Page 889 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

864 CHAPTER 4

VetBooks.ir 4.180 is also a complete eversion of the ampula recti, but
it is complicated by an intussusception of the peri-
toneal portion of the rectum. Type 4 prolapse is
an intussusception of the peritoneal rectum and a
variable length of the small colon, both protruding
through the anus (Fig. 4.180).

Diagnosis
The initial diagnosis of rectal prolapse is made by the
observation of an abnormal mass of tissue protrud-
ing beyond the anus. The tissue is usually inflamed
and cyanotic. The degree of trauma and necrosis is
variable. Rectal palpation should be performed and
will help with the differentiation between types 2 and
3 rectal prolapse cases. Horses with a type 3 or 4 rec-
tal prolapse may develop septic peritonitis, therefore
abdominocentesis should be performed in these cases.
Fig. 4.180 Type 4 rectal prolapse.
Management
4.181 Acute and circumscribed types 1 and 2 rectal pro-
lapses should be treated conservatively. The treat-
ment involves topical application of lidocaine jelly
onto the protruded tissue, repeated administra-
tion of epidural anaesthesia to reduce straining and
placement of a purse-string suture for 48–72 hours.
This suture is made of a double strand of 6 mm
(1/4 inch) umbilical tape applied 1–2 cm lateral to the
anus with four wide bites (Fig. 4.181). The suture
should be opened every 2–4 hours in order manually
to remove the faeces from the rectum. The horse
should receive mineral oil and be fasted for 24 hours.
Fig. 4.181 Purse-string suture correction of a type 1 A laxative diet should be fed for 10 days following
rectal prolapse. purse-string removal. Most importantly, the pri-
mary cause for straining should be treated. Long-
4.182 standing or recurring types 1 and 2 rectal prolapses
are treated surgically using a submucosal resection
technique (Fig. 4.182).
Types 3 and 4 rectal prolapses should be manu-
ally reduced immediately after they occur. However,
they are usually associated with severe vascular
injury to the rectum and/or distal small colon and an
exploratory laparotomy is recommended. If rupture
of the mesocolon and vascular supply has occurred,
the affected segment has to be resected. Most often,
anastomosis between two consecutive viable seg-
Fig. 4.182 Submucosal resection technique for ments is not possible and the only surgical option is
treatment of long-standing or recurrent type 1 or 2 to perform a permanent end colostomy.
rectal prolapse.