LAMENESS OF THE HORSE VETERINARY PRACTITIONERS' SERIES, NO. 1 TEXT

penetrant wounds. Sharp shoe-calks afford a means of infliction of penetrant wounds which may occasion open joint and infectious arthritis. Classification.--A practical manner of classifying inflammation of the elbow is on an etiological basis. Eliminating the forms of elbow inflammation, such as are caused by metastatic infection and other conditions which properly belong to the domain of theory of practice, we may consider this affection under the classification of _contusive wounds_ and _penetrative wounds_. Symptomatology.--Any injury which is of sufficient violence to occasion inflammation of the elbow causes marked lameness and manifestation of pain. The degree of lameness and distress manifested by the subject, depends upon the nature and extent of the involvement. A contusion suffered as the result of a fall, which occasions a circumscribed inflammation of the structures covering this joint and where little inflammation of the articulating parts exists, marked evidence of pain and lameness might be absent. On the other hand, if a true arthritis is incited, there will be evident distress manifested, such as hurried respiration, accelerated pulse, inappetence, mixed lameness, local evidence of inflammation and particularly marked supersensitiveness of the affected parts. Considering these two extremes of manifested distress and injury, one may readily conclude that in the frequently seen case, wherein contusion has occasioned a moderate degree of injury, prognosis is favorable and recovery ordinarily follows in the course of a few weeks' treatment. In cases of arthritis due to penetrative wounds (because of the important function of this joint and its large capsule, which when inflamed discharges synovia in a manner that closure of such an open joint is seldom possible) a very grave condition results. Treatment.--Inflammation of the elbow, such as is frequently seen in general practice where horses are turned out together and exposed to kicks and other injuries, yields to treatment readily, if an open joint does not exist. Hot packs supported in contact with the elbow and kept around the inflamed articulation for a few days, materially decrease pain and tend to reduce inflammation. The subject must be kept quiet in a comfortable stall and, if necessary, a sling used. Where it is impossible for the animal to support much weight with the injured member the sling should be employed. As inflammation abates, which it does in the course of from one to three weeks in uncomplicated cases, the subject may be allowed the freedom of a comfortable box stall. Vesication of the parts is in order, and this may be repeated in the course of two weeks, if it is deemed necessary. Penetrative wounds resulting in open joint are not treated with success as a rule, and because of the handicap under which veterinarians labor, methods of handling such cases, where large, important articulations are affected, are not being rapidly improved. Prognosis is usually unfavorable, and for humane and economic reasons, animals so affected should be destroyed. Ordinary wounds of the region of the elbow are treated along general lines usually employed. They merit no special consideration, except that it may be mentioned that with such injuries concomitant contusion of the parts occasions injury that does not recover quickly. Fracture of the Ulna. Etiology and Occurrence.--Fractures of the ulna in the horse are not common in spite of the exposed position of the olecranon. This bone when broken, is usually fractured by heavy blows and any form of ulnar fracture is serious because of its function and position in relation to the joint capsule. Transverse fractures do not readily unite because of the tension of the triceps muscles, which prevent close approximation of the broken ends of the bone. Thompson[16], however, reports a case of transverse simple fracture of the ulna in a mare, the result of a kick, in which complete recovery took place. He kept the subject in a sling for six weeks and then allowed six months rest. Symptomatology.--The position assumed by a horse suffering from a transverse fracture of the ulna, is similar to that in radial paralysis. Crepitation may be detected by manipulating the parts, and in some instances of fracture of the olecranon, there occurs marked displacement of the broken portions of the bone. Lameness is intense and the parts are swollen and supersensitive. The capsular ligament of the elbow joint is usually involved in the injury because fracture of the ulna may directly extend within the capsular ligament. In such cases, there is synovitis, and later arthritis causes a fatal termination. Treatment.--The impossibility of applying a bandage in any way to practically immobilize these parts in fracture of the ulna, prevents our employing bandages and splints. Therefore, one can do little else than to put the patient in a sling and try to keep it quiet and as nearly comfortable as circumstances allow. Fracture of the Radius. Etiology and Occurrence.