298 BUILDINGS, SANITATION, AND DISEASES 



siderable time, possibly several weeks or even two or three 

 months. Often the pig becomes a complete wreck, and death 

 at last occurs. 



Treatment. When a hog once contracts the disease, little 

 can be done in the way of treatment. Preventive measures 

 are the only effective means for fighting this disease. In case 

 the disease should be found in a herd, it is safer to divide the 

 herd up into small groups, keeping hogs which have been ex- 

 posed to the disease 'separate from those which have not. Dis- 

 eased carcasses should be burned, and thorough disinfection of 

 the premises and the animal's should be made. The disease 

 enters the system through the stomach, and, therefore, care 

 should be exercised at all times in providing clean water and 

 feed. The importance of quarantine, isolation, and disin- 

 fection, and methods of conducting the 'same, have been dealt 

 with under " Sanitation," which see. 



Immunization. To the investigations of the Bureau of 

 Animal Industry of the U. S. Department of Agriculture, we 

 are indebted for the production of a serum which seems likely 

 to play an important part in the suppression of hog cholera. 

 Briefly, the serum is prepared from the blood of hogs which 

 have been treated in such a way as to render them immune from 

 the disease. The serum is injected under the skin of healthy 

 hogs which it is desired to protect from the disease. It is not 

 a cure for cholera, but is wholly preventive in character, bearing 

 the same relation to hog cholera as vaccine bears to smallpox. 



In an address before the American Veterinary Medical 

 Association, Dr. A. D. Melvin, Chief of the Bureau of Animal 

 Industry, U. S. Department of Agriculture, gives results of 

 extensive tests, involving several thousand hogs upon farms, 

 under practical conditions. In the course of his address, 



