334 VETERINARY BACTERIOLOGY 



the spores only after prolonged contact. A rennet-like enzyme 

 and ferments which digest casein, gelatin, and blood-serum are 

 produced. Acids and gas are not formed. 



Pathogenesis. Experimental Evidence. Guinea-pigs, mice, and 

 rabbits are very susceptible to experimental inoculation. The 

 subcutaneous injection of anthrax bacilli results in the develop- 

 ment of a quickly fatal septicemia having the characters of the 

 disease as it occurs in the larger animals. The carnivora are 

 relatively immune. Birds show a high degree of immunity. 

 Inoculation of cattle, sheep, swine, and other susceptible domestic 

 animals with pure cultures of the organism invariably produces 



Fig. 137. Bacillus anthrads colony Fig. 138. Bacillm anthracis, stab 

 (Giinther). culture in gelatin (Giinther). 



the disease, so that there is no question of the causal relationship 

 of this organism. 



Character of Disease and Lesions Produced. As it occurs in 

 animals the disease is usually a distinct and rapidly fatal septi- 

 cemia. Hemorrhagic and serous infiltration of the subcutaneous 

 and other connective tissues and subepidermal hemorrhages are 

 characteristic. The spleen is much enlarged, often several times 

 its normal size. The liver, kidneys, and lungs are usually congested 

 and ecchymotic. The organism is to be found in great numbers 

 everywhere in the blood-stream. Cutaneous infections in horso 

 and man, rarely in cattle, develop as carbuncles from which the 

 organism may not invade the general circulation, and healing 

 may occur. Commonly, however, this infection terminates 



