• horse;
  • gastric ulceration;
  • risk factors;
  • epidemiology


Reasons for performing study: The prevalence (up to 93% in Thoroughbred racehorses) and severity of equine gastric ulceration syndrome (EGUS) has been associated with type of training and differing management practices. However, there have been few studies to confirm these findings in nonracehorses in Europe.

Objectives: To investigate the prevalence of EGUS in a population of Danish horses, during winter when the horses had been housed and fed for at least 8 weeks and to analyse the influence of feed, work level and environment on the risk of EGUS of §grade 2 in severity.

Methods: A total of 201 horses, not in active race-training, were evaluated, representing 23 different stables from all 5 regions within Denmark. All horses were considered to be healthy and not on medical treatment for EGUS. Endoscopically observed ulcer lesion scores were based on the number present (0–4) and severity (0–5). Univariate and multivariable mixed effects logistic regression models were developed using EGUS score as the dependent variable. An ulceration severity score of §2 was regarded as being clinically significant. Separate models were developed for horses with ulcers in either the glandular or nonglandular regions of the stomach graded §2 (EGUS §2) and for those horses that had nonglandular ulcers graded §2 (NG §2).

Results: In this population, 53% (107/201) of horses were graded as having EGUS §2 with 95 (47%) horses having NG §2. Three variables were significantly (P<0.05) associated with EGUS §2: straw being the only forage available; exceeding 2 g/kg bwt of starch intake/day or §1 g/kg bwt/meal; and water not being available in the turn out paddock. Risk of NG §2 significantly increased when straw was the only forage available, 1 g/kg bwt of starch/meal was exceeded, water was not available in the turnout paddock and the interval between forage feeding was <6 h.

Conclusion and potential relevance: This study has confirmed that components of the diet, readily modifiable, may have an important impact on the risk of EGUS in the nonracehorse. Differences in the multivariable models produced for all ulcers and nonglandular ulcers support differences in the aetiology of ulcers in different locations of the stomach.