CLINICAL EVIDENCE OF VALUE OF SERUM 485 



any case, the results obtained were good. The herd passed through 

 the balance of the fall and winter without any signs of sickness, and 

 protection from the disease was apparently complete. 



Here, again, we have an example of the undesirability of using 

 an untested virulent blood. The blood used in this herd was not 

 tested out until after it had been injected. As it proved to be 

 rather weak, it is almost impossible to say whether these animals 

 really received the benefits of a single or double method of treat- 

 ment. It would seem more likely, however, that the virus was 

 sufficiently active to cause formation of germ-destroying bodies, 

 as the protection lasted throughout the balance of the season. 



Herd number thirty-one of the experimental series was 

 located in the northwest quarter of Section 22, Grant Town- 

 ship, Story County, Iowa. This farm was right in the center 

 of a widely infected district, and was surrounded on all sides 

 by cholera herds. At the time the herd was visited the animals 

 had been in considerable danger for some time, on account of 

 the close proximity of cholera-infected droves. Treatment was 

 given on October 23, 1907. At this time all of the hogs seemed 

 well with the exception of one old sow. The principal symptom 

 in this old sow was a marked diarrhea, which the owner believed 

 to be due to the fact that she had been fed with pumpkins. 



Twenty-five shoats, weighing from 60 to 100 pounds, were 

 each given 20 c.c. of the serum plus 2 c.c. of blood from a diseased 

 animal. Seven old hogs, weighing from 250 to 350 pounds, were 

 given 40 c.c. each of the serum and 2 c.c. of the virulent blood. 

 Twelve sucking pigs received 10 c.c. each of the serum alone. 

 Four shoats of various sizes, 1 old sow, and 4 sucking pigs from 

 the same Utter as those treated were left untreated to serve as 

 checks. 



After-results in this herd showed that the old sow, which was 

 left as a check, died two days after the herd was treated. One 

 of the treated shoats also died four days after injection. On 

 November 1st 3 of the checks and 1 treated shoat were sick. 

 Later the treated shoat and 2 of the check shoats died. A 

 final report on this herd showed that of the 4 check shoats, 

 2 died and the other 2 became sick, but afterward recovered. 

 The 4 sucklings which were left as checks all died, while all 



