CHAPTER VI 



ACUTE DISEASES PRODUCED BY MICROSCOPIC 



ORGANISMS 



Anthrax (Splenic Fever).— This disease is also 

 known in cattle as " splenic fever." In man the disease 

 is termed "malignant pustule" or "wool-sorter's 

 disease." The animals most commonly attacked are 

 cattle, sheep, swine, and more rarely horses and man. 



Etiology/. — The B. anthracis. In cattle the disease 

 is generally in the form of an acute septicemia, and 

 in the British Isles it is notifiable. It is prevalent 

 in all countries, and in cattle, among which it is 

 commonest, on account of its acute nature, there is 

 very little chance of treatment, the animal generally 

 being found dead. Prophylactic measures, however, 

 can be adopted with very real success. 



1. Immunity. — Active immunisation by vaccination 



has been extensively practised. The first method 



developed was that of Pasteur, and is still the one 



most commonly used. The organism is grown at a 



temperature of 42° to 43° C. for varying lengths of 



time. The pathogenicity gradually decreases until 



injections no longer kill the rabbit ; longer growths 



attenuate it until the guinea-pig is not susceptible, 



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