The Bulletin 17 



recovered from an attack of cholera. One attack of cholera confers life 

 immunity. Into this ''immune" hog five cubic centimeters of vims are 

 injected direct into the circulation for every pound of live weight. This 

 hog is then known as hyper-immune. 



In the course of eight to ten days the hyper-immune is bled by the tail, 

 taking as much blood as the hog will stand. As soon as the hog recovers 

 from the etlect of having a large quantity of blood removed from it, 

 which is about a week, the hog is tlien bled again and this is continued 

 until four bleedings have been made. Then the hog is re-hyperimmun- 

 ized and bled four more times. This is continued until the tail becomes 

 short, when the final bleeding is made by cutting the throat, and all of 

 the blood is removed. 



The blood from the tail and throat of the hyper-immunized hog is 

 defibernated (the clot is removed) leaving the liquid portion of the blood 

 which is the serum. To this serum is added enough carbolic acid to 

 make one-half of a one per cent solution. The acid is added as a pre- 

 sen-ative. This serum is a preventive to hog cholera and cannot produce 

 hog cholera because it contains the anti-bodies which are antagonistic to 

 the germs of hog cholera. 



There are thousands of dollars spent annually for so-called sure hog 

 cholera "cures." Agricultural papers are full of very attractive adver- 

 tisements of fake remedies. To spend money for such "fakes" is nothing 

 less than throwing it away. 



It would be well to bear in mind that all products advertised as "cures" 

 for hog cholera are worthless; also that a large per cent of the serum and 

 vaccines will not prevent hog cholera. 



Anti-hog cholera serum, if ])roperly prepared and administered, will, 

 without a doubt, prevent hog cholera, but very little is claimed for it as a 

 curative agent. 



Virus 



The virus used to liy])cr-iinmunize the immune hog is secured by in- 

 jecting a small amount of virus (the liquid portion of the blood) from 

 an acute case of hog cholera into a susceptible hog, or by exposing a 

 susceptible hog to hog cholera infection. "When the hog has developed an 

 acute case of cholera, the hog is bled by the throat and the blood is then 

 defibernated. The virus or liquid ])Oition of the blood is injected direct 

 into the circulation of the immune hog. 



Ways of Vnccinatiny 



There are two ways by which hogs may be vaccinated with anti-hog 

 cholera serum, the Serum Alone Method and the Semm Simultaneous 

 Method. The Serum Alone Method consists of injecting the required 

 amount of serum into the tissues of the hogs with a hypodermic syringe. 



