Sweat it Out, Replenish Smart - Electrolytes for Horses

Thirsty for info on electrolytes? Drink in some knowledge!

Updated March 28, 2024

What Are Electrolytes?

Electrolytes are minerals in the body that carry an electric charge. There are a number of electrolytes, most notably:

• Sodium
• Potassium
• Magnesium
• Calcium
• Chloride
• Bicarbonate

Sodium, potassium, and chloride are especially important to horse owners because these are the major ones lost in sweat. The only way horses can replace all these nutrients is through their diet.

What Do Electrolytes Do in the Horse’s Body?

Electrolytes are critical for nearly every bodily function, such as helping control internal fluid balance. They affect hydration, blood pH, and play an important role in muscle contraction and nerve conduction.

Every horse that is sweating will need to replenish these minerals for their body to function properly. Whether your horse is a four-star eventer, reliable lesson pony, or a senior with Cushing’s Disease that might have a long hair coat in the summer, electrolytes are essential to all horses who are sweating.

Signs of an Electrolyte Imbalance or Deficiency

• Dehydration: May present as sunken eyes, dry mucous membranes, or decreased urination and can cause digestive issues, like colic.
• Muscle contraction issues: Cramping, stiffness, or weakness.
• Poor performance: A change in performance or not recovering as well after training can be subtle signs of a deficiency.
• Reduced sweating: An electrolyte deficiency can hinder your horse’s ability to sweat normally, potentially causing him to overheat.
• Decreased appetite: Horses may be reluctant to eat which can lead to weight loss.

In cases of severe electrolyte deficiency, horses may tie up (exertional rhabdomyolysis), collapse, or develop “thumps” (synchronous diaphragmatic flutter).

Replacing Key Minerals Lost in Sweat

Dehydration is a serious threat to your horse’s overall health and performance. Hay, pasture, and even fortified grains don’t provide enough salt (sodium chloride) to meet many horses’ nutritional needs. While salt licks can help, they may not always be sufficient as it’s tough to monitor that your horse is getting his full daily dose.

Electrolyte supplements are daily formulas specifically made to replace the macro-minerals horses lose when they sweat. A balanced electrolyte formula will not only replenish essential minerals, but can also encourage your horse to drink more water. This helps rebalance internal fluids, promotes proper digestion, and helps your horse feel their best.

Finding the Right Electrolyte Supplement for Your Horse

Sweat contains approximately twice as much sodium as potassium and twice as much chloride as sodium. The first step in to looking for an electrolyte supplement for your horse is to pay attention to the label and find one that mimics these proportions. There are powder, pellet, water additive, and paste electrolyte products available so you can find a form that best suits your horse.

How Much Electrolytes to Give Your Horse

Once you find a product with the right ratio, consider the amount of work your horse does. You can calculate how much of the electrolyte supplement to feed based on your horse’s sodium loss.

At low rates of sweating, a horse loses 11.2 grams of sodium per hour. While at the highest rates, drenched in sweat, he may lose as much as 44.8 grams of sodium per hour.

When you think about your horse’s total sweat loss, be sure to remember he still sweats while cooling down. After calculating the total sweat loss, divide that by the amount of sodium per dose of your product to get number of doses.

For example, if a product has 8 grams of sodium per scoop, you need 11.2/8 = 1.4 or just under one and a half scoops per hour of light sweating.

It’s best to not simply rely on a manufacturer’s recommendations when feeding your unique horse who may have an increased or decreased need depending on the amount he sweats. Also, since your horse may drink more water while receiving an electrolyte, he may also urinate more.

Ask the Vet Video on Electrolytes for Horses

Frequently Asked Questions About Electrolytes

When competing, should I give my horse electrolytes the day before, the morning of, and/or after we get home?

Unfortunately, it’s not possible to store electrolytes in the body. So, trying to “preload" a horse with doses of electrolyte paste several days before an athletic event or long-distance transport isn’t the answer. Also, putting electrolytes in the horse’s water for the first time at a competition may backfire, causing him to drink less and become dehydrated.

Research has shown that daily electrolyte supplementation in the grain is a safe way to make sure nutrient losses caused by exercise, hot weather, and shipping are replaced. An electrolyte paste can be used as an occasional “booster” of sorts in certain situations, like on a long trail ride.

Should I put electrolytes in my horse’s grain or water on a daily basis?

Yes, you can top dress your horse’s grain with a powder or pellet electrolyte supplement. There are some flavored pelleted options too that your horse may find tasty.

You can also give electrolytes in your horse’s water buckets, but it’s recommended to also offer a bucket of plain water. The bucket with electrolyte water will encourage your horse to drink, so you want to provide an option that fulfills that need without making him perpetually thirstier.

If my horse’s electrolyte supplement has salt in it, will that cover his sodium needs, too?

Although electrolytes contain some sodium, it’s usually not enough to fully meet horse’s daily salt requirements. You can give your horse both a salt and electrolyte supplement every day to help him stay healthy and hydrated. Continue learning by reading this article on the differences between salt and electrolytes.

Sweating the Details – Key Takeaways for Horse Owners

• Supporting your horse with an electrolyte can help replace the important minerals lost in sweat, while also providing additional salt to support healthy hydration.
• Feeding supplements daily during training (not just on show day) is a safe way to ensure nutrient losses are being properly replaced.
• Always ensure your horse has access to clean, fresh water.

By keeping a serving of electrolytes in your horse’s SmartPaks, you can help ensure that he stays happy, healthy, and hydrated all year long.