142 SPRING-TIME SURGERY 



extension of the extensor pedis tendon, and also 

 of the anterior part of the capsular ligament. 

 This, combined with the bruising of the skin, from 

 contact with the ground sets up a thickening over 

 the joint that is apt to remain. 



In some colts the flexure is at the carpus. In 

 such cases the metacarpal muscles and check liga- 

 ments are most affected; in some cases delivery 

 is effected with the front legs flexed. I have seen 

 a few cases of this condition in the hind legs, with 

 the contractions at the fetlock and the flexor ten- 

 dons most affected. 



Etiology. — This malformation is caused, I be- 

 lieve, by the limbs becoming flexed in utero and 

 for some inexplicable reason, remaining that way 

 too long. It may possibly be hereditary in some 

 cases, when one or both parents have upright 

 shoulders and short straight pasterns. I know 

 of a mare of such conformation that has had two 

 colts in succession, sired by the same horse, that 

 knuckled completely over on one front fetlock, 

 and could touch the ground with only the toe of 

 the other leg. Her colts were sound when sired 

 by another horse. 



