SCOTTISH METROPOLITAN VETERINARY MEDICAL SOCIETY. 833 
into the rectum, knuckling of the hind fetlocks, and cold sweats. As 
dissolution approaches, gradual muscular exhaustion, tympany, or jerk¬ 
ing breathing. These symptoms may accompany other forms of intestinal 
obstruction, and many of them may be absent. 
After death there may be an entire absence of congestion or inflamma¬ 
tion of the colon ; the small intestine usually presents punctiform hae¬ 
morrhage, and the gastro-mucous membrane is more or less inflamed, 
this being the result of irritation of the retained ingesta and the medi¬ 
cines. The stomach, intestines, and the cardiac end of the oesophagus 
are distended with gas and fluid. 
The differential signs of these three forms of colic displacement, then, 
are plain. In the first we sometimes have a prior period of enteralgia, 
which may be, and usually is, attributed to indigestion or enteritis, 
accompanied by a full strong pulse and injected mucous membranes, and 
the jugulars can be readily distended. This is followed by gradual 
emptying of the jugulars, failure of the pulse, lowering of the tempera¬ 
ture, diminution in the colour of the membranes, the pallor of the latter 
never being so extreme as in ordinary cases of internal haemorrhage. 
Confirmatory signs are sometimes obtained by rectal exploration. In the 
second we have the intense and uninterrupted agony, the injected con¬ 
dition of the mucous membranes, the fullness and strength of the pulse 
the fulness of the jugulars, and the rapidity with which death takes 
place. It may be asserted that these symptoms are those of phlegmo¬ 
nous enteritis. To some extent they are, but the dry, furred, and livid 
condition of the buccal membrane, so characteristic of enteritis, is 
absent, and the temperature is not so high; moreover, death rarely 
takes place from enteritis in so short a time as six or eight hours, many 
of the so-called cases of inflammation of the bowels being nothing more 
than one of these two first forms of colic torsion. 
The difference between the train of symptoms here alluded to is easily 
explained. In those cases in which there is only venous obstruction the 
blood is constantly being pressed into the veins through the arteries, 
and, as it cannot escape by its natural channels, the former become dis¬ 
tended with blood to their utmost limits, and, the pressure continuing, 
the fluid parts of the blood are finally forced through the walls of the 
capillaries into the intestinal cavity, into the peritoneum and the sub¬ 
mucous and subserous tissues, the denser portions of the blood and the 
red corpuscles accumulating in the obstructed veins. In many 
instances the walls of the capillaries give way, and extravasations 
result. 
The culmination of all this is death by internal haemorrhage, the in¬ 
testine acting the part of a sponge, through which the life of the animal 
is gradually drained and squeezed into the peritoneal and intestinal 
cavities and the connective tissue of the bowel; hence the diminution in 
the colour of the injected membranes, the failure of the pulse, and the 
progressive emptying of the jugulars. 
Where there is arterio-venous obstruction mortification takes place 
rapidly, and death is produced by nervous exhaustion. The amount of 
blood lost to the circulation is so slight as not to interfere with the pulse 
or the jugular veins. 
The rationale of the symptoms in the third form of development is as 
follows:—There is none or but slight strangulation of the large vessels 
of the displaced colon, consequently circulation is not obstructed, as in 
the first form, nor is pain produced. The compression exerted by the 
colon on the small intestines (duodenum or jejunum) forms an effectual 
barrier to the further passage of ingesta, consequently all the fluids in* 
