What are electrolytes and what do they do?
Horses, just as in people, use electrolytes, which are electrically charged ions that are used by the body’s cells, especially the nerves, the heart and muscles, to maintain voltages across the cell membranes and to carry electrical impulses, such as nerve impulses and muscle contractions.
Generally, these electrolytes are salts and minerals, which, when dissolved in the body, carry an electrical charge. This electrical charge helps to regulate water balance in your horse.
Electrolytes are essential for muscle and nerve function and, due to their role in hydration, also help to regulate temperature as well as the movement of nutrients and waste products throughout your horse.
Sodium, potassium and chloride are the most significant electrolytes, whilst calcium and magnesium have a lesser role to play.
A horse’s composition is 65% water, and to maintain hydration, an average horse may consume 20-25 litres of water each day, which can increase significantly with exercise and heat.
Electrolytes are vital to maintaining hydration but are easily lost from the horse’s body when in sweats.
Horses sweat to regulate their body temperature and to reduce the heat in the body and muscles during hot weather and exercise. The foam that you will often see is due to a protein called latherin that helps to disperse the sweat across the horse’s coat to increase evaporation and heat loss.
One litre of sweat contains approximately 5.6g of chloride, 3.5g of sodium and 1.2g of potassium, as well as calcium, magnesium and phosphate. During moderate work and average temperatures/humidity, a 500kg horse can lose approximately five litres of sweat each hour.
That equates to a lot of electrolytes that the body has to replenish.
Feeding electrolyte supplements
Good quality forage can help to replace lost electrolytes, however, if you are not sure about the composition of your forage, your horse does not consume at least 2% of its body weight daily in dry forage or your horse works more intensely, sweats freely or the climate is hotter/humid, then you should consider providing supplementary electrolytes.
Remember that electrolyte supplements will usually have much less sodium than plain salt, therefore, you should not substitute a salt lick with electrolytes but make both available.
Also, bear in mind that a horse cannot store electrolytes, so adding salt and electrolyte supplements can only replace deficient levels and therefore, it is typically more beneficial to provide them after sweating/exercise than before.
Indeed, by providing electrolytes before exercise or sweating may cause horses to not drink enough water and then subsequently become dehydrated, which will reduce performance and increase the risk of tying up.
Sadddlesdane has a range of electrolyte supplements available for your horse.
Always follow the manufacturer’s instructions and if in doubt, contact a qualified equine nutritionist.