INFECTIOUS DISEASES OF CATTLE. 413 



by the sharp and pointed parts of plants which penetrate the mucous 

 membrane and carry with them the fungus. The disease is therefore 

 inoculable rather than contagious. The mere presence of the diseased 

 animal will not give rise to disease in healthy animals unless the acti- 

 nomyces grains pass directly from the diseased into some wound or 

 abrasion of the healthy, or else drop upon the food which is consumed 

 by the healthy. Not only are these views deducible from clinical 

 observation, but they have been proved by the positive inoculation of 

 calves and smaller animals with actinomyces. The danger therefore 

 of the presence of actinomyces for healthy animals is a limited one. 

 Nevertheless an animal affected with this disease should not be allowed 

 to go at large or run with other animals. If the fungus is being scat- 

 tered by discharging growths we certainly can not state at this stage 

 of our knowledge that other animals may not be infected by such dis- 

 tribution, and we must assume that this actually occursmntil more 

 positive information is at hand. 



It is, however, the opinion of the majority of authorities that when 

 a< tinomycosis appears among a large number of animals they all con- 

 tract it in the same way from the food. Much speculation has there- 

 fore arisen whether any particular plant or group of plants is the source 

 of the infection, and whether any special condition of the soil favors 

 it. Very little positive information is at hand on these questions. It 

 would be very desirable for those who live in localities where this 

 disease is prevalent to make statistical and other observations on the 

 occurrence of the disease with reference to the season of the year, the 

 kind of food, the nature of the soil (whether swampy or dry, recently 

 n -claimed or cultivated for a long time) upon which the animals are 

 pastured or upon which the food is grown. 



It is highly probable that such investigations will lead to an under- 

 standing of the source of the fungus and the means for checking the 

 spreading of the disease itself. Veterinarian Jensen, of Denmark, made 

 sMjne observations upon an extensive outbreak of actinomycosis, about 

 ten years ago, which led him to infer that the animals were inoculated 

 liv <-uting barley straw harvested from pieces of ground just reclaimed 

 from the sea. While the animals remained unaffected as long as they 

 pa -tured on this ground, or ate the hay obtained from it, they became 

 diseased after eating tlie straw of cereals from the name territory. 

 Others have found that cattle grazing upon low pastures along the 

 banks of streams and subject to inundations are more prone to the dis- 

 ease. It has also been observed that food gathered from such grounds 

 may give rise to the disease even after prolonged drying. Much addi- 

 tional information of a similar kind must be forthcoming before the 

 source and manner of infection in this disease and its dependence upon 

 external conditions will be known. It is not at nil improbable that 

 these may vary considerably from place to place. 



Treatment This has been until recently almost entirely surgical. 



