218 SWINE DISEASES 



ucts of milk are used for swine feed. A relatively large 

 percentage of dairy cattle is tuberculous, and the infection 

 gains entrance to the milk on filth that is contaminated 

 with infected discharges, such as saliva and feces. The 

 organism may also be eliminated direct from the mammary 

 gland into the milk. 



Swine from some sections of the United States have 

 been found by experience to be so extensively tuberculous 

 that some packers will buy them only subject to post- 

 mortem inspection. 



. In Germany from 2.46 to 2.81 percent of swine 

 slaughtered at abattoirs were condemned on account of 

 tuberculosis. The disease is very prevalent in Belgium, 

 France, Norway, and Sweden, and porcine tuberculosis 

 is a common disease in the British Isles. According to 

 the annual report of the Bureau of Animal Industry for 

 1911, 29,920,260 carcasses of swine were inspected in 

 abattoirs, and of that number 31,517 carcasses and 870,361 

 parts were condemned on account of tuberculosis. The 

 disease is becoming more extensive in swine in the United 

 States and should receive more consideration than it 

 does, for the economic loss annually is enormous. 



Etiology. The cause of tuberculosis is the tubercle 

 bacillus or the Bacillus of Koch. It is a rod-shaped 

 organism from 1.5 to 4 microns long and .3 to .5 micron 

 in width, and is usually curved or slightly bent. It 

 may contain granules or the body may be uniform. It 

 is nonmotile and does not form spores. This organism 

 is covered with a waxlike substance which renders it more 

 difficult to stain than ordinary bacteria, but after the 

 organism has been stained, which can be accomplished 

 by applying steaming carbolfuchsin for five minutes, it 

 retains the stain even when subjected to the action of 

 acids; for this reason it has been called an acid-fast 

 bacterium. It is an aerobe, and grows with relative 

 slowness. It grows luxuriantly in egg albumen culture 

 medium, and fairly well on glycerine agar and in glycerine 

 bouillon. Tubercle bacilli from different sources manifest 

 different cultural characteristics, and on this basis some 



