478 DISEASES OF SWINE 



injected, each receiving 20 c.c. of serum and 1 c.c. of virulent blood. 

 Two old sows received 40 c.c. of the serum, with an accompanying 

 dose of 2 c.c. of virulent blood. 



The results in this herd were very satisfactory. The entire 

 herd remained healthy and thrifty throughout the outbreak, and 

 there can be no doubt that this was in large measure due to the 

 protection given by the treatment administered. 



We again have in this case an example of how readily the spread 

 of a hog-cholera outbreak can be checked by the use of this new 

 method of handling the disease. 



Herd Number Twenty-eight. — The twenty-eighth herd in this 

 series of experimental tests was located at a considerable distance 

 from the last three herds mentioned. This herd was located in the 

 southeast quarter of Section 19, Washington Township, Story 

 County, Iowa. It was a very valuable herd, composed largely of 

 pure-bred Duroc-Jersey hogs of different ages and sizes. This herd 

 was first visited on October 22, 1907, and at this time the animals 

 appeared to be in good health, with the exception of 3 shoats, which 

 were of about 100-pound size. These animals appeared to be a 

 little droopy, and had been so for three or four days. 



On a neighboring farm, about one-quarter of a mile distant, 

 hogs had been dying for some time from a disease which was prob- 

 ably cholera. As the animals in Herd Number Twenty-eight were 

 of a pure-bred stock, the owner had been feeding them high with a 

 view to hastening their development and growth. As a result, a 

 majority of the animals, and especially the young gilts, were ex- 

 ceptionally fat. The 3 sick shoats had been running with the 

 gilts and old sows, so that the entire herd had been more or less 

 exposed by contact with the sick hogs. The young boars in this 

 herd had been kept in a separate feed lot, and, consequently, had 

 been less exposed than the other animals. 



As this was a pure-bred herd, and the 3 sick shoats were of con- 

 siderable value, they were not regarded as sick enough to warrant 

 their being slaughtered for purpose of making a postmortem diagno- 

 sis. The method of treatment in this herd was as follows: 



Twenty-nine spring gilts, each weighing about 200 pounds, were 

 given 30 c.c. of serum, with an accompanying dose of 1 c.c. of the 

 virus blood. Four smaller gilts, of about 100 pounds' weight, re- 



