20 DISEASES OF THE HOESE. 



THE EXAMINATION OF THE DIGESTIVE TRACT. 



The first point in connection with the examination of the organs of 

 digestion is the appetite and the manner of taking food and 'drink. A 

 healthy animal has a good appetite. Loss of appetite does not point 

 to a special diseased condition, but comes from a variety of causes. 

 Some of these causes, indeed, may be looked upon as being physio- 

 logical. Excitement, strange surroundings, fatigue, and hot weather 

 may all cause loss of appetite. Where there is cerebral depression, 

 fever, profound wealaiess, disorder of the stomach, or mechanical 

 difficulty in chewing or swallowing, the appetite is diminished or 

 destroyed. Sometimes there is an appetite or desire to eat abnormal 

 things, such as dirty bedding, roots of grass, soil, etc. This desire 

 usually comes from a chronic disturbance of nutrition. 



Thirst is diminished in a good many mild diseases unaccompanied 

 by distinct fever. It is seen where there is great exhaustion or depres- 

 sion or profound brain disturbance. Thirst is increased after pro- 

 fuse sweating, in diabetes, diarrhea, in fever, at the crises of infec- 

 tious diseases, and when the mouth is dry and hot. 



Some diseases of the mouth or throat make it difficult for the 

 horse to chew or swallow his feed. T\Tiere difficulty in this respect 

 is experienced, the following-named conditions should be borne in 

 mind and carefully looked for: Diseases of the teeth, consisting in 

 deca}^, fracture, abscess formation, or overgrowth; inflammatory 

 conditions, or wounds or tumors of the tongue, cheeks, or lips; 

 paralysis of the muscles of chewing or swallowing; foreign bodies 

 in upper part of the mouth between the molar teeth; inflammation 

 of throat. Difficulty in swallowing is sometimes shown by the S3^mp- 

 tom known as " quidding." Quidding consists in dropping from the 

 mouth well-chewed and insalivated boluses of feed. A mouthful of 

 hay, for example, after being gi'ound and masticated, is carried to the 

 back part of the mouth. The horse then finds that from tenderness 

 of the throat, or from some other cause, swallowing is difficult or 

 painful, and the bolus is then dropped from the mouth. Another 

 quantity of hay is similarly prepared, only to be dropped in turn. 

 Sometimes quidding is due to a painful tooth, the bolus being 

 dropped from the mouth when the tooth is struck and during the 

 pang that follows. Quidding may be practiced so persistently that 

 a considerable pile of boluses of feed accumulate in the manger or on 

 the floor of the stall. In pharyngitis one of the symptoms is a 

 return through the nose of fluid that the horse attempts to swallow. 



In some brain diseases, and particularh'^ in chronic internal hydro- 

 cephalus, the horse has a most peculiar manner of swallowing and 

 of taking feed. A similar condition is seen in hyperemia of the 

 brain. In eating the horse will sink his muzzle into the grain in 



