We often talk about the importance of electrolytes, and about how you should supplement your horse with them after intense work, or in warm conditions. But what actually are they, and what role do they play within the body?
What are electrolytes?
Electrolytes are essential minerals found in the body, and are required for several processes such as hydration, blood regulation, nutrient absorption, and nerve and muscle function. The five key electrolytes are sodium, chloride, potassium, calcium and magnesium. Because the body has no storage mechanism for electrolytes, they must be provided in the diet. Whilst they are found in the horse’s natural diet, modern pastures and forages are commonly low in sodium, and concentrations of calcium and magnesium can vary greatly. It is therefore important to be aware that your horse may need to be supplemented with electrolytes.
It is a common misconception that electrolytes are only lost from sweat, but actually, they are also lost by both breathing and urinating. So, just because a horse hasn’t become sweaty after an intense workout, it doesn’t mean that they haven’t lost any electrolytes. Because electrolytes are used to maintain equilibrium within the body, athletic horses are likely to have a higher requirement for electrolytes than a horse at rest, because of the stress and metabolic responses induced by training.
However, It is not just athletic horses that are at risk of electrolyte deficiency. Muscle spasms, ulcers, colic, aggression, nervousness and exhaustion can all be attributed to the loss of electrolytes.
So, now we know why electrolytes are important – but what do they actually do?
What do electrolytes do within the body?
The five key electrolytes all have different functions within the body – after all, they are vital components of any horse’s diet.
Sodium and Chloride: are essential for maintaining water balance, which is needed for cell function and acid base balance. Sodium deficiency is not uncommon, and typically presents as poor performance. Chloride deficiency is less common unless extreme prolonged sweating has occurred.
Potassium: is also required for cell function and acid base balance. Potassium is found in significant amounts in forages, so deficiency is less common. However, it is worth remembering that after strenuous exercise, the horse may not eat normal quantities of forage, and choose to rest instead. There is no body “store” for sodium, chloride or potassium so losses must be accounted for after exercise.
Calcium and Magnesium: Requirements for these ions increases with workload, but the increase in requirements is not down to sweat loss alone, they are needed for muscle function, lactate trapping and bone turnover. They are stored in bone, but accessing to the store is slow.
So, now that we know what each of the key electrolytes are responsible for within the body, we need to understand how the body processes them, and what can happen if a horse does not receive enough…
Electrolyte uptake and absorption
Most electrolytes are mixed into feed, fed using a syringe, or added to water. Once intake has occurred, the electrolytes travel through the gastrointestinal tract. They are then absorbed in the first section of the small intestine, called the duodenum, where uptake is optimal. Next, they are taken up by muscles and transported by blood to the skin, and anywhere else that they need replacing. Horses must consume an adequate amount of water with electrolytes, in order to maintain homeostasis and promote gastric emptying and intestinal absorption.
What happens if a horse doesn’t receive enough electrolytes?
As electrolytes have so many vital roles within the body, there are several issues that can occur from deficiency. Excess sweat loss can lead to a multitude of issues, from dehydration and fatigue, to more severe issues such as muscle weakness, tying up, and colic.
These issues are often unlikely to occur suddenly, and can often be the result of long-term deficiency. For example, having one ride where your horse gets quite sweaty is unlikely to cause your horse to become severely dehydrated and exhausted, but if this happens repeatedly, it is likely to have a negative effect on the body.
How do I ensure that my horse is receiving enough electrolytes?
Although electrolytes are present in the horse’s natural diet, knowing the levels in each type of grass and forage would be incredibly difficult. Modern day forage and grazing has much lower concentrations of electrolytes than would be ideal, so the reality is that most horses that are in work or regularly sweating, likely need to be supplemented.
A complete electrolyte supplement provides all of the key electrolytes, in simple and absorbable forms. It means that, instead of a horse having to eat 10kg hay to receive the required amount, they can have one serving in a feed and receive the entire requirement. This is particularly beneficial for horses that are away competing, or on restricted diets. For horses in low level work or resting, supplementing sodium and chloride in the form of salt is generally sufficient, as they are likely to ingest the other electrolytes from their feed. However, if the horse is sweating more frequently than this, or has a predisposition to any other health conditions, such as tying up, a complete electrolyte would be more supportive.
Providing readily available electrolytes means that exercise recovery is promoted, rehydration occurs more rapidly, and the incidences of associated illnesses are reduced.
Science Supplements offer two different electrolyte products: SafeSalt and Complete Electrolytes. SafeSalt contains sodium and chloride, whilst Complete Electrolytes contains all of the key electrolytes. You can find out more about them here
Take Away
Commonly, horse owners only think of feeding electrolytes through the summer, or around the time of a competition. Being aware of the importance of electrolytes, and the roles that they play within the body can help us to understand why we should be looking to supplement them, and of the risks involved if a horse becomes severely deficient. If you are ever wondering why your horse doesn’t seem to have enough energy, have a think: are you replenishing the electrolytes lost through exercise?
For more information on our equine supplement range, click here or contact us.
References
Coenen, M. (2013) Macro and trace elements in equine nutrition. In: Geor, R., Harris, P. and Coenen, M., eds. (2013) Equine Applied and Clinical Nutrition. China: Saunders Elsevier, pp. 191-228.
Farina Alshut, Venner, M., Gunilla Martinsson, & Vervuert, I. (2023). The effects of feeding sodium chloride pellets on the gastric mucosa, acid‐base, and mineral status in exercising horses. Journal of Veterinary Internal Medicine, 37(6), 2552–2561. https://doi.org/10.1111/jvim.16851
Lindinger, M. I., & Ecker, G. L. (2012). Gastric emptying, intestinal absorption of electrolytes and exercise performance in electrolyte-supplemented horses. Experimental Physiology, 98(1), 193–206. https://doi.org/10.1113/expphysiol.2012.065185
Lindinger, M. (2022). Oral Electrolyte and Water Supplementation in Horses. Veterinary Sciences, 9(11), 626. https://doi.org/10.3390/vetsci9110626
Walker, W. T., Callan, R. J., Hill, A. E., & Tisher, K. B. (2014). Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride. The Canadian veterinary journal = La revue veterinaire canadienne, 55(8), 765–771.
Waller, A. P., & Lindinger, M. I. (2021). Pre‐loading large volume oral electrolytes: tracing fluid and ion fluxes in horses during rest, exercise and recovery. The Journal of Physiology, 599(16), 3879–3896. https://doi.org/10.1113/jp281648