof presents a fibrous appearance and consists of very fine hom fibers or tubes, similar to hairs, running downward and forward and held together by a cementing substance. The hom fibers of wall, sole, and frog all run in the same direction, down- ward and forward, the only difference being that those of the frog are much finer and softer and run in wavy Unes, whereas the fibers of wall and sole are straight. The hom fibers grow from the small viUi, which cover the surfaces of the coronary band, sensitive sole, and sensitive frog. Circulation of hlood through the foot. Tn previous study of the arteries we have seen that the large metacarpal of the fore leg and the great metatarsal of the hind leg each divides just above the fetlock into two branches. These branches are called the external and internal digital arteries, one on the inner and one on the outer side of the fetlock joint. They follow the borders of the flexor tendons downward and terminate inside of the wings of the os pedis. Each of the internal and external digital arteries gives off five branches — the perpendicular, transverse, artery of the frog, pre plantar ungual, and plantar ungual. The perpendicular artery is given off at right angles about the middle of the os suffraginis, descends on the side of the pastern, bends forward and joins with the artery of the same name from the opposite side and forms the superficial coronary arch. From this arch branches descend to the coronary band. The transverse artery conies off under the upper border of the lateral cartilage, runs .forward, and joins its fellow from the opposite side between the' extensor pedis tendon and the os coronse. The deep ANATOMY, 45 coronary arch is the name given to this arrangement of the arteries, and branches from this arch also supply the coronary band. The artery of the frog rises behind the pastern joint at the upper border of the lateral cartilage. It has two branches — a posterior, which runs back and supplies the bulb of the heel, and an anterior, which runs forward and downward through the plantar cushion and supplies the sensitive frog. The pre plantar ungual artery is given off inside the wing of the os pedis, passes through the preplantar notch, and runs forward along the preplantar groove on the side of the bone. It helps supply the sensitive laminae with blood and sends some small branches into the bone to join branches from other arteries. The plantar ungual artery is the terminal or last branch of the digital artery (is a continuation of that artery) and entere the os pedis at the plantar foramen. The two plantar ungual arteries run forward within the bone and unite to form the circulus arteriosus. From this circle spring ascend- ing and descending branches. The ascending branches, called the anterior laminal arteries, leave the bone through the small openings (foramina) and supply the sensitive laminae in front. The descending branches, called the inferior communicating arteries, are about fourteen in number and emerge from the bone by the openings just above its lower edge ; they unite to form a large trunk, running around the toe of the OS pedis, called the circumflex artery, and this artery gives off ascending and descending branches. The ascending branches pass into the sensitive laminse, and the descending branches, called the solar arteries, numbering about fourteen, run backward through the sensitive sole to form a second circle, called the inferior circumflex artery. The veins of the foot are arranged in networks, each network or plexus named from the parts in which it is located. The solar plexus is found running all through the sensitive sole. The laminal plexus runs through and under the sensitive laminae. The coronaiy plexus surrounds the os coronae and upper part of the os pedis, just under the coronary' band. The veins of the frog are those found in the plantar cushion and sensitive frog; the interosseous veins form a network within the os pedis. The veins of the foot all unite above to form a large tmnk, called the digital vein, which runs along the digital artery and carries the blood back toward the heart. The veins of the foot are valveless below the middle of the pastern, an arrangement which allows the blood to flow in either direction when pressure is applied and thus prevents injury. 