UNSOUNDNESS 



205 



Fig. 78. — Unsound hock joint, 

 showing bog spavin. 



thigh bone and the large tendon back of it. By pressing 

 with the fingers either on the outside or the inside of the 

 enlargement, the swelling may be 

 made to oscillate back and forth. 



Spavin. — Spavins are of two kinds . 

 bone spavin and bog spavin. The 

 bone spavin affects the bones of the 

 hock, and generally appears as an 

 enlargement at the lower inner as- 

 pect of the hock joint. When form- 

 ing, they are small and painful, and 

 are called "jacks" by some horsemen. 

 The bog spavin appears as a swell- 

 ing of the entire hock joint. The 

 sweUing generally appears on the inside of the hock, al- 

 though the entire joint may be affected. 



Curb. — Curb shows as a swelling 

 at the back of the hind leg just below 

 the hock. It is usually associated 

 with " sickle " or crooked hocks. 

 Sometimes curb appears upon well- 

 formed legs, and may be due to a 

 hard pull or a sudden strain. 



Stringhalt. — This is a disease of 

 the nerves, that usually appears in 

 only one of the hind legs. In the 

 case of affected animals, the feet are 

 lifted quickly from the ground, raised 

 abnormally high, and set down with 

 the same \'igor. If the horse is 

 " warmed up " it is often not noticeable, but if the animal 

 is allowed to stand quietly for some time and then sud- 



Fig. 79. — Unsound hock 

 joint, showing large curb. 



