DISEASES OF HORSES 221 



SPAVIN. 



This affection, popularly termed bone spavin, is an exostosis of 

 the hock joint. The general impression is that in a soavined hock 

 the bony growth should be seated on the anterior and internal part 

 of the joint, and this is partially correct, as such a growth will con- 

 stitute a spavin in the most correct sense of the term. But an en- 

 largement may appear on the upper part of the hock also, or pos- 

 sibly a little below the inner side of the lower extremity of the shank 

 bone, forming what is known as a high spavin; or, again, the growth 

 may form just on the outside of the hock and become an outside, or 

 external, spavin. And, finally, the entire under surface may become 

 the seat of the osseous deposit, and involve the articular face of all 

 the bones of the hock, and this again is a bone spavin. There would 

 seem, then, to be but little difficulty in comprehending the nature of a 

 bone spavin, and there would be none but for the fact that there are 

 similar affections which might confuse one if the diagnosis is not 

 very carefully made. 



But the hock may be spavined, while to all outward observation 

 it still retains its perfect form. With no enlargement perceptible to 

 sight or touch the animal may yet be disabled by an occult spavin, 

 an anchylosis in fact, which has resulted from a union of several of 

 the bones of the joint, and it is only those who are able to realize 

 the importance of its action to the perfect fulfillment of the function 

 of locomotion by the hind leg who can comprehend the gravity of 

 the only prognosis which can be justified by the facts of the case a 

 prognosis which is essentially a sentence of serious import in respect 

 to the future usefulness and value of the animal. For no disease, if 

 we except those acute inflammatory attacks upon vital organs to 

 which the patient succumbs at once, is more destructive to the use- 

 fulness and value of a horse than a confirmed spavin. Serious in its 

 inception, serious in its progress, it is an ailment which, when once 

 established, becomes a fixed condition which there is no known means 

 of dislodging. 



Cause. The periostitis, of which it is nearly always a termina- 

 tion, is usually the effect of a traumatic cause operating upon the 

 complicated structure of the hock, such as a sprain which has torn a 

 ligamentous insertion and lacerated some of its fibers; or a violent 

 effort in jumping, galloping, or trotting, to which the victim has 

 been compelled by the torture of whip and spur while in use as a 

 gambling implement by a sporting owner, under the pretext of im- 

 proving his breed ; or the extra exertion of starting an inordinately 

 heavy load; or an effort to recover his balance from a misstep; or 

 slipping upon an icy surface ; or sliding with worn shoes upon a bad 

 pavement, and other kindred causes. And we can repeat here what 

 we have before said concerning bones, in respect to heredity as a 

 cause. From our own experience we know of equine families in 

 which this condition has been transmitted from generation to gener- 

 ation, and animals otherwise of excellent conformation rendered 

 valueless by the misfortune of a congenital spavin. 



