DOMESTIC ANIMALS. 169 



tist. There are very few animals besides the horse 

 'whose teeth grow throughout life. 



There are many diseases to which the teeth are sub- 

 ject, but we shall only notice one, viz. : 



ULCERATION OF TEETH NECROSIS ROTTEN 

 TOOTH. 



Fortunately the horse is not as liable to necrosis of 

 the teeth as is man ; in fact, it is rather rare except in 

 very old animals. In many cases horses undoubtedly 

 suffer from ulceration of the teeth and the consequent 

 pain for some time before discovery. The animal will 

 lose flesh, the hair looks dry and there is a general ap- 

 pearance of poor nutrition. In advanced cases there is 

 sometimes swelling of the glands under the jaw, with 

 foul-smelling breath ; a little later, if an upper tooth is 

 the subject of ulceration, we are likely to have a foul- 

 smelling discharge from the nostril of the affected side. 

 I have known this condition to continue for many 

 months without the true cause being discovered. 



The mouth should be examined by inserting the 

 mouth speculum, shown in figure 60. The tongue 



Fig. 60. Mouth speculum. 



