446 DISEASES OF SWINE 



The final outcome in this herd was rather unsatisfactory, for 

 some reason which apparently could not be determined. The 

 animals injected all continued well until the morning of the 24th, 

 when one shoat appeared droopy and refused to eat. At noon of 

 the same day 2 other animals were noticed to be rather droopy. 

 Word was sent to the Ames Station, and when the herd was visited 

 on the following morning 4 shoats were showing sj^mptoms of 

 cholera. 



On this date the entire herd was reinjected with 20 c.c. each of 

 serum alone. On the 26th, 2 more were sick, and on the 28th, 2 

 were dead and 7 were sick. When seen on November 1st, 5 had 

 died and 3 of the sick ones appeared to be much better. One more 

 died after this date, making a total of 6 that died and 30 which 

 survived. 



One of the shoats that died was opened up and examination made 

 for the purpose of making certain that the animals were really 

 dying from cholera. The results of this examination left no doubt 

 as to the cause of death. The glands in the flanks were swollen 

 and red in appearance, the spleen was large and black in color, the 

 kidneys showed the regular spotted appearance of hog-cholera, 

 and everything pointed clearly to hog-cholera as the cause of death. 



This is one of the very few bad results that have been reported 

 following the use of the double treatment where the serum used 

 was of proper quahty. Just why this unusual result was met with 

 in this case is rather hard to make out. It would seem, however, as 

 if the dose of virus given was perhaps a little large and the dose of 

 serum a httle small. It is certainly a larger dose of virus and a 

 smaller dose of serum than would be advisable for regular field work. 

 However, the same serum was used here as in the previous herds 

 mentioned in this series of experiments, and it had apparently been 

 capable of protecting against a 2-c.c. dose of virus without any 

 trouble. 



As these animals were all young shoats, it is possible that they 

 were more easily affected by the virus blood, and this may, in part 

 at least, account for the undesirable outcome of the experiment. 



In spite of the unfortunate result in having cholera develop, 

 there are a number of interesting and noteworthy points to be found 

 in this experiment: 



