Electrolyte supplements are a hot topic in the horse world right now.

What are electrolytes and do they really help my horse?

Electrolytes are ionized salts - that means they have a charge and separate out in water. The electrolytes that are most important to your horse are sodium (Na), potassium (K+), and chloride (Cl-). Calcium (Ca+) and magnesium (Mg+) are also electrolytes that may affect your horse's well-being.

Electrolytes become important when your horse sweats. Horse sweat contains more Na+, Cl-, and K+ than human sweat. Horses can sweat gallons just standing around in hot, humid weather. They really sweat when worked hard, such as at a competitive trail ride or cross country event. Even regular work can trigger quite a bit of sweat with corresponding electrolyte loss. Along with electrolyte loss comes dehydration - in fact, the two conditions go hand in hand.

Your horse's normal diet should provide plenty of potassium and calcium. Grass hay, alfalfa or clover, and grains tend to cover the needed amounts of those electrolytes. The electrolytes most often deficient in a horse's diet are those in salt - NaCl. Most horse owners have salt blocks available for their horses to help counter that deficiency. If sodium is well-regulated, chloride generally is too. Under normal conditions, that free choice salt block (plain or mineral) may be adequate to keep your horse's electrolytes at good levels.

It is important to track salt block usage by your horses. One horse may chew at a block and others may avoid it altogether. In hot, humid weather or at times of heavy work, you may choose to supplement your horses' diets instead to be sure each horse is getting the right amount of electrolytes.

When do horses need electrolytes?

Melissa Mazan, DVM Dipl. ACVIM, Associate Professor and Director of Equine Sports Medicine at Cummings School of Veterinary Medicine at Tufts University, feels that horses don't need electrolyte supplements all the time.

"In hot weather and with hard work, horses will lose sodium and chloride in sweat. They may need supplementation then - though it is equally important to keep them cool and hydrated." Signs to look for in a horse that is dehydrated include weak pulse, skin tenting, and poor capillary refill.

A horse who is electrolyte depleted may be unusually nervous, have muscle tremors, or move very stiffly. Your horse's heart can also be affected.

Tickle your horse's taste buds to ensure adequate hydration

The old saying that "you can lead a horse to water but you can't make him drink" is true. However, there are ways you can make water more attractive to your horse during hard workouts. For long trail rides or trips, condition your horse ahead of time by adding some Gatorade or flavoring to his water. Unfamiliar water will then be at least somewhat disguised by the flavoring.

Dr. Hal Schott

Dr. Schott recommends preconditioning horses to an electrolyte additive before going on the road.
© 2012 by Michigan State University

Dr. Hal Schott, DVM PhD Dipl ACVIM of Michigan State University, has a couple of additional suggestions. "Horses will drink more if they get a drink of lightly salted water first, then plain water. To make the lightly salted water add one or two rounded tablespoons of table salt (that is 1 ounce or 30 grams) to a five gallon bucket of water. Remember to do this at home a few times first, so your horse is accustomed to both types of water." The lightly salted water helps with electrolyte status and also encourages the horse to drink more when offered the plain water. That will improve his hydration.

Horses prefer water that is about 68 degrees F in temperature during the summer. They won't drink as much if the water is really cold or quite warm. In cold weather, tepid water stimulates more drinking.

Making your own electrolyte supplements

There are electrolyte supplements on the market, but many veterinarians suggest you can make up your own supplements much less expensively. Many commercial products have sugars and flavorings that you are paying for that don't benefit your horse's health.

From Dr. Schott, "As an acceptable alternative to commercial electrolyte formulas, try equal parts of table salt (NaCl) and "lite salt" (a mixture of KCl and NaCl) as an easy recipe for hard working horses in the summer. Feed 1 to 2 ounces of this mix daily with your grain." This is for the average horse - about 1000 lbs.

Dr. Mazan adjusts the recipe a bit for the average working horse. She suggests, "Mix 3 parts table salt with 1 part lite salt. Feed 2 ounces of this mix on a cool day - going up to 3 to 5 ounces on a hot day with a hard working, sweaty horse."

There are many other homemade electrolye recipes. Some of these include magnesium and calcium. This recipe is quite popular: 2 parts table salt, 2 parts lite salt, and 1 part crushed Tums tablets or dolomite powder (for calcium and magnesium). Your horse would get 2 ounces daily on days of hard work and heavy sweating.

Electrolyte cookies, anyone?!

For the horse who is fussy about anything added to his feed, you can try baking some "electrolyte cookies." This does add some sugar to your horse's diet, but only in small amounts.

Cookies?? Yes!!

Some fussy horses my refuse water with electrolyte additives, but may happily accept an electrolyte cookie.

Most cookie recipes use 2 cups of grain, 2 cups of rolled oats, 24 ounces of electrolyte mix (commercial or homemade), 3 cups bran, 1 to 2 cups of water and then 1 cup of molasses, maple syrup, or applesauce to sweeten the taste. Mix well and divide into 24 cookies. Cook at 350 degrees for 25 to 30 minutes. Each cookie should have an ounce of electrolytes.

It is very important to remember that giving your horse electrolytes - whether powder, paste, homemade mix, or commercial preparation - should only be done if your horse is drinking. Risks from over-supplementing electrolytes are low but can be complicated if your horse is not drinking to rehydrate himself.

Is there any benefit to "loading" my horse with electrolytes?

There have been no studies that show a great benefit of "loading" your horse with electrolytes ahead of an event. Also, remember that electrolyte depletion is closely tied to the amount your horse is sweating. If your horse tends to sweat traveling in the trailer to an event, giving him a dose of electrolytes ahead of time might help. Any event held during hot, humid weather is more likely to deplete electrolytes, but very hard work at any time can do this as well.

Feeding some electrolytes, or at least giving some salt water at stops along the way on a long trail ride or endurance ride, can be helpful. Always provide plain water as well as the salted water. Most horses will need a couple of days after a hard workout or event to reset all of their electrolytes to normal. Giving some electrolytes for a few days post event can't hurt and might help. Make your own mix for some savings and use it as needed for maximum benefit and cost.

Electrolytes are for real, but only need to be used in moderation and in response to heavy workouts and sweating.