HOG CHOLERA 333 



subjected to the preventive treatment in which the virus 

 has been employed within six weeks. Animals purchased 

 should he kept in <|iiarant Sue for four weeks and then al- 

 lowed to come in contact with a small number of the herd. 

 If these exposed animals remain healthy after two or 

 three weeks' exposure, it is safe to place the purchased an- 

 imals with the herd. It is not essential Iliat a rigid quar- 

 antine he established in the case of the purchased animals, 

 for the prevention of intimate contact will usually suffice. 

 The method of keeping hogs in separate houses rather 

 than in one large house has many advantages, one being 

 that if cholera breaks out in one of the yards, it can often 

 be prevented from spreading to the remaining sections of 

 the herd. 



lln^-s ihal have been shown at fairs are likely to be ex- 



1 to infection, not only at the place of exhibition but 



also during shipment. Care should be taken in allowing 



such animals to mingle with the herd, until time has shown 



the animals to be free from infection. 



The virus of hog cholera can be carried on objects from 

 one farm to another, h is probable that this is one of the 

 chief ways in which the disease progresses in any locality 

 into which it has been introduced. The farmer should re- 

 member that any object transferred from an infected farm 

 to his own may serve to carry the infection. The visiting 

 of the hoi: --yards in which an outbreak has made its ap- 

 pearance, the transfer of tools or wagons, or of animals 

 such as dogs or cows, are ways in which the disease spreads. 

 It seems probable that, if the farmer takes care of those 

 factors that he can control, he will have little trouble with 

 Iho^e he can not control. 



The herd should be kept in as healthy a condition as 

 possible by providing clean, well ventilated pens, clean 

 feeding-troughs, and proper feed, since anything that tends 



