204 SWINE DISEASES 



authorities claim that a hog immunized by the simul- 

 taneous method does not eliminate the virus unless he 

 dies of the disease, but this statement has not been clearly 

 proved. Even though the virus is eliminated only in 

 case of fatal illness of the immunized hog, the procedure 

 is dangerous to say the least. The extensive epizob*tic 

 of hog cholera in Iowa and adjoining states in 1913 bears 

 the earmarks of the results of infection from simultaneous 

 immunization. 



To say the least, the use of the simultaneous method is 

 contrary to good sanitation. 



A so-called double method has been advocated by 

 some for the prevention of cholera. It consists of the 

 serum-alone immunization, followed ten days later by 

 the simultaneous method. This method is quite efficient, 

 but is rather expensive. 



In time, the application of serum in the control of 

 hog cholera will be rationally adjusted, and this, combined 

 with the proper enforcement of efficient sanitary regula- 

 tions, will result in diminishing the losses from this dis- 

 ease, and the swine industry may then be profitably pur- 

 sued. 



SWINE PLAGUE 



Swine plague is a specific infectious disease caused 

 by the Bacillus suisepticus and is characterized, except 

 in the septicemic form, by a catarrhal and necrotic 

 pneumonia, with or without a fibrinous pleurisy. 



The existence of this disease is doubted by some good 

 authorities. In various sections of the United States a 

 disease of swine, primarily confined to the lung and pleura 

 and in its manifestations distinct from cholera, has been 

 observed. The same disease has been identified in various 

 other countries by other investigators. This disease is 

 not so fatal, neither is it so widespread, as cholera. It 

 may occur sporadically or enzcotically, but it rarely 

 assumes an epizootic form. The percentage of losses in 

 affected herds varies from one percent to seventy percent. 



Etiology. The cause of swine plague is the Bacillus 

 suisepticus. This microorganism is a representative of 



