444 DISEASES OF SWINE 



apparently not yet affected, and which were of about the same size, 

 received the same dose of serum, with the addition of 1 c.c. of virus 

 blood. Three old sows, which averaged about 200 pounds each, 

 were each injected with 30 c.c. of serum alone. Three other old 

 sows, weighing about 400 pounds each, received 40 c.c. of serum 

 alone. The balance of the herd, consisting of about 25 animals, 

 were left untreated. 



The results in this herd were most excellent. Only one of the 

 treated hogs died, and this in spite of the fact that over half of 

 those injected were sick at the time of treatment. This one animal 

 that died was an old sow which developed a very severe abscess 

 swelling at the point of injection, and the absorption of poisonous 

 material from this abscess was very likely in part the cause of death. 



Of the 25 animals that were left untreated as checks, 15 died — 

 2 old sows and 13 shoats. A number of the 10 hogs that remained 

 of the untreated 25 developed a slow, lingering type of the disease 

 and were left stunted and practically worthless. 



The disease in this herd was not of as deadly a type as has been 

 described in some of the other herds reported in this series of experi- 

 ments, and this in great measure accounts for the large number of 

 check animals that survived. However, the results from the use 

 of the serum treatment were most brilliant, and we can learn a few 

 valuable pointg from the method followed in this case : 



Here the hogs which were apparently sick received serum alone, 

 and while the dose given in these animals was a Uttle smaller than 

 I would consider desirable, yet the results obtained would seem to 

 prove that small doses of a properly made serum are capable of 

 producing excellent results, even when the disease is quite well 

 developed, as it was in this case. No one should hesitate to use 

 serum, even after the disease has made its appearance in the herd, 

 if he is certain that the serum he uses be of good quality. 



In this herd the disease was well established and several ani- 

 mals had already died. Yet the use of the serum here stopped the 

 disease at once in the animals so treated, only one more death 

 occurring in the treated animals, and that probably from secondary 

 causes rather than from cholera. 



In this herd also we have an example of the proper use of the 

 double treatment in an infected herd. In treating herds of this 



