SPAVIN. 
469 
and hence should be viewed as simply a neoformation of bone 
to complete the bone-forming process. 
It is claimed by some German authors that large horses, 
with powerfully developed muscles of the hind quarters, are, 
from the powerful mechanical action of flexion and extension 
of the limb on the hock, much predisposed to spavin, also that 
long, weak-backed animals are often affected with the disease. 
I have often seen spavin occur in mares that had passed 
through a severe attack of parturient laminitis, in which the 
major portion of the weight of the body was thrown upon the 
posterior part of the body. In this affection, articular arthritis 
is a common sequel and often ends in ostitis and anchylosis. 
Semiology. —Mr. Percivall, in speaking of the symptoms of 
. spavin, says: “ The symptoms of spavin are, in general, plain 
and simple and unequivocal.” With all due deference to such 
a distinguished author, I must say that in my experience, where 
the exostosis is not yet present, spavin is one of the most diffi¬ 
cult forms of lameness to properly diagnose. There is, perhaps, 
no other form of lameness of the horse in which the practitioner 
should be more guarded in his opinion, moreover, the young 
and inexperienced one. 
The idea that certain characteristic movements of the hock 
joint are always indicative of spavin lameness is in a great many 
cases erroneous. A much more certain sign of spavin lameness 
would, in my opinion, be the wearing away of the toe of the 
shoe or hoof, as this condition is almost invariably present in 
cases of spavin lameness, where the exostosis is not present and 
the ostitis is not extensive ; being confined to the inner angle of 
the scaphoid and the cuneiform bones, the diagnosis can be 
made certain only by inference, such as the history of a slight 
lameness, which would disappear after a certain amount of ex¬ 
ercise had been taken. The absence of any pathological lesion 
around the foot, such as sidebones, ringbone, tendonitis, curb, 
patellar lameness (gonitis chronica), hip-joint disease, or long 
standing lameness with atrophy of the gluteal and patellar mus¬ 
cles from repeated attacks of azoturia, etc. All these conditions 
