CLINICAL EVIDENCE OF VALUE OF SERUM 475 



postmortem examination. The balance of the herd had not been 

 visibly affected at this time. 



In the treatment of this herd, one old sow was given an injec- 

 tion of 40 c.c. of serum plus 2 c.c. of the virus blood. Thirty- 

 eight shoats, averaging from 50 to 100 pounds, were each given 

 20 c.c. of serum and 2 c.c. of virulent blood. One small pig re- 

 ceived 10 c.c. of serum alone. 



Five shoats, of the same average size as the treated shoats, 

 and the one shoat which was sick at the time, were left untreated 

 to act as checks. 



The sick shoat continued to grow worse, and was killed a few 

 days later for postmortem examination. The findings in this 

 examination were not those of typical hog-cholera. Most of the 

 changes found were in the chest cavity, and resembled in many 

 ways those of pneumonia rather than hog-cholera. 



As there was no further loss among the checks or the treated 

 animals, it would seem probable that this herd did not have cholera, 

 and the value of the experiment in this herd was of little import- 

 ance. 



In connection with the injection of virulent blood in the herd 

 it was afterward found that the blood used in this case, as well as 

 that used in Herd Number 22, was not of a sufficient strength to 

 produce death even in suceptible pigs when unprotected by serum. 

 This, in large measure, destroys the value of these experiments. 



Herd Number Twenty-four. — This herd was located about 

 30 rods from the herd just described, and was visited on the 

 same day. It was found to consist of about 83 head. Many 

 of these animals were suffering from some form of respiratory 

 trouble, which was believed to be cholera. One of the sickest 

 shoats was killed and a postmortem examination made. This 

 examination failed, however, to show any signs of cholera. As a 

 precautionary measure the herd was injected. 



Sixty-two shoats, weighing from 40 to 90 pounds, were each 

 treated with 20 c.c. of the serum plus 1 c.c. of virulent blood. 

 Eight small pigs each received 20 c.c. of the serum alone. Thirteen 

 shoats of various sizes were left as checks. 



Later observations of this herd showed that neither the treated 

 nor untreated animals became sick, and so it must be concluded 