46 THE ARMY HOKSE IN ACCIDENT AND DISEASE. Nerves of the foot. The nerves of the foot supply feeling or the sense of touch to the parts. The large nerve cord on either side of the limb divides at the fetlock joint into three branches, called the digital nerves — the anterior, the posterior, and the middle. The anterior digital nerve passes downward and forward and sup- plies the anterior or front part of the foot. The posterior digital nerve, the largest of the three, passes down behind the digital artery to supply the structures in the posterior part of the foot. It gives off a branch which passes through the notch in the wing of the os pedis (in company with the preplantar ungual artery) to supply some of the sensitive laminse; it also sends branches into the os pedis with the plantar ungual artery. The middle branch is veiy small, is said to always join the anterior branch, and supplies the sensitive sole and fetlock pad. The functions of most of the parts of the foot have been mentioned in passing, but there are some points in connection with the physi- ology of the foot which need to be explained more in detail. Expansion and contraction. When weight comes upon the leg, the Os pedis descends slightly and causes the sole to descend and flatten. The plantar cushion and horny frog are compressed between the ground below and the structures above; this compression causes them to spread out side- wise, carrying outward the lateral cartilages and bars and the wall at the quarters. This is called expansion. When weight is removed from the leg, the plantar cushion becomes thicker and narrower, and the lateral cartilages and quarters move inward to where they were before expanding. This is" called contraction. The elastic lateral cartilage is merely a flexible extension of the wing of the os pedis and would appear to have been specially designed for expansion and con- traction at the quarters. It is also to be noted that the bars are a provision for this same purpose, since expansion and corTtraction could not take place if the wall formed a solid unbroken ring around the hoof. In addition to breaking the j ar when the foot comes to the ground, the plantar cushion has another important use. It assists in the circulation of the blood through the veins of the foot. When weight is placed upon the foot the pressure on the plantar cushion forces the blood upward through the veins; then, when the foot is lifted and the pressure is removed from the homy frog and plantar cushion, the veins of the frog again fill with blood, and this pumping action is. repeated with each step. Proof of this statement is seen when a digital vein is cut, by accident or in experiment. If the horse is walked, a jet of blood spurts out each time he puts the foot to the ground; but if he is allowed to stand the blood flows in a steady ANATOMY. 47 stream from the vein. Great injury to the foot results from starting the horse off suddenly at a fiist gait on a hard road after he lias heen standing for some time or when he first comes out of the stable. The circulation (just explained) and the structures of the foot should have time to gradually adapt themselves to the change from rest to severe work. Moisture. The wall of the healthy hoof, is, by weight, about one-fourth water, the sole more than one-third, and the frog almost one-half. This water is supplied by the blood and preserves the horn in a tough and elastic condition. The hoof, particularly the frog, is capable of absorbing moisture from the ground. The periople, which covers the wall, prevents the evaporation of water, and therefore should never be rasped. As there is no similar covering for the sole and the frog, the layers of horn on their exposed surfaces dry out and die. The dead layers are hard and brittle, and gradually fall or flake off; but, as they preserve the moisture in the layers of live horn beneath, they should not be removed in preparing the hoof for shoeing. _ ^ Shoeing. Shewing is a necessaiy evil, but by remembeiing the functioi\s of the various parts of the foot the damage resulting may be limited to a comparatively small amount. The following rules may serve as a guide for the shoeing of healthy feet: 1. The wall, being the weight bearer, should be rasped perfectly level or the foot will be thrown out of its true position, causing extra strain on some of the ligaments. 2. Fit the shoe accurately to the outline of the foot; do not alter the latter to fit the shoe. Rasping away the exterior of the crust to fit the shoe not only renders the horn brittle but is so much loss of bearing surface. 3. The sole should not be touched with the knife; loose flakes may be removed with a blunt instrument. 4. The bars should not be cut away; they are a part of the wall and intended to caiTy weight. The shoe should rest on them. '). The frog should not be cut, but left to attain its full growth. No frog can perform its functions unless on a level with the ground surface of the shoe. 6. The shoe should have a true and level bearing and rest well and firmly on the wall and bars. A plain light-weight shoe is the best — plain on both ground and foot surface. 7. High nailing is injurious; do not use any more nails than are absolutely necessary, as the nails destroy the horn. CHAPTER IV. ADMINISTRATION OF MIKICINES— WEIGHTS AND MEASURES. ADMINISTRATION OF MEDICINES. Medicines may enter the body through any of the following designated channels: First, by the mouth; second, by the lungs and upper air passages; third, by the skin; fourth, under the skin (hypodermically) ; fifth, by the rectum; and sixth, by intravenous injection. By the mouth. — Medicines can be given by the mouth in the form of powders, balls, and drenches. By the air passages.