156 Agricultural Bacteriology. 



Swine plague. It is believed that swine plague is a 

 distinct disease from hog cholera, produced by a different 

 organism. The diseases often occur together, each pro- 

 ducing its peculiar lesions in the body of the animal. 

 From the standpoint of prevention, all that has been 

 said concerning hog cholera applies to swine plague. It 

 is not certain whether the method of vaccination against 

 hog cholera is of any value in cases of swine plague. It 

 is claimed by some that there is but one disease caused 

 by an organism so small that it cannot be seen with the 

 most powerful microscope, and that the organisms sup- 

 posed to be the cause of hog cholera and swine plague are 

 of secondary importance. Others claim that there are 

 three distinct diseases. 



The disease of swine plague is primarily one of the 

 lungs and it is supposed that the infection occurs through 

 the lungs. The lungs may show consolidated areas, in 

 which the organ has the appearance of solid flesh or liver, 

 instead of the spongy normal texture, and the air pas- 

 sages may be filled with an exudate. 



