46 



DISEASES OF THE DIGESTIVE APPARATUS. 



the nerve, aud thus exposing it to the atmosphere, inflames it and 

 makes it very sensitive. 



There are certain microbes found in calcareous teeth ; but whether 

 they are directly connected with the decay of the teeth is not defi- 

 nitely known. True dental caries is very rare in the dog. Necro- 

 sis of the teeth is frequently mistaken for caries. In old dogs we 

 often see an acute inflammation of the periosteum, and the alve- 

 olar process becoming inflamed the tooth is lifted out of its socket 

 and finally thrown out. In these cases the alveolar periosteum is 

 destroyed, and the necrotic condition of the tooth causes it to be- 

 come yellow; this is generally termed false caries of the teeth. 

 Alveolar periostitis commences with the formation of an abscess 

 at the root of the tooth, and the pus formed finds its way to the 

 outside through the alveolar process and the gums. It forms a 

 fluctuating swelling on the gums (abscess of the gums) ; the open- 

 ing generally remains so, and if it is in the superior maxillary open 

 fistulous tracts may form under the eye, just below the lower eye- 

 lid, and unless carefully examined may be mistaken for a lachry- 

 mal fistula. By means of a flexible probe the diagnosis can be 

 made with safety. 



In all these cases the animals seem to have a more or less 

 severe toothache; they are irritable, eat very slowly and irregu- 

 larly, drop more or less saliva, refuse to 

 have the mouth examined, and, if the af- 

 fected tooth is struck with anything (a key 

 is the best), howl and evince great pain, 

 keeping the mouth open for some time after- 

 ward. 



When there is more or less pus present 

 the radical treatment is to remove the 

 offending tooth. For this purpose open 

 the mouth by the method described on page 

 27, or a wedge, and with an ordinary molar- 

 forceps (Fig. 15) extract the tooth, being 

 careful to avoid breaking the crown. The 

 tooth is firmly seized with the forceps as far 

 down on the root as possible; it is first loos- 

 ened by twisting from side to side several times and then drawn out 

 with a strong pull. The mouth must then be thoroughly cleansed 



Fig. 15. 



Tooth forceps. 