— Medicines are administered to the lungs and upper air passages by inhalations and nasal douches. By the sTcin. — Care must be taken in applying some medicines over too large a portion of the body at any one time, as poisoning and death may follow from too rapid absorption through the skin. For domestic animals medicines are to be applied to the skin for local purposes or diseases only. By the rectum. — Medicines may be given by the rectum when we can not give or have them retained by the mouth; when we want local action; to destroy the small worms infesting the large bowels; to stimulate the natural movement of the intestine and cause an evacuation; and to nourish the body. WEIGHTS AND MEASURES. Solid measure.o- 60 grains (gr.). 1 dram (5). 8 drams 1 oiince (J). 16 ounces 1 pound (lb.). Liquid measure. 60 minims (min.) 1 fluid dram (f . 5). 8 fluid drams - 1 fluid ounce (f. ^). 16 fluid ounces 1 pint (O.). 32 fluid ounces 1 quart (Oii.). 4 quarts 1 gallon (Ci.)- «The difference in weight between the apothecaries' ounce (480 grains) and the^ ounce avoirdupois (437.5. grains) is neglected in handling veterinary or bulky medi- cines. 48 WKIGilTB AND MKASURES. 49 PRESCRIPTIOXS, In writing? proscriptions, Roman iniincrals are used instead of Arabic (ordinary figures) and tiie numerals follfiw the symbols, thus: 5 vii for 7 drams; f 5 xii for 12 fluid drams, etc. S. S. signifies one half, thus: 5 ii s. s. for 2^ drams. FIELD EXPEDIENTS. In garrison, doses must be accurately measured by scales or graduates, according to the tables of dry or hcjuid measure, but in the field the following rough expedients may be used: Dry mcasxrc. (1 Dunce of lead acetate. All ordnance spcKui h "unce of zinc sulphate. ( Heapinfj full.) )- rdnance l in cuj) | of a quart. Full day's ration of medium-weight oats. 14 cups. Liquid mrnmn-r. A drop 1 minim. A leaspoonful *- ] fluid dram. A tablespoonful J fluid ounce. Xhi cup 28 ounces= J of » quart. V "\ ^; CIUPTER V. WOUNDS, SPRAINS, BRUISES, ABRASIONS, AND ABSCESSES. ^ WOUNDS AND THEIR TREATMENT, Wounds (separations of the soft tissues) are classed as: Incised wouTids, or cuts ; lacerated wounds, or tears ; and punctured wounds, or holes. A dressing is a local, periodically repeated treatment, producing a continued action, and often following the performance of an opera- tion. It is the application upon the surface of the wound of healing substances, which, in some cases, are mechanically held in place by bandages, stitches, etc. Before applying a dressing the wound should be thoroughly cleansed and freed from blood, pus, the remains of previous dressing, and, in a word, of any foreign or other substances capable of becoming sources of irritation. Tliis is best done with water, but the effect is frequently greatly improved by combining with it some of the anti- septics, such as carbolic acid, creolin, bichloride of mercury, etc. Antiseptics are remedies which prevent putrefaction, or rotting, and their combinations with water are called solutions. The solution may be apphed by carefully passing a saturated ball of oakum over the surface of the wound, or it may be used more freely in larger ablutions (washings). Crusts or scabs, if present, may be removed with the scissors or scraped away with the knife, but the finger nails must never be used for such a purpose, for the practice is both filthy and dangerous. The wound is to be handled only when necessary; all needless handling irritates. If the wound is deep, it should be cleansed by syringing. The essential condition of cleanliness apphes not only to the wound but also to the materials used for dressings, and soiled cloths or bandages and dirty oakum must be rigorously rejected; everything coming in contact with a wound must be alxsolulcly clean, hands Jis well as instruments and dressings. Instruments, however, should never be immersed in the bicldoride solution, wliicli rapidly c«)rrodcs metal. 50 WOUNDS, .-^PRAINS, BRri.-^F.<. ABRASIONS. AND ABSCESSES. 