ACTINOMYCOSIS— OR LUMPY JAW 



159 



times affects the lungs and other internal organs, and may be 

 mistaken for tuberculosis. The lung symptoms, as seen on ex- 

 amination post mortem, vary so much that it is rather difficult 

 to describe them. Sometimes the lungs resemble those seen in 

 ordinary bronchopneumonia. Considerable areas of the lung 

 tissue may be changed to a gray mass, soft to the touch. In 

 still other cases there are developed distinct abscesses with fluid 

 contents. 



Fig. 53. — Actinomycosis — Lumpy Jaw. (M. E. B.) 

 Note the enlarged jaw and the raw, granulating tissue exposed. 



This disease is usually of slow development. A small swell- 

 ing appears somewhere about the head, perhaps under the 

 tongue ; or the bones of the face near the teeth begin to bulge 

 slightly outward and the enlargements continue very slowly. 

 The animal may remain thrifty for a long time, or indeed until 

 the disease involves the teeth, tongue, or other organs and inter- 

 feres directly with nutrition. 



Prevention. — There is so little known concerning the life his- 

 tory of the parasite and the methods of infection that a study 

 of prevention can be only partially satisfactory. It is generally 

 agreed that animals develop lumpy jaw only after inoculation, 



