METHODS OF USING ANTI-HOG-CHOLERA SERUM 137 



3. Produces an active and permanent immunity 

 in many pigs less than twelve weeks old which are 

 definitely infected with cholera near the time of 

 treatment, but cannot be depended on to produce 

 permanent immunity in all young pigs. 



4. Does not affect other diseases unfavorably, 

 and if it is carefully administered, untoward re- 

 sults following its use are practically negligible. 



Indications for serum alone. 



1. In seemingly well and exposed animals in in- 

 fected herds. 



2. In all cases in which a four-week immunity 

 will meet the requirements. (Show hogs under 

 some circumstances, those near the end of the 

 fattening period, breeding animals crated for 

 shipping.) 



3. In all cases in which immediate protection 

 is required and simultaneous treatment cannot be 

 safely administered. (Sows near farrowing time, 

 weak unthrifty animals temporarily threatened 

 with hog cholera.) See also follow-up treatment. 



C ontra-indications for serum alone. Serum 

 alone is contra-indicated when the following con- 

 ditions coexist in the same herd or animal. 



1. A permanent immunity is desired. 



2. Hog cholera infection does not exist. 



3. Simultaneous treatment may safely be ad- 

 ministered. 



Simultaneous or double treatment. This 



