SPAVIN. 253 



cuneiform, and metatarscal bones, and extends to the articular cartilages 

 (p. 257) of the affected joint. Hence the best treatment consists in 

 hastening the bony union of the diseased surfaces, which, as a rule, show 

 little or no tendency to recover their normal condition. Rest, as complete as 

 possible, is a very important factor in obtaining the desired bony union. 



In bone spavin there is, as a result of inflammation, a deposition of bone on 

 the inner and lower part of the hock, commencing, usually, between the 

 middle cuneiform and the cannon bone, or between the middle and large cunei- 

 form bones. The higher this bony formation extends, the more serious is the 

 disease. When the spavin is low down, being then confined to the joint 

 between the middle cuneiform and the cannon bone, it is of little consequence ; 

 as bony imion of that joint does not affect the horse's action to any appreci- 

 able extent. 



Fig. 93- Fig. 94. 



Spavin. No Spavin. 



CAUSES. — ^We may reasonably assume that the usual cause of 

 spavin is unduly severe compression of the bones of the hock, be- 

 cause we find that work which entails this form of injury is 

 specially liable to bring on spavin; and that the more weight is 

 put on the forehand, the less susceptible are horses to this com- 

 plaint. Hence, racehorses do not suffer from spavin nearly so much 

 as hunters, high school horses, and cart horses which have to drag 

 heavy loads up hills. My experience is, that circus horses which, 

 when in the ring, have to walk about a good deal on their hind 

 legs and to perform such feats as cantering backwards and canter- 

 ing with one fore leg continually kept off the ground, are more 

 inclined to develop spavin than any other class of animal. We 

 should here note that the nearer to a perpendicular direction the 

 weight of a horse and rider falls on the hocks while these joints 

 are being straightened out during movement, the more will the 

 bones of the hocks be compressed. Sprain of the short (inter- 



