Part 66

Cause.--From whatever cause this lesion may arise, it can hardly be considered as of a traumatic nature, no external violence having any apparent agency in producing it, and it is our belief that it is due to a peculiar degeneration or softening of the bones themselves, a theory which acquires plausibility from the consideration of the spongy consistency of the sesamoids. The disease is a peculiar one, and the suddenness with which different feet are successively attacked, at short intervals and without any obvious cause, seems to prove the existence of some latent, morbid cause which has been unsuspectedly incubating. It is not peculiar to any particular class of horses, nor to any special season of the year, having fallen under our observation in each of the four seasons.

Symptoms.--The general fact is reported in the history of most cases that it makes its appearance without premonition in animals which, after enjoying a considerable period of rest, are first exercised or put to work, though in point of fact it may manifest itself while the horse is still idle in his stable. A hypothetical case, in illustration, will explain our theory: An animal which has been at rest in his stable is taken out to work, and it will be presently noticed that there is something unusual in his movement. His gait is changed, and he travels with short, mincing steps, without any of his accustomed ease and freedom. This may continue until his return to the stable, and then, after being placed in his stall, he will be noticed shifting his weight from side to side and from one leg to another, continuing the movement until rupture of the bony structure takes place. But it may happen that the lameness in one or more of the extremities, anterior or posterior, suddenly increases, and it becomes evident that the rupture has taken place in consequence of a misstep or a stumble while the horse is at work. Then, upon coming to a standstill, he will be found with one or more of his toes turned up; he is unable to place the affected foot flat on the ground. The fetlock has dropped and the leg rests upon this part, the skin of which may have remained intact or may have been more or less extensively lacerated. It seldom happens that more than one toe at a time will turn up, yet still the lesion in one will be followed by its occurrence in another. Commonly two feet, either the anterior or posterior, are affected, and we recall one case in which the two fore and one of the hind legs were included at the same time. The accident, however, is quite as liable to happen while the horse is at rest in his stall, and he may be found in the morning standing on his fetlocks. One of the earliest of the cases occurring in my own experience had been under care for several weeks for suspected disease of the fetlocks, the nature of which had not been made out, when, apparently improved by the treatment which he had undergone, the patient was taken out of the stable to be walked a short distance into the country, but had little more than started when he was called to a halt by the fracture of the sesamoids of both fore legs.

While there are no positive premonitory symptoms of these fractures known, we believe that there are signs and symptoms which come but little short of being so, and the appearance of which will always justify a strong suspicion of the truth of the case. These have been indicated when referring to the soreness in standing, the short, mincing gait, and the tenderness betrayed when pressure is made over the sesamoids on the sides of the fetlock, with others less tangible and definable.

Prognosis.--These injuries can never be accounted less than serious, and in our judgment will never be other than fatal. If our theory of their pathology is the correct one, and the cause of the lesions is truly the softening of the sesamoidal bony structure and independent of any changes in the ligamentous fibers, the possibility of a solid osseous union can hardly be considered admissible.

Treatment.--In respect to the treatment to be recommended and instituted it can be employed only with any rational hope of benefit during the incubation, and with the anticipatory purpose of prevention. It must be suggested by a suspicion of the verities of the case, and applied before any rupture has taken place. To prevent this and to antagonize the causes which might precipitate the final catastrophe--the elevation of the toes--resort must be had to the slings and to the application of firm bandages or splints, perhaps of plaster of Paris, with a high shoe, as about the only indications which science and nature are able to offer. When the fracture is an occurred event, and the toes, one or more, are turned up, any further resort to treatment will be futile.

DISEASES OF JOINTS.

Three classes of injury will be considered under this head. These are, affections of the synovial sacs, those of the joint structures, or of the bones and their articular surfaces, and those forms of solution of continuity known as dislocations or luxations.

DISEASES OF THE SYNOVIAL SACS.

Two forms of affection here present themselves, one being the result of an abnormal secretion which induces a dropsical condition of the sac without any acute, inflammatory action, while the other is characterized by excessive inflammatory symptoms, with their modifications, constituting synovitis.

SYNOVIAL DROPSIES.

We have already considered in a general way the presence of these peculiar oil bags in the joints, and in some regions of the legs where the passage of the tendons takes place, and have noticed the similarity of structure and function of both the articular and the tendinous bursae, as well as the etiology of their injuries and their pathological history, and we will now treat of the affections of both.

WINDGALLS.

This name is given to the dilated bursae found at the posterior part of the fetlock joint. They have their origin in a dropsical condition of the bursae of the joint itself, also of the tendon which slides behind it, and are therefore further known by the designations of articular and tendinous windgalls, or puffs. (See also p. 401.)

They appear in the form of soft and somewhat symmetrical tumors, of varying dimensions, and generally well defined in their circumference. They are more or less tense, according to the quantity of secretion they contain, apparently becoming softer as the foot is raised and the fetlock flexed. Usually they are painless and only cause lameness under certain conditions, as when they begin to develop themselves under the stimulus of inflammatory action, or when large enough to interfere with the functions of the tendons, or again when they have undergone certain pathological changes, such as calcification, which is among their tendencies.

