CONTROL AND ERADICATION OF HOG CHOLERA 241 



infection. He should, with the advice of his 

 veterinarian determine whether his herd is to be 

 maintained immune to hog cholera, or whether it 

 is to remain susceptible and be kept under obser- 

 vation. In case the former plan is adopted the 

 practice of immunizing should not be allowed to 

 lag, and in case the latter seems advisable he 

 should report promptly any infectious disease 

 that appears. 



The practicing veterinarian's part consists in 

 snuffing out the outbreaks as fast as they appear, 

 in aiding owners to clean up their herds so that 

 they will not serve to infect others in the vicinity, 

 in doing the vaccinating incident to maintaining 

 immune herds, and in advising his clients relative 

 to methods by which their herds can best be pro- 

 tected. Only when the need for police power ap- 

 pears does the province of the practitioner ter- 

 minate and that of the official veterinarian begin. 



The official veterinarian's primary duty is to 

 bring pressure to bear on the three principal 

 practices that serve to spread hog cholera from 

 locality to locality. By placing restrictions on the 

 sale of hogs from infected herds and from public 

 stockyards ; by a far more severe interpretation of 

 hog-cholera-like lesions in the administration of 

 meat inspection regulations ; by restricting the use 

 of virus so that only trained men may handle 

 it; and by continued supervision of commercial 



