ACTINOMYCOSIS 15 



Not quite so frequent, but yet common enough, is 

 actinomycosis of the tongue. In all forms this disease 

 shows a decided preference for young or middle-aged 

 cattle; old cattle are only occasionally affected. 



While it is presumed to be infectious it is generally 

 found in isolated instances. One cow in a herd of 

 dairy cattle may have the disease in a well-marked 

 form and not another animal in the herd become 

 affected ; but often more than one become affected, the 

 number sometimes including twenty-five per cent of 

 large herds. 



When the disease makes its appearance at the angle 

 of the jaw it is in the form of a smooth tumefaction 

 or lump, or ''bunch." In the early stages this tume- 

 faction increases in size, becomes more firm, and 

 usually tends to become anchored or fixed to the bone. 

 Still later the center becomes necrotic, and the typical 

 stringy, marrow-colored pus is discharged. 



If the case is not checked at this time it may pro- 

 gress until the bone itself is involved in the disease 

 process, and the treatment then becomes difficult. 



When actinomycosis involves the tissues lying be- 

 tween the rami of the inferior maxilla we find this 

 space completely filled with a mass of dense, appar- 

 ently fibrous, tissue. If the disease has existed here 

 for some time the enlargement can be seen plainly 

 with the animal in the standing position; the under 

 side of the jaws between the chin and throat appears 

 curved from before backwards with a considerable belly 

 towards the bottom. 



After variable periods of time this swelling breaks 

 down in one or more places. Usually there are three 

 or four openings, and from these escapes actinomycotic 

 pus. The pus in this location is not so characteristic, 

 being thin and lighter in consistency. 



