Dysentery of Cattle. 241 



Defiyiition. An infective, ulcerative inflammation of the large 

 intestine but especially of the colic and rectal mucosae. 



It is well recognized as a disease of the ox, and the older writ- 

 ers allege its existence also in horses, swine and dogs, though 

 this is not admitted in all modern veterinary works. 



Causes. It was formerly ascribed to improper hygiene, chills, 

 cold rain storms, night dews, hoar frost, malarious emanations, 

 putrid, stagnant or iced water, irritants in food, green, fermented 

 or musty food, a too liberal diet after .starvation, overtaxation in 

 very hot weather, and bad odors from decomposing carcas.ses. 

 These can only be accepted as predisposing causes begetting a 

 general debility, or debility of the alimentary canal and laying 

 that open to the attacks of specific microbes. The close aggrega- 

 tion of cattle on ship-board, in besieged cities, and in the parks 

 of armies in the field, has apparently contributed to the propaga- 

 tion of the dysentery. The removal of a victim to a herd with 

 free healthy range .seldom .starts a new center of the disease. In 

 all infected herds huddled in small compa.ss there is every facility 

 for the propagation of a germ already present, and especially in 

 the commissariat of a belligerent army there are enough privations, 

 over-exertions and other trying conditions to favor predisposition. 

 Faulty food like stale bread, nuLsty hay, have been .suppo.sed to 

 cause it. For man and beast alike dysentery is preeminently a 

 disease of the tropics, and of hot .seasons, and will often subside on 

 the advent of cold weather. 



Its propagation on given (swampy) .soils, and in particular (foul) 

 stables .strongly suggests a special germ, though for the cow this 

 has not been perfectly identified. Gerlach vainly attempted 

 to inoculate it, and it does not often propagate itself beyond 

 the foul and infected localities or stables, yet its persistence in 

 them for years bespeaks unequivocally the operation of a special 

 pathogenic ferment. 



It may also be fairlj^ assumed that it is not necessary that the 

 .same factor should be pre.sent in all cases alike, but that one 

 operates predominantly in one case and another in another. In 

 other words dysentery must be recognized as not one disease, but 

 several, of which the true pathogenic microbes have not yet been 

 fully demon.strated, but which are classed together becau.se of the 

 similarity of the attendant lesions. 

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