202 TUBERCULOSIS IN SWINE 



pleura are sometimes the seat of an eruption of fine granula- 

 tions which remain in a state of miliary nodules. Lesions like 

 those in the liver may exist in the lungs, but generally there 

 is found in these organs an innumerable number of minute, 

 translucent, gray granulations, caused by the dissemination of 

 tubercle bacteria through the blood stream, in which case the 

 liver, the spleen, the kidneys, the medulla of the bones, and 

 the mammae may be infiltrated with similar growths. 



Mohler has reported the results of the examination of 

 120,000 infected hogs of which 933 per cent had tuberculous 

 glands. 



It is common to find lesions localized in one or several 

 lymphatic glands. The pharyngeal and submaxillary glands 

 are the ones most often affected. They become voluminous, 

 hard and knotty, as they have undergone a true fibrous trans- 

 formation and, consequently, are difficult to cut. This is 

 shown by the creaky sound under the cutting instrument. In 

 section they have the appearance of old fibrous tissues; here and 

 there small yellow foci are seen of a softer consistency, almost 

 caseous; sometimes veritable purulent collections are found, 

 either encysted or in communication with the exterior. If 

 one submits the caseous or purulent matter to a bacteriological 

 examination, tubercle bacilli are not usually found. The bac- 

 terium, however, is present and if this matter is inoculated 

 into the peritoneal cavity or the subcutaneous tissue of guinea 

 pigs it will produce tuberculosis. 



These chronic glandular lesions, with their very slow pro- 

 gress, have long been looked upon as constituting the scrofula 

 of swine, and to scrofula was also assigned the tuberculous 

 lesions of bones (ribs, vertebrae, articulations, shoulder blades, 

 hip bones) which are common in pigs, both young and old. 



The older authors noted that the ancient scrofula was 

 often accompanied by visceral tuberculosis, but they refused to 

 admit the identity and even the relationship of the two af- 

 fections. 



The generalization of the disease, especially in the mus- 

 cular tissue, is reported by several observers. Moule called at- 



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