THE EXAMINATION OF A SICK HORSE. 21 
the feed box and eat for a while without raising the head. Long 
pauses are made while the feed is in the mouth. Sometimes the 
horse will eat very rapidly for a little while and then slowly; the 
jaws may be brought together so forcibly that the teeth gnash. In 
eating hay the horse will stop at times with hay protruding from 
the mouth and stand stupidly, as though he has forgotten what he 
was about. 
In examining the mouth one should first look for swellings or for 
evidence of abnormal conditions upon the exterior; that is, the front 
and sides of the face, the jaws, and about the muzzle. By this means 
wounds, fractures, tumors, abscesses, and disease accompanied by 
eruptions about the muzzle may be detected. The interior of the 
mouth is examined by holding the head up and inserting the fingers 
through the interdental space in such a way as to cause the mouth to 
open. The mucous membrane should be clean and of a light-pink 
color, excepting on the back of the tongue, where the color is a yel- 
lowish gray. As abnormalities of this region, the chief are diffuse 
inflammation, characterized by redness and catarrhal discharge; 
local inflammation, as from eruptions, ulcers, or wounds; necrosis 
of the lower jawbone in front of the first back tooth; and swellings. 
Foreign bodies are sometimes found embedded in the mucous mem- 
brane lining of the mouth or lodged between the teeth. 
The examination of the pharynx and of the esophagus is made 
chiefly by pressing upon the skin covering these organs in the region 
of the throat and along the left side of the neck in the jugular gutter. 
Sometimes, when a more careful examination is necessary, an esoph- 
ageal tube or probang is passed through the nose or mouth down the 
esophagus to the stomach. 
Vomiting is an act consisting in the expulsion of all or part of the 
contents of the stomach through the mouth or nose. This act is more 
difficult for the horse than for most of the other domestic animals, 
because the stomach of the horse is small and does not lie on the floor 
of the abdominal cavity, so that the abdominal walls in contracting 
do not bring pressure to bear upon it so directly and forcibly, as is 
the case in many other animals. Beside this, there is a loose fold of 
mucous membrane at the point where the esophagus enters the stom- 
ach, and this forms a sort of valve which does not interfere with the 
passage of food into the stomach, but does interfere with the exit of 
food through the esophageal opening. Still, vomiting is a symptom 
that is occasionally seen in the horse. It occurs when the stomach is 
very much distended with food or with gas. Distention stretches the 
mucous membrane and eradicates the valvular fold referred to, and 
also makes it possible for more pressure to be exerted upon the stom- 
ach through the contraction of the abdominal muscles. Since the 
