208 ANIMAL DENTISTRY. 



EROSION OF THE ENAMEL. 



Definition — A disease of the anterior face of the superior 

 incisor teeth, characterized by a gradual upward denuding of 

 the external enamel covering. 



Etiology — The cause depends solely upon a faulty con- 

 struction of the teeth, both anatomically and morphologi- 

 cally. The disease occurs in animals having an observable 

 softness of all the teeth. The dentine is devoid of its char- 

 acteristic hardness and the crusta petrosa is deficient in qual- 

 ity as well as quantity. Defective cementing of the enamel 

 to a soft underlying dentine favors the gradual breaking 

 and wearing away of the former. Iron feed boxes, cribbing 

 and the habit 6f gnawing hard objects hurry the denuding 

 process, but are never solely responsible. 



Treatment — Polishing with emery paper to give a better 

 appearance is the only possible help. 



TARTAR. 



Definition — An accumulation of calcareous matter along 

 the gingival margin of the teeth. 



Etiology — Tartar simulates calculi in other parts of the 

 body. It is the result of the chemical action of saliva and 

 mucus on the calcium salts of the food. It is composed of 



Phosphates 80. 



Mucus 11.^ 



Ptyaline I. 



Animal matter 7 e 



Symptoms — Tartar occurs as a yellow incrustation along 

 the gums. In animals it is found mostly on the canines and 

 incisors; on the canines it frequently accumulates in large 

 quantities and gives the crown the appearance of a mon- 

 strosity (odontoma). It is differentiated from the latter by 

 being readily removed, and from the normal crusta petrosa 



