Print Friendly, PDF & Email

Why do Horses Need Electrolytes

Sweaty horse face and neck with bridle on.When horses are  working  the muscular activity associated with training and competition results in a rapid increase in body temperature. The only way for horses to lose this excess body heat is via sweat production; in fact efficient muscle function is dependent on it. Sweat is the major route of fluid and electrolyte loss in horses, taking with it significant amounts of water and electrolytes from the body. It is a natural process so why worry about it – well the loss of water alone is debilitating but combined with a serious loss of vital salts and minerals can result in negative neuromuscular reactions from muscle cramping to tying up, systemic alkalosis. Without replacing the losses, the horses’ ability to sweat is reduced and therefore the ability to reduce body temperature is also reduced. It seems ironic but when the sodium is reduced by sweating, the horses’ thirst is also reduced and so it will not want to drink and therefore it exacerbates the condition of dehydration. In this instance a quick replacement is needed, ideally with chelated actives which are absorbed more quickly than standard salts and minerals. A product such as Quicklyte has been developed to help resolve the problem. Working a horse without providing electrolytes may result in dehydration which can damage the health of the horse .

When do Horses Need Electrolytes

In very light work, or just resting in a paddock, a horse may get by without extra supplementation, and conditions are not unusually hot, or the horse not sweating under his cover or getting stressed and running around – in other words no sweat. Sweating for whatever reason, training or competing or just hot weather does create a need for proper electrolyte supplementation, the harder the work or the hotter the condition – the greater the need. A salt lick is definitely not enough and anyway it has been proven that it is not possible for a horse to determine for itself how much it needs. Some horses chomp away and overdo the intake, others will not take enough. A horse does not have an innate ability to work out what they need, the human has to help. So when things get more serious and horses get ridden, the owner has to provide a correct electrolyte supplement. The greater the combination of hard work and hot weather – then the need will also be for an instant fast acting electrolyte. Otherwise for more normal conditions a horse can be kept well balanced with a daily supplement to the feed. Horses with gastric illness that creates diarrhoea will need electrolytes to prevent dehydration from the water lost from the gut.

What are Electrolytes for Horses

Salts and minerals are a necessary daily requirement to support the health of the horse. The harder the work – the greater the level of supplementation. It’s not just about fast work as in racing or eventing, but Dressage and Showing is work too and often in hot conditions. It is important to know what constitutes sweat, what is lost and to check out what you are using to replace the losses with.

Electrolyte composition of sweat:


So you see that it is more than just sodium chloride and merely giving a horse some salt is not going to replace the losses. We talk about the Dietary Electrolyte Balance (DEB) as being the total amount of electrolytes, a standard type mixed diet is usually not enough to meet the required DEB. To demonstrate this point, consider a basic diet of 6kg Grass/Hay + 3kg Oats + 3kg Sweet feed with no added electrolyte supplement. If we analyse this diet it equates to:

Crude Protein1200gm1300gmSodium18gm42gm
Digestible Energy30mCal30mCal

Side on view of horse with harness on. Horse is covered in sweat.

This diet has a low DEB with Chloride, Magnesium and Sodium levels being low. Potassium is rarely deficient in diets based on grass and hay. An increase in the work of a horse will create a requirement for an increase in daily electrolyte supplementation as horses do not store sodium, potassium or chloride from one day to the next. Therefore electrolytes need to be adjusted according to the work level of the horse and the environmental conditions. Working in hot conditions will create a higher rate of sweat and therefore a need for greater replacement. When not in work the horse needs less, if over supplemented, it will increase water intake and urine loss. A correctly formulated Electrolyte supplement should contain Chloride and Sodium at a ratio of approximately 2:1 as well as Calcium and Magnesium at low le