Electrolytes and Your Horse
By Dr. Martin Adams
Here’s some advice on electrolytes to help every horse show lover during this hot, busy season. Electrolytes are minerals in the horse’s body fluids and tissues that help regulate muscle contraction, thirst, nerve function and maintain your horse’s blood pH. Commercial horse feeds, hay and pasture contain electrolytes, but horses involved in performance, trail and show events, especially when travel is involved, need additional electrolytes to maintain good health and performance.
Horses sweat as their major cooling system. It keeps them healthy during hot weather and exercise. Electrolytes replace minerals lost from sweat and increase the thirst response due to water loss. There must be sufficient water and minerals in the horse’s body to allow sweating at the proper rate and amount to keep the horse’s body temperature regulated. Heat stress from dehydration reduces muscular performance, and can result in heat stroke or exhaustion, which can be fatal. Sweat and urine losses can be great enough due to exercise, heat and stress to result in impaction colic.
Depletion of electrolytes interferes with muscle contraction and causes fatigue or poor performance, and severe loss of potassium results in symptoms similar to tying up disease. Electrolyte deficiency can produce nerve irritability that causes synchronous diaphragmatic flutter or "thumps", a condition where the diaphragm contracts in rhythm with the beating of the heart. Lack of electrolytes and/or dehydration is also responsible for an exercise-related syndrome that causes reduced intestinal motility (a common reason why endurance horses are pulled from competitive rides at vet checks).
Horse sweat contains the electrolytes chloride, sodium, potassium, calcium, magnesium, and other trace minerals. Electrolytes lost most are sodium and chloride, which is salt, so a proper electrolyte should be salt-based. Five pounds of horse feed contain about an ounce of salt and ten pounds of hay contain virtually no salt but will supply the potassium needs for all other horses but a working horse in hot weather.
Most show, trail, or performance horses receiving a normal daily diet of ten to fifteen pounds of hay and five to ten pounds of fortified horse feed only require one or two ounces of additional salt per day. This means providing two to four ounces of electrolyte daily, as the composition of a proper electrolyte for horses should be about 50% salt, so four ounces of an electrolyte will provide two ounces of salt. EquiMin® Horse Mineral contains 25% salt; two ounces daily would provide ½ ounce of salt, so additional electrolytes might be needed in hot and humid weather for a hard-working horse that is also fed EquiMin Horse Mineral.
When looking for an electrolyte for your horse, sodium chloride should be listed first on the ingredient list, followed by potassium chloride as the second ingredient.
Electrolytes can be sugar-based instead of salt-based. Horses like the sugar-based electrolytes, but you won’t meet the salt requirements without feeding a lot of it. Keep the following recommendations in mind when looking for a good electrolyte:
Recommended Composition of a Good Equine Electrolyte
45-55% Chloride
20-25% Sodium
15-20% Potassium
1% Calcium & 0.5% Magnesium
5-10% Sugar (Dextrose)
Methods to administer electrolytes include adding water and oral dosing with a syringe, adding them to water for the horse to drink, and mixing them into the horse’s feed. Oral dosing with a syringe is similar to dosing your horse with an oral deworming paste, and it can be difficult getting the electrolytes into the horse as some will avoid it or spit it out. When adding electrolytes in drinking water, always provide additional water without electrolytes to make the horse drink more water. Many horses are not used to the taste, and it takes time for them to get accustomed to it.
A good recipe for providing electrolytes is to add two ounces of electrolytes to a cup (6 ounces) of shredded beet pulp in a quart-sized container or plastic bag. Then add a cup of water to the electrolyte-beet pulp mixture. Let the mixture soak for at least fifteen minutes and then add it to the horse’s grain meal or feed separately. If you need to provide electrolytes often throughout the day, or the horse has mouth lacerations or stomach ulcers, add a tablespoon of corn oil to the electrolyte-beet pulp mixture. This will make the electrolyte mix less caustic and prevent or reduce any irritation to the mouth, esophagus or stomach due to frequent electrolyte administration.
