326 DAIRY CATTLE AND MILK PRODUCTION 



Unless the herdsman is thoroughly informed regarding the 

 treatment of cattle ailments, he will seldom have occasion 

 to administer medicine other than Epsom or Glauber salts 

 except under the direction of a veterinarian. 



Tuberculosis. This insidious disease is of the greatest 

 importance to dairy cattle owners as well as to milk con- 

 sumers. Since the discovery by Koch in 1882 that tuber- 

 culosis is caused by a certain bacteria, our knowledge of the 

 subject has so broadened that were it possible to apply at 

 once what is now known regarding the disease, it could be 

 entirely eradicated within a few years. The well-established 

 fact that the disease may be communicated from the cow to 

 the human family through the milk of an affected animal 

 makes it necessary to give this source of infection the most 

 careful consideration. 



This disease is caused by a specific agent, an organism 

 too small to be seen by the naked eye, but easily seen under 

 a powerful microscope. It cannot develop in an animal from 

 methods of handling or from the surroundings but must be 

 communicated in some way from one animal to another. It 

 is not inherited. The germs that cause the disease escape 

 from the affected animal with slobber from the mouth, with 

 the dung, and in badly affected animals with the milk. 

 The disease spreads to the healthy cow mostly from eating 

 or drinking out of troughs that are infected from the affected 

 animals. Hogs following tuberculosis cattle are readily 

 affected from the manure. If a diseased animal is placed in a 

 healthy herd, other cases are sure to follow soon. It is 

 believed now by the best authorities that the most dangerous 

 animal from the standpoint of human health is often the one 

 that may appear perfectly healthy, but which passes the 



