CLINICAL EVIDENCE OF VALUE OF SERUM 433 



lent blood. The date of administering the treatment in this herd 

 was September 25th. 



On the following day one of the treated shoats appeared some- 

 what off feed and droopy. Two days later one of the old sows 

 became sick, showing loss of appetite and other symptoms. The 

 condition of this sow gradually became worse and she died nine 

 days after treatment. Postmortem examination was made and 

 the usual lesions of hog-cholera were found — engorged spleen, 

 congested liver, hemorrhages in kidneys, and well-marked ulcera- 

 tion of the cecum and colon. The shoat which showed symptoms 

 of illness also became worse and finally died. 



The shoat which had escaped, and was consequently left un- 

 treated, also became sick and died. In the case of the sucking pigs 

 left untreated, the disease rapidly wiped out all of them, the entire 

 litters dying in each case. The remaining 28 treated shoats and the 

 2 old sows remained well and thrifty, showing no signs of illness. 



At first glance there might be a tendency to think that the 

 death of the old sow and the shoat had been due to the use of 

 the virus treatment. If we stop a moment to consider what we 

 have learned about the incubation of hog-cholera, we will readily 

 see that this could not have been the case. The incubation period, 

 even in animals which have been injected with the virus and have 

 received no simultaneous protective dose of serum, is seldom less 

 than five days, and rarely, if ever, less than three days. 



In this case the shoat showed signs of illness within twenty- 

 four hours after injection, and the sow was sick within three 

 days. The conclusion which we must of necessity arrive at in 

 this case then is, that the disease must have already been carried 

 to the premises and was in the incubation stage at the time tHe 

 treatment was administered. 



When we stop to consider the effects of the treatment in this 

 herd, we cannot be other than impressed with the efficiency of 

 the serum treatment again, both as a prophylactic and as a cura- 

 tive agent. The subsequent sickening and death of the one shoat 

 and the old sow shows that the disease was already present on 

 the premises, and many of the other injected animals were un- 

 doubtedly developing cholera at the time the treatment was 

 given. 



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