Vitamin E concentrations in hospitalized adult horses and foals

To determine the prevalence of vitamin E deficiency in horses at admission and at the time of discharge. The hypothesis was that vitamin E concentrations would decrease during hospitalization.

A prospective cohort study was performed of client-owned horses admitted as patients or companions through the emergency service at a tertiary referral center. Exclusion criteria included vitamin E supplementation. Whole blood was collected into an additive-free tube at the time of admission for all horses and at discharge if the horse was hospitalized for a minimum of 5 days. Serum vitamin E concentration was obtained with high-performance liquid chromatography. Data were analyzed with mixed-effects linear regression and the Spearman rank correlation for confounding factors.

A total of 12.7% of horses were deficient at admission, including 16.5% of adults and 5.5% of foals (< 3 months old). Of horses hospitalized for a minimum of 5 days, 6.7% were deficient at the time of discharge, including 0% of foals and 10% of adults. Duration of hospitalization had no significant effect on vitamin E concentration when all patients were considered.

Vitamin E deficiency is prevalent in horses. Horses admitted to the hospital do not require vitamin E supplementation to maintain adequate concentrations.

Approximately 1 in 6 horses presented to the emergency service were deficient in vitamin E. Vitamin E concentrations should be measured routinely in horses and supplemented if indicated by the presence of deficiency or the patient's underlying disease pathophysiology.