560 NEKVOUS DISEASES. 



side, a way of escape for the air, will render it impossible for the 

 horse to force backwards the air in his mouth; and that it can in 

 no way check eructation. 



The swallowing of air in cribbing or windsucking appears to serve 

 no useful end; for its prevention does not injure the health in 

 any way. 



FREQUENCY OF THE ACT AND MODIFYING CIRCUM- 

 STANCES. — The frequency of the practice of this vice varies 

 greatly in different cases. " We may see animals engaged at it 

 during and after feeding. Some practise it at each mouthful. 

 Others begin only after having had their food. The nature of the 

 food and the process of digestion have no influence on its fre- 

 quency " (Cadeac). The affected animal loves to indulge in this 

 vice in solitude, and will often refrain from it, if any person, and, 

 sometimes, if another horse be present. Bellanger tells us that 

 a cribber refrained from cribbing during the entire duration of 

 the Italian war, and took to it again only when he returned to 

 his stable. Ponsecchi records the same thing with respect to 

 cavalry horses which were employed during manoeuvres. Hard 

 work often checks it for the time being, and so does illness, in 

 which case, as Cadeac remarks, its renewal may be regarded as a 

 sign of convalescence. 



CAUSES. — There is evidently a close connection between the vice 

 of crib-biting and the diminution of work which domesticity en- 

 tails on the front teeth of stabled horses; the teeth, being a form 

 of epidermal growth, which is stimulated by pressure (p. 190). In 

 the case of mankind, cooking, by softening the food, is a great 

 cause of dental decay. The human practice of chewing toothpicks, 

 straws, and other comparatively hard substances, is an action 

 obviously prompted by the requirements of dental growth. Horses 

 in a state of nature use their front teeth in the prehension and 

 pulling of their food, far more than they would do in a box or 

 stall, especially when their hay takes the form of " chop '^ ; hence 

 the almost invariable tendency which stabled horses have to 

 gnaw wood-work. I am unable to trace the connection between 

 this habit and the serious vice of wind-sucking:. 



Idleness and ennui are two potent predisposing causes of this 

 vice, even if they do not give rise to it. Irritability while groom- 

 ing may prompt a horse to crib, by inducing him to catch hold 

 of his manger with his teeth. '' Want of food disposes horses to 

 lick their manger and the walls oi their stalls, and thus to con- 

 tract this vice " (Cadeac). Charles Martin regards insufficiency 

 in the volume of the food and arrangements of the manger which 