51 111 the treat inen( of all wounds (•Iraiiliiics:^ is nf more impor- tance than medicHtion, but the two in combination, when thoroughly uiid intelligently carried out. will leave no room for the propagation and ravages of those germs that cause the formation of pus and retard the heahng process. The farrier, or the man who is to care for the injured animal, should have his hands thoroughly clean, and should procure in a clean can or bucket a solution of creolin or other antiseptic, and several clean pieces of cotton, gauze, or oakum. Sponges are cleaned with difhculty and should not be used. If hemorrhage (l^leeding) is profuse the first step is to arrest the flow of blood by ligatiug (tying) the blood vessel or vessels with a piece of silk, or if none is at hand, with a clean piece of string; if the blood vessels can not be tied, a thick pad made of cotton or of several layers of gauze or clean cloth, folded so as to cover the wound, and held firmly in place by one or more cotton bandages, \s'ill check the flow of blood. This arrangement, called a comprfsfi, should be left on until the hemorrhage ceases, and the wound treated as de- scribed later. In applying dressings (except compresses) unnecessary pressure should be avoided, especially on the soft tissues. Incised urmnds. — If the injury is one that can be sutured (sewed) a needle and silk should be immersed in a solution of creolin — creolin 1 part, water 50 parts: the hair around the wound should either be shaved or be clipped with a pair of shears, and the wound thoroughly cleansed by washing it \s-ith cotton saturated with the creolin solu- tion; all dirt and hair must be removed, all ragged edges, if any, cut away, and the edges of the wound placed in contact with each other if possible and held in place by the aid of sutures, care being taken to allow free drainage; the wound should then be "wiped dry with a fresh piece of cotton or gauze, and over the surface should be dusted some iodoform or acetanilid. If the location will permit, the wound should be covered with a pad of gauze or absorbent cotton, and a cotton bandage wrapped around the parts to hold the pad in place. The wound should be dressed once or twice a day until the formation of pus ceases; when the wound is dr\', only the powder should be used. LaceraUd wounds. — If the wound is a large one, with the skin and tissues so badly torn and lacerated as not to admit of the use of sutures, the torn and ragged edges (especially if the lower part of the wound hangs down) should be removed with the knife or scissors and the wound dressed as above directed. When the wound begins to granulate (fill with new tissue) care should be taken that the granulations are not allowed to grow^ out higher than the skin, caus- ing the condition known as yroudffsh. 52 THE ai:mv iioiisi: ix accident and disease. Tlu" i rraf MK'iil of |)i'ou\ the jip|>li(ation of a red- hot iron; burnt alum or salicylic a<'i(l dusted upon the surface of the wound will also destroy the unhealthy granules. Punctured vjounds.- — Punctured wounds (except those around joints) should be ex])lored with a probe to ascertain if any foreign bodies are in tlu^ channel; if so, they should b(> renioveil, and if neces- sary a dependent opening ho made to allow ]x>rfect drainage. The parts should then be syringed out thoroughly with a solution of creolin, 1 to 50; oarbolie acid, 1 to 20 or 30; or bichloride of mercury, 1 to 1,000, and the outside opening sprinkled with iodoform. This treatment should be applied twice daily. For a few days the wound shoidd be swabbed with tincture of iodine or packed with strips of gauze saturated with this drug in order to destroy infection, check the formation of pus, and promote the growth of healthy tissue. Wounds of the lips, nostrils, and eyelids heal very rapidly; if of several days' standing, they should have their edges scraped and then be sutured, and iodoform or acetanilid dusted over the surface twice daily. An excellent antiseptic solution for the treatment of wounds during fly time is made by dissolving 8 ounces of gum camphor in 3 ounces of carbolic acid. Apply with a clean swal) several times daily. One ounce of creolin to H ounces of olive oil is a good substitute. Punctured grounds around joiids. Open joint is a wound situated on a joint and extending through the capsular ligament, allowing the joint oil to escape. Treatment. — Remove the hair and thoroughly clean the parts around the wound with a solution of bichloride of mercury, 1 to 1,000; unless a foreign body is known to be hxlged in it, do not probe or explore, as the introduction of any instrument, even if thoroughly clean, will be the means of setting up considerable inflammation. Apply a blister of biniodide of mercury 1 part, cosmoline 4 parts, for the purpose of closing the opening, limiting motion, and relieving pain. Use the slings if the wound is very painful. If the wound is so large that a blister will not close it, the treatment shouhl be as prescribed for an open wound. A punctured tendon sheath is treated like a punctured joint. CAUSE AND TREATMENT OF SPRAINS. Sprains affect muscles, tendons, and ligaments. The fibers of which they are -composed are severely stretched, sometimes torn in serious cases, causing inflammation and subsequent contraction, and, in case of muscles, atroph}- or sweeny (wasting away). PLATE X. Fig. 1 , Curb. Fig. 2, Bursal enlargement. Fig. 3, Sprain of the flexor tendons (bowed tendons). Fig. 4, Line firing. Fig. 5, Capped hock. WOUNDS. SPRAINS, BRUISES. ABRASIONS. AND ARSCESSES. 