282 BOG SPAVIN. 



cated joint. Some of these are found on the inside of the joint, 

 which could not be represented in Fig. 45. From over exertion 

 of the joint, they become inflamed, and considerably enlarged. 

 They are wind-galls of the hock. The subcutaneous vein passes 

 over the inside of the hock, and over some of these enlarged 

 mucous reservoirs, and is compressed between them and the 

 external integument — ^the course of the blood is partially ar 

 rested, and a portion of the vein below the' impediment, anrf 

 between it and the next valve, is distended, and causes the sofi 

 tumor on the inside of the hock, called Bog or Blood sjjavin. 



This is a very serious disease, attended with no great, but 

 often permanent lameness, and too apt to return when the en- 

 largement has subsided under medical treatment. It must be 

 considered as decided unsoundness. In a horse for slow draught, 

 it is scarcely worth while even to attack it. And in one des- 

 tined to more rapid action, the probability of a relapse should 

 not be forgotten, when the chances of success and the expenses 

 of treatment are calculated. 



The cause of the disease — ^the enlarged mucous sack or cap- 

 sule — lies deep, and is with difficulty operated upon. Uniform 

 pressure would sometimes cause the absorption of the fluid con- 

 tained in cysts or bags like these, but in a joint of such exten 

 sive motion as the hock, it is difficult, or almost impossible, to 

 confine the pressure on the precise spot at which it is required. 

 Could it be made to bear on the enlarged bag, it would likewise 

 press on the vein, and to a greater degree hinder the passage of 

 the blood, and increase the swelling below the obstruction. The 

 old and absurd method of passing a ligature above and below 

 the enlarged portion of the vein, and then dissecting out the 

 tumor, is not, in the advanced stage of veterinary science, prac- 

 tised by any surgeon who regards his reputation. The only 

 method of relief which holds out any promise even of temporary 

 success, IS exciting considerable inflammation on the skin, and 

 thus rousing the deeper-seated absorbents to carry away the 

 fluid eftused in the enlarged bag. For this purpose, blisters or 

 firing may be tried : but in the majority of cases, the disease 

 will bid defiance to all appliances, or will return and baffle our 

 hopes when we had seemed to be accomplishing our object. 



A horse with bog spavin will do for ordinary work. He may 

 draw in a cart, or trot fairly in a lighter carriage, with little detri- 

 ment to his utility ; but he will never do for hard or rapid work.* 



_ * Note hy Mr. Spooner. — Our observations under the head of thorough- 

 pins equally apply here ; only that bog spavins are generally more serious, 

 the capsular ligament having a larger amount of surface at the lower part 

 of the hock than at the upper It must not be forgotten that it is the joint 

 itself that is affected, and not the parts exterior to it. 



