METHODS OF USING ANTI-HOG-CHOLERA SEKUM 147 



mal. Thus it is the abuse of simultaneous treat- 

 ment rather than its use which incriminates it. 



Elimination of hog cholera virus in the excre- 

 tions of simultaneously treated pigs sometimes 

 takes place for a few days during the resulting 

 reaction. There was a time when this fact was 

 denied, but no person experienced in handling hog 

 cholera would seriously question it to-day. Beac- 

 tions vary between one extreme in which no tem- 

 perature elevation is recorded, and the other 

 rather unusual one in which death takes place. In 

 the first instance virus elimination is rare, but as 

 the latter extreme is approached, it is the rule. 

 Most hogs do not eliminate infectious material, 

 but the exceptions to the rule are so numerous that 

 it is not safe to keep susceptible animals with 

 those that receive simultaneous treatment. 



Because of the danger of virus elimination, a 

 period of quarantine is usually imposed on simul- 

 taneously treated hogs. The duration of this 

 quarantine is prescribed by law in most states, the 

 usual time varying between twenty-one and thirty 

 days, with extension in case "vaccination chol- 

 era" appears. Hogs that have shown no physical 

 evidence of disease are very rarely eliminating 

 virus at the end of twenty-one days following 

 serum- virus immunization. 



" Virus breaks " are not manifest until several 

 weeks following simultaneous treatment, and they 



