HANDLING HOG CHOLEEA IN THE FIELD 159 



numbers, where hog cholera is not common and 

 its spread is not rapid, most herds do not require 

 immunization. Moreover, in the corn-belt where 

 hog raising is a business, methods of swine hus- 

 bandry are relatively much better than they are 

 in sections in which it is a mere adjunct to 

 other farming operations. The average corn-belt 

 breeder has had more or less experience with hog 

 cholera, he knows what it means to have it sweep 

 unchecked through his herd, and he is not in- 

 clined to be dissatisfied with measures that will 

 check it, even though these measures may not 

 always be perfect in their operation. On the other 

 hand, the Eastern breeder whose herd we are 

 called on to handle very often is having his first 

 experience with the disease, he is inclined to be 

 skeptical as to the merits of protective serum, and 

 to doubt its value if he loses a few animals after it 

 has been administered. Frequently also, the herd 

 is found in unthrifty condition due to poor meth- 

 ods of swine husbandry and heavy parasitic in- 

 festation. Virus cannot be used as freely in such 

 surroundings as it can under circumstances where 

 its effects will be more correctly judged. 



Despite these differences, though, and despite 

 the fact that methods of swine husbandry have a 

 direct and important bearing on the handling of 

 disease, the principle holds that hog cholera is 

 hog cholera the country over, and not, as some 



