Omeprazole Reduces Calcium Digestibility in Thoroughbred Horses.

The research article investigates how omeprazole, a type of medication used for reducing stomach acid, affects the digestion of calcium in racehorses. Results show that omeprazole significantly reduces calcium digestibility in horses, while its effect on other minerals is negligible.

Study Design

• The study used Thoroughbred horses as subjects.
• They were fed diets containing different sources of calcium, either limestone or marine-derived calcium (BMC).
• The diets were administered over four 21-day periods, each featuring a 15-day adaptation phase and a 6-day collection phase.
• In the collection phase, researchers collected total fecal matter for five days for examination. On the 6th day, they took blood samples and performed a gastroscopy.
• Horses in the omeprazole group were given daily doses of the medication, GastroGard, for the last 14 days of each period.

Key Findings

• Omeprazole had a significant impact on the gastric pH of the treated horses, increasing its level compared to untreated horses.
• Use of omeprazole doubled serum gastrin levels in treated horses.
• Despite affecting calcium digestion, omeprazole did not have any influence on the digestion of other minerals like phosphorus, magnesium, potassium, sodium, iron, copper, zinc, or manganese.
• Based on the results, omeprazole decreased calcium digestion by 20.3% in horses given limestone and by 15.6% in those given BMC.
• Moreover, the type of mineral source for calcium also impacted its digestion. BMC resulted in higher calcium digestibility (50.8%) than limestone (46.7%).

The results of this research have implications in racehorse nutrition, particularly in animals being treated with omeprazole. Care must be taken to ensure these horses receive adequate calcium intake, given the reduction in digestion caused by the medication.