Principles that will help you know when and how to supplement horses with electrolytes.

One topic that horse owners repeatedly wonder about is that of electrolytes and specifically how and when they should be used. In general, horses participating in most equestrian sports don’t need electrolyte supplementation. A horse that sweats during a short training ride or competition might lose some body water and salts, but these losses are usually replenished quickly upon eating hay, drinking, or visiting the salt block. However, there are other situations, involving horses that compete in distance riding pursuits (endurance, competitive trail, or the cross-country phases of eventing or combined driving), for example, when electrolyte supplementation is important to the horse’s safekeeping and welfare. Electrolytes are salts–notably potassium, chloride, sodium, calcium, and magnesium–and are essential to proper body function.

Research conducted at endurance and competitive trail rides has demonstrated that many horses experience the greatest loss of fluids and electrolytes within the first 20 miles of exercise. Long-distance transport to an event adds to dehydration and electrolyte losses before the horse even begins to perform, so this, too, must be factored in. A horse that participates in protracted exercise, such as a distance trail horse, is working for many hours and, at times, for multiple consecutive days. Staying ahead of salt and fluid losses is instrumental in maintaining hydration, efficient muscle function, and the ability of the horse to perform to a safe standard and with enthusiasm for his work.

So, let’s look at some principles that will help you decide when it is appropriate to provide electrolyte supplementation.