Page 847 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

822 CHAPTER 4

VetBooks.ir Diagnosis Postoperative complications such as prolonged ileus
and laminitis are common. Other complications,
NG reflux is usually present. Multiple loops of dis-
tended small intestine are typically palpable per
dehiscence or stricture, can occur.
rectum. Occasionally, small intestine will not be such as adhesions, anastomosis-site abscessation,
palpable, but will be detected ultrasonographi-
cally (Fig. 4.149). Round, distended, non-motile SMALL-INTESTINAL VOLVULUS
small intestine is suggestive of intestinal compro-
mise. Peritoneal fluid changes occur as the intestine Definition/overview
becomes compromised, initially with protein levels Volvulus of the small intestine involves a rotation
and WBC numbers increasing, followed shortly by of more than 180° around the long axis of the mes-
changes in colour and turbidity (see Fig. 4.116). entery of the small intestine. It may involve only a
segment of intestine (Fig. 4.150) or the entire small
Management intestine if the rotation is at the base of the mesen-
A NG tube must be passed to relieve gastric reflux. tery. It most often occurs in horses less than 3 years
The tube should be left in place if reflux is pres- of age.
ent. Nothing should be given p/o or via a NG
tube. Prompt surgical intervention is required. Aetiology/pathophysiology
Stabilisation via intravenous fluid therapy, gas- The volvulus can be primary or secondary to another
tric decompression and analgesia administration is lesion such as an anastomosis site, entrapment or a
required prior to surgery. The strangulating lipoma mesodiverticular band. These lesions probably pro-
should be removed, along with any other lipomas vide a fixed axis for rotation of the bowel. Volvulus
that are identified. Frequently, devitalised intestine occurs in the mesenteric portion of the small intestine
is identified and resection is required. from the jejunum to the distal ileum. The duodenum
has a short mesenteric attachment that cannot rotate.
Prognosis Following rotation of the intestine around an
The prognosis is guarded to fair. The length of axis, the peristalsis of the intestine orad to the lesion
affected intestine and the degree of compromise causes further mesenteric twisting, bringing both
are important factors. Intestinal resection is usu- orad and aborad intestine into the volvulus. After
ally required, and complications are not uncommon. the volvulus occurs, increased intestinal movement

4.149 4.150

Fig. 4.150 Post-mortem specimen of a small-
Fig. 4.149 Small-intestinal distension in a horse intestinal volvulus. Note the typical appearance
with a strangulating lipoma. Note the extremely of small-intestine haemorrhagic strangulation.
thickened intestinal wall (arrow). (Photo courtesy S Laverty)