328 



SWINE PRACTICE 



strated to protect against natural infection in other animals and 

 probably would be equally valuable in swine. 



This disease can be prevented by sterilization of instruments, the 

 proper after-care of immunized swine and swine that have been oper- 

 ated upon. 



Anthrax (Charbon) 



Anthrax is a specific infective disease caused by the B. anthracis and 

 characterized by changes in the blood, spleen and lymph-glands. 



This disease prevails in some sections of the country, but occurs 

 more frequently in mules, horses, cattle and sheep than in swine. 

 Many cases have been reported in swine from different localities, but 

 fortunately the outbreaks have been confined to a few animals, or at 

 least to one farm. Porcine anthrax usually occurs in swine that have 

 been fed the carcass of an animal dead of anthrax. 



Etiology. — The specific cause of anthrax is the B. anthracis. The 

 B. anthracis is a rod-shaped non-motile bacterium averaging about 4 



microns in length and 1 to II/4 mic- 

 ron in diameter. This bacterium is 

 characterized by relatively square or 

 concave ends when obtained from 

 lesions. They stain readily with 

 ordinary aniline dyes. Oval spores 

 form in the center of the rods. Spores 

 of the B. anthracis are very resistant 

 to external influences, to chemical dis- 

 infectants, and to the usual means of 

 sterilization. 



The B. anthracis is areobic and 

 grows readily on any ordinary cul- 

 ture medium at body temperature. 

 Long threads of filaments are common in cultures of B. anthracis. 



Source of infection. — The most common and usual source of infec- 

 tion from B. anthracis in swine is f^om the discharges and carcasses 

 of animals dead of anthrax. More rarely infection may be obtained 

 from contaminated water, feed or soil. 



Channel of Entrance. — The usual channel of entrance of the B. 

 anthracis in swine is the digestive tract in feed or water. 



Lesions. — Anthrax in swine is usually localized in the beginning, 

 although it frequently becomes generalized or of the septicemic type 



Fig. 95. BACILLUS ANTHBACTS, 



(Prom Hutyra & Marek.) 



