264 A STUDY OF FARM ANIMALS 



Accredited herds are now being established all over the 

 United States by the U. S. Bureau of Animal Industry, in 

 co-operation with state veterinarians or cattle commissioners. 

 An accredited herd must pass a 100 per cent tuberculin test 

 for three successive years, showing it to be free from tuber- 

 culosis. There are now thousands of accredited herds in 

 this country with interest in this subject steadily increasing. 



As there is no known cure for tuberculosis, the thing for 

 the stockman to do is to use preventive methods. The 

 stable should be well lighted and ventilated. In making 

 the highest grade of milk that is, certified it is recom- 

 mended by the U. S. Bureau of Animal Industry that each 

 cow be allowed at least 4 square feet of window light and 500 

 cubic feet of air space. Sunlight is a stable disinfectant. 

 Water troughs and mangers should be kept clean, as the 

 disease is distributed through these mediums. The stables 

 should be kept whitewashed, or sprayed at frequent intervals 

 with disinfectants, as, for example, a 5 per cent solution of 

 creolin, which may be purchased at most drug stores. 



Lump jaw is a disease that appears as a hard swelling or 

 tumor on the jaws of cattle. It is caused by a fungous disease 

 that grows on some forms of grasses and stubble. If the 

 jaw is badly diseased, it becomes ulcerated, the cattle find it 

 difficult to chew their food, and sometimes die. This disease 

 is not communicated to other animals by one that is affected. 

 What is known as iodine treatment may cure the disease in 

 its early stages, but as a rule, it is recommended to fatten and 

 slaughter cattle having this disease, as the carcass is suitable 

 for food when only the head is affected. The udder of the 

 hog is sometimes affected by this disease. 



Blackleg is a very contagious disease caused by a germ 

 known as the blackleg bacillus. The animal becomes in- 

 fected through an abrasion on the skin, and the disease is 

 transmitted by contaminated animals by discharges from the 

 skin wounds. The symptoms are first a high fever and loss 



