16 



farmers' bulletin 834. 



All animals that die on the farm, as well as the entrails removed 

 from animals at butchering time, should be properly disposed of by 

 burning to ashes, or by burying with quicklime away from streams 

 and low places. Unless disposed of in this way they will serve to 

 attract buzzards, crows, and dogs that may bring or carry away the 

 germs of hog cholera. 



Newly purchased stock, stock borrowed or loaned for breeding pur- 

 poses, and stock exhibited at public fairs should be placed in isolated 

 pens and kept there for at least 15 days before being turned in with 

 the herd. During this quarantine care should be used to prevent 

 carrying infection from these to other pens by those who feed or 

 care for stock. 



Hogs should not be allowed to follow newly purchased stock unless 

 such stock has been dipped or driven through a suitable disinfectant. 



If hog cholera appears on the farm a notice should be posted at 

 the entrance to the premises reading " HOG CHOLERA — KEEP 

 OUT,"' and all neighbors should be warned so that they may protect 

 their herds. The infected herd should be confined to limited quar- 

 ters that can be cleaned daily during the presence of the disease and 

 sprayed occasionally with a disinfectant consisting of 1 part of 

 compound cresol solution to 30 parts of water, or with a recognized 

 substitute therefor. 



PREVENTION BY INOCULATION. 



Up to the present time no drug or combination of drugs is known 

 which can be regarded as a preventive or cure for hog cholera in a 

 true sense of the word. It is true that a number of preparations on 

 the market composed of drugs and chemicals are advertised to pro- 

 tect hogs against cholera or to cure hogs affected with cholera. 

 Many of these so-called cures have been tested by Federal or State 

 institutions, and one and all have been found to be worthless. 

 Farmers therefore are warned against investing their money and 

 placing their faith in hog-cholera medicines. Only one agent known 

 can be regarded as a reliable preventive. That agent is " anti-hog- 

 cholera serum," prepared according to the methods originally worked 

 out by the Bureau of Animal Industry. This serum is prepared as 

 follows : 



Hogs that are immune against cholera, either naturally, as a result 

 of exposure to disease, or as a result of inoculation, are injected with 

 large quantities of blood from hogs sick of cholera. The blood, which 

 contains the virus from the sick hogs, even in minute quanti- 

 ties, would kill susceptible pigs but does not injure immunes; on the 

 contrary, it causes immunes to become more highly immune. After 

 the immunes are injected with virus as stated, they are called " hyper- 

 immunes.'" About 10 days or 2 weeks after an immune has been 



