410 CHRONIC INFECTIOUS DISEASES 



INTESTINAL PARATUBERCULOSIS— JOHNE'S DISEASE. 



Specific Chronic Enteritis of the Ox. Chronic 

 Bacterial Dysentery. 



Definition. — A chronic contagious disease of the bqwels of 

 cattle, which in the majority of cases leads to intermittent 

 diarrhea, anemia, cachexia, and death. It is due to an 

 acid-fast bacillus. 



Occurrence. — The disease was discovered in, 1895 by 

 Johne and Frothingham in Germany. It is not uncommon 

 in the United States. Sporadic outbreaks and enzdotics 

 have been reported from several States. England and the 

 continent of Europe are badly infected. In Switzerland and 

 Denmark it causes considerable losses. It is probably much 

 more prevalent than usually suspected, being confused with 

 other chronic enterites and bowel tuberculosis. 



Etiology. — An acid-fast bacillus resembling the tubercle 

 bacillus of avian type. The bacilli are found in the intestinal 

 mucous membrane, and in the mesenteric lymph glands. 

 The germ does not grow artificially unless cultivated on a 

 special medium. It is probably distinct from the tubercle 

 bacillus. (See Bacteriology.) 



Natural Infection. — The causal organisms are eliminated 

 with the feces. They enter the body of a susceptible animal 

 via digestive tract. The contagiousness of Johne's disease 

 has been proven by feeding experiments and successful 

 transmission intravenously. This is further confirmed by 

 the practical observation that when once introduced into a 

 herd it spreads. 



Necropsy. — The cadaver is usually emaciated. The lesions 

 are confined to the bowels and mesenteric lymph glands. 

 In typical cases the mucous membrane of the small intestine 

 and occasionally the colon and cecum is greatly thickened 

 (sometimes fourfold) and thrown into folds or convolutions, 

 some of them transverse, some longitudinal, giving the bowel 

 a corrugated appearance. Coating the affected mucosa is 

 a turbid, grayish-yellow, slimy exudate which is readily 

 scraped off. The surface of the folds is usually smooth; the 



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