CONTROL AND ERADICATION OF HOG CHOLERA 237 



ately before shipping, will do much to minimize 

 this danger, but the ideal will be reached only 

 when feeder hogs are permanently immune to hog 

 cholera before they are shipped long distances. 



It will take time to provide for an adequate 

 supply of immune feeders so that shipping suscep- 

 tible and recently-immunized hogs from public 

 stockyards will not be necessary, but there are 

 hopeful indications that this will be brought about. 

 Men experienced in the feed-yard even now are 

 eagerly seeking means of avoiding the heavy 

 financial losses associated with "vaccination 

 cholera " immediately following simultaneous 

 treatment and shipping. Among such men there 

 is an active demand for immune feeder shoats, 

 and efforts are being made, though as yet on a 

 limited scale, to supply this demand. The prac- 

 tice of assembling and immunizing feeders, and 

 shipping them only after the resulting reaction 

 is over is already being adopted by some serum 

 companies. This is a step in the right direction, 

 and our belief is that a promising field is open to 

 others who will make a business of supplying the 

 trade with carefully selected cholera - immune 

 feeder shoats. When the supply of these animals 

 is equal to the demand the practice of shipping 

 susceptible and recently-immunized feeders from 

 public stockyards will cease. 



Indiscriminate use of hog cholera virus in im- 



