Hydration and electrolyte depletion remain important factors to consider in endurance horses. Yet the impact of electrolyte supplementation on performance remains unclear, and potential side effects might exist, relayed Harold Schott II, MS, DVM, PhD, Dipl. ACVIM, a professor at Michigan State University's College of Veterinary Medicine at the 2010 Kentucky Equine Research Nutrition Conference held in Lexington April 26-27.

In Schott's presentation, "Challenges of Endurance Exercise: Hydration and Electrolyte Depletion," Schott explained that exercising horses, particularly endurance competitors, can lose both body water and electrolyte stores that could lead to serious medical problems or even "exhausted horse syndrome" if not properly addressed.

In adverse ambient conditions, an exercising horse can lose up to 10-12 liters of sweat per hour. Not only does this result in total body water loss, but also the electrolytes sodium, chloride, and potassium.

Over the past few decades, electrolyte supplementation has become a mainstay in minimizing fluid and electrolyte losses. Research has demonstrated that horses exercising for more than an hour or two in hot, humid climes will likely benefit from supplementation with salt water