Horse owners beware of extreme heat: Quick tips for horse owners

Farm Forum

BROOKINGS, S.D. – As temperatures continue to rise, horse owners need to take steps to keep their equines safe during extreme heat and humidity.

“Horses can experience heat stress when they are exposed to extreme heat multiple days and nights in a row. This creates unique challenges for horse owners,” said Heidi Carroll, SDSU Extension Livestock Stewardship Associate.

Below Carroll outlines tips for horse owners to implement during days of extreme heat.

Tips for pastured and stabled horses

Provide water: Horses should have access to fresh water.

When the temperatures rise, their consumption may increase. Observe water sources more frequently during your daily routine to ensure that horses have ample sources.

Consider the number of sources and the space per animal around each source to minimize competition between individuals during intense heat events.

“As horses sweat they lose salts along with water,” Carroll explained. “Electrolyte balance, which is critical for bodily function, is dependent on a horse’s access to both salt and water.”

Horses that are working hard in the heat and sweating, may need additional replenishment of electrolytes beyond what salt can offer.

Consult your veterinarian and nutritionist concerning these requirements.

Provide shade: Shade is the most effective way to assist horses and any animal exposed to the heat. Shade helps them cope with heat stress and regulate body temperature.

“If horses are on pasture or in turnout lots, evaluate the type and shaded space available,” Carroll said.

Is there enough room for all horses to stand in the shade? If turnout paddocks do not have shade, can you provide a temporary shade structure or adjust the time of turnout?

Consider horse’s age:Younger and older horses may struggle more with prolonged heat events, especially when evenings do not cool to below 70 degrees Fahrenheit or humidity persists. More frequent observations throughout the day are recommended.

Barn ventilation and air quality: Proper airflow and air quality should be more closely monitored during heat advisories.

Even well designed horse barns can benefit from strategically placing large fans to circulate air.

This may be the best option for older remodeled buildings that only have a couple windows or doors that facilitate airflow if the wind is blowing.

Be honest about the air quality, keep stalls cleaned daily to limit ammonia and manure buildup to ensure horses are not having to cope with poor air quality while trying to regulate their elevated body temperature.

Horses and other livestock should not be kept in buildings where airflow and ventilation are not adequately managed.

Fly control: Observe your horses daily to determine if additional fly control measures need to be implemented. Increased fly pressure on horses means they spend more energy on stomping and kicking to alleviate the pain and annoyance.

More flies also impacts the time horses may spend grazing, so monitor body condition scores weekly/monthly to ensure the pasture and forage provided is meeting all animal’s maintenance requirements.

Evaluate pasture quality and growth: During hot summer months, the grazing pressure that horses put on grass/plant growth is huge.

To maintain the pasture quality and prevent damage to the plants, consider pulling horses off pasture and feeding supplemental hay to allow pastures to recover. This is especially important for horse owners in counties that are under severe drought conditions.

Protecting your pastures during a drought will ensure future productivity.

Reproductive performance impacts: Heat stress has huge impacts on the reproductive performance of both mares and stallions.

Heat and humidity have been implicated in possible reduction of reproductive performance in breeding stock.

Basic environmental conditions, such as heat, should be managed in order to provide optimal production potential.

For additional information about stallion reproductive impacts during performance events and shows, please visit and read “Can Heat Stress during Performance Affect Stallion Reproduction?”

Tips for transporting horses

Avoid traveling in the heat of the day: As with all livestock hauling, choose the cooler parts of the day to be on the road because trailers are typically exposed to direct sunlight throughout the trip raising solar radiation heat.

“Think of how it feels in the truck cab when the sun beats in the window on your skin even with the air conditioning blowing on you; it’s still hot and uncomfortable in the direct sunlight,” Carroll said.

Horses hauled between 11 a.m. to 4 p.m. will be exposed to the hottest temperatures and absorb the most heat during transport than horses hauled during cooler times of the day.

Remember, it takes time for the horse to dissipate the heat (increased body temperature, increased respiration rate, increased sweating) and recover before it is expected to perform at its top potential. For more information on the transportation of horses visit

Keep horses hydrated: This may mean offering electrolytes along with cool, fresh water.

Horses should be offered water prior to and immediately following transport, regardless of distance traveled. Plan to pack at least 2 to 3 gallons of water per horse while traveling; or know your route of where to stop with sufficient water hydrants.

The temperature of the water should be cool to the touch, but not cold. Warm water may also limit water intake, which could lead to slight dehydration.

Be proactive and consult your veterinarian and nutritionist concerning electrolyte requirements prior to travel or shows.

Open trailer ventilation slots or windows to maximize airflow. Airflow through vents and windows is typically the only air exchange to assist horses coping with the heat stress of transportation.

Remember to properly secure any windows and have safety bars in place so horses are not able to stick their heads outside the trailer; also ensure proper rope lengths for ties in the trailer.

Avoid keeping horses in a parked trailer for any period of time – Parked trailers only have the airflow from a breeze that is blowing, which is minimal and impacted by the structures the vehicle is parked next to.

A horse kept in parked trailers will have a faster rise in body temperature and struggle to relieve itself from the heat inside even a well-ventilated trailer.

Assess horse health: Monitor vital signs and signs of heat stress before, during, and after transporting horses.

While traveling, you can easily check the capillary refill time through a trailer window. Transporting horses of any age, regardless of health status, has a direct impact on their immune system from the general stress it imposes.

Do not haul horses that are not healthy or those who are not handling the heat well. Hauling compromised horses will increase the chance of dehydration or other stress related health conditions, such as colic.

Spare tires and maintenance: Take the time to properly service trucks and trailers before every trip. Inflate all tires properly, including the spare tire(s).

Do not forget to make sure the truck is in good running condition; do not procrastinate repairs or oil changes that could lead to emergency breakdowns during summer heat.

Additional tips on heat stress prevention while transporting horses can be found at