Electrolyte Supplements for Horses - prevent dehydration

Electrolyte supplements can improve performance If your horse or pony has been working hard and is sweating after exercise he may need an isotonic solution of electrolytes to correct an imbalance and prevent dehydration.

This article gives advice on choosing and giving electrolyte supplements to your horse.

The use of an equine electrolyte supplement has the potential to improve a horse's performance, aid recovery after strenuous exercise and avoid dehydration.

Electrolytes or "salts" are minerals dissolved in the blood and tissues of the horse's body, which carry a negative or positive charge and bind with another ion to make a "salt".

When a horse sweats during exercise, or stressful activity such as travelling, he loses "salts" such as sodium, chloride and potassium.

These losses can be considerable, especially in hot weather and can cause tiredness, muscle stiffness, dehydration and equine colic.

Without the presence of electrolytes a horse's body cannot retain water so just offering water after exercise will not rehydrate your horse.

Electrolytes should be added to either the water or the feed of a dehydrated horse.

Sweating controls the body temperature of a horse during exercise - 90% of a horse's weight loss after exercise is due to sweating.

Poor equine performance can result if this weight loss is not monitored and the fluid and electrolyte losses replaced.

During normal exercise a 500kg horse can lose 10 litres of sweat during two hours - in hot conditions or during heavy work or competitions these can increase dramatically!

Choosing an equine electrolyte supplement

  • Check the label carefully.
  • Look for chloride and/or acetate combinations such as sodium chloride, potassium chloride, calcium chloride or calcium acetate - these are quickly and easily absorbed.
  • The amount of of sodium plus potassium should be about the same as the amount of chloride in the supplement
  • There should be small amounts of calcium and magnesium
  • Avoid supplements that use di-calcium phosphate - horses don't absorb these very well.
  • Also avoid products that list dextrose, sugar, or corn syrup as the first ingredient - however these ingredients should be present at lower levels to increase palatability and increase the rate of absorption.
  • Electrolyte supplements manufactured for cattle, other animals or even humans may be unsuitable for horses - look for an equine supplement

Benefits of electrolytes

  • Research has shown that giving electrolytes before and during heavy exercise can increase the time before the horse gets fatigued by up to 23 %
  • Recovery from strenuous exercise is improved when horse are given electrolytes within an hour of finishing work - enabling them to perform well over several days.


A large single dose of electrolytes can cause the horse to absorb water from the blood vessels surrounding the gut.

This ca actually worsen the effects of dehydration in the short term.

horses in heavy training may need electrolytes

How to give electrolytes to your horse

The ideal way to help your horse rehydrate after exercise is to give him an isotonic solution of electrolytes mixed in water, ideally within an hour of finishing exercise.

Performance horses with extended periods of vigorous exercise which makes them sweat or horses sweating whilst travelling should frequently be offered an electrolyte solution.

  • The equine electrolyte supplement that you choose should have instructions on how to make up the solution ready for your horse to drink.
  • If your horse is reluctant to drink an electrolyte solution try adding apple juice or sugar beet water to make it more tempting!
  • Electrolytes can also be given in the horse's feed - make sure that that the feed is wet.
  • Equine Electrolyte pastes are also available and can be administered via syringe directly into your horse's mouth if he is reluctant to drink an electrolyte solution.
  • If electrolytes are given in the feed or by a syringe into the mouth it is essential that he drinks plenty of water - taken with insufficient water electrolytes can actually cause dehydration. 

Signs of electrolyte deficiency 

  • Poor performance
  • Listlessness
  • Dark urine
  • Sunken eyes
  • Dull coat

Article: Advice about the benefits of giving electrolytes to horses for dehydration