DISEASES OF SWINE 461 



method it is best to use separate syringes, injecting the serum in one 

 thigh and the virulent blood in the other. The serum from a hyper- 

 immunized hog also possesses some curative effect when used very 

 early in the disease. There is little or no danger in spreading the 

 disease when vaccination is properly carried out. The practical ap- 

 plication of vaccinating against hog cholera is not by any means a 

 difficult problem, when once the serum production has been per- 

 fected in a given state. This, however, as already indicated, neces- 

 sitates an expenditure of a certain amount of money for the equip- 

 ment of premises, for hogs, and for qualified men. But the expense 

 is not so great, when the annual losses from hog cholera are consid- 

 ered. The hyperimmune hogs after the final bleeding may be used 

 for food purposes. Vaccination to produce temporary immunity, as 

 above outlined, is very simple, consisting in the subcutaneous injec- 

 tion of the serum alone. This may be easily done by the average 

 intelligent farmer, and is of special use when shipping hogs from 

 one place to another, as is frequently done with show animals. The 

 serum-simultaneous vaccination, to produce a permanent immu- 

 nity, is more complicated, .since it calls for the bleeding of diseased 

 hogs to obtain the virulent blood. This latter method will demand 

 trained men who can be sent to the seat of different outbreaks of hog 

 cholera. (Tenn. B. 85.) 



Vaccinating Instruments. Two hypodermic syringes are used 

 in vaccinating. One for the serum which holds 20 cc., and one for 

 the virulent blood holding 5 cc. The two sizes are used to prevent 

 any mistakes being made. A thermometer is used for taking the 

 temperatures, as we make it a rule not to use virulent blood if the 

 temperature is high, using only the serum. 



Strong antiseptics are also used to disinfect the point of injec- 

 tion, especially where the virulent blood is injected. If this is not 

 done the small particles of a drop or so on the end of the needle may 

 infect the whole premises. This is very important. (Kan. Bui. 

 163.) 



Simultaneous Inoculation. In this form of vaccination the 

 same serum is used as is employed when the serum alone is used, but 

 in addition to the serum there is injected on the opposite side of the 

 body, in the same manner as the serum, a very small amount of 

 blood taken from a hog sick of hog cholera. This simultaneous in- 

 jection of serum and virulent blood confers upon the injected pig a 

 permanent and lasting immunity, and is therefore to be recom- 

 mended in cases of well herds which may not be exposed for some 

 months after the treatment. (F. B. 379!) 



To give hogs permanent immunity against hog cholera, a dose 

 of blood from a virulent case of hog cholera is injected beneath the 

 skin of the hog, and at the same time the serum from a hyper-im- 

 mune hog is injected. This is called the "Serum Simultaneous" 

 method. There is a considerable risk associated with the use of viru- 

 lent hog-cholera blood, hence the "Serum Alone" method is the one 

 commonly used. The "Serum Alone" immunization can be applied 

 by any intelligent person, but the "Serum Simultaneous" inocula- 



