06/05/2026
Electrolytes help regulate water levels within the body to maintain a balance between dilution and dehydration.
➡Sodium and Chloride maintain blood volume and these two electrolytes are lost the most when a horse sweats.
➡ Potassium is required for muscle contraction and relaxation.
➡ Calcium is essential for normal muscle contraction and building strong bones.
➡ Magnesium is important to regulate nerve and muscle function (including heart health)
So where does my horse get these electrolytes from?
➡ Feed cannot adequately supply Sodium and Chloride so salt which is made up of Sodium and Chloride needs to supplemented to replace lost sweat.
➡ Potassium is found in grazing and forages, but mostly through grazing on grass paddocks. Legumes (Lucerne, soya) are also high in potassium. Molasses is also high in potassium.
➡ Calcium is also found in forages and especially high in legumes so lucerne is a great source of calcium. Most commercial diets supplement with calcium.
➡ Magnesium is found in forages and high in raw materials such as wheaten bran and soya hulls.
So from this you can see the most important electrolyte to supplement daily with is salt. (Sodium Chloride) The most heavily lost electrolyte through sweating and most difficult to obtain through grazing and feed.
It is not advised to give concentrated electrolytes to a dehydrated horse.
Water follows sodium in the body so hypertonic solutions (solutions higher in electrolytes than the body) consumed will draw water into the stomach and intestine from the body. Further dehydrating the horse.
Sodium is the primary driver of the thirst mechanism in a horse so adequate sodium will keep your horse drinking water.
However when sodium levels are low in the blood this thirst mechanism switches off and the horse does not want to drink, which is then when intravenous fluids administered by your veterinarian are advised.
Concentrated electrolytes at an event can also aggravate or cause gastric ulcers by burning an empty stomach.
In summary be cautious when administering electrolytes at events. Rather feed salt daily to ensure Sodium Chloride levels are always replenished.