218 ANIMAL DENTISTRY. 



palate, usually in the region of the fifth molar, and traverse 

 upward between the teeth and along the alveolar border. 

 They are first observed by the appearance of a diffused swell- 

 ing of the palate extending along the molars and transversely 

 across the raphe. They extend upward into the alveolar 

 cavities around two, three, or even four molars, into the 

 sinuses, and even produce bulging of the facial bones. The 

 molars loosen and fall out or are easily extracted with the 

 fingers, and their removal is always followed by severe 

 hemorrhage. After the teeth are removed the cavities rapidly 

 fill with sarcomatous tissue, which will bleed profusely when 

 disturbed by mastication. The course of the process is slow 

 in the early stages but very rapid after the teeth have be- 



FlG. 148. 

 A Sarcoma of the Jaw Involving the Entire Molar Arcade. 



come seriously involved. They occur as clinical conditions 



in horses past the age of ten years, but probably escape 



notice during the early period of growth. They belong in the 



category of incurable diseases. The disease must not be 



designated "osteo-sarcoma," a condition we have never had 



the opportunity of seeing in the domestic animals, although 



its existence is not doubted. (See Fig. 148.) 



ACTINOMYCOSIS. 



Synonym — Lumpy jaw. 



Definition — Actinomycosis is a chronic infectious disease 

 due to the actinomyces, characterized by the formation of a 

 neoplasm at the seat of infection. 



Susceptible Animals — Ox, sheep, swine, horse and man. 

 The disease is not entirely foreign to any of the domestic 