53 Strains of the rawnies. Muscle strains occur in various parts of the trunk and limbs; thus, a horse may strain the neck muscles, as a result of falling on the head; the muscles of the dorsal region may be strained by the hind feet slipping backward. Wlien a muscle is strained the injury is succeeded by pain, swelling, heat, and loss of function. An inflamed muscle can no hmger contract; hence in some strains the sympU)ms resemble those of paralysis. S-prains of the suspeiisory ligament andjlexor tendons. (" Breakdown'' and " Bowed tendons.") The fibrous structures situated behind the cannon bone, both in the front and hind legs, are often the scat of lacerations or sprains resulting from violent efforts or sudden jerks. The injury is easily recognized by the changed appearance of the parts, which become more or le«s swollen; the swelling usually extending from the knee down to the fetlock and occasionally ev*en farther. Tt is always characterized by heat and is variously sensitive, ranging from a mere tenderness to a degree of soreness wliich shrinks from the lightest touch. The degree of lameness corresponds to the severity of the injurj'. Sprain of the flexor tendon is shown in Plate X, figure 3. Sjyrains ofli/famentft. The calcaneo-cuboid ligament, situated at the back part of the hock and uniting the calcaneum, the cuboid, and the external splint bones, is frequently sprained. This condition is known as a "curb'' (Plate X, Fig. 1). The various ligaments entering into the formation of joints are subject to sprains and injuries. This condition is indicated by lameness, accompanied by pain, heat, and swelling. The capsular ligament when sprained very often becomes weak- ened, resulting in distention of the synovial sac (Plate X, Fig. 2). Bursal enlargements receive different names, according to their location. Bog spavin is a characteristic bursal enlargement. It is found on the front and inner side of the hock joint and varies in size with the amount of distention of the capsular ligament. The trouble is usually caused by slipping, hard and fast work, irregular exercise, and high feeding. Draft animals, pulling heavy loads over rough or slippery ground, are particularly subject to this injury, which is also more commonly seen in young than in mature animals. The swell- ing can be readily detected; under pressure it fluctuates; heat may or may not be present; lameness rarely results unless the injury be accompanied by complications, such as hone spavin or bony deposits. 54 THE ARMY flORSE IN ACCIDENT AND DISEASE. Til sprain of tlic stifle joint, tho ligaments holding it in position are severely stretched, in sonic cases spraine{ flaxseed meal, to which has been added an antise])tic, sucli as creolin, carbolic acid, etc. Bruises caused by kicks or running against an obstacle shoidd be treated by applications of water, and if painful, an anodyne (pain reducing) liniment. The following makes a good anodyne: Witch- hazel 2 parts, tincture opium 1 part, tincture aconite \ part, water 2 parts. Apply locally with the hand. Artillery horses are subject to the same injuries, produced b}'^ the saddle and cinch, as are cavalry horses, and, in addition, may be bruised about the neck and shoulders by the collar. If the collar has not broken or chafed the skin (see 'Abrasions") treat the bruises a^i previously directed. The white lotion, composed of 1 ounce each of sugar of lead and sulphate of zinc, water 1 quart, is a most excellent remedy for bruises and aJso for abrasions. Bruises of the sole and heel. These are quite frequent, and should be treated by hot or cold applications, accomplished by holding the foot in a tub or pail of water, or by incasing the foot in a hot flaxseed-meal poultice. If pus forms, the underrun horn must be removed and the parts kept clean and covered. Capped elhow — shoe hoil. This is a bruise at the point of the elbow, and is caused by the horse lying on the heels of his shoe; to prevent further injury, place a large roll around the pastern at night, and apply tincture of iodine twice daily, until the swelling is removed. In case of great swelling and heat, apply hot and cold water, or the white lotion, imtil the heat disappears; then proceed as above. Capped hock. (Plate X, Fig. 5.) Capped hock is a swelling, more or less soft, found on t he point of the hock, and usually caused by kicking in the stall, or by bruising the parts during transportation by rail or sea. Tincture of iodine is a very good remedy for this injury. Only in extreme cases is it advisable to use the knife in the treat- ment of shoe boils and capped hock. As soon as the parts are opened PLATE XI. Fig. 1 , Fistulous withers. Fig. 2, Poll evil. WOUNDS, SPRAINS, BRUISES, ABRASIONS, AND ABSCESSES. 