640 Paratuberc-ulosis of Cattle. 



of local cheesy foci or abscesses, and in most cases they were 

 of a completely negative character. This disease occurs oc- 

 casionally also m herds that are entirely free from tuberculosis. 

 Many of the animals do not react to tuberculin and upon post- 

 mortem examination are found absolutely free from any tuber- 

 culous lesions whatever (Bang). 



Recently Stiiurniaii reported that he has succeetled in producing pure cultures 

 of the organism from guinea pigs and rabbits that had been infected with material 

 from naturally infected animals. These cultures were similar in many respects 

 to those of the avian tubercle bacillus. The results of alimentary administration 

 of pure cultures were however negative. 



The fact tliat the disease is contagious was demonstrated 

 by Bang when he succeeded in infecting six calves by feeding 

 the scrapings of the intestinal mucous membranes of infected 

 cows in large quantities (300 to 1,500 gm.). Miessner also 

 succeeded in infecting cattle in this manner as well as by in- 

 travenous administration. These positive results point to the 

 probability that natural infection results from ingestion of 

 contaminated feces. However, the pathogenicity of the disease 

 is also demonstrated by the observation of its introduction 

 into herds previously free from the same. 



Anatomical Changes. At post-mortem examination we find 

 the following: The cadavers are frequently excessively 

 emaciated, the walls of the small intestine considerably 

 tliickened, either uniformly through its entire extent or in local 

 areas only. Tliese changes may extend also to the cecum and 

 colon. The surface of tlte intestines is smooth and pale. The 

 nmcous membrane of tlie affected regions is increased to from 

 4 to 5 times its normal tliickness, being transformed into ir- 

 regular folds running longitudinally or transversely so as to 

 resemble the convolutions of the brain (Fig. 98). These areas 

 are covered with a dirty looking, grayish-white or grayish- 

 green, slimy fluid resembling meal soup. At the crest of the 

 folds the mucous mem])rane is reddened in spots or dotted 

 with hemorrhages, and usually smooth on the surface; between 

 the folds it has a delicately warty appearance (no nodules) 

 as though gnawed by fine teeth. The mesenteric glands and 

 Peyer's patches are slightly swollen. 



Meyer found specific changes in the fourth stomach in 50% of the cases 

 examined. Of the various regions of the intestines, the duodenum was macro- 

 seoi)ically infected in 1.3%, the jejunum in (5S%, the ileum in 82%, the cecum in 

 36%, the colon and rectum in 32%, the mesenteric glands in 60%. Microscopical 

 examination of the hypertrophied areas of the mucous membrane revealed extensive, 

 diffuse, cellular infiltration, the villi having assumed irregular and clumsy forms. 

 The diseased cell masses frequently contained great numbers of large epitheloid as 

 well as giant cells and great masses of small acid-fast rods. 



These ro'ds are occasionally found also in great numbers in the feces in 

 which they are easily <lemonstrated by staining processes adapted for tubercle 

 bacilli (the bacilli also stained according to Gram's method and with carbo- 

 methylene blue). When the rectal mucous memlirane is atfected the diagnosis can 

 readily be made intra vitam by removing a small ])ortion of the mucous membrane 

 with the aid of the fingernail or with a curette and examining it microscopically. 



