A comparison of three doses of omeprazole in the treatment of equine gastric ulcer syndrome: A blinded, randomised, dose-response clinical trial.

This study investigates the effect of three different doses of omeprazole in treating equine gastric ulcers, concluding that lower doses of 1.0 and 2.0 mg/kg might be as effective as the higher 4.0 mg/kg dose, particularly when administered before exercise and after a short period of fasting. However, the treatment was found to be less effective on glandular ulcers compared to squamous ulcers.

Objective of the Study

• The purpose of this research was to explore further the dose-response relationship of omeprazole in the treatment of gastric ulceration in horses under conditions that may enhance omeprazole efficacy like fasting and administration prior to exercise.
• Another objective was also to evaluate any difference in how squamous and glandular ulcerations respond to omeprazole treatment.

Methods Used in the Study

• The researchers conducted a blinded randomised dose-response clinical trial with sixty thoroughbred racehorses.
• The horses, which had grade ≥2/4 squamous and/or glandular ulceration as identified by gastroscopy, were divided into groups to receive omeprazole doses of either 1.0, 2.0, or 4.0 mg/kg before exercise.
• A follow-up gastroscopy was performed after approximately 28 days to assess the healing progress.

Key Findings of the Study

• The study’s results indicated that lower doses of 1.0 and 2.0 mg/kg of omeprazole were not inferior to the reference dose (4.0 mg/kg), particularly in treating squamous ulceration.
• However, the healing progress was remarkably slower in glandular ulceration than squamous ulceration (14% versus 86%).
• Also, improvement in ulcer grade was more likely in squamous lesions than glandular lesions (96% vs. 34%). There was even worsening of the glandular ulcer grade observed in 36% of horses.

Conclusion From the Study

• The researchers concluded that under the conditions examined in the study, lower doses of omeprazole (1 mg/kg), administered before exercise and after brief fasting, could be as effective as higher doses.
• The research also highlighted that the proportion of glandular ulceration that healed with 28 days of omeprazole therapy is less than that of squamous ulceration. This suggest that different types of gastric ulcers might need varied therapeutic strategies.