174 THE HORSE 



part, the result of disease. Predisposition to digestive 

 trouble may be brought on through one or more ante- 

 cedent attacks. Both old and young horses are liable to 

 irregularities in connection with the molar or grinding 

 teeth. In every case when a horse is not thriving 

 properly, the mouth gag should be brought into requisi- 

 tion, the tongue grasped with the left hand, and the teeth 

 critically examined by illuminating the mouth with an 

 electric torch. Old horses sometimes have what is known 

 as a "shear-mouth" caused by the molar teeth wearing 

 away after the manner in which the blades of a pair of 

 shears overlap. Shear-mouth varies. The deformity 

 may be shght or it may be excessive. In the former case, 

 rasping the teeth will assist matters a little, but in the 

 latter the case is quite hopeless. Sometimes a molar 

 tooth is decayed and in other instances the fang is the 

 seat of disease. In colts, during the shedding of the tem- 

 porary molars and their replacement by permanent 

 teeth, it occasionally happens that the teeth become 

 entangled, i.e. the fang of the old tooth becomes fixed on 

 the crown of the new one. As a rule this is not a difficult 

 trouble to deal with. It is absolutely essential that the 

 grinding teeth be in good order. When a diseased molar 

 tooth is removed the cavity fills up shortly afterwards, 

 but sometimes the opposing tooth, or rather, what was 

 the opposing tooth, becomes too long and presses on the 

 opposite jaw. The overgrowth can be removed with the 

 tooth-shears, but this is a dental operation for a veterinary 

 surgeon to perform. The gullet is occasionally the seat 

 of obstruction, either owing to disease of its wall or 

 through some foreign body lodging in it. The stomach 

 may be over-distended with gas as in flatulent colic, 

 in which complaint the intestines are extensively im- 

 phcated. Worms of various kinds, more especially 

 sclerostomes, are not uncommonly found in its mucous 

 lining. When horses are affected with these parasites 

 they are always in a more or less debilitated condition. 



