The heat can play havoc with your horse’s health. It can result in dehydration, lethargy and general malaise. Severe heat stress may result in diarrhea and even colic. Janet Johnston DVM, board-certified in surgery and internal medicine, and an emergency critical care veterinarian at University of Pennsylvania School of Veterinary Medicine’s New Bolton Center, suggests the following ten tips to keep your horse comfortable and safe in the summer heat.

1. Choose your turnout times. If your horse has a stall, but is turned out for part of the day, provide turnout during the cooler hours. Overnight is ideal, but if that’s not possible, as early as possible during the day is best.
2. Give him shade. If he lives outdoors, or must be out during the day, provide relief from the sun. A run-in shed is best. Trees are a source of shade as well, but as the sun moves, so will the shade. Make sure that no matter what time of day it is, the available trees are really offering shade.
3. Move that air. Fans are a great way to help keep the air moving in the barn, but use them wisely. Your horse will benefit most if the fan is pulling the hot air out of the stall, not pushing air into the stall. And always ensure that cords and plugs can’t be reach by your horse.
4. Mist it. If you are lucky enough to have a system to mist your horse, use it. As the moisture is absorbed from your horse’s skin, it will take away some of the heat as well. Frequent misting is far more effective than a single dousing with the hose.
5. Lead him to water. Make sure your horse has plenty of fresh, cool water. A bucket hanging on a fence will get warm, too warm to be appealing to your horse. Left long enough it will also become stagnant and unhealthy. If you are providing clean, cool water and your horse doesn’t seem to be drinking, encourage him by providing a salt block, or even misting hay with salt water.
6. Electrolytes. If your horse is sweating a great deal, water laced with electrolytes can help keep his body in balance. Whenever you offer electrolytes, however, be sure to offer fresh water as well. Too many electrolytes can be harmful.
7. Slow down the work. Don’t think that because your horse has been working intensely at 1 pm every day that he can take the heat when the temperature tops 90 degrees. If you’ve got to work him in the heat, lighten the work or break it up into a couple of short sessions. This is especