What hot weather means for your horse

Summer brings longer days and more opportunities to enjoy riding, but prolonged periods of hot weather can place significant stress on your horse's body. Horses rely on a delicate balance of hydration, nutrition and thermoregulation to stay healthy, and when temperatures rise, these systems are put under increased pressure.

Understanding the effects of heat on your horse can help you make informed management decisions and reduce the risk of heat related illness.

Hydration: more than drinking water

One of the biggest challenges during hot weather is maintaining adequate hydration. Horses lose substantial amounts of water through sweating, with working horses capable of losing 5-15 litres of sweat per hour of exercise, depending on weather and exercise intensity. Alongside water, they also lose essential electrolytes such as sodium, chloride and potassium, which play a vital role in muscle function, nerve transmission and maintaining fluid balance.

Dehydration can develop surprisingly quickly, particularly during periods of intense heat or exercise. Early signs may include:

• Reduced skin elasticity

• Dry or tacky gums

• Dark or concentrated urine

• Lethargy

• Elevated heart rate

• Reduced appetite

To encourage adequate water intake:

• Ensure fresh, clean water is always available.

• Regularly clean water troughs and buckets.

• Offer palatable soaked feeds to support water intake.

• Offer salt to stimulate a normal thirst response, and provide electrolytes for horses in work.

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Saracen Re-Covery Mash supports hydration, recovery, and muscle function in all horses. Its formulation is specifically intended for it to be able to be fed alongside any other feeding programme and is not designed to replace the existing ration. A 1kg serving of Saracen Re-Covery Mash provides added electrolytes to support hydration and recovery during periods of warm weather. Horses that have sweated heavily producing white, foamy sweat are likely to have greater electrolyte losses and may benefit from additional electrolyte supplementation, such as KER Restore. As with any electrolyte, it is important to ensure fresh drinking water is available at all times.

White, foamy sweat is commonly associated with heavier sweating, as the foam forms from latherin, a naturally occurring protein in horse sweat. While foamy sweat itself isn't a measure of electrolyte depletion, it is a practical indicator that the horse has sweated substantially and may need additional electrolyte replacement.

Reduced forage intake during hot weather

Many horses naturally eat less during periods of extreme heat, particularly during the hottest parts of the day when they are perhaps seeking shelter. Reduced forage intake can have wider consequences than simply consuming fewer calories.

Adequate forage intake is essential for maintaining digestive health, supporting the hindgut microbiome and providing a steady source of fermentable fibre. A reduction in fibre intake may increase the risk of digestive disturbances, such gastric ulcers, loose droppings or colic. Studies have shown that providing sufficient fibre during the hours of 7am-7pm is particularly important (Husted, 2009). Poor pasture quality can compound the problem. During hot, dry spells, grass growth often slows dramatically, reducing both forage availability and nutritional value. For horses turned out during the day on sparse grazing, supplementary forage may need to be offered.

Where forage intake is compromised, alternative fibre sources can help maintain fibre consumption without relying solely on grazing or hay. Products such as Saracen Super Fibre Cubes provide a highly digestible fibre source that can be soaked to support additional water intake while supporting digestive health. Their versatility makes them particularly useful for horses with reduced appetites, older horses, or those requiring additional fibre during dry weather.

The three main ‘Super-Fibres’ are beet pulp, soya hulls and alfalfa. They are classed as ‘Super-Fibres’ due to their increased digestibility and higher energy content compared to many traditional fibre sources, without the risks associated with feeding high levels of cereals that supply an increase in starch and sugar.

Heat stress and cooling the horse

A horse's normal body temperature sits between approximately 37.2°C and 38.3°C. During exercise, muscles generate large amounts of heat, and horses rely primarily on sweating and evaporation to cool themselves.

When environmental temperatures and humidity are high, this cooling mechanism becomes less effective. Without prompt cooling, horses are at greater risk of developing heat stress.

Signs of heat stress include:

• Excessive or prolonged sweating

• Rapid breathing

• Elevated heart rate

• Weakness or reluctance to move

• Delayed recovery after exercise

• High rectal temperature

Heat stress in horses is a serious condition, and veterinary intervention and immediate cooling is essential.

Current research has found that the application of constant cold water is the most effective cooling method. Continuously apply cold water over the large muscle groups, particularly the neck, shoulders and hindquarters. Scraping of water is shown to have no effect and is not necessary. Moving the horse into shade and encouraging airflow with fans can further improve cooling (Pagan et al., 2025).

Adjusting daily management

Simple management changes can significantly reduce heat related risks:

• Ride during the early morning or late evening when temperatures are lower.

• Provide adequate shade in fields and turnout areas.

• Ensure good ventilation within stables.

• Monitor water intake daily.

• Check horses regularly for signs of dehydration or heat stress.

• Adapt exercise intensity according to temperature and humidity.

Every horse responds differently to heat. Older horses, overweight horses, youngstock and those with underlying health conditions may require closer monitoring.

Supporting your horse through summer

Hot weather presents a combination of nutritional and management challenges. Maintaining hydration, encouraging consistent fibre intake and using effective cooling strategies all contribute to keeping horses comfortable and healthy throughout the warmer months.

Where grazing quality declines or forage intake falls, incorporating a digestible fibre source such as Saracen Super Fibre Cubes or Saracen Re-Covery Mash can help support digestive function while also providing an opportunity to increase water intake through soaked feeds.

By recognising the early signs of dehydration and heat stress, and making small adjustments to your horse's daily routine, you can help ensure they continue to thrive even during the hottest days of summer.

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References :

Pagan, J.D., M.S. Todd, S.M. Esposito, S. Dezalak, and R.W. Springer. 2025. Validation of different cooling methods in exercising two-year-old Thoroughbred racehorses using percutaneous thermal-sensing microchips. Journal of Equine Veterinary Science 148:105537.

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