CHAPTER XV. 

 DISEASES OF HOGS. 



The hog may be affected by a number of the diseases 

 that have already been treated, such as tuberculosis. By 

 far the most important disease that especially affects the 

 hog is hog cholera. It is probable that there are two 

 and possibly three diseases, caused by different kinds of 

 organisms to which this term is usually applied. The 

 veterinarians have called one of these diseases hog 

 cholera, another swine plague, and within recent years y 

 it has been found that there is still a third kind of or- 

 ganism which causes trouble in the hog. These diseases 

 may be discussed together since methods of prevention 

 are identical. 



The knowledge of no other important group of dis- 

 eases of the domestic animals is in such an unsatisfac- 

 tory condition as that concerning the diseases of the 

 hog. This is true both with reference to he causal or- 

 ganisms, and to methods of prevention by means of vac- 

 cine or serums. Until very recently no progress had 

 been made in methods of fighting the diseases of the hog 

 for twenty years. ; 



Distribution. Hog cholera is supposed to have been 

 imported to this country in the hogs introduced from 

 Europe. The first outbreak of which record is had was 

 in Ohio in 1833. Since that time it has spread to every 

 state. In the great corn growing states it causes greater 

 annual losses than any other disease of the domestic ani- 



