DISEASES 01' THE ALVEOLAE PROCESSES. 507 



which will become enlarged, as will also the Haversian canals 

 in which they ramify. The osseous laminae surrounding these 

 canals will be partially absorbed, and to some extent separated 

 from each other, and the enlarged spaces thus produced will be 

 filled with inflammatory exudation. Hence the soft, spongy state 

 of the gums, their tendency to bleed from slight causes, and as 

 their periodontal membrane is separated from the teeth ; hence 

 also their looseness in the alveoli." 



Symptoms. — Imperfect mastication of food, "quidding," with 

 loss of condition ; the faeces containing much ill-digested aliment. 

 Examination of the mouth will show to the practitioner that 

 there are spaces between the teeth filled with hay, corn, &c., 

 which, from long detention, may have become fcetid. 



Treatment. — The treatment recommended by Professor Varnell 

 in those cases where it is considered advisable not to destroy the 

 animal, is the removal of the impacted matters from between 

 the teeth with water and a brush constructed for the purpose ; 

 the parts to be afterwards washed out with a solution of chloride 

 of hme. 



Very old horses are subject to this disease of the gums and 

 alveolar process, as well as to looseness of the teeth in their 

 alveoli from natural decay. In such cases no good can be done 

 by any operation or treatment. 



In addition to the treatment of Professor Varnell, the filling 

 of the interdental spaces with gutta-percha might prove of great 

 service. 



CARIES OF THE TEETH. 



Caries, dental gangrene, or decay, is almost exclusively con- 

 fined to the molar teeth, although I have seen the incisors in 

 that condition. 



Caries of the molars may commence primarily in the fang, 

 neck, or crown of the tooth. 



Caries of the fang arises from inflammation of the pulp, and 

 may be caused by a constitutional predisposition or external in- 

 jury. Inflammation of the pulp does not always cause caries. 

 I have several cases on record where the fangs were enlarged 

 from periodontal deposit, with abscesses surrounding the fangs, 

 without caries. Caries commencing at the fang may be due to 

 obliteration of the pulp cavity, at an age when the vitahty of 

 the tooth depends upon the integrity of the pulp. 



