128 



ANNUAL EEPORTS OF DEPARTMENT OF AGRICULTURE. 



The next table shows the results in herds which were affected with 

 hog cholera at the time of treatment. 



Results of serum treatment of herds affected icith ling cholera, 1D13-I.'j. 



Although approximately 38 per cent of the hogs were sick when 

 treated, the sickness being indicated either by the physical appear- 

 ance of the hog or by its temperature, only 13.T per cent died. This 

 indicates clearly that the serum has a distinct curative action when 

 administered in the early stages of the disease. 



Observations of the effect of inoculation upon pregnant sows are 

 presented in the following table : 



It is fair to assume that the higher percentage of abortions among 

 sows treated with serum alone is attributable to the fact that some of 

 these soAvs were, affected with hog cholera when treated, whereas, 

 although some of those given the simultaneous method may also have 

 been infected, it is probable that the proportion was less. These fig- 

 ures indicate that the simultaneous method does not produce abortion 

 in pregnant sows. 



Extensive observations and comparisons of treated and untreated 

 sows in Dallas County, Iowa, in 1913 and 1911 lead to the conclusion 

 that the simultaneous method, when properly applied, does not pro- 

 duce sterility in sows. Out of 1,716 sows in 126 herds treated by the 

 simultaneous method, 98, or 5.62 per cent, proved sterile, while 74 

 untreated sows out of 1,103 in 87 herds, or 6 per cent, were sterile. 



The next table summarizes the sources of infection as reported by 

 field inspectors. The sources of infection have been arranged in 

 three groups. The first includes near-by sources; the second, dis- 

 tant sources; and the third, indefinite or indeterminate sources. The 

 sources of infection were of course not determined with absolute cer- 

 tainty, as that would be impossible ; but inspectors in the field were 

 instructed to make careful inquiries at each infected farm, and the 

 results here reported are a summary of their conclusions. Approxi- 

 mately 58 per cent of the outbreaks appear to have come from near-by 

 sources, 23 per cent from distant sources, and 19 per cent are reported 

 as indefinite. 



