COLIC. IOI 
As intimated, closure of the intestine may also be effected by acrid or irri- 
tating matters. In such cases probably a spasm occurs in the intestinal walls, 
and the tube is contracted. Obstruction is also produced by what is termed 
intussusception. By this is meant that one portion of the intestine slips into 
another, stovepipe-like; the outer part then contracts upon the inner and holds 
it fast. An intestine may twist and so become closed ; it may even tie itself up 
into something like a knot. These are a few of the causes of obstruction. 
Beyond the generation of gases during decomposition there is yet a powerful 
influence that is capable of producing them, and which authors have apparently 
failed to recognize; namely, intense nervous excitement, as caused by fright. 
Indeed the rapidity with which it acts in this direction is something to marvel at, 
as shown by a case which fell under the eyes of the writer. It was that of a pug 
caught in the jaws of a huge mastiff. The little one was not bitten, but merely 
held firmly at the fore shoulders, no other parts being touched by the teeth; yet 
within three minutes after her rescue — which was almost on the instant — her 
abdomen was of enormous size, and the distention clearly due to gas. 
Colic is more easily detected in some dogs than in others. As a rule, when 
it occurs in house pets they plainly indicate their sufferings by moaning and ear- 
piercing cries. But large dogs seldom give such expression when in distress ; 
therefore an attack of this sort in them is quite likely to be overlooked except 
by the most observing masters. All the victims of the trouble are very restless. 
They lie down, but in a moment are up and walking about, with tails tucked 
between their legs ; and likely their backs are arched. In two or three minutes, 
however, they again lie down; but the recumbent position seems to intensify 
their sufferings, and they are soon on their feet. This extreme restlessness, 
by the way, is quite conclusive evidence of pain in some part of the body. If in 
the abdomen, the walls are retracted and hard; but when the attack is wind colic 
the abdomen is distended, and if tapped with the fingers it is resonant, like a 
drum. Another pronounced peculiarity exhibited by sufferers is their tendency to 
slink away and conceal themselves. This they will generally do if not quickly re- 
lieved ; and once away they seldom return until the attack has entirely passed off. 
Vomiting sometimes occurs; and if so, and the troublesome gas is in the 
stomach, much is generally expelled and the relief immediate. But vomiting is. 
the exception rather than the rule when the stomach is so distended; and the 
pain seldom subsides, except under narcotics, until the gas has passed downward 
and out of the body. When the gas is confined to the intestines the pain is as 
severe as when the stomach is involved; but there is less danger in such an at- 
tack, for the expulsion of gas is as a rule more easily effected from the intestines 
than from the stomach. 
Pure and simple colic is at first not attended by inflammation; therefore 
fever is absent, the nose remains cold, and the pulse is only a little more rapid 
than usual. But if the attack is severe and has persisted for several hours, and 
