338 AGRICULTURAL BACTERIOLOGY 



The larger quantity of serum is used with the virus in 

 order to protect the animal against the v-irus, which by 

 itself would cause death. The virus is usually applied at 

 some other point than the serum, as beneath the skin at the 

 center of the space between the fore legs when the serum is 

 applied in the arm-pit. 



For a few days after the serum is administered the feed 

 should be reduced to about one half the normal amount, 

 gradually increasing until at the fourth week the full feed 

 may be given. When only the serum is given, there should 

 be little or no reaction. With the double or the simul- 

 taneous treatment in six to ten days after the injection, 

 the reaction fever sets in and the temperature may rise to 

 106 F. The animals may lose appetite, have chills, and 

 present the symptoms of a mild case of hog cholera. The 

 more susceptible animals may die from the effects of the 

 virus. The hogs that show symptoms may eliminate the 

 virus, and be the starting-point of an outbreak of cholera 

 in case they come in contact with susceptible animals. 



The results that have been obtained with the serum have 

 been such as to recommend its use. When applied in herds 

 in which the disease had already made its appearance, more 

 than 80 per cent, of the animals were saved, while the 

 treatment applied before the infection of the herd took 

 place has protected more than 90 per cent, of the animals 

 against infection. 



