Equine gastric ulcer syndrome in adult donkeys: Investigation on prevalence,anatomical distribution,and severity

The study was performed on 39 live donkeys that underwent gastroscopic examination. The lesions were recorded in accordance with the European College of Equine Internal Medicine Consensus Statement guidelines. The presence of Gasterophilus sp. larvae was also recorded. Larvae were collected and identified to species level. Fisher's exact test was used to compare different prevalence values for sex, age, and anatomical distribution of lesions. Gastric lesions were present in 20/39 (51.3% [35.6–67%]) donkeys; 19/39 (48.7% [95% confidence interval = 33–64.4%]) were affected only by equine squamous gastric disease (ESGD), while 1/39 (2.6% [0–7.5%]) showed both ESGD and equine glandular gastric disease (EGGD), thus 95% of positive donkeys showed lesions located in the nonglandular mucosa. The ESGD grade was 0/4 (48.7% [33–64.4%]) in 19/39, 1/4 (12.8% [2.3–23.3%]) in 5/39, 2/4 (25.6% [11.9–39.5%]) in 10/39, 3/4 in 4/39 (10.3% [0.7–19.8%]) and 4/4 in 1/39 (2.6% [0–7.5%]) donkeys, respectively. The EGGD lesion was a mild depression in the ventral glandular fundus. ESGD was primary in all the donkeys included and lesions were located around the cardia and along the lesser curvature. Gasterophilus sp. larvae were present in all animals and were identified as third‐stage larvae of Gasterophilus intestinalis. No animals showed clinical signs of equine gastric ulcer syndrome (EGUS). No significant differences relating to sex, age or breed were found in the prevalence of EGUS in this study, while the proportion of donkeys affected by ESGD was statistically higher than those affected by EGGD. To the best of our knowledge, this is the first report on the gastroscopic evaluation of EGUS in live donkeys. Our results show a higher prevalence of EGUS in live donkeys than values previously reported by other authors in donkeys that were dead or had been subjected to euthanasia. The detection of third‐stage G. intestinalis larvae was not unexpected since these can be found in the stomach of equids throughout the year, and G. intestinalis has been reported as the most common Gasterophilus sp. in Italy.     

Phenylbutazone induces equine glandular gastric disease without decreasing prostaglandin E2 concentrations

In equids, phenylbutazone at high doses induces gastric disease, primarily in the glandular portion of the stomach. However, the mechanism of nonsteroidal anti‐inflammatory drug (NSAID)‐induced gastric disease in horses has yet to be determined. While phenylbutazone‐associated ulceration is often attributed to a decrease in basal gastric prostaglandins, this has not been demonstrated in the horse. Twelve horses were randomly assigned to treatment (n  = 6; 4.4 mg/kg phenylbutazone PO in 20 ml molasses q 12 hr for 7 days) or placebo (n  = 6; 20 ml molasses PO q 12 hr for 7 days) groups. Before treatment and 3 and 7 days after initiation of treatment, gastroscopy was performed and glandular gastric biopsies were collected and frozen at ?80°C. Glandular disease was assessed on a scale of 0–4. Prostaglandin E₂ concentrations in biopsies were measured using a commercially available enzyme‐linked immunosorbent assay. All phenylbutazone‐treated horses developed grade ≥2 glandular disease. Prostaglandin concentrations increased over time (p  = .0017), but there was no effect of treatment (p  = .49). These findings indicate that despite induction of glandular disease grade ≥2, phenylbutazone did not decrease basal glandular gastric prostaglandin E₂ concentration.     

A comparison of the prevalence of gastric ulceration in feral and domesticated horses in the UK

Equine gastric ulcer syndrome is common in domesticated horses, especially those performing in athletic endeavours. However, the prevalence of equine gastric ulcer syndrome in feral populations of horses is not documented. This study investigated the prevalence and severity of squamous and glandular gastric ulceration in an abattoir population of horses in the UK. Both squamous and glandular ulceration were more prevalent in domesticated horses when compared to the feral horses studied.     

Prevalence of gastric ulcer syndrome in high-level endurance horses

Reasons for performing the study: Equine gastric ulcers syndrome (EGUS) prevalence studies are rare in the endurance horse and none has been carried out to date in horses competing at high level. Objectives: To determine the prevalence of EGUS in high‐level endurance horses. Methods: Thirty endurance horses competing at high level were selected and submitted to 2 gastroscopic examinations. The first gastroscopy was performed during the interseason period, and the second during the competition season within 2–3 days following a ride of 90–160 km. Data related to housing, feeding, training system as well as age, breed and gender were recorded for each horse. Results: The prevalence of squamous gastric ulcers was 48% during the interseason period (mean score 0.85 ± 0.13 on a scale from 0–4) and 93% during the competition season (mean score 1.60 ± 1.15) with a highly significant difference between the seasons (P = 0.001). Most of the lesions were situated in the squamous portion of the stomach but 33.3% of horses showed also glandular lesions. Significant influence of training and performance level on the gastric score (according to the distance of the ride preceding the second gastroscopy) was shown (P = 0.038). There was also a significant influence of housing on the gastric score (P = 0.002) showing higher scores in the horses kept totally on pasture (mean score: 2.14 ± 0.14) vs. horses housed in a mixed environment (stable + pasture, mean score: 1.43 ± 0.17). Both the pastured and (stabled + pastured) groups were receiving a grain supplement but the pastured group received a higher daily starch intake, which might explain the higher ulcer prevalence. There was no influence of age, breed or gender on the gastric scores. Conclusions: The high prevalence of gastric lesions observed in this study is probably related to the high level of training and performance of the horses examined compared to the population of horses included in the prior study. Potential relevance: This prevalence of EGUS in high‐level endurance horses is comparable to the prevalence established in racing horses. The equine veterinarians may take into consideration EGUS as a potential cause of poor performance.     

Rethinking equine gastric ulcer syndrome: Part 1 – Terminology,clinical signs and diagnosis

Equine gastric ulcer syndrome (EGUS) is a common condition in the horse. A series of recent articles highlighting differences in healing of squamous and glandular ulceration have reinvigorated interest in the condition. The purpose of this series of articles is to review the current thinking on EGUS with particular emphasis on the differences between diseases of the squamous and glandular mucosae. This article, the first will review the terminology, clinical signs and diagnosis of EGUS in the horse.     

Poor performance associated with equine gastric ulceration syndrome in four Thoroughbred racehorses

Equine gastric ulceration syndrome (EGUS) is commonly recognised in Thoroughbred racehorses. Although EGUS has previously been associated with reduced athletic performance, no objective studies have been reported. This case report describes 4 racehorses referred for investigation of poor athletic performance where EGUS was the only abnormal finding during a thorough investigation of all body systems. All horses showed considerable improvement in performance following treatment with omeprazole. Therefore, this is the first report in which evidence is presented suggesting a direct link between EGUS and decreased performance, other causes of poor performance having been excluded.     

Courses for horses: Rethinking the use of proton pump inhibitors in the treatment of equine gastric ulcer syndrome

Oral omeprazole has been the cornerstone of equine gastric ulcer syndrome (EGUS) treatment for nearly 20 years. However, approximately 15–30% of equine squamous gastric disease (ESGD) cases and 75% of equine glandular gastric disease (EGGD) cases fail to heal within current treatment guidelines. Recently, a number of factors that may affect the efficacy of oral omeprazole have been highlighted and the pharmacodynamics of a number of novel proton pump inhibitors (PPIs) have been described in the horse. The purpose of this article is to review the factors that affect oral omeprazole efficacy, with the goal of maximising therapeutic response, and the novel PPIs recently described.