DISEASES OF THE HORSE. 293 



the surgeon for the operation of nourectom}', or the free and deep 

 application of the firing- iron. 



This affection, popularly termed hone spavin., is an exostosis of the 

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

 bon}" growth should be seated on the anterior and internal part of the 

 joint, and this is partially correct, as such a growth will constitute a 

 spavin in the most correct sense of the term. But an enlargement 

 ma}" appear on the upper part of the hock also, or possibly a little 

 below the inner side of the lower extremity of the shank bone, form- 

 ing what is known as a Idgli spavvti; or, again, the growth ma}^ form 

 just on the outside of the hock and become an outside,, or external., 

 spavin. And, finall}", 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 Tjone 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 affec- 

 tions which might confuse one if the diagnosis is not ver}^ carefully 

 made. 



But the hock ma}" be "spavined," vv'hile 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 anchy- 

 losis 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 useful- 

 ness and value of the animal. For no disease, if we except those acute 

 inflammatory attacks upon vital organs to whi(5h the patient succumbs 

 at once, is more destructive to the usefulness and value of a horse than 

 a confirmed spavin. Serious in its inceDtion, 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 termination, 

 is usually the effect of a traumatic cause operating' upon the.compli- 

 cated structure of the hock, such as a sprain which has torn a liga- 

 mentous insertion and lacerated some of its fibers; or a violent effort 

 in jumping, galloping, or trotting, to which the victim has been com- 

 pelled by the torture of whip and spur v/hile in use as a gambling 

 implement by a sporting owner, under the pretext of "improving 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 