Cause.--Windgalls may be attributed to external causes, such as severe labor or strains resulting from heavy pulling, fast driving, or jumping, or they may be among the sequelae of internal disorders, such as strangles or the resultants of a pleuritic or pneumonic attack.

Unnecessary anxiety is sometimes experienced respecting these growths, with much questioning touching the expediency of their removal, all of which might be spared, for, while they constitute a blemish, their unsightliness will not hinder the usefulness of the animal, and in any case they rarely fail to show themselves easily amenable to treatment.

Treatment.--When in their acute stage, and when the dropsical condition is not excessive, the inflammation may be checked during the day by continuous, cold-water irrigation by means of a hose or soaking tub and at night by applying a moderately tight-roller bandage. Later absorption may be promoted by a Priessnitz bandage, pressure by roller bandages, sweating, the use of liniments, or if necessary by a sharp blister of biniodid of mercury. This treatment should subdue the inflammation, abate the soreness, absorb the excess of secretion, strengthen the walls of the sac, and finally cause the windgalls to disappear, provided the animal is not too quickly returned to labor and exposed to the same factors that occasioned them at first.

If the inflammation has become chronic, however, and the enlargement has been of considerable duration, the negative course will be the wiser one. If any benefit results from treatment it will be of only a transient kind, the dilatation returning when the patient is again subjected to labor, and it will be a fortunate circumstance if inflammation has not supervened.

Notwithstanding the generally benignant nature of the swelling there are exceptional cases, usually when it is probably undergoing certain pathological changes, which may result in lameness and disable the animal, in which case surgical treatment will be indicated, especially if repeated blisters have failed to improve the symptoms. Line firing is then a preeminent suggestion, and many a useful life has received a new lease as the result of this operation timely performed. Another method of firing, which consists in emptying the sac by means of punctures through and through, made with a red-hot needle or wire, and the subsequent injection of certain irritating and alterative compounds into the cavity, designed to effect its closure by exciting adhesive inflammation, such as tincture of iodin, may be commended. But they are all too active and energetic in their effects and require too much special attention and intelligent management to be trusted to any hands other than those of an expert veterinarian.

BLOOD SPAVIN, BOG SPAVIN, AND THOROUGHPIN.

The blood spavin is situated in front and to the inside of the hock and is merely a varicose or dilated condition of the saphena vein. It occurs directly over the point where the bog spavin is found, and has thus been frequently confused with the latter.

The complicated arrangement of the hock joint, and the powerful tendons which pass on the posterior part, are lubricated with the product of secretion from one tendinous synovial and several articular synovial sacs. A large articular sac contributes to the lubrication of the shank bone (the tibia) and one of the bones of the hock (the astragalus). The tendinous sac lies back of the articulation itself and extends upward and downward in the groove of that joint through which the flexor tendons slide. The dilatation of this articular synovial sac is what is denominated bog spavin, the term thoroughpin being applied to the dilatation of the tendinous capsule.

The bog spavin is a round, smooth, well-defined, fluctuating tumor situated in front and a little inward of the hock. On pressure it disappears at this point to reappear on the outside and just behind the hock. If pressed to the front from the outside it will then appear on the inside of the hock. On its outer surface it presents a vein which is quite prominent, running from below upward, and it is to the preternatural dilatation of this blood vessel that the term blood spavin is applied.

The thoroughpin is found at the back and on the top of the hock in that part known as the "hollows," immediately behind the shank bone. It is round and smooth, but not so regularly formed as the bog spavin, and is most apparent when viewed from behind. The swelling is usually on both sides and a little in front of the so-called hamstring, but may be more noticeable on the inside or on the outside.

In their general characteristics bog spavins and thoroughpins are similar to windgalls, and one description of the origin, symptoms, pathological changes, and treatment will serve for all equally, except that it is possible for a bog spavin to cause lameness, and thus to involve a verdict of unsoundness in the patient, a circumstance which will, of course, justify its classification by itself as a severer form of a single type of disease.

We have already referred to the subject of treatment and the means employed--rest, of course--with liniments, blisters, etc., and what we esteem as the most active and beneficial of any, early, deep, and well-performed cauterization. There are, besides, commendatory reports of a form of treatment by the application of pressure pads and peculiar bandages upon the hocks, and it is asserted that the removal of the tumors has been effected by their use. Our experience with this apparatus, however, has not been accompanied with such favorable results as would justify our indorsement of the flattering representations which have sometimes appeared in its behalf.

OPEN JOINTS, BROKEN KNEES, SYNOVITIS, AND ARTHRITIS.

The close relationship which exists among these several affections, their apparently possible connection as successive developments of a similar, if not an essentially identical, origin, together with the advantage gained by avoiding frequent repetitions in the details of symptoms, treatment, etc., are our reasons for treating under a single head the ailments we have grouped together in the present section.