ON BONY DISEASES OF THE HOCK, 427 
For this purpose there may be specified three places on the 
hock where spavins may appear. 
1st. What Mr. Percivall calls low spavins , p. 182. In p. 125, 6, 
he minutely describes the mode of examination for spavin, and di- 
rects the eye to the seat of spavin. Now, it may be fairly doubted 
whether the swelling so visible at the head of the shank bone be 
a spavin at all, inasmuch as it may be, and generally is, confined 
to the head of the sliank bone, without at all interfering with the 
jointing of that bone with the cushion bone above ; and the splent 
of the hind leg may be also free from this joint, and, if not very 
large, would not be visible from the position he puts the observer 
into : and both these swellings, if full grown, may be perfectly inno- 
cent, and generally are so. Indeed, Mr. Percivall himself, p. 182, 
pronounces them to be so. Swellings, also, apparent very high 
on the hock, though seemingly within the above definition, are, in 
reality, not spavins ; that is to say, swellings either on the inter- 
nal malleolus of the tibia or on the os calcis, above its jointing 
with the other bones of the hock. 
2dly. The swelling may appear on either of the middle bones 
forming the hock ; namely, the cuneiform or wedge bones, and 
may be clear of the jointing with the next bone, as described 
in “ The Horse,” p. 364, 1843 edit. Spavin so situate may be 
also innocent. 
3dly. When the bony swelling, however originating, affects the 
jointing of any two bones, the spavin becomes noxious and pro- 
ductive of more or less mischief. Veterinary science has certainly 
not advanced so far as to pronounce with certainty the mode or ex- 
tent of mischief produced by spavins even on the jointing ; for an 
experienced and skilful veterinary surgeon has recently shewn the 
writer of this a specimen of spavined hock with diseased bone 
across and uniting the two bones. The horse, when living, was 
under his eye daily ; and though the spavin was apparent, there 
was scarcely any lameness. 
Looking at spavin with a view to a proposed purchase, or in 
case of dispute, the veterinary surgeon’s duty is certainly difficult : 
he must ascertain as well as he can the precise position of the ap- 
parent spavin in a horse going perfectly sound; the history and age 
of it; and unless he can fairly see his way to the opinion that the 
spavin, though now innocent, is in its ordinary progress (p. 142) 
likely to damage the horse, he ought not to reject the horse as un- 
sound. The common knots or jacks, as the dealers call them, certainly 
ought not to be considered unsoundness, unless there be lameness. 
The other disease usually confounded with spavin is called im- 
properly an “ occult hock lameness” — there being, in fact, a lame- 
ness visible, but the cause occult — in the present state of veterinary 
