"Sore shoulders" is an expression which is applied to a variety of pathological conditions, from the most superficial abrasion to inflammation and abscess deeply seated in the structure of the part. It is almost exclusively confined to harness horses and others engaged in heavy draught, and for the reason, no doubt, that the collar they wear is the exciting cause of the malady. Young horses which are collared for the first time, horses with thin, delicate, and sensitive skin, and others on whose shoulders small fibrous tumours or eczematous eruptions appear, are most frequently the victims of sore shoulders.
Now and again animals with none of these predisposing conditions are made to suffer by violent irritation to the surface and contusion of the deep-seated tissues.
Collars that are ill-fitted, badly-formed, and imperfectly-stuffed, are the actual or inducing causes, and their mischievous effects are intensified by cold, wet weather, when the skin is chafed and chapped.
The more numerous and simple forms of the affection are mere abrasions. The cuticle is rubbed off, the sensitive skin is exposed and thickened by inflammatory swelling, and maybe the hair leaves its follicles. It is, besides, hot and sore, and when seen on a white horse there is more or less redness of the surface.
In this condition the application of the collar provokes pain, and the animal obstinately refuses to throw himself into it, and attempts to remove the pressure by backing. Young horses are frequently ill-used by ignorant grooms on account of this resistance to suffering, and from quiet, willing workers are converted into unmanageable and useless brutes.
In some horses the skin on the site of the collar is studded with small tumours about the size of a bean or a marble, which are caused to enlarge by the constant chafing, and sooner or later to break into obstinate sores.
Eczematous and other eruptions in this situation are also soon converted into superficial wounds by the same means.
Now and again an inflammatory swelling appears, at first of limited. extent, but gradually increasing in size over a period of weeks or months until it reaches the dimensions of a cricket ball or a moderate-sized turnip.
Its growth is slow, and may for some time be hardly perceptible. At first it does not seriously incommode the animal, but as it develops soreness increases, and the time sooner or later arrives when the collar cannot be borne. It commences as a hard, diffused fulness, which slowly spreads. After several weeks or months a fluctuating point appears on the surface, indicating the presence of an abscess, which in due course breaks and discharges its contents.
In all cases of sore shoulders, whatever its form may be, the cause should be removed. This will require that the use of the collar be discontinued, or substituted by a breast collar. Frequently this is all that will be necessary, but a dose of physic and a few days' rest will hasten recovery.
Where a local application is needed, the part should be well washed and dried, and then dusted over with a powder composed of boracic acid and Hour twice or thrice a day. A weak solution of alum or carbolic acid is also a useful application.
Shoulder abscess, to which we have referred above, is usually deeply seated among the muscles of the part, and requires a considerable time to come to the surface. It is usual with some practitioners to apply a repetition of blisters to the part at suitable intervals, with the object of exciting inflammation in the tissues, to hasten its formation, and those who are not skilled in surgical practice might safely adopt this course and wait results. Others cut down upon the abscess, evacuate the pus, and lay the cavity open; or, should no pus be found to exist, the growth is removed wholly or in part, according to circumstances, and the wound treated in the ordinary way. (See Special Treatment of Wounds, p. 410.)