BACILLUS NECROPHORUS INFECTIONS 171 



Infection occurs in all these diseases by inoculation, through 

 wounds of skin or mucous membranes, as when little pigs are 

 teething. The lesions produced depend on the point of inocula- 

 tion, age and species of the animal, the virulence of the infec- 

 tion and the character of the associated bacteria. 



Losses are often serious, especially in lip and leg ulceration, 

 canker sore mouth, and foot-rot. 



In dealing with any of these diseases, it is of the utmost 

 importance that one be on guard. for the first case. Prompt 

 treatment with early isolation checks or lessens their spread. 



Foot-Rot 



Foot-rot is a very old and familiar disease. It is often insidi- 

 ous at first, the appetite appearing good, and the lameness 

 slight; but it must be taken seriously at the beginning, and 

 treated promptly, lest it extend to the deeper structures and 

 involve even the bone. Most outbreaks are infectious. 



Cause. — A large percent- 

 age of these cases are caused 

 by Bacillus necrophorus, 

 which is commonly found 

 in dirt and barn yard filth. 



General symptoms. — This 

 disease usually affects the 

 feet and produces lameness, 

 slight and perhaps in one 

 fore foot only at first, be- 

 tween and above the claws. 

 Later the lameness becomes 

 severe. There is a dis- 

 charge, with very offensive odor, and the hoof itself becomes 

 rotten in places. Loose pieces are detached and the sole may be 

 affected in the same way. The sensitive parts may be exposed 

 in very severe cases with a development of profuse granulations. 

 The skin above and between the hoofs is red, tender and swollen, 

 and the toes are widely spread. The animal is lame and, of 

 course, unthrifty. 



The discharge is at first fluid and fetid. After one or two 

 weeks it becomes cheesy and foul, and seems to destroy the horn 

 and skin which it touches. In from twenty to thirty days the 



Fig. 58.- 



-Poot-Rot op Sheep. 

 A plain case. 



