Hydration is often front of mind during the summer months, but water is only part of the picture. Alongside fluid, horses lose essential minerals known as electrolytes which play a key role in maintaining hydration, muscle function, and overall performance.
Understanding the difference between salt and electrolytes, and when each is required, is key to supporting your horse through warmer weather and increased workload.
What Are Electrolytes?
Electrolytes are body salts involved in fluid balance, nerve transmission, and muscle function. The key electrolytes for horses are:
- Sodium
- Chloride
- Potassium
These are lost daily, primarily through sweat. During exercise or in hot conditions, these losses can increase significantly, with horses losing both water and electrolytes together.
Why Salt Still Matters
It is difficult to talk about electrolytes without first considering salt (sodium chloride).
Forage-based diets are naturally low in sodium, meaning that even horses receiving concentrate feed or supplements often require additional salt in the ration .
For horses at rest or in light work:
- Around 30g of table salt per day is typically sufficient for a 500kg horse
- Salt can be added to the feed or provided via a lick (although intake from licks can be variable)
Salt plays a key role in maintaining baseline electrolyte balance and supporting thirst response.
When Are Electrolytes Needed?
For horses in light work, salt alone is usually sufficient, as potassium is typically well supplied by forage.
However, as workload increases or during hot and humid conditions electrolyte supplementation becomes increasingly important.
A 500kg horse can lose:
- 5–7 litres of sweat per hour in moderate work
- Up to 10–12 litres per hour in hot conditions
Alongside this, approximately 10g of electrolytes are lost per litre of sweat .
This is where electrolyte products become essential, helping to:
- Restore electrolyte balance
- Stimulate thirst
- Support hydration and recovery
Powder or Syringe?
Both powdered and syringe electrolyte products have their place:
- Powders are typically suited to daily or routine use (for example, products such as Everyday Electrolytes)
- Syringes are useful for targeted support during travel, competition, or periods of higher demand
- For horses in harder work or more intensive competition schedules, products that combine electrolyte replacement with recovery support (such as Restore-Lyte powder or liquid) may also be considered
Electrolytes can be fed in wet feed or diluted in water, but should always be offered alongside fresh, plain water.
The choice of product should reflect the intensity and frequency of work, as well as the individual horse’s needs.
Supporting Hydration and Recovery
Electrolyte supplementation is not just about replacing losses it is also about encouraging drinking.
Electrolyte balance is key to triggering the thirst response, making both water and electrolyte provision essential components of any hydration strategy .
Fibre also plays an important role, acting as a reservoir for water and electrolytes within the gut, reinforcing the importance of maintaining adequate forage intake.
Practical Considerations
- Always ensure free access to clean water when feeding electrolytes
- Introduce electrolyte products gradually, particularly in fussy eaters
- Monitor water intake- this is key to assessing effectiveness
- Consider offering multiple water sources (plain and flavoured) where intake is low
Take-Home Points
- Salt is essential and often required even in horses at rest
- Electrolytes become increasingly important with work, heat, and sweating
- Hydration is not just about water - electrolyte balance is key
- Fibre supports hydration by acting as a reservoir in the gut
- Match supplementation to workload and monitor intake closely
