136 VETERINARY DENTAL SURGBRT. 



than when in a natural condition. These symptoms 

 are not confined to that portion of the mouth just 

 back of the incisor teeth, but often exist in the bars 

 between the molar teeth, where they escape the 

 notice of the casual observer. The inside gums of 

 the lower jaw, also the outside occasionally, are 

 sometimes affected in a similar manner. First there 

 is congestion and in some instances it is followed by 

 more or less inflammation, sometimes but rarely 

 terminating in suppuration. In young horses it is 

 undoubtedly due to teething or external injury. In 

 some instances aggravated cases have been observed 

 in aged horses. The cause of its appearance in such 

 animals, has not been satisfactorily explained up to 

 the present time. Some ascribe it to the continua- 

 tion of the growth of the teeth during life, others to 

 the constant pushing up of the teeth from their 

 alveolar cavities. It is due, no doubt, in some in- 

 stances to external violence, such as a hard substance 

 bruising the parts and separating the gums from the 

 teeth. 



The immediate or exciting causes of tumefac- 

 tion of the gums are local irritation, produced by 

 salivary calculus (tartar), by carious, dead or loose 

 teeth, or roots of teeth. A projecting molar may 

 be, and often is a source of irritation to the dental 

 periosteum and gums, which gradually extend until 

 the whole becomes involved. This may explain the 



