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Electrolyte Oversupplementation: A Real Risk for Horses?By Kentucky Equine Research Staff · August 30, 2016

Routine electrolyte supplementation is part and parcel in the diets of performance horses. Intricacies of electrolyte nutrition are sometimes not well understood, especially the implications of oversupplementation.

Wait, is it possible to oversupplement electrolytes?

“Oversupplementing electrolytes on a daily basis would be difficult to do, particularly if products are given according to the manufacturer’s recommendations and only fed when the horse has access to water,” explained Kathleen Crandell, Ph.D., a longtime nutritionist for Kentucky Equine Research (KER).

If more electrolytes are given than the horse requires, healthy kidneys will filter the excess sodium and other electrolytes, and excrete them in the urine.

“As you can imagine, in order to flush large amounts of sodium, the body would need a lot of water. If too much salt or electrolyte is fed, a horse will drink more water because its body will attempt to dilute higher concentration of sodium in body cells,” expounded Crandell. “If there is not enough water in the body, it could present a problem, especially if a horse is dehydrated. If electrolytes are given without water to a dehydrated horse, further dehydration will occur, causing significant fluid-balance problems, including the possibility of salt toxicity.”

Signs of salt toxicity are irregular heartbeat, muscle tremors, abdominal pain, diarrhea, and central nervous system manifestations, such as circling, blindness, seizures, and partial paralysis.

Overuse of electrolytes might cause physical injury, namely ulcers, to mouth and stomach tissues. In addition to following manufacturer recommendations, other management strategies to avoid ulcers when supplementing electrolytes include never administering electrolytes on an empty stomach, mixing electrolytes with some type of stomach buffer, feeding alfalfa, and rinsing the mouth with water if dosing electrolytes with a syringe.

Some electrolyte products, such as Restore Paste, contain a buffering agent designed to support gastrointestinal comfort. Restore Paste and its companion product, Restore SR, are available in the U.S. and other markets. Australian horse owners should look for these other proven products.