SOME COMMUNICABLE DISEASES 



373 



ing may be noted, especially after exercise. When the intestines 

 are extensively involved a persistent diarrhea is present. The 

 lymph glands of tubercular organs always show lesions of the 

 disease, as they catch the germs carried away by the lymph. 

 In cattle the lymph glands on the sides of the pharynx are most 

 frequently affected; next in frequency are the bronchial glands 



Fig. 97. Portion of spleen of hog showing many tuberculous nodules scattered 



over the surface. 



at the bifurcation of the bronchi; then the mediastinal glands 

 between the lungs. When lesions occur on the diaphragm they 

 resemble pearls, hence the name "pearl disease." In hogs the 

 lymph glands of the neck are affected in about 93 per cent, of 

 all cases of tuberculosis. The spleen is also commonly involved 

 (Fig. 97). 



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