304 



ACTINOMYCOSIS 



§ 230. Infection. While actinomycosis is an infectious 

 disease it does not seem to be transmitted directly from one 

 animal to another. Numerous investigators have tried to pro- 

 duce the disease by inoculating cattle, calves, sheep, goats, 

 pigs, dogs, cats, rabbits and guinea pigs with actinomycotic 

 lesions. The results have almost invariably been negative 

 when pus was used, but the disease has developed after inocu- 



FiG. 72. Head of a steer zvith actinomycosis of the lower jaw. 

 ( Photograph ed by Hopkins ). 



lating cattle with pieces of tissue containing the fungus in its 

 vegetating state. 



It is believed that the infection occurs in susceptible 

 species by the introduction of the fungus on food stuffs. The 

 supposition is that the parasite gains entrance to the living 

 tissues through slight wounds of the mucous membrane of the 

 mouth or throat and perhaps the alveoli of diseased teeth or 

 during the shedding of the milk teeth. It multiplies and 

 extends from the points of entrance. After the infected awns 



