510 DISEASES OF SWINE 



(8) Hogs that have received the simultaneous treatment can 

 be left in the same lots with untreated hogs without danger to 

 the untreated animals. The virus injected into the hogs that are 

 treated will not infect the untreated hogs unless some of those 

 that are treated become sick. 



(9) In an occasional case some of the hogs that receive the 

 simultaneous method may prove to be unusually susceptible to the 

 action of cholera virus and may develop symptoms of an attack 

 of cholera. 



(10) These cases should immediately receive a second injection 

 with serum alone in large doses. This method of handling the 

 case will nearly always check the threatened outbreak. 



(11) Those cases in which an attack of cholera follows use of 

 the simultaneous method are nearly always due to some avoidable 

 cause, such as poor serum, too large dose of virus, not enough 

 serum, or injection of double treatment in hogs that are already 

 coming down with a natural infection. 



