CLINICAL EVIDENCE OF VALUE OF SERUM 499 



case of the acute form of the disease. The sick and well animals 

 had all been running together, and all the herd was exposed, with 

 the exception of 5 male shoats that had been kept confined in 

 a hog-shed removed from the balance of the drove. 



There were 28 shoats in the herd that would weigh between 

 100 and 150 pounds. These had all been exposed to the disease, 

 and each was given 40 to 50 c.c. of the serum alone. One shoat 

 that was quite sick received 80 c.c. of serum. The 5 boars that 

 had not been exposed directly to the sick animals were each given 

 50 c.c. of serum. These boars weighed about 175 pounds each. 

 One old sow that was sick at the time of treatment was injected 

 with 100 c.c. of serum. Another old sow that was sick did not 

 receive treatment. Ten shoats of various ages and sizes were 

 left untreated to serve as checks. 



Final report on this herd showed that 3 of the treated animals, 

 including the sick shoat which received 80 c.c. of serum, died. 

 The balance of the treated animals all survived, and appeared to 

 be thrifty and well on last inspection. All of the untreated checks 

 died except 2. One of these did not become sick; the other one 

 passed through an attack of the disease, but was left stunted and 

 valueless. 



Results from the use of serum in this herd are very encouraging. 

 Here the outbreak was already under good headway, and if tem- 

 peratures had been taken a large percentage of the treated animals 

 would no doubt have been found sick at the time of injection. 

 In spite of this fact, only 3 died after the treatment was given, 

 and one of these was in an almost dying condition when given the 

 large dose of serum. The old sow that received 100 c.c. of serum 

 was among those that recovered. The postmortem findings 

 were not those of an acute form of the disease, but the fact that 

 all but 2 of the checks died is good evidence that the losses 

 would have been very much higher without the use of serum. 



In the case of the one untreated check that did not take the 

 disease we have another example of those occasional cases of 

 natural immunity that are met with. Frequently during an out- 

 break on a farm one, two or more of the hogs will be able to fight 

 off the germs and keep well. 



The 5 boars that were injected did not afterward become sick, 



