274 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



because the tubercle organisms are being thrown off from the body, 

 in the sputum, manure and milk. 



Is It Wise to Introduce an Unsound or Unhealthy Cow Into 

 Your Herd? Any farmer about to purchase a horse examines it 

 for soundness because he knows an unsound horse will be of doubt- 

 ful value to him. Yet spavin, ringbone, heaves, cribbing, and 

 balking are not directly transmissible troubles. Tuberculosis, an 

 unsoundness of cattle and hogs, is transmissible to other animals; 

 hence every tubercular cow is likely to cause the farmer more loss 

 than ten spavined horses because: 



1. Tuberculosis causes the death of a certain number of ani- 

 mals after it has become established in a herd. 2. Tuberculosis 

 causes a waste of food when it is fed to animals that cannot give an 

 adequate return. 3. Tuberculosis causes heavy loss through the 

 infection of other animals. 4. Tuberculosis reduces the produc- 

 tive and market value of cows. As soon as an animal shows phy- 

 sical evidence of the disease, it has no market value. 5. Tubercu- 

 losis destroys the good reputation of a herd, rendering it difficult 

 to sell animals and often hard to dispose of their products. Es- 

 pecially is this true in pure-bred herds. 



It is estimated by the Federal authorities that tuberculosis of 

 cattle and hogs causes an annual loss of $23,000,000 in the United 

 States. 



What Per Cent of Domestic Animals Have Tuberculosis? It 

 varies widely in different countries and in different parts of the 

 same country. From July, 1908, to July, 1910, over 90,000 ani- 

 mals, largely milch cows, were examined for tuberculosis in Wis- 

 consin and about five per cent were found to be diseased. The tests 

 in earlier years revealed a much greater per cent of tubercular 

 animals. It is believed that the spread of the disease is being con- 

 stantly checked through the agency of a number of factors. One 

 of the most important is the realization by many farmers of the 

 economic importance of the disease, which has led them to elimin- 

 ate the diseased animals from their herds and to maintain healthy 

 herds. In some other states a much greater per cent of tubercular 

 cattle is found, since no active measures are taken to educate the 

 farmer concerning 'the importance of tuberculosis, and hence no 

 adequate efforts have been made to prevent the introduction of dis- 

 eased animals into the herds. 



What Is the Sanitary Significance of Tuberculosis of Cattle 

 and Hogs? It has been shown beyond all doubt that tubercle 

 bacilli from cattle are able to cause the disease in human beings. 

 If infected foods, such as meat and milk, are consumed in a raw 

 state there is opportunity for infection. It is not believed that 

 adults acquire tuberculosis easily from the use of such food, but 

 with children the case seems to be far different. From the data 

 collected within the last 10 years, it seems probable that about 20 

 per cent of tuberculosis in children, i. e., those under 16 years 

 of age, is due to organisms coming from cattle. 



