290 



FOOT-ROT IN SHEEP 



\ 



Fig. 65. 



from their organs it can be obtained in pure culture. The 

 time required to kill these animals is usually from four to 



twelve daj's. 



The period of incuba- 



tio7i in small animals is 



but a few days. In the 



naturally contracted dis- 



I / \ ^ \ I ^^^^ ^° sheep it is uucer- 



I \ ^ \ V \ tain. In cases produced 



by inoculation of the 

 I \ • -^ specific bacillus from 



\ " % / three to ten or more days 



elapse before symptoms 

 appear. 



§ 216. Symptoms. 

 Lameness is the first 

 symptom noted. If ex- 

 amined prior to this, 

 Mohler reports a moist area of the skin just above the horny 

 part of the cleft of the foot. The inflammatory condition 

 extends rapidly to tissue beneath the horny part. There is 

 often a discharge of a thin, purulent fluid. Mohler states that 



the discharge emits a pungent, dis- 

 agreeable odor which is character- 

 istic of this infection. There is 

 emaciation which ma}' be due quite 

 as much to the inability of the lame 

 sheep to procure food as from the 

 specific action of the bacillus. 



The duration of the disease varies 

 from a few weeks to several 

 months. The cases are said usual- 

 ly not to terminate fatally. 



Bacillus necrophorus {after 

 illohler) . 



Fig. 66. Necrotic area in 

 the liver of a i-abbit ; C, 

 liver cell, B, inflammatory 

 zone. A, necrotic center 

 {Mohler). 



§ 217. Morbid anatomy. The 

 tissue changes are those of a purulent exudative inflammation. 

 As the process undermines the horny portion of the hoof it 



