Caring for Horses in Extreme Heat

With summer’s sunny days can come extreme heat. Such situations can cause worry for owners as they struggle to help their horses adjust, stay healthy, and remain comfortable. But with a well-thought-out management plan, horses can stay cool and comfy in the midst of summer.

To help get you started on the right track, caught up with Nancy Loving, DVM, an equine practitioner in Boulder, Colorado, to find out what the most important things to consider are when caring for horses in extreme heat.

When dealing with hot temperatures, Loving said the most important thing an owner can do is provide his or her horse with plenty of fresh water.

“Clean water should always be available; an average horse needs five to seven gallons of water per day in cool weather, while in hot weather, requirements for maintenance and to compensate for losses in sweat may prompt intake of 20 gallons or more per day,” she explained. “Horses in a herd should have access to a couple of water tanks spaced a distance apart so dominant horses don’t prevent a thirsty, more timid horse from drinking.

Adding an electrolyte supplement to your horse’s diet could help keep him drinking and restore the electrolyte balances disrupted by sweating, and horses should have access to a salt block or receive a daily salt supplement (no more than a tablespoon per day) to allow them to meet their dietary sodium chloride requirements.

Additionally, she added that for a horse that doesn’t drink well, offering a watery gruel of a supplement (such as a complete feed pellets) rather than feeding them dry can help increase the horse’s water intake.

Insects are another concern that accompany increasing temperatures, Loving said.

“Hot weather brings insects so don’t forget to use fly sheets, insect repellant, and during active insect times of day, it can help to bring your horse into the barn and use fans to create air flow that foils the ability of flying insects to hover around your horse,” she added, as many biting flies are poor fliers.

Horse standing in stall with fan

Loving also encouraged owners to provide their turned out horses “with a stand of shade trees or a loafing shed (run-in shed) with good ventilation. Having areas to get out of the direct sun offers respite, particularly if they have air circulation, also wards off the insects.

“In hot and humid climates your horse might appreciate being hosed down with cool water,” she added.

One concern many horse owners have in hot temperatures is heat stress, but Loving explained that this ailment typically affects horses in hard work rather than those lounging in a pasture.

“Heat stress is typically a concern for horses exercising in rigorous athletic pursuits (such as distance riding, speed and/or sprint events) in hot and humid weather,” she said. “Light riding isn’t likely to bring on a state of heat stress, unless there are extenuating circumstances like extreme heat and humidity and/or over-riding for the conditions of the day.”

Loving explained that horses that sweat for prolonged periods are more at risk of heat stress due to the effects of dehydration and electrolyte imbalances along with internal heat generated by the working muscles during physical exertions.

“If you think you horse is experiencing heat stress, strip off his tack and equipment,” she explained. “Take a rectal temperature to determine the extent of internal heating—rectal temperatures higher than 103.5°F (about 39.8°C) indicate heat stress.”

Loving advised, “Move the horse out of the direct sun when possible. Immediately soak the horse down with cool water, scraping it away and applying it continuously— this cooling process should stop once the chest feels cool to the touch and/or rectal temperature drops below 103.5°F.”

She cautioned to be mindful of too rapid cooling, as in some cases, this can lead to muscle cramping. She suggested interspersing periodic walks for five to 10 minutes in order to allow for the release of heat from inside the horse’s muscles.

With some careful consideration and help from their owners, most horses should adjust to the warmer temperatures without much problem. If you have concerns about how your horse is handling the heat, your veterinarian will be able to help you pinpoint and resolve the problem.