12/02/2026
Electrolytes for Horses: When and How to Use Them 🐴
Electrolytes—primarily sodium, chloride, potassium, magnesium, and calcium—are essential for normal body function. Adequate electrolyte intake supports hydration, nerve transmission, muscle contraction, and acid–base balance.
A horse’s electrolytes are depleted every day through sweating, urination, and the passage of faeces. Horses in work, particularly those that sweat heavily, then require regular electrolyte replacement to maintain performance, thermoregulation, and recovery.
The kidneys play a key role in maintaining electrolyte balance, excreting substantial quantities of potassium and calcium on a daily basis. Because electrolytes are tightly regulated and not stored in the body, excess intake is simply eliminated via the urine.
Electrolytes are involved in multiple critical functions, including:
• Maintenance of acid–base balance
• Normal nerve transmission
• Proper muscle contraction
Heavy electrolyte losses can lead to neuromuscular disturbances and serious issues including muscle cramping, tying up, synchronous diaphragmatic flutter (thumps), and systemic alkalosis.
Horses experiencing significant electrolyte loss may also show reduced sweating rates, impairing their ability to regulate body temperature effectively. Electrolyte concentrations in the blood also influence the horse’s thirst response.
Unfortunately, when large amounts of sodium are lost through sweat, the thirst mechanism may become depressed, resulting in inadequate fluid intake and increasing the risk of dehydration.
When Should I Feed Electrolytes?
Increased electrolyte supplementation should be targeted to periods of anticipated loss, as excess intake will simply be excreted. As electrolytes are not stored in the body, providing them when the horse is already in balance will simply result in excess being excreted by the kidneys.
Supplementation is most beneficial during periods of increased electrolyte loss, such as:
• Hot or humid weather
• Travel
• Competition
• Prolonged or intense exercise
In these situations, electrolytes may be provided during extended work or shortly after exercise to assist in replacing losses and supporting hydration and recovery.
How to Feed Electrolytes
Dosage
• Always follow individual product instructions and adjust based on workload and sweat rate.
• If you are feeding salts remember to calculate first what your horse is receiving from ALL other feeds, pasture and hay and supplement accurately with care.
• Many commercial feeds already contain adequate levels of minerals such as sodium!
Acclimation
• Introduce electrolytes gradually so horses adapt to the taste and continue drinking normally.
• It might be helpful to bring water from home; this can help keep them drinking on the truck and get them started once a new location is reached.
Other Key Points
Supplement composition
• Effective electrolyte supplements should contain a balanced combination of:
o Sodium
o Chloride
o Potassium
o Magnesium
o Calcium
• If sugar is listed on the label (dextrose or glucose) it is for palatability and should be less than 10%.
Remember to calculate what your horse is already receiving from all other feed sources and balance the diet from that. Balance is crucial.
Many horses (not in hard work) can benefit from a small amount of simple table salt added to their feed daily.
Salt blocks
• Salt licks provide sodium and chloride only.
• They are not sufficient to replace full electrolyte losses in horses working hard or sweating heavily.
• Many horses don’t like the abrasiveness of having to lick a salt block.
When your horse is likely to lose large amounts of electrolytes—such as during travel, hot weather, or competition—supplementing during a long ride, competition day or soon after can help restore what has been lost.
ALWAYS give access to fresh water!💧
