With the temperatures soaring, the grass becoming crispy, and our horses either maintaining their workload or coming back into work in anticipation of hunt season, hydration is of the utmost importance in our heavily sweating equine friends. It is common practice to include electrolytes in our horse’s intake, either as a top dressing on their concentrate, as an additive in their water, or in paste form administered directly into their mouths. With that known, what exactly are electrolytes? What should we look for in this common supplement? Let us take a look.

What are electrolytes?

They are salts that conduct electricity when dissolved in liquid; commonly listed salts are Sodium (Na+), Potassium (K), Calcium (Ca), Chloride (Cl), and Magnesium (Mg).

Electrolytes are responsible for normal cellular function. This has a cascade effect all the way up to every system in the horse’s body.

Depleted electrolyte levels can cause muscle soreness, stiffness, tying up, decreased blood volume, colic, fever, shock, and in severe cases, death.

Horses can drink 27- 30 liters of water daily

They can lose 10- 12 liters of water per hour in sweat alone when in heavy work in hot climates. This has the largest impact on Na+, K, Cl levels.

Loss of fluids increases the concentration of solutes in the blood. This triggers the thirst response.

Offering mildly salted water (dissolved electrolytes) to horses to immediately after work encourages this response, and more fluid is replaced than when plain H20 is offered.

It is important to start exercise with adequate electrolyte levels to facilitate skeletal muscle function. This is particularly important during these extremely hot, humid months. Many horses show the same physiological state coming out of the field as horses that have already been worked. Tying up and colic is a huge risk.

Commercially available electrolytes come in both powder as well as paste. Powder is designed to be added as a top dressing for feed and dissolved in water. The paste is most effective in situations where the horse is either already depleted, or just finished heavy work. The paste is dissolved in the horse’s mouth and is bio-available within minutes. Many pastes are loaded with sugar as well. This not only makes it more palatable but also serves to “jump-start” the metabolic process.

It is important to look for powdered electrolyte supplements where sugar(Dextrose) is NOT the main ingredient. Most use a little sugar as a flavor aid. However, there should never be more than 15% included on the label. This can ‘jump-start” the animal, however, the salts levels are still depleted.


I hope that this abbreviated guide helps you and your charges to remain healthy, happy at HYDRATED. Stay cool, my fellow enthusiasts, and as always, thank you for reading. I will see you in the field.