CHAPTEK XXI. 



BACILLUS OF SYMPTOMATIC ANTHRAX. 



Occurrence and Historical. The disease known as symptomatic 

 anthrax, black-leg, black-quarter, quarter-ill, Sarcophysema hsemor- 

 rhagicum bovis; "Kalter Brand, Rauschbrand" (German); charbon 

 symptomatique, charbon bacterie (French), generally affects cattle 

 and occasionally other animals, like sheep and hogs. It is due to a 

 specific anaerobic gas-forming microorganism known as the Bacillus 

 or Clostridium sarcophysematos bovis, bacillus of symptomatic 

 anthrax or Bacillus chauveaui. The disease is particularly prevalent 

 in mountainous countries, with deep and marshy valleys, also in flat 

 countries, in which the pastures are exposed to periodical inundations. 

 It is most prevalent during the hot season, and attacks particularly 

 cattle between six months and two years old. The disease has un- 

 doubtedly been known for a long time, but it was formerly generally 

 mistaken for anthrax. Bellinger (1875) and Feser (1876) first pointed 

 out the difference between true anthrax and black-leg. They 

 showed the specific bacilli in the emphysematous swellings and 

 inoculated material containing them into ruminants and rabbits. 

 Several French authors studied the organism in the following years, 

 and Roux (1887) and Kitasato (1889) were the first to cultivate it 

 artificially. The pathology and bacteriology of the disease were first 

 more extensively investigated by Kitt, whose studies were made in 

 the Bavarian Alps. The disease is quite prevalent in the United 

 States, the majority of cases having been reported from Texas, Okla- 

 homa/ Kansas, Nebraska, Colorado, Indian Territory, and a number 

 of Northwestern and Western States. According to Moore, infected 

 localities have also been recently found in New York. Black-leg 

 occurs in Germany, Austria-Hungary, Switzerland, and the other 

 European countries. It has also been observed in Africa from 

 Algiers to the Transvaal. 



Pathologic Lesions. The most important objective changes char- 

 acterizing the disease are rapidly forming, rather diffuse, ill-defined 

 swel ings of the skin and superficial muscles, which are first very 

 firm and solid, but soon become infiltrated with air (emphysematous), 

 so that they are crepitant to the touch and tympanitic upon percussion. 

 To the palpitating finger these swellings impart a feeling as if there 

 was paper beneath the skin. The most common seat of these 

 emphysematous lesions is in the thick muscles of the hind- or fore- 

 legs, from which fact the names black-leg and quarter-ill are derived. 



