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Benefits of Electrolytes for Performance Horses

A well-balanced diet is essential for working horses to ensure they receive all the required nutrients that are important for fitness, recovery and overall health. Plenty of forage and a well formulated performance horse feed is a great start; however, when deciding on which supplements to include, the huge number of different products available in the market can sometimes make this a challenging decision. While the majority of these supplements offer considerable benefits and play an important role in the diet, the first supplement that should be considered for a working horse is electrolytes.

Electrolytes are salts that play an important role in maintaining osmotic pressure, fluid balance, and normal nerve and muscle activity. The most important electrolytes are sodium (Na+), potassium (K+), chloride (CI-) and magnesium (Mg++). These are lost daily through sweat and urine in vast amounts when the weather is hot and the horse is working hard, trying to dissipate excessive body heat. The major losses are of chloride followed by sodium and potassium. Therefore, these are the most important electrolytes to replace. 

All horses that work hard enough to break a good sweat will require electrolytes if they are to recover quickly and rehydrate. Travel and stress can also induce heavy sweating - a horse travelling a few hours to a competition on a hot day may lose up to 25 litres of sweat and if these losses are not replaced, the horse may start the competition already dehydrated. Some horses sweat more than others, so it is important to monitor sweat loss to determine what needs to be replaced. Underestimation of sweat losses can occur on hot dry days due to rapid evaporation from the skin as the horse may dry quickly even though there has been a considerable electrolyte loss.

Substantial loss of electrolytes causes fatigue and muscle weakness, eventually decreasing the thirst response to dehydration. Research has also found that electrolyte deficiencies are a significant causative factor for muscle soreness and tying up in horses. The restoration of correct dietary electrolyte balance can significantly improve this condition. Since most of the electrolyte loss in the horse occurs through sweating, one method of calculating electrolyte requirements can be based on different amounts of sweat loss. Body weight loss during exercise is a good way to estimate the amount of fluid loss, where 1kg of body weight loss equals 1 litre of body water and salt loss.

When choosing an electrolyte, it is important to select a product that contains the correct proportions of the nutrients lost in sweat. McMillan Electrolytes have been formulated to mimic the composition of horse’s sweat, so all nutrients are replaced in the correct proportions. 


For further information on McMillan Electrolyte, contact McMillan Equine Nutritionist Luisa Wood at 

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