ANIMAL DENTISTRY. 



219 



or wild herbivora and omnivora, and it has been produced 

 experimentally in rodentia and carnivora. 



Etiology — The cause of lumpy jaw is the growth of the 

 actinomyces in an infected tissue. The organism is a 

 saprophyte of forage, through which medium it gains 

 entrance into the body by inhalation into the air passages 

 and by ingestion into the digestive tract. Eruption of teeth, 

 dental irregularities and wounds produced by fibrous forage 

 produce favorable channels of entrance, hence the frequency 

 of the disease about the mouth and pharynx. The organism 

 is, however, capable of producing its pathogenicity in the 



Fig. 148A. 

 Lumpy Jaw in the Ox. 



nasal cavities, lungs, stomach and liver where wounds are 

 not etiological factors. 



Affected Organs — Mouth, lips, nostrils, tongue, jaws, 

 salivary glands, Schneiderian membrane, velum, pharynx, 

 rumen, omasum, liver, lungs, and mammae. 



Diagnosis — The early signs of actinomycosis located in 

 visible parts of the body, consist of the formation of one or 

 more wart-like nodes which may, when first noticed, be only 

 the size of a pea. These nodes contain a calcareous or case- 

 ous center. In the tongue the condition usually remains 

 unnoticed until the organ has become indurated (wooden 

 tongue). In the jaw the disease is first manifested by the 



