5i6 



Journal of Agriculture. 



[9 Sept., 1907. 



Of course, it is only in horses witli a formation of hock recognised 

 as defective that such causes would produce an untoward effect, and it is 

 almost invariable that spavins do not occur on well-shaped hocks, that is, 

 hocks which are symmetrical, and which have such a due mechanical 

 balance of shape as to satisfy the sense of proportion in the observer. On 

 the other hand, hocks too much bent or sickle-shaped, and those which are 

 "deep" from front to back, and at the same time narrow or "tied in'' 

 at the junction of the hock with the cannon bone, are the ones most prone 

 to be affected with sj^avin. It is because such defects of conformation are 

 notoriously transmitted hereditarily that the disease which they princi- 

 ])ally predispose to, viz., spavin, is regarded as an hereditary unsoundness; 

 not that the disease itself is transmitted, but that the shape of hock in 

 which it most often occurs is. 



Symptoms. — Very often lameness is present before there is any obvious 

 enlargement at the seat of spa^'i^. The inflammatory action is going on 



""mm 



Fit 



c)0. Front view of spavined hock. 

 (After Dollar.) 



)i. Back view of spavined hock. 

 (After Dollar.) 



before any bone is thrown out, but the local heat is seldom sufficient to be 

 detected except by those having the most acute sense of touch. In some 

 cases when pressure is applied to the seat of spavin pain may l>e evinced 

 by the animal lifting the leg up, but this is not a reliable test, as a 

 fidgety horse will do this under any circumstances. The " action," how- 

 ever, of spavin lameness is usually of so distinctive a character as to enable 

 a diagnosis to be made, and the peculiarities may be summarized as 

 follows: — 



{a) When standing in the .'Stable the weight is taken off the 

 affected limb, which is placed in a forward position, the heel being 

 raised from the ground continuously. This causes the back tendons 

 to gradually contract, in consequence of which, and of the lack of 

 bending of the hock during progression, the toe of the shoe is 

 always the most worn. 



(b) When a spavined horse is made to " stand over " suddenlv 

 in the stall, he exhibits lameness by a sudden dropping and quick 

 jerking up again of the lame limb ; he also always steps over on his 



