CLINICAL EVIDENCE OF VALUE OF SERUM 447 



In the first place, it shows that with an outbreak of hog-cholera 

 in the neighborhood the use of the double method of treatment, 

 even though it be followed by an outbreak of the disease, results 

 in a much smaller total loss than would have been the result had 

 the disease reached the herd in the usual manner and run the usual 

 course of a hog-cholera outbreak. In this herd, where the disease 

 followed the double treatment, there were only 6 animals lost out 

 of a total of 36; a very small loss as compared with that which 

 usually follows an outbreak occurring in the natural way. 



This experiment also shows the proper method of dealing with 

 an emergency of this kind. If for any reason an outbreak of the 

 disease should follow the giving of the double treatment, the proper 

 thing to do is to get a supply of first-class serum at once, and go 

 back into this herd and reinject with serum alone. In this way the 

 outbreak can be controlled in nearly every case and the loss kept 

 very low. 



Herd Number Twelve. — The herd which is reported as the 

 twelfth in this series of experiments was located in the southeast 

 quarter of Section 26, Grant Township. This was also close to the 

 town of Shipley, and as the disease was very widespread in this 

 part of the state at the time of these experiments, it is quite likely 

 that infection of the herd took place from some of the nearby in- 

 fected farms. 



Two of the young pigs on this farm were noticed to be sick on 

 October 12th. United States veterinarians from the Ames Experi- 

 ment Station visited the farm on October 15th. At this time they 

 found that these 2 pigs were decidedly sick, and several other 

 animals in the herd were off feed and ailing. The animals showed 

 the usual signs of cholera: they were droopy, remained in their 

 nests buried under the litter, and cared little or nothing for feed. 



In order to make sure of the diagnosis, the sickest of the 2 pigs 

 was killed and the body opened up. This examination proved very 

 clearly that the animals were really suffering from cholera. Small 

 red spots were seen in the kidneys and on the surface of the lungs. 

 In addition to this, there were also a number of beginning ulcers 

 to be seen in the large bowel. 



In this herd there was a total of 92 head. Of this number, 62 

 shoats, weighing from 35 to 100 pounds, were injected with serum 



