INFECTIOUS DISEASES OF CATTLE. 491 



The amount thus released covers 56,528 square miles, an area larger 

 than the entire State of Virginia. 



Congress again this year has shown its desire to sustain adequately 

 these operations by an appropriation of $250,000, so if the States will 

 do their part in appropriating money and enforcing satisfactory laws 

 in the infected districts, it would become merely a matter of a rela- 

 tively short period of time before the fever tick would be extermi- 

 nated and southern cattle permitted to reach the more favorable 

 markets of the North at any time of the year without restraint. 

 Prices would then be higher, the demand greater, and the 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 cooperation must be had between the farmer and the State 

 and Federal Governments before such a desirable result is possible. 

 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 follow 

 their thorough understanding of Texas fever and their intelligent 

 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 

 bacillus and characterized by marked diarrhea, anemia, and emacia- 

 tion, 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 Mohler 

 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 bovine 

 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 micron wide. It stains more 



