ON THE NAVICULAR DISEASE AND SPAVIN. 
157 
of time as to cause continual lameness. This infirmity, which 
may truly be designated as one, sometimes only occurs in one 
leg, and the horse so affected soon becomes totally incapable to 
perform any kind of work. The causes of this disease are not 
well known; but they have been attributed by some to a shorten¬ 
ing of the flexor muscles and tendons of the thigh; others assert, 
that the disease exists in the hock joint. The latter opinion, 
less probable than the former, appears to have no foundation; 
and dissections hitherto have thrown no light whatever on the 
subject. Many proprietors work their horses lame from this 
cause, and we know of no remedies for this kind of peculiar and 
uncontrolable lesicn. 
“ The osseous tumour which constitutes the true spavin gene¬ 
rally occasions lameness, and is of the nature of curb and other 
exostosis ; and the treatment which is employed for curbs and 
exostosis is equally applicable here.” 
That exostosis does occur at the part already described by these 
celebrated veterinary writers, I am willing to admit; and I have 
seen many of them exist, of considerable size, without producing 
lameness. 
I do not know whence the term spavin is derived; but, under 
such denomination, it appears to me, as Mr. Percivall has said, 
that diseases very different in their nature are described. 
It is but of too frequent occurrence that authors trust to their 
predecessors for accurate descriptions of disease ; and in this way 
erroneous notions become handed down to us without fear of their 
being disputed ; and the same indefinite ideas have been quoted 
from book to book, till the practitioner has never thought of ques¬ 
tioning the truth of these ancient and, perhaps, unscientific 
definitions. 
Before Mr. Turner pointed out the seat of lameness in the fore 
legs, we were referred to the shoulders and, in fact, to every other 
part but where it really was, for the cause of it; so I believe 
the case to be with the frequent lameness that occurs in the hind 
legs. It is my belief that, when lameness commences behind, 
although it is usually attributed to the round bone, to the stifle 
joint, or perhaps to the loins, the seat of it is in the synovial mem¬ 
brane that covers the cuneiform bones of the hock. 
I shall now relate to you the history of the case I here pre¬ 
sent to you; and as it corresponds minutely with others from 
which I have derived my notions respecting spavin, I need only 
trace the symptoms that were present in this instance, to put you 
in possession of my experience on this disease. 
The subject, in this case, was a harness horse of unusual per- 
