DISKASE3 OF SHEEP. 79 



to circumstances, over the wliole foot, and sometimes, though 

 rarely, over all four. 



A few days after infection the naked skin in the cleft of 

 the hoof appears somewhat redder and warmer than in its 

 normal condition. On the inner side of the affected claw, 

 where the upper edge of the horny shoe unites with the 

 skin of the fleshy crown at the balls, forming the so-called 

 seam or suture of the hoof, an aqueous, badly-smelling 

 liquid exudes, and the skin separates at the suture. If 

 the aifected claw is pressed with the hand at the ball, the 

 sheep shows by a convulsive jerk with the foot that it suffers 

 pain. The ball at the diseased side is somewhat swollen 

 and hot, and the animal is but little lame during the first 

 six or eight days. 



As the disease advances, the inner horny wall separates 

 more and more from the hoof-bone, and the secretion, which 

 was clear before, now becomes more copious, thicker and 

 dark. It flows downward behind the horny wall toward 

 the sole of the hoof, and destroys all connection of the 

 inner side of the horny capsule with the foot, so that the 

 former falls off. 



The secretion is very corrosive, and attacks not unfre- 

 quently the ligaments, tendons and even the bones, es- 

 pecially the hoof-bone, which it destroys to a greater or less 

 extent. It is frequently mixed with blood, flocules of morti- 

 fied cellular tissue, etc., and always smells badly. While 

 these changes occur within, the external surface of the horny 

 capsule becomes friable, cracked, very long and misshapen, 

 and is covered with rings and knots. The toe turns up- 

 ward, and the outer wall is folded inward and under the 

 sole. 



After the capsule has fallen off, a new one is formed, and 

 this is repeated several times, but the new claw is always 

 more or less deformed and crippled. 



