CLINICAL EVIDENCE OF VALUE OF SERUM 489 



protected animals became sick. This is a good example of what 

 can be done in preventing spread of the disease even with the single 

 method of injection. Personally, I am more favorable to the use 

 of the double method of treatment in cases of this kind. How- 

 ever, where for any reason there is a prejudice against the double 

 method, the single treatment may be used with excellent results 

 in preventing the immediate danger. 



The main disadvantage of the double treatment lies in the fact 

 that the protection given is only temporary in nature, and three to 

 six weeks later the animals are again unprotected, and must be 

 again treated or they will contract the disease if exposure again 

 occurs. 



Herd Number Thirty-four. — The thirty-fourth herd of this 

 series was also an exposed one, located in the neighborhood of 

 Herd Number Ten, and was treated for the purpose of preventing 

 the spread of the disease to neighboring farms from this infected 

 premises. This herd was treated on October 27th, and, as the ob- 

 ject was to prevent spread of the disease, all the animals on the 

 place were treated. 



Thirty-two shoats, weighing from 60 to 100 pounds each, re- 

 ceived 20 c.c. of serum, and 8 old hogs, weighing from 350 to 450 

 pounds each, received 40 c.c. of the same serum. 



In this case also the results were all that could be hoped for. 

 The entire herd remained well, and the spread of the disease in this 

 direction was checked. We have had in these herds immediately 

 surrounding infected Herd Number Ten an excellent example of 

 what may be accomplished by prompt action in an infected neigh- 

 borhood. By getting right into the neighborhood at the com- 

 mencement of the outbreak the United States Government ex- 

 perts were in this case able to limit the disease almost to this one 

 farm, and equally good results can be obtained by other competent 

 men in other parts of the country if action be taken immediately 

 there is an outbreak started and a good grade of serum used. 



Herd Number Thirty-five. — The thirty-fifth herd of this series 

 was located in the northeast quarter of Section 34, Jackson 

 Township. It was first visited on November 6, 1907, in re- 

 sponse to a very urgent request from the owner. The herd con- 

 sisted of pure-bred Duroc-Jersey swine of different ages. 



