What electrolytes should I give my horse?

Long summer days mean more time in the saddle for horse owners.  With all the extra exercise, should we be supplementing electrolytes?

What are electrolytes?

Electrolytes are body salts, or minerals, that regulate the function of the cells - specifically body fluids, blood pressure, muscle control, and nerve activity.  The five major electrolytes are Calcium (Ca+), Sodium (Na+), Potassium (K+), Chlorine (Cl-), and Magnesium (Mg++).  Since electrolytes are suspended in water, they are mostly lost through sweat and urine.  During strenuous exercise, electrolytes lost in sweat will appear as a foamy, white sticky lather.  However, a well-trained, well-conditioned horse will lose fewer electrolytes per volume of sweat.  For the most part, the loss of electrolytes can contribute to fatigue and neuromuscular depression (low-frequency nerve stimulation).  Additional effects involving specific mineral are shown below:

How many electrolytes should I give my horse?  

In truth, the average horse's electrolyte needs are met from forages, grain mix, and a premixed mineral - even after light to moderate exercise.  The chart below depicts the daily electrolyte requirements:

For the most part, as long as the horse is in good condition, is fed a balanced diet, and has plenty of access to fresh, clean water, it should be able to maintain their electrolyte balance on their own on a daily basis.  The only exception would be after a particularly grueling workout (think endurance trail riding), or during extreme temperature and humidity.  A general rule of thumb for extreme temperature and humidity is when the sum of the temperature and humidity exceeds 150.  

How to supplement electrolytes?

There are several commercial electrolyte solutions available on the market.  Make sure to read the label thoroughly before administering it.  Some electrolytes are best suited to be added to water, while others are formulated to be added to grain mixes.  If you are supplementing electrolytes in water, be sure to use two buckets - one with the electrolyte solution and one with plain, freshwater.  Also, keep in mind, that some horses, even those with mild electrolyte depletion, may not be inclined to drink water.  It is also recommended to supplement grain-fed electrolytes 2-4 hours before exercising and again 2 hours after exercising. 

Check out this short, mini-podcast for more information on SELECTING THE BEST ELECTROLYTE FOR YOUR HORSE.  Or listen to the full, 1-hour podcast on HOT SUMMER DAYS AND YOUR HORSE.