CHAPTER XIII. 



Diseases Common to Swine and Sheep 



HOG CHOLERA 



The above cut shows how hog cholera makes its first appearance in a herd. 

 Notice the emaciated condition of the small shote below. 



Hog Cholera is an acute febrile disease. So far as is known, 

 affects only hogs, and is characterized by extreme contagiousness and 

 a very high death rate. We have two forms, i. e., the acute and the 

 chronic. That is because the disease in some cases is sudden in its at- 

 tack and rapid in its course, while in others it lingers for weeks or 

 months before death or recovery. The causative agent is the same in 

 both, the difference being due to the variation in virulence of the germs 

 and the resisting power of the hogs. 



While the specific cause of hog cholera is the minute organism, 

 there are many factors which may render a herd more susceptible to 

 the disease; in general anything which tends to lower the vitality of 

 the animal may be regarded as a predisposing cause. The germ is 

 always present in the bodies of sick hogs and is thrown off in the excre- 

 tions, hence the most dangerous factor in spreading hog cholera is the 



