546 SWINE IN AMERICA 



to each 200 pounds' weight of hogs to be treated, and 

 given once a day. 



PREVENTION BY INOCULATION 



"The Bureau of Animal Industry has endeavored for 

 a number of years to find a medicine or serum which 

 could be used for preventing hog cholera or for curing 

 hogs sick of that disease. It is a well-known fact that 

 hogs which have recovered from hog cholera are there- 

 after immune against that disease. The experiments of 

 the Bureau resulted in the discovery that it is entirely 

 possible to protect hogs if they are treated with serum 

 from a properly treated immune hog. 



"The method of producing the serum is briefly as fol- 

 lows : 



"A vigorous immune hog — that is, one which has re- 

 covered from an attack of hog cholera or one which has 

 been exposed to the disease without contracting it — is 

 treated with a large cjuantity of blood from a hog sick 

 of hog cholera. After a week or two blood is drawn 

 from the immune by cutting off the end of the tail. 

 After standing, the blood clot is removed and the serum 

 or fluid portion of the blood is mixed with a weak solu- 

 tion of carbolic acid and filled into sterilized bottles. 

 We have in this fluid portion of the immune's blood the 

 serum which will protect hogs from cholera. This serum 

 is used in either one of two ways, namely, (i) the 

 serum inoculation, and (2) the simultaneous inocula- 

 tion. These two methods of treatment are carried out 

 as follows : 



"Serum inoculation. — The hogs which are to be pro- 



