SCIENCE SUPPLEMENTS – Electrolytes: why, what, when and how!

Kirstie Pickles BVMS MSc PhD CertEM(IntMed) DipECEIM MRCVS

The term ‘electrolyte’ is used to describe an important group of minerals found in the body which includes sodium, chloride, potassium, calcium and magnesium. Electrolytes are capable of conducting electricity and are essential for things like muscle contraction, nerve impulses and maintaining hydration. We take great interest in electrolytes because they can be lost from the body, most importantly in sweat. Low levels of electrolytes within the body can lead to problems such as poor performance, fatigue, tying up and dehydration. We feed electrolytes to avoid these complications, but also to promote a rapid and healthy recovery from exercise, so the horse is ready to work again.

How do I know how much to give?

The electrolyte supplementation required by a horse will depend on how much and how often the horse sweats, along with how much and what type of additional feed the horse is being fed (as most compound feeds contain a small amount of salt).

Why do I need to supplement electrolytes?

One litre of horse sweat contains approximately 10g (2 teaspoons!) of electrolytes. A horse can easily lose 5 litres of sweat per hour at moderate exercise (mainly trot with some canter), resulting in 50g of lost electrolytes. Sweat losses can be a lot higher than this in hot, humid conditions.

The frequency of sweating is important (how many times a week) because we know it takes the kidneys 2-3 days to correct for lost electrolytes. As a rule, if a horse sweats more than twice a week, daily supplementation with a complete electrolyte supplement is needed. This will provide ample amounts of readily absorbable electrolytes for the horse, helping to quickly correct for sweat losses, preventing deficiencies from occurring.

For horses in light work which do not sweat more than twice a week, the addition of table salt to the diet is sufficient to balance the diet and compensate for any minor losses.

Should I feed electrolytes all year round?

Instead of thinking about the competition season alone, consider your horse’s workload at different times of the year. If you have an event horse (working hard through the spring and summer, but doing less over the winter) he probably requires a daily complete electrolyte through the training and competition season, but perhaps only salt through the winter months. Conversely, if you have a hunter (working hard through the autumn and winter, but resting or light work through the summer), the opposite will be needed.

My horse has a salt lick – is that not enough?

We know that horses do not self-regulate salt intake for their salt requirements. Horses in regular work should be supplemented with either salt (light work) or a complete electrolyte mix (moderate to heavy work).

Can I feed electrolytes to my horse which has had gastric ulcers?

It is wise to be cautious about giving electrolytes to horses with a history of gastric ulcers. That said, if the horse is in work, it is very important that the horse is given electrolytes. Electrolytes should never be fed on an empty stomach and concentrated pastes are best avoided. Keep serving sizes small, and electrolyte requirements split between multiple small meals instead of one large meal. The safest way to give electrolytes to an “ulcer prone” horse would be to use an encapsulated electrolyte (coated in a fine oil) which prevents electrolytes dissolving in the stomach and potentially aggravating the sensitive stomach lining.

Instead, the electrolytes pass through into the small intestine, where the oil is broken down, allowing for absorption.

For all Electrolytes to suit your horse or pony please CLICK HERE 

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