--From heavy blows received such as kicks, collision with trees or in falls in runaway accidents, the radius is occasionally fractured. In very young foals, fracture of the radius, as well as of the tibia and other bones, results from their being trampled upon by the mother. Symptomatology.--Excepting in some cases of radial fracture of foals where considerable swelling has taken place, there is no difficulty in readily recognizing this condition. The heavy brachial fascia materially contributes to the support of the radius, and in cases where swelling is marked, crepitation may not be readily detected. In fact, a sub-periosteal fracture may exist for several days or a week or more and then, with subsequent fracture of the periosteum, crepitation and abnormal mobility of the member are to be recognized. In such cases, the subject will bear some weight upon the affected member, but this causes much distress. In one instance the author observed a transverse fracture of the lower third of the radius which was not positively diagnosed until about ten days after injury was inflicted. In this case, without doubt, the subject originally suffered a sub-periosteal fracture of the bone and because the animal was a good self nurse, the brachial fascia supported the radius until the periosteum gave way and the leg dangled. In this instance infection took place and suppuration resulted. It was deemed advisable to destroy this animal. Prognosis.--In adult animals, radial fracture constitutes a grave condition; generally speaking, prognosis, in such cases, is unfavorable. Because of the leverage afforded by the extremity, immobilization of the radius is difficult. Any sort of mechanical appliance, which will immobilize these parts, is likely to produce pressure-necrosis of the soft structures so contacted. There is occasioned thereby much pain and the subject becomes restive, unmanageable and sometimes the splints are completely deranged because of the animal's struggles, and much additional injury to the leg is done. Occasionally, an otherwise favorable case is thus rendered hopelessly impossible to handle, and the subject must be destroyed several days after treatment has been instituted. Consequently, unless all conditions are good, and the affected animal a favorable subject, young, of good disposition, and the fracture a simple transverse one, complete recovery is not likely to result from any practical means of handling. Treatment.--Mature subjects ought to be put in slings and kept so restrained throughout the entire time of treatment. Immobilization of the broken parts of the bone is the object sought. This is attempted by practitioners who employ various methods, and each method has its advocates. Casts are used by some and serve very well in many cases; but because of their bulk and unyielding and rigid nature, they are not well adapted to use on fractures of bones proximal to the carpus and tarsus. This is in reference to plaster-of-paris casts or those of any similar material. Appliances which depend on glue or other adhesive substances combined with leather, wood or fiber for their support, are efficacious but not comfortable. The use of heavy leather when the member has been suitably padded with cotton and bandages, constitutes a very good manner of reducing fracture of the radius or of the tibia. Leather when cut to fit both the medial and lateral sides of a leg, and firmly held with bandages, will form a firm support that yields slightly to changes of position, thus making for comfort of the subject. Such a splint or support should extend from the fetlock region to the elbow, but the cotton and bandages are to reach to the foot. When one considers that, with the supportive appliance placed on each side of the affected member, rigidity is accomplished as much from tensile strain put upon the leather as from its own stiffness, it is seen that the leather need not be of the heaviest--sole leather is unnecessary. Because of the more comfortable immobilizing appliance, the subject is less restive, and chances for a successful outcome are materially increased thereby. In the mature subject, six or eight weeks' time is required for union of the parts to occur sufficiently so that splints may be dispensed with. Rearrangement of the supportive apparatus, however, is possible and usually necessary during the first few weeks of treatment. By employing care in handling the parts, the subject will be unlikely to do itself injury at the time readjustment of splints is being effected. In foals, it is best to give them the run of a box stall with the mother. Being agile, they get up and lie at will without doing injury to the fractured member. The splints (leather is preferable in these cases also) are looked after and readjusted as necessity demands. Three or four weeks time is all that is required