288 



DISEASES OF THE HORSE'S FOOT 



filled with a yellow, semi-solid material, the remains of the 

 inflammatory exudate and new horn secreted by the kerato- 

 genous membrane. The laminae, both horny and sensitive, 

 are greatly enlarged. This is a hypertrophy, resulting from 

 the continued effects of the inflammation, and leads in time 

 to the formation of laminae quite three or four times their 

 normal size It is this hypertrophy of the laminae and 

 the pressure of the exudate that causes the bulging and 

 increased growth of the horn at the toe (see Fi.g 125), and 



Fig. 125. — Longitudinal Section of a Foot with Laminitis of 

 Several Years' Duration. 



contributes towards the oval formation of the foot we have 

 mentioned before. 



In the longitudinal section the first thing noticeable is 

 the change in position of the bones, more especially in that 

 of the os pedis. The circumstances we have mentioned 

 before — pressure of the exudate upon it in front and tension 

 of the perforans on it behind — have caused it to assume a 

 more upright position than is normal, so much so that in a 

 bad case the front of the bone becomes quite vertical. This 

 vicious direction the other bones of the digit follow (see 

 Fig. 125). 