57 pus rapidl}' furnis, and the inllamiiiatioii (infe(;tion by germs) may extend to the inner structures, causing a condition that will not rea(hly yield to treatment. Sitfast. Sitfasts are patches of dry, dead skin, and may involve the deeper tissues; they are caused by continuous pressure of the saddle, cinch, or collar, and may be situated on the side of the body, back, side of withers, shoulder, or neck. Treatment. — With the knife remove all dead and bruised tissue, stimulate the sore at the sides by the use of lunar caustic, and treat as a common wound. When there is no more formation of pus, and the parts are perfectly dry, do not apply liquids, but use iodoform until well. Fistulous withers. (Plate XI. Fig. 1.) Fistulous withers is an abscess (gathering) having a more or less chronic discharge of pus from one or more openings situated in the immediate vicinity of the withers; it may involve only the soft struc- tures, or the bones may also be affected; it is caused by a bruise, and generally, in the army, by a bruise from an ill-fitting saddle. Treatment. — Treat as explained under "Abscesses." If, after a reasonable length of time, results are not satisfactory, a surgical opera- tion is necessary. Poll eml. ablate XI, Fig. 2.) Poll evil is the result of a bruise on the poll. It is similar to fistulous withers, and should receive the same treatment. ABRASIONS. An abrasion, or chafe, is an inflammation of the skin, resulting from friction. Parts of the equipment frequently wear away the hair and leave the skin raw and tender. Treatment. — One ounce of tannic acid in a pint of witchhazel is especially valuable for collar chafes; zinc oxide as a dusting powder is efl"ective, and the white lotion is always beneficial. In emergencies, bathe the parts with cold water to which a little salt has been added. Rope burn. Rope burn is an abrasion, usually at the back of the pastern, and caused by the animal becoming entangled in the halter shank, picket line, or lariat. The injury may be simply a chafe of the superficial 58 THE ARMY HORSE TN ACCIDENT AND DTSEASE. layer of the skin or it may involve the deeper structures. In the latter case it is of a serious nature and requires careful attention. Treatment. — If possible, give the animal complete rest. Clip the hair from the injured parts, at the same time removing any torn skin; wash with some good antiseptic, such as solution of creolin or carbolic acid, and apply a is wanting. Treatment.— When the purging arises from the presence of some offending matter in the intestinal canal (sand, worms, imdigested food, etc.) its expulsion jinist be aided by a moderate dose of linseed oil (1 1 ])ints). If the purging arises from no apparent cause, or if the bowels do not regain their normal condition after the action of the oil has su))si(h'd, it will be necessary to give astringents (binding medicines), such as tannic acid, 1 to 2 drams. The following prescription jnay also be used: Gum camphor 1 ounce, opium, powdered, 1 ounce. Mix. Make eight powders and give one powtler every three or four hoiu's, according to the severity of the case. Great cai'e niust be exercised, as evil results may follow if the bowels are checked too soon. Diseases of the Urinary System. acute nephritis inflammation of the kidneys. Causes. — It is at times produced by the action of cold; it also happens frequently in the course of infectious (catching) diseases. The kitlnej's become irritated by the presence of waste materials of the food, such as mold, rust, etc., or by the passage of certain medi- cines, such as turpentine, cantharides, etc. Inflammation and partial or total clogging of the organ results. Cantharides will reach the kidneys after absorption from a large blistered surface. Symjdoms. — The most important and often the only manifesta- tions of nephritis (in the course of infectious diseases, for instance) are furnished by the urine. Its quantity is diminished; it is thick- ened; of abnormal color; occasionally it is the color of blood. Mic- turition (pissing) is painful; the urine often runs off drop by drop only, notwithstanding the violent efforts made by the patient. In serious cases the urinary secretion may be completely suppressed. 68 THE ARMY HORSE IN ACCIDENT AND DISEASE. The lumbar rcj^ion is very sensitive to tlie pressure of the hand. At the beginnineated several times daily. Give a physic composed of 6 to 8 drams of aloes, 1 dram ginger, and water to make a ball. Give at once. After the physic has operated give jounce doses of nitrate of potash twice daily. After the pain diminishes, moderate exercise and hand rubbing will be of benefit. If the glands sup- purate, open, and wash them out with an antiseptic. The irrigations must be continued until the gland is well. If caused by a wound, similar treatment should be pursued, together with thorough disLnfe...:^ ->*•■: ..,:.i^J ij.,^ . -^ ^. -'ii^;- ,•••18,. i«£l ■■,*■!/.