Q: I live in Northern Illinois where the summers can be very hot and humid. My question is - where is the best place for a horse during the hottest part of the day--in a barn with fans or outside? We are on a hill, so we usually have a pretty brisk breeze blowing.

My thermometer in the barn is at 96 degrees right now, probably hotter than outside in a shady spot. One place seems about as bad as the other in the heat. Any ideas?

Dusti Coyle
Wilmington, Illinois

A: We all know how it feels to stand in the baking heat of the sun without respite. When overly hot, a horse will sweat, which is a normal process to eliminate heat from the body to maintain a stable body temperature between 97-101°F. One way to determine how solar radiation is affecting your horse is to measure his respirations, which are normally 18-24 breaths per minute. On a hot day, he's likely to breathe more rapidly to dissipate heat from his body. A dark-haired horse tends to be more affected by direct sunshine. It helps to compare one horse's respiratory rate to a few others experiencing the same ambient conditions.

The presence of a breeze helps to wick heat from the horse's body, improve the air that he breathes, and keep the insects at bay. It's also valuable to consider whether your horses can find shade under a tree or run-in shed or alongside a building or structure.

Most horses compensate quite well living outside in the summer heat of temperate climates provided they have ample water to replenish fluids lost in sweat and a big enough area that they can move around to find optimal air circulation and available shade.

When electing to confine a horse inside, remember that a barn environment doesn't always present ideal conditions for a horse's airways--breathing in particulates and ammonia fumes is particularly difficult for a horse with airway inflammation. Respiratory secretions circulate through the barn in droplets dispersed with coughing, sneezing, and movement, increasing the chance of passing infectious disease. Still air in a barn makes for a stifling environment, particularly as equine body heat continues to be released.

There are situations where a horse should remain in a barn during the heat of the day, such as an anhydrotic horse that has lost the ability to sweat. Until this condition is resolved, the anhydrotic horse should be kept inside with cooling fans and misters. Other situations that necessitate indoor stabling include a need to protect against insects, or to shield a horse with skin photosensitivity or eye issues.

Whenever possible, horses fare better outside in turn-out where they can roam at leisure, graze a little green grass or nibble some hay, and mingle with others in the herd. This is the best mental and physical situation any time of the year for a herd animal like a horse.

About the Author

Nancy S. Loving, DVM

Nancy S. Loving, DVM, owns Loving Equine Clinic in Boulder, Colorado, and has a special interest in managing the care of sport horses. Her recent book, All Horse Systems Go, is a comprehensive veterinary care and conditioning resource in full color that covers all facets of horse care (available at Shop.TheHorse.com or by calling 800/582-5604). She has also authored the books Go the Distance as a resource for endurance horse owners, Conformation and Performance, and First Aid for Horse and Rider in addition to many veterinary articles for both horse owner and professional audiences.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from TheHorse.com. Learn More

Free Newsletters

Sign up for the latest in:

From our partners