Page 851 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

826 CHAPTER 4

VetBooks.ir Diagnosis Management
Exploratory laparotomy is indicated in horses with
Small-intestinal distension may be palpable p/r if total
luminal obstruction is present. It may be possible in
some cases to palpate the impacted diverticulum as severe signs of small-intestinal obstruction, perito-
nitis or chronic signs of colic. A longitudinal resec-
a blind sac with firm contents. Ultrasonographic tion of the diverticulum with a transverse closure is
examination of the abdomen may demonstrate dis- recommended. A local resection of the ileum may be
tended small intestine aborally to the diverticulum. necessary. In the case of strangulation, the affected
If a necrotic diverticulum is present, the peritoneal intestine is resected and an anastomosis performed.
fluid WBC count and total protein may be elevated.
Haematological changes are non-specific and variable. Prognosis
The prognosis is good if rupture and resulting peri-
tonitis are not present or if resection is not needed.
In the presence of strangulation or volvulus the
4.152
prognosis is fair.

MESODIVERTICULAR BAND

Definition/overview
A mesodiverticular band is a congenital abnormal-
ity that results in the formation of a band extending
from one side of the mesentery to the antimesenteric
surface of the small intestine. It results from the per-
sistence of the paired vitelline vessels as they extend
from the aorta to the umbilicus.

Fig. 4.152 A mesodiverticular band that was Aetiology/pathophysiology
associated with a small-intestine volvulus (arrow). A triangular space is created where the mesodiver-
This picture was taken after correction of the ticular band forms one edge of the triangular hiatus
volvulus. Note the haemorrhagic strangulation lesion and the adjacent mesentery and jejunum form the
on the small intestine (left side of the picture). others. These structures form a sac where hernia-
tion can occur.
4.153 Incarceration of the small intestine can result
when a loop of small intestine, most commonly the
jejunum, passes into the depths of the hernial sac
and becomes trapped within it (Fig. 4.152). The dis-
tension of the entrapped intestine creates pressure
on the mesentery, resulting in a rent. Strangulation
of a segment of jejunum in the mesenteric rent
(Fig. 4.153) may provide a fulcrum around which
the surrounding intestine may form a volvulus.

Clinical presentation
The clinical signs are consistent with small-intestine
strangulation. These signs include mild to severe
signs of colic and moderate to severe elevations in
heart rate, with eventual gastric reflux. It also can be
Fig. 4.153 Post-mortem specimen of a mesenteric an incidental finding on exploratory laparotomy or
rent located close to the root of the jejunal mesentery. necropsy. There is no age or sex predilection.