230 ANIMAL DENTISTRY. 



over the gums, ulcers and vacant tooth cavities after the 

 saliva has been wiped aw^ay v\rill frequently arrest the pro- 

 cess, and would undoubtedly prove a specific if its toxicity 

 did not prevent its repetition. 



RETENTION CYSTS. 



Besides the large cyst that occurs in the fraenum of the 

 tongue (ranula), the mucous membrane of the mouth of 

 horses is occasionally the seat of mucoid cysts varying from 

 the size of a millet seed to that of a pea. The common 

 location is around the commissures, either superiorly or 

 inferiorly. Anatomically they consist of a dilated mucous 

 follicle resulting from an obstructed outlet. They are per- 

 fectly benign and yield to evacuation of the contents by 

 incision. 



TUMORS OF THE MUCOUS MEMBRANE OF THE 



MOUTH. 



The following is an enumeration of the various tumors 

 affecting the mucous membrane of the mouth : 

 (i) Actinomycosis, see page 218. 



(2) Sarcoma, see page 218. 



(3) Carcinoma, see page 217. 



(4) Ranula, see page 250. 



(5) Retention cysts, see page 230. 



LAMPAS. 



Definition — Tumefaction of the hard palate just behind 

 the superior incisor arcade. 



Etiology — Lampas is a physiological condition occurring 

 from dental nutrition during the growth of the teeth. It 

 occurs at a time when the crowns of the teeth are still too 

 short to overlap the first bars of the palate. In old horses 



