Effect of repeated oral administration of hypertonic electrolyte solution on equine gastric mucosa

Electrolyte supplementation is common in horses during endurance competitions, but the effect on the gastric mucosa is unknown.

Repeated oral administration of hypertonic electrolyte solution is associated with exacerbation of gastric ulcers in mature horses.

The study design was a randomised, blinded, crossover trial. Fourteen horses were divided randomly into equal groups and administered either 60 ml water (placebo) or 56.7 g commercial electrolyte supplement mixed with 60 ml water by dose syringe orally once an hour for 8 h. The minimum concentration of individual constituent electrolytes/28.35 g dry commercial product used was: sodium (5528 mg); chloride (11,886 mg); potassium (3657 mg); calcium (754 mg); and magnesium (153 mg). Gastric lesions were scored prior to and after oral treatments, and analysis of variance procedures were then performed.

Administration of hypertonic electrolytes resulted in a significant increase in mean ulcer number (P = 0.0174) and severity (P = 0.0006) scores in the nonglandular stomach. Mean ulcer number score was 3.6 and mean ulcer severity score 2.7 after hypertonic electrolyte treatment.

Oral hypertonic electrolyte administration to horses in this model was associated with exacerbation of gastric ulcers.

Our findings suggest that one schedule of electrolyte supplementation used commonly in endurance horses may be harmful to the gastric mucosa.