Electrolytes for horses are particularly important as they are required by many functions of the body, including nerve, muscle, and digestive function. Electrolyte supplements commonly consist of the 5 major electrolytes which are sodium (Na +), potassium (K +), chloride (Cl−), calcium (Ca2+), and magnesium (Mg2+).
It is important that electrolytes are balanced with the bodies fluid levels as it consists of mainly water. So, the many functions mentioned above are only possible because of balanced homeostasis (the body’s ability to maintain a stable internal environment).
During exercise, the rate of energy used is met by anaerobic oxidation of glucose to lactic acid; this is the main cause of metabolic acidosis observed during training. Plasma volume decreases because water moves from the vasculature to the intracellular and interstitial spaces at the onset of exercise. These fluid shifts, together with active ion-exchange between blood and tissue, cause marked changes in electrolyte concentrations.
It is often that horses do not receive enough (not well balanced) electrolytes which over a few weeks or months can become a serious issue, due to homeostasis being out of balance. The most common signs of electrolyte deficiency include muscle conditions (tying up), poor performance, condition, and recovery. Restoring electrolyte balance is not a quick fix.
Electrolytes are excreted by the horse every day through urine and faeces, and lost even more during exercise, hot weather and sweating. We recommend feeding electrolytes daily with the same dose and not just on hotter days or for competition. Rarely do horses suffer with an overdose of electrolytes but often suffer a deficiency. Furthermore, by feeding salt daily, fussy horses adapt to the taste better rather than only feeding large amounts on competition days, which can also irritate the gut.
Research has shown that the administration of electrolytes is more beneficial than water alone in restoring fluid, electrolyte, and acid base balance after loss.
Clinical trials have shown that horses do not regulate their salt intake and therefore do not always freely intake it from salt licks or blocks and it should be provided in their feed /water also.
Many factors contribute to how many electrolytes your horse will need, including diet, exercise, fitness, and weather. Therefore, it is recommended to feed daily balanced electrolytes rather than occasionally because what they do not require will be excreted. Always follow the recommended dosing when using electrolytes for horses.
Drs SHL Donker DVM, Founder of Synovium Horse Health (Equine Supplements) and an FEI Veterinarian.