Page 798 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Gastrointestinal system: 4.1 The upper gastrointestinal tr act 773

VetBooks.ir Clinical presentation 4.100
The clinical signs are non-specific, including signs
similar to oesophageal obstruction. Discomfort
when ingesting including gagging, bruxism, hyper-
salivation and anorexia may all be exhibited. The
inflammation can also cause oesophageal hypomo-
tility, with secondary obstruction with food if the
horse continues to eat.

Differential diagnosis
Colic in foals, gastric ulceration, cardiac sphincter
stenosis, oesophageal obstruction.

Diagnosis
Thorough oesophagoscopy after clearing obstruc- Fig. 4.100 Ulcerated mucosa in a foal with reflex
tions to examine for signs of oesophagitis is oesophagitis.
indicated (Fig. 4.100). The presence of patchy or
linear ulceration is diagnostic for oesophagitis.
A careful examination for any underlying cause their fibrinolytic activity to help reduce the like-
including gastroscopy is necessary to prevent lihood of fibrous stricture formation at the distal
chronic recurrence. oesophageal sphincter. Their use should be care-
fully restricted in neonates to avoid increasing the
Management possibility of gastric ulceration. Gastric protectants
Any primary cause such as oesophageal obstruc- such as sucralfate are of questionable benefit but
tion should be removed. Treatment with H2 may contribute by giving physical protection to the
receptor antagonists (e.g. ranitidine or cimeti- ulcerated mucosa. The feeding of semi-liquidised
dine) or by using oral medication with omeprazole food will help reduce the likelihood of oesophageal
are beneficial in reducing gastric acid production obstruction at the distal oesophageal sphincter.
and ongoing chemical damage of the oesopha- Stricture of the distal oesophageal sphincter as a
geal mucosa. Alteration in feeding regimes to result of fibrosis is thought to be a consequence of
promote continuous gastric outflow can also help chronic reflux oesophagitis and is occasionally diag-
reduce symptoms. NSAIDs may be indicated for nosed in young and adult horses.

ACQUIRED OESOPHAGEAL DISORDERS

OESOPHAGEAL OBSTRUCTION of motility disorders within the oesophagus has been
(‘CHOKE’) cited as a cause but is unproven. Sugar beet pulp that
is inadequately soaked is the most commonly impli-
Definition/overview cated foodstuff in the UK, although obstruction with
Physical obstruction of the oesophagus with ingesta. other foodstuffs can occur. Primary grass choke is
rare and its occurrence suggests an underlying prob-
Aetiology/pathophysiology lem. Absorption of saliva by the food bolus results in
Physical obstruction of the oesophagus with an it swelling and the bolus can become lodged in the
impacted food bolus is the most commonly diagnosed oesophagus, commonly at the thoracic inlet where
oesophageal disorder in the adult horse. Inadequate the diameter is narrowest and where the oesophagus
soaking of proprietary or preserved foods is cited as changes direction. Spasm of the oesophageal muscle
the most frequent predisposing cause. The presence distal to the bolus can occur, preventing its further