DISEASES OF CATTLE 345 



odium attached to ticky cattle at the stock yards removed. Purebred 

 northern cattle could then be brought into the South to improve the 

 native breed without danger of death from Texas fever, southern 

 animals could enter the show rings of the North without restriction, 

 and the total cost of tick extermination would be far less than the 

 amount saved in the first year after it had been accomplished. How- 

 ever, much co-operation must be had between the farmer and the 

 State and Federal Governments before such a desirable result is pos- 

 sible. And in the meantime, with such conditions attainable, laxity 

 should not be allowed in enforcing the present regulations, national, 

 state, and local, and equal care should be taken to enlighten the 

 stock raisers of the infected district as to the benefits which will fol- 

 low their thorough understanding of Texas fever and their intelli- 

 gent assistance in its eradication. 



CHRONIC BACTERIAL DYSENTERY. 



Chronic bacterial dysentery is a chronic infectious disease of 

 bovines caused by an acid-fast bacillus simulating the tubercle bacil- 

 lus and characterized by marked diarrhea, anemia, and emaciation, 

 terminating in death. 



Recently this disease has been observed in the United States for 

 the first time by Pearson in Pennsylvania cattle, and later by Moh- 

 ler in Virginia cattle, and in an imported heifer from the island of 

 Jersey at the Athenia quarantine station of the Bureau of Animal 

 Industry. 



The former has proposed the name chronic bacterial dysentery 

 for this affection, and it has also been termed Johne's disease, chronic 

 bacterial enteritis, chronic hypertrophic enteritis, and chronic bo- 

 vine pseudotuberculosis enteritis by various European investigators. 

 The disease was first studied in 1895 by Johne and Frothingham in 

 Dresden, but they were inclined to attribute the cause of the peculiar 

 lesions of enteritis which they observed to the avian tubercle bacillus. 

 In 1904 Markus reported this disease in Holland, and subsequently 

 it was observed in Belgium, Switzerland, Denmark, and Great 

 Britain. 



Cause. The bacillus, which has been invariably demonstrated 

 in the intestinal lesions and mesenteric lymph glands in this disease, 

 is a rod about 2 to 3 microns long and 0.5 microns wide. It stains 

 more or less irregularly like the tubercle bacillus, and moreover the 

 similarity goes further in that the organism is also strongly acid- 

 fast, which facts led Johne and Frothingham to surmise that the dis- 

 ease was caused by avian tubercle bacilli. However, it has now been 

 plainly demonstrated that the bacillus of chronic bacterial dysentery 

 is readily distinguished from the latter organisms, for while it re- 

 sembles the tubercle bacillus in form and staining qualities, no one 

 has succeeded in growing it in culture media or in reproducing the 

 disease by injecting experiment animals. 



Symptoms. Probably the first symptom noticed is that the 

 animal is losing condition despite the fact that its appetite is good 

 and the food nourishing. This is soon followed by a diarrhea which, 

 while moderate at first, soon becomes excessive and may be either 



