10 Anthrax. 



secretions of the affected or dead animals. The disease may 

 also be transmitted through infected food, straw, stable utensils, 

 surgical instruments, har^^ess, hands and cloths of attendants, 

 the stable floors and water. The injuries may be of the most 

 varied origin (bites, phlebotomy, shearing of sheep, surgical 

 wounds, spinous plants, wounds caused by sharp pointed ob- 

 jects, etc.), whereas the transmission by flies and insects is 

 considered doubtful according to recent investigations (Nuttal, 

 Miihling). 



According to Dalrymple the earbuneular form of anthrax predominates in 

 Louisiana, the infection being transmitted to healthy animals by horse flies known 

 there as charbon flies. 



Inasmuch as an artificial infection through inhalation of 

 air containing spores is possible even when the respiratory 

 mucous membrane is uninjured (Feser, Buchner, Enderlen) 

 such infection may occur under natural conditions when 

 the animals are fed very dirty infected feed. However, in- 

 halation anthrax has never yet been positively established in 

 domestic animals (in man a primary affection of the lungs 

 does actually occur. See page 31). 



Anthrax is not frequently transmitted directly from animal 

 to animal. This kind of infection occurs only when the blood 

 or infectious excrement of affected animals comes in direct 

 contact with injuries on the skin or mucous membrane. Never- 

 theless the diseased animal is a source of danger for its 

 neighbors as its excrement contaminates the straw, food and 

 the ground by contact with which other animals are indirectly 

 infected in the manner above mentioned. 



Susceptibility. Of the domestic animals the herbivorous 

 mammals are the most susceptible, among which may be first 

 mentioned sheep, horses and cattle, and the goat to a less 

 extent. Considerably less susceptible are hogs, dogs, cats, and 

 carnivorous mammals in general. Buffalo appear to become 

 affected but rarely. Wild ruminants may l)e classed with the 

 domestic ruminants as regards their susceptibility to anthrax. 

 Domestic fowls are very resistant to artificial infection with 

 the exception of the somewhat more susceptible pigeon (the 

 occurrence of anthrax in fowls through natural infection has 

 not yet been established with certainty). 



The susceptibility is probably influenced to some extent 

 by the breed, since certain breeds are more susceptible than 

 others. Thus, according to the experiments of Chauveau, 

 Algerian sheep manifest a remarkable resistance to artificial 

 infection which was only overcome by large doses of the virus. 

 Age has an influence, inasmuch as young animals are more 

 susceptible than older ones. Fatigue, starvation and chilling 

 increases the susceptibility; it also appears that well nourished 

 and carefully stabled animals are more easily affected than 



