Tuberculosis. 113 



are often said to look like corn meal. The healthy 

 lymph glands are of uniform color throughout, or in the 

 older animals they may be filled with a black pigment. 

 The tuberculous gland will, on section, show a larger or 

 smaller diseased area, apparent by its yellow color. 



The lungs of a healthy animal are light pink in color 

 and spongy in texture; when tuberculous, the tissue is 

 consolidated, abscesses or affected areas appearing in the 

 lung tissue or even raised from the surface. The bron- 

 chial glands located at the fork of the windpipe and 

 imbedded in the lung tissue are often early affected. 

 The diseased organs are usually much enlarged and 

 owing to the consolidation of tissue may be very heavy. 



The udder is sometimes affected. The normal udder 

 should be uniformly soft; the tuberculous udder often 

 contains hard bunches or nodules. As the disease 

 progresses an entire quarter may become enlarged, and 

 very hard. There is no fever or painful swelling as in 

 garget. Tuberculosis of the udder is important because 

 the milk is then certain to contain the tubercle or- 

 ganisms. 



The bacteria are discharged from the body of an 

 animal in a number of ways. The tubercles in the lungs 

 may discharge their contents into the air passages; the 

 material is coughed up, a portion ejected from the 

 mouth during the act of coughing, the major -part being 

 swallowed. The sputum is digested, the tubercle 

 bacilli set free, and they pass unharmed through the 

 stomach and intestines and are voided with the manure. 

 When the intestines are involved, the organisms also 

 appear in the manure. From diseased kidneys or blad- 

 der, they pass off in the urine, and from the udder, in 

 the milk. Animals shedding organisms in this way are 



