Page 837 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

812 CHAPTER 4

VetBooks.ir and is particularly useful in foals. Definitive diagno- Prognosis
If there is not a prompt response to treatment, medi-
sis is made at surgery.
Management cal therapy is unlikely to be effective. While success-
ful surgical treatment has been reported, the overall
Medical treatment should be attempted initially in prognosis is guarded to poor.
case gastric outflow is being affected by inflamma-
tion, not stenosis. Proton-pump inhibitors should GASTRIC RUPTURE
be administered as for EGUS, although systemic
administration is preferred over oral administration Definition/overview
as proton-pump inhibitors are acid labile and delayed Gastric rupture (Fig. 4.140) is a fatal condition that
gastric emptying may reduce oral bioavailability. is usually secondary to distension of the stomach
General supportive care, including i/v fluid therapy, with gas, ingesta or fluid.
may be required. Dietary change can be instituted
initially, depending on the severity of clinical signs. Aetiology/pathophysiology
This should consist of frequent feeding of small meals A variety of situations can result in the develop-
of grass, slurries or a pelleted ration. If oral feeding ment of gastric distension that can proceed to gas-
is not tolerated, parenteral nutrition should be con- tric rupture. Primary distension from excessive gas
sidered, particularly in foals. Bethanecol (0.025–0.10 production, grain engorgement and excessive water
mg/kg s/c q6–8 h or 0.3–0.4 mg/kg p/o q6–8 h) or consumption after exercise can occur. Distension
metoclopramide (0.05–0.25 mg/kg s/c q6–8 h or 0.6 secondary to obstructive small- intestinal lesions,
mg/kg p/o q4 h) can be used in an attempt to increase proximal duodenitis/jejunitis and ileus is more
the rate of gastric emptying. Both drugs can be asso- common. Less commonly, gastric impaction
ciated with adverse clinical signs. Medical treatment, or infarction of an area of the stomach wall may
particularly nutritional support, may be most useful be encountered. Perforation of gastric ulcers is
for improving the horse’s condition prior to surgery. uncommon. There is no apparent age, breed or
Surgical intervention may be required. It has been gender predisposition.
recommended that if improvement is not evident The stomach of an average adult horse has a
within 5 days, surgical intervention should be consid- capacity of 15–25 litres under maximal distension.
ered. Successful treatment via gastrojejunostomy or Rupture can occur from the forces of excessive dis-
gastroduodenostomy has been reported. tension and/or ischaemic necrosis of the gastric wall.
Once the stomach wall has been perforated, severe
septic peritonitis will develop rapidly. The majority
4.140 of tears occur along the greater curvature.

Clinical presentation
Once the stomach ruptures, there may be a short
period where the horse appears to improve clinically
because the pain associated with gastric distension
will have been relieved; however, as septic perito-
nitis develops there will be a rapid deterioration.
Progressive signs of depression, colic, toxaemia,
dehydration, cardiovascular compromise, sweating,
and shaking will develop. Heart rate will increase
and can be severely elevated (>100 bpm). Mucous
membranes may be dark red, purple or blue, and
Fig. 4.140 Spontaneous gastric rupture in a horse. CRT may be markedly prolonged. Borborygmi will
Note the area of serosal tearing and the large perforation. be decreased or absent.