for the average young colt to be kept in splints when suffering from simple transverse fracture of the radius. Compound fractures are necessarily more difficult to treat than are the simple variety, but even in such cases recovery results sometimes, and the practitioner is justified in attempting treatment after having explained the situation to his client. Oblique fractures, even when simple, do not completely recover. Muscular and tendinous contraction, together with the natural tendency for the beveled contacting parts of the broken bone to pass one another in oblique fracture, results in shortening of the leg and, if union results, a large callus usually forms. Where shortening of bones occur, necessarily, permanent lameness follows. Wounds of the Anterior Brachial Region. Etiology and Occurrence.--Contusions and lacerations of the forearm are of frequent occurrence in horses and are troublesome cases to handle; particularly is this noticeable where extensive laceration of the parts occurs. These injuries are caused by animals being kicked; by striking the forearm against bars in jumping; and in sections of the country where barbed wire is used to enclose pastures, extensive lacerated wounds are met with when horses jump into such fences. Symptomatology.--Any wound which causes inflammation of the structures of the anterior half of the forearm, is characterized by swinging-leg-lameness. Depending upon the nature and extent of the injury, manifestation varies. In cases where laceration has practically divided all of the substance of the extensor tendons, it is, of course, impossible for the subject to advance the leg; but where lacerated wounds involve only a part of the extensor apparatus of the foreleg, not so much inconvenience is evident, unless the wound is seriously infected and inflammation involves contiguous structures. Therefore, in many instances, lameness is more pronounced in contusions of the anterior brachial region than where tissues have been divided more or less keenly. In every instance diagnosis is easily established. The injury is quite evident, and the manner of locomotion is not in itself an essential feature to be considered in a discussion of symptoms. Where a contusion of the anterior brachial structures occurs, there is, in addition to lameness, swelling which is painful because of the pressure occasioned by the heavy non-yielding brachial fascia. And where suppuration occurs, there is then an intensely painful condition which is not relieved until pus has been evacuated. Rather frequently, drainage for wound secretions is a difficult problem, and approximation of the divided ends of muscles is always difficult to maintain. Treatment.--Contused wounds of the anterior brachial region are treated along usual lines; that is, attempt is made to stimulate prompt resolution. Hot or cold applications are employed throughout the acute stage of the affection. Complete rest is provided for until all pain has subsided. Later, stimulating liniments are beneficial. Where no injury is done the periosteum or bone, complete resorption of all products of inflammation usually occurs, though in many instances, this is tardy--six weeks or more are sometimes required for recovery to take place. If suppuration occurs, it is necessary to provide for drainage as soon as it is possible to distinguish the presence of pus. Due regard is given the manner of establishing drainage because of the usual existence of sub-fascial fistulae. In these cases, one avoids injecting solutions of aqueous antiseptics. By gently compressing the parts, pus is caused to drain out and in enforcing a moderate amount of exercise at a walk, when lameness is not intense, drainage is maintained. Cotton packs, moistened with hot antiseptic solutions, and kept around the forearm for several hours daily, are helpful because drainage is facilitated, and resolution is stimulated by the increase of blood thus attracted to the parts, and pain materially diminishes. In lacerated wounds of the anterior brachial region, after having controlled hemorrhage, an area around the wound margin is freed of hair by clipping or shaving. The wound is carefully examined, and the best site for drainage is selected and a suitable opening for wound discharge is provided for. Where the extensor carpiradialis (metacarpi magnus) with other structures, is divided and the distal portion is torn downward, as frequently is the case in barbed wire cuts, it is necessary to make careful provision for drainage. The wound is thoroughly cleansed by means of ablutions if necessary; but preferably by swabbing with pledgets of cotton or gauze which are moistened in antiseptic solutions. All shreds of macerated tissue are clipped with scissors and finally the whole wound surface is painted with tincture of iodin. If drainage is made by cutting through the tissues in the median portion of the structures that have been displaced, the opening should be packed with gauze so that it may remain patent after swelling has occurred. Such packing is left _in situ_ for twenty-four hours. The pendant muscular portions of tissues are sutured up by means of tapes and, while perfect apposition is not ordinarily possible, it is very essential to train the pendant tissues in their normal position even if they require resuturing within a week. This minimizes granulation of tissue, and there results less scar if the detached portions are kept near, even if not in contact with the proximal wound margins. The skin together with subcutaneous fascia is sutured on either side unless drainage is to be provided for on one side, and the lowermost part of that side is left unsutured. After-care.--Where extensive suturing of tissues has been necessary, subjects must be kept quiet. They are best confined in box stalls and not taken out for several weeks. Particularly is this true where transverse division of extensors has taken place. Sutures are removed at the end of from ten days to three weeks as cases permit. Drainage of wound secretions, which usually become infected, is necessary, because with obstructed drainage in an infected wound of this kind, there will result an early destruction of tissue at some point sutured. Daily irrigation done in a manner that practical asepsis is carried out, is necessary for about a week. All irrigation is done by way of the drainage opening, and this with warm aqueous solutions of suitable antiseptics. After a week or ten days' time, the wound should not be dressed more frequently than twice weekly. If it is necessary to leave a portion of the wound uncovered, as in cases where skin is destroyed, the frequent (three or four daily) application of a suitable antiseptic powder is necessary to check exuberant granulation. This may be directly effected by the use of an astringent or desiccant preparation, and such dressing serves as a mechanical protection as well. When such wounds are kept clean, where drainage is properly maintained, and the subject kept quiet, no particular attention other than the local application of an astringent lotion (such as the zinc and lead lotion) is necessary after the first three or four weeks. Usually, if the animal gnaws at the parts or otherwise manifests evidence of discomfort, it is an indication that new areas of infection are being established because of obstructed drainage or retained eschars. A thorough cleansing of the wound with a two per cent solution of Liquor Cresolis Compositus and this followed by moistening every part of the wound with tincture of iodin, will check all such disturbance if done promptly. Where practically all of the anterior surface of the radius has been denuded, recovery is tardy and there is in some cases imperfect extension of the leg for months after the wound has healed. But in such instances, animals gradually regain complete use of the affected member and in the course of a year function is fully restored. Inflammation and Contraction of the Carpal Flexors. Anatomy.--The structures which are usually considered as true flexors of the carpus are a group of three muscles, which have separate heads of origin and different points of tendinous insertion. The _flexor carpiradialis_ (flexor metacarpi internus) originates from the medial epicondyle of the humerus. It is inserted to the proximal end of the medial metacarpal (inner metacarpal or splint) bone. This muscle is the smaller of the three and is not usually divided in doing carpal tenotomy. The _flexor carpiulnaris_ (flexor metacarpi medius) has two heads of origin; one, the larger, originates from the epicondyle of the humerus and the other from the posterior surface of the olecranon. The two heads unite at the upper third of the radius and the muscle, becoming tendinous, as is the case with the other carpal flexors, is attached by one point of insertion to the accessory carpal bone (trapezum). The other blends with the posterior annular ligament of the carpus. The _ulnaris lateralis_ (flexor metacarpi externus) has its origin from the lateral epicondyle of the humerus and inserts to the proximal extremity of the fourth metacarpal (outer splint) bone and by another attachment to the accessory carpal bone (trapezium) with the tendon of the flexor carpiulnaris (flexor metacarpi medius). Acting together, these muscles flex the carpus or extend the elbow and this action is antagonized by the biceps brachii (flexor brachii) and extensors of the carpus and phalanges. Etiology and Occurrence.--Inflammation of the muscular or tendinous parts of the carpal flexors, does not occur as frequently as does inflammation of the flexors of the extremity. They are subject to injury such as is occasioned by hard work and concussion and contract as a result; but, more frequently a congenital malformation of the leg is responsible for undue strain upon these parts. Horses that are "knee sprung" or that have a congenital condition where in the anterior line,