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INFECTIOUS DISEASES 



Anti-Log-eholcra serum is produced by injecting directly, or 

 indirectly, into the blood-vessels of an immune hog a large quan- 

 tity of cholera virus, secured by bleeding a hog that is fatally 

 sick with acute cholera, and bleeding the injected animal after 

 it has completely recovered from the injection. The injection 

 of the cholera blood is for the purpose of stimulating the produc- 

 tion of antibodies by the body tissues, and raising the protective 

 properties of the immune hog's blood. An animal so treated is 

 called a hyperimmune (Fig. 85). The blood from the hyper- 

 immunes is defibrinated and a preservative added, and after it 



Fig. 85. — Hyperimmune hogs used for the production of anti-hog-cholera serum. 



has been tested for potency and freedom from contaminating 

 organisms, it is ready for use. 



The Vaccination of Hogs with Anti-hog-cholera Serum. — 

 The vaccination of a hog by the single method consists in inject- 

 ing hypodermically or intramuscularly anti-hog-cholera serum. 

 The immunity conferred may not last longer than three or four 

 weeks. 



The vaccination of a hog by the dnuhle method, consists in 

 injecting hypodermically or intramuscularly anti-hog-cholera 

 serum and hog-cholera blood. 



The vaccination or treatment of a cholera hog showing notice- 



