CLINICAL EVIDENCE OF VALUE OF SERUM 477 



outbreak can in this manner be effectually stamped out at its very- 

 beginning. Prompt action is the keynote to success in a new 

 outbreak of hog-cholera. 



Herd number twenty-six of this series of experimental tests 

 was located in the southeast quarter of Section 36, Franklin 

 Township, Story County, Iowa. This herd was located about a 

 mile distant from infected Herd Number Ten, previously described. 

 On account of the close proximity of the infected farm, it was con- 

 sidered probable that the infection might spread to this farm. 



In order to prevent, if possible, the spread of the disease, the 

 animals on Farm Number Twenty-six were visited and treated on 

 October 21, 1907. The method of treatment used in this case was 

 as follows: 



Fifty-eight shoats, weighing from 35 to 100 pounds each, were 

 injected with 20 c.c. of serum, accompanied by 1 c.c. of virus blood. 

 As it was desired in this case to prevent if possible the spread of 

 the disease, no checks were left untreated in this herd. 



Later observations in this herd showed that no loss occurred, 

 and all the animals remained well and thrifty. This is again an 

 excellent example of the good results which may be accomplished 

 in preventing the spread of an outbreak of cholera simply by early 

 and proper treatment of the herds located on the surrounding 

 farms. 



This herd also gives an example of the harmless nature of the 

 double or simultaneous method of treatment when applied in a 

 healthy herd for the purpose of preventing spread of the disease. 



Herd Number Twenty-seven. — This herd was also located in 

 the same section of Story County as were Herds Number Ten and 

 Twenty-six. The twenty-seventh herd was located about mid- 

 way between these two herds, and was, accordingly, in an exposed 

 position. This herd was visited and treated on October 21, 1907. 

 When treated, all the animals in the herd were apparently well, 

 and the treatment was given for the purpose of preventing, if pos- 

 sible, the spread of the disease from the infected herd on farm 

 Number Ten. As it was desired to limit if possible the spread of 

 the disease, all the animals on this farm were treated and no 

 checks were left. 



Twelve shoats, of an average weight of about 90 pounds, were 



