676 
ON THE DISEASES OF THE HOCK. 
called the attention of veterinarians to a disease in some Te- 
spects similar in the hind extremity. Disease of the hock joint, 
attended with lameness, but unaccompanied by enlargement, 
was unknown (as to its seat) to the old round bone persecutors, 
whilst more modern practitioners have styled it u spavin” “ in¬ 
cipient spavin” or said that “ spavin was comingbut either 
present or future, it has been for some time past included under 
the term spavin . On inspection of the hock joint, we ob¬ 
serve a prominent ridge, and two concavities, on the tarsal end 
of the tibia, and two corresponding convexities and one deep 
depression on the upper portion of the astragalus. The articu¬ 
lation of the astragalus with the ossa cuneiformia, and these 
with the metatarsi, are nearly flat, and have scarcely any extent 
of motion. If a mere mechanic were shewn the hock joint, and 
asked what parts he should imagine were most disposed to 
“ wear and tear” he would, I am sure, at once point to the 
w edge-like protuberance on the low'er part of the tibia, and the 
corresponding- concavity in the upper surface of the astragalus, 
as being- nearest the centre of motion. He would fix upon these 
parts in preference to the gibbosities on the astragalus, as the 
summit of the former is much more sudden than of the latter, 
and consequently it has less extent of surface to bear its pro¬ 
portion of superincumbent weight. He w r ould pass over the 
surfaces of the cuneiform bones, as parts possessing only the 
simplest office of a joint—“ the diminution of concussion;” and 
this supposition would in some measure be borne out by the 
physiological aphorism, that in proportion as parts are used, or 
capable of being- used, they are rendered liable to become dis¬ 
eased. It is, then, this part w r hich strikes the mechanic as being 
most likely to receive injury, which I contend is the frequent 
seat of disease, which, is often affected in cases of true spavin, 
and generally in those cases where no enlargement is visible. 
I would not for a moment doubt, that the surfaces of the cunei¬ 
form bones may be liable to inflammation, ulceration, or caries; 
but what I wish to point out is, that the prominent ridge on the 
tibia and narrow' cavity on the astragalus are the parts most 
disposed, from their formation and uses,, to receive injury; most 
likely when injured to occasion pain and lameness, and are in 
fact very frequently found diseased: in support of w hich opi¬ 
nion, I will proceed to mention a few r morbid specimens now 
lying' before me. 
No. 1, is a specimen of diseased hock procured at the knackers 
in London: it presents a sad mass of disease, the exostosis being- 
very considerable, and all the bones of the hock completely an- 
chyldsed; but besides this, there is a small exostosis in the hollow 
