CAPPED HOCK. 285 



The account of the diseases of the hock is not yet completed. 

 It is well known that the horse is frequently subject to lameness 

 behind, when no ostensible cause for it can be Ibund, and there 

 •is no external heat or enlargement to indicate the seat of il . It 

 is often pronounced an aflection of the stifle, or of the round 

 bone ; or, if there is a stiffness about the hock, the commence- 

 ment of spavin. Yet in the latter case, the joint may be of its 

 natural size and neither heat nor tenderness perceptible ; and 

 months and years elapse without any appearance of spavin. 

 Repeated dissections have shown that m these cases of incurable 

 lameness behind, where there are no indications, during life, to 

 point out the seat of it, it is occasioned by injuries to the deli- 

 cate and sensible membranes with which the upper and lower 

 wedge-bones are invested. Ulceration of the synovial mem- 

 brane between the upper and lower wedge-shaped bones some- 

 times takes place, and the bones themselves become carious oi 

 ulcerated. 



CAPPED HOCK. 



The point of the hock is sometimes swelled. A soft, fluctuat 

 ing tumor appears on it. This is an enlargement of one of the 

 mucous bags of which mention has been made, and that sur- 

 rounds the insertion of the tendons into the point of the hock. 



It is seldom accompanied by lameness, and yet it is a some- 



the bones themselves. When such is the nature of the case, treatment 

 will, to a great extent, prove unavailing. The amount of enlargement that 

 may exist, therefore, offers no criterion as to the greater or lesser serious 

 ness of the case, for a large exostosis may occur without this ulceration, 

 which latter may exist in some instances with very little enlargement, and, 

 in others, none whatever. Indeed, as stated in the text, in the greater 

 number of cases of lameness of the hind extremities, where no cause is 

 externally perceptible, the seat of injury is the hock. In the majority of 

 cases, the synovial surfaces of the small bones of the hock are affected, in 

 others the larger articulation between the tibia and astragalus is the seat 

 of mischief, the synovial membrane and cartilage being similarly affected. 



With regard to the treatment of these hock cases, as we before ob- 

 served, the result is extremely uncertain and unsatisfactory. If any ex- 

 ternal inflammation is present, we cannot do better than commence by 

 abstracting blood from tlie vein above, and use cooling applications to the 

 hock ; after which we may resort either to the blister, the seton, or the 

 iron. The first is the milder remedy, and if resorted to, should be repeated 

 several times. With regard to the.seton, and the iron, we have both suc- 

 ceeded and failed with each. It may be urged in favor of the seton that 

 the marks and blemishes of the iron are avoided. 



In otherwise incurable lameness of tlie hock, the operation of neu- 

 rotomy has been adopted with success, excising the nerve on the inside only 

 a few inches above the hock. The merit of this operation is principally due 

 to Professor Spooner, of the Royal Veterinary College of Loudon, who 

 was ;he first to perform and introduce it. 



