Fig. 69.—Schema of hernial strangulation.
(2.) In pelvic hernia a loop of intestine passes between the spermatic cord and the walls of the pelvis. The fissure in this case is in the serous fold which supports the large testicular arteries and the vas deferens. The fold is often ruptured during castration, especially during the practice of “bistournage,” in consequence of traction exercised on the cord.
(3.) Pseudo-ligaments and fibrous bands due to chronic peritonitis.—In local, subacute or chronic peritonitis false membranes may become organised, forming fibrous cords or folds connecting the parieto-visceral or inter-visceral surfaces. If by accident a loop of intestine insinuates itself beneath one of these fibrous bands, the passage of digestive material is first impeded and then stopped. The intestine becomes engorged, and symptoms of strangulation soon follow.
The symptoms appear suddenly, and are similar to those of invagination. They consist of very acute colic, which disappears after ten to twelve hours.
The peristaltic movements drive the semi-digested food, whether liquid or gaseous, towards the lower (strangulated) end, from which it cannot escape. It therefore distends the herniated loop and sets up intestinal engorgement. This constitutes the first stage of strangulation, and is accompanied by severe disturbance in the local circulation. The mucous membrane of the intestine becomes swollen and infiltrated, so that it alone soon fills the entire neck of the hernia. Necrosis of the loop of intestine is then only a matter of time.
The diagnosis of colic by strangulation is difficult. The condition cannot often be recognised at an early stage, and may easily and excusably be confused with invagination. Only in rare cases will rectal and abdominal examination enable one to detect a pelvic or mesenteric hernia.
The prognosis is even graver than in cases of invagination. Intestinal hernia progresses very rapidly, necrosis soon sets in, and is followed by fatal consequences if the condition be not relieved.
The treatment is exclusively surgical. As a general rule, whenever colic is recognised as resulting from strangulated hernia, it is immediately necessary to perform laparotomy in the right flank, and after having discovered the cause of strangulation, to divide the mesentery, epiploon, serous fold supporting the testicular cord, or accidental fibrous bands, so as to free the herniated loop and avoid necrosis. If necrosis already exist, the intestine may be resected, exactly as in invagination.
DISEASES OF THE STOMACH.
In ruminants diseases of the gastric compartments are numerous, and, although they have been recognised since the earliest times, much remains to be discovered concerning at least some of them. This fact results from the imperfect state of our knowledge concerning the essential phenomena of gastric digestion in ruminants. Digestion really consists of a number of different acts—some mechanical or neuro-motor, some chemical; in addition to which must be reckoned the phenomena of sensation, concerning which patients cannot give any information.