Evaluation of the effects of omeprazole on physiological indices of performance of horses during incremental treadmill exercise.

Omeprazole is a proton-pump inhibitor recently approved in the United States for the treatment of gastric ulcer disease in horses. A study was designed to determine the effects of omeprazole treatment on the physiological indices of performance of horses during incremental treadmill exercise. In a crossover-design study carried out over 2 weeks, five horses completed standardized incremental exercise tests on a high-speed treadmill either with no treatment or treatment with omeprazole. No statistically significant effects of omeprazole were found on the mean maximum responses for specific oxygen consumption, specific carbon dioxide production, number of steps completed, concentration of plasma lactate, heart rate achieved, or total run time during the standardized incremental exercise protocol. The results indicate omeprazole treatment is unlikely to be associated with marked enhancement of athletic performance.