Page 846 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Gastrointestinal system: 4.2 The lower gastrointestinal tr act 821

VetBooks.ir 4.146 4.147

Fig. 4.147 Pedunculated lipoma (white arrow)
causing strangulation of the small intestine (red arrow).

4.148

Fig. 4.146 Longitudinal ultrasound image of an
ascarid that was free within the abdomen of the foal
in 4.144. Intestinal rupture occurred following ascarid
impaction.

STRANGULATING LIPOMA

Definition/overview
Strangulating lipomas are the most common cause
of small-intestinal strangulation in older horses.
Fig. 4.148 After removal of the lipoma depicted in
Aetiology/pathophysiology 4.147, a marked line of demarcation is evident at the
Lipomas are fatty masses that can develop in the mes- site of strangulation.
entery of older horses. They are thought to be most
common in fat, older horses and ponies. A lipoma,
in itself, is inconsequential, but over time it may gastric distension; however, tachycardia and signs
enlarge and develop a pedicle that may wrap around of colic are usually still apparent and may continue
a section of small intestine, resulting in strangulation to be severe. Signs of toxaemia (hyperaemic mucous
(Figs. 4.147, 4.148). Once the vasculature is compro- membranes, prolonged CRT) and cardiovascular
mised, the affected intestine rapidly loses viability. compromise are often present. Borborygmi are often
absent. Response to analgesics may be poor.
Clinical presentation
Acute, severe colic is the most common presentation. Differential diagnosis
Horses may be in great pain and markedly tachy- Other causes of small-intestinal distension, includ-
cardic (up to 120 bpm). A NG tube should be passed ing small-intestinal volvulus, epiploic foramen
immediately on any horse in severe abdominal pain. entrapment, proximal enteritis, ileal impaction and
Some relief of pain may be achieved via easing of intussusception, should be considered.