290 THE PRACTK'E OF VETERINARY MEDICINE. 



last described, with the exception that the limb inclines 

 forward instead of backward. It is not so well marked as 

 sprain of the flexor metatarsi. 



Treatment. — Is the same as for^sprain^of flexor metatarsi. 



BOG SPAVIN. 



A bog spavin may be defined to be a soft pufl'y 

 tumour situated on the antero-internal aspect of the hock 

 joint, and consisting of a distension of the capsular liga- 

 ment with synovial fluid, which, in consequence of some 

 irritation, has become greatly augmented in quantitj^, and 

 causes a bulging out where the capsular ligament is not 

 bound down. Bog spavin is similar to, but is a more 

 serious condition than wind gall, because in the former con- 

 dition the capsular ligament is involved. In the healthy 

 hock joint there is usually about 5ii. of synovial fluid to be 

 found, while in a hock where there is bog spavin there may 

 be 5vi. or ^i. found, and a very large hock may contain a 

 greater quantity still. Bog spavin is most frequently met 

 with amongst heavy horses, and in such animals very little 

 importance is attached to its presence unless actual lameness 

 is present in connection with it. But in light horses, or 

 horses used for fast work, the presence of bog spavin or any 

 unnatural fulness in the region of the hock should always 

 be viewed with the greatest suspicion. Neither thorough- 

 pin nor bog spavin, except in very rare cases, appears to do 

 any harm when occurring in heavy horses. Bog spavin and 

 thorough-pin usually coexist. 



Symptoms. — The symptoms of bog spavin are very plain : 

 the tumour can be easily seen. It varies greatly in size and 

 is usually compressible and cool ; such a bog spavin is not 

 likely to do any harm. If tense and hot it shows that there 

 is a certain amount of irritation in connection with it, and 

 a deposition of calcareous matter may be taking place, or if 



