434 THE MANAGEMENT AND FEEDING OF CATTLE 



of the body. It is caused by the presence and activity 

 of a vegetable organism. This fungous parasite is 

 known as Actinomyces. As it multipHes and spreads, the 

 tumor growths increase. The animals chiefly affected 

 are cattle, sheep, and horses, but it also occurs in the 

 human family. The disease develops slowly. A small 

 swelling appears somewhere, more commonly about the 

 head, sometimes it is under the tongue, but more fre- 

 quently it is on the lower jaw, though, in some instances, 

 the upper jaw is also affected and likewise the throat. 



The disease is not directly communicable from one 

 animal to another. It is now generally believed that it 

 reaches its subject through the medium of the food, but 

 that it cannot be taken into the system in any other way 

 than through inoculation, which, if true, means that the 

 germs can only reach the system through some abrasion, 

 as, for instance, the mucous membrane of the mouth, 

 gullet, or stomach. Avenues of entrance may also be 

 furnished by decayed teeth or w^hen teeth are being shed. 



That the organism comes from the food finds coun- 

 tenance in the facts, first, that the presence of a diseased 

 animal before discharge occurs from the tumors is no 

 menace to the health of the other animals of the herd; 

 second, that when animals graze on certain pastures, the 

 disease is of more frequent occurrence than if grazed 

 on other pastures ; and, third, in different areas, there 

 would seem to be some relation between the parts of 

 the animal most frequently attacked and the germ-bear- 

 ing plants that produce the disease. The parasite, it is 

 thought, may live through one stage of its development 

 in the tissues of such fodder plants as barley and rye. 

 This view finds countenance in the quantities of the 

 fungus that have been found between the vegetable 

 fibers of barley which have penetrated the gums of cattle 

 and on the awns of certain grains imbedded in the 

 tongues of cows. 



