3^4 SYMPTOMS OF PROLAPSE OF THE ANUS. 
or excessively hot clysters. They also appear during colic or obstruction 
of the bowel, sometimes in difficult parturitions; in cows in connection 
with prolapse of the vagina, and in horses which struggle violently when 
cast with hobbles. In two cases noticed by Mauri, which occurred during 
castration, the prolapsed rectum was ruptured, and coils of small intestine 
protruded through the opening. 
Symptoms. In prolapsus ani, a red, slightly painful, hemispherical 
swelling of the mucous membrane appears behind the anus, which shows 
at its centre a shallow depression ; sometimes only a few folds appear at 
one side. In simultaneous prolapse of portions of the rectum (prolapsus 
recti) the swelling is larger and harder, but even then does not attain 
the size usual in prolapse complicated with invagination, where portions 
of L bowel a yard in length may protrude through the anus. In dogs, 
Fig. ] 54. 1 rolapsus lecti with, invagination in the hitch (semi-diagrammatic). 
Moller has repeatedly seen prolapses 12 to 20 inches in length. On 
account of the tension on the mesentery, the prolapsed portion sometimes 
becomes twisted upwards in horses (fig. 155). 
When the prolapse attains such dimensions no doubt can exist in 
diagnosis, but it is otherwise when only small portions of bowel project 
beyond the anus. In simple prolapsus ani et recti the ring-shaped 
swelling shows an opening at its centre, through which feces are dis- 
chaiged, at its periphery it is impossible to pass the finger towards the 
pelvis. The case is different where prolapse is complicated with invagi¬ 
nation ; then the finger, and in large animals the entire hand, can be 
introduced alongside the prolapsed part into the pelvic portion of the 
rectum. It is of importance to note this, as it at once differentiates 
the two conditions, and affords important indications for treatment. 
