THE MOST COMMON DISEASES OF SWINE 53/ 



One is called the acute and the other the chronic form. 

 This is because of the fact that in some cases the dis- 

 ease is sudden in its onset and rapid in its course, 

 \vhereas in others, the affected hogs linger for weeks or 

 months before death or recovery. Notwithstanding the 

 dissimilarity in the symptoms and lesions observed in 

 these two types, the causative agent is the same in Ijoth, 

 the difference in the manifestations of the disease being 

 no doubt due to a variation in the virulence of the germs 

 which cause the disease, and possibly to some extent 

 also to a variation in the resisting power of hogs. Wliile 

 outbreaks may occur at all seasons of the year, the great 

 majority take place during the late summer and fall. 

 The mortality is as high as loo per cent in some herds, 

 while the average is probably from 70 to 80 per cent, 

 and many of the hogs which survive are comparatively 

 worthless, owing to their being weakened and stunted in 

 gruwth. 



THE GERM WHICH CAUSES CHOLERA 



"The germ or microbe which causes cholera is present 

 in the blood of sick liogs, and also in the excretions 

 from such hogs, particularly in the urine. It has Ijeen 

 shown that the disease can be prcjduced almost without 

 fail l)y inoculating well hogs with the blood or urine 

 from sick hogs. The germ whicii is in this blood and 

 lu-ine is so small, or else of such structure, that it can 

 not be seen with the strongest microscopes. 



"While the specific cause of cholera is the minute mi- 

 cro-organism or germ just referred to, there are many 

 factors which may render a herd more susceptible to 



