The Head and Neck 87 



erosion of the enamel in an unaccountable manner, particularly dur- 

 ing a severe attack of Distemper. 



Treatment. Fractured teeth where there is evident pain from 

 exposure of the pulp cavity, should be extracted or filled. 



mORUSTATIONS OP TARTAR. 



Incrustations of tartar occur very commonly, especially in city 

 dogs. Chemically, tartar consists of calcium and magnesium car- 

 bonate, calcium phospate, and some organic substances, and is re- 

 garded as a precipitation of these salts from their soluble condition 

 in the saliva by the action of certain microorganisms. The latter 

 have been isolated by Galippe and cultivated by Vignal. 



The effect of tartar on the neighboring tissues is purely an irri- 

 tative one. By constant accretion, the deposit gradually works its 

 way in between the neck of the tooth and the wall of the alveolar 

 cavity, so that the tooth becomes loosened and may eventually drop 

 out. Should these accretions continue to extend, the peridental mem' 

 brane (alveolar periosteum) becomes involved, when a far more 

 severe condition exists, viz.. Calcic Pericementitis. 



A brief reference here to the popular notion that the gnawing 

 of bones serves to "keep the teeth clean" will not be out of place. 

 This is surely a misconception, since tartar collects round the roots 

 of the teeth where any rubbing process of bone on tooth can scarce- 

 ly take place. On the other hand, bone-eaters are notoriously prone 

 to suffer from worn teeth, not to speak of other internal disorders 

 engendered by splinters and fragments of bone. Hence, bone can 

 hardly be regarded as a suitable diet for the dog. 



Symptoms and Diagnosis. In the early stages tartar is observed 

 on the teeth as a yellowish or greenish-brown deposit The seat of 

 the deposit is usually the base of the external face, but the vvhole 

 crown may be encircled. When it has invaded the alveolar cavity 

 the gums assume a more or less livid color and evince tenderness to 

 the touch. At the same time a foul odor is emitted from the mouth. 



Treatment. Calcic incrustations are removed by the operation 

 of Scaling. 



CALCIC PERICEMENTITIS. 



This term is applied to inflammation of the peridental mem- 

 brane deoendent upon deposits of tartar, sometimes described as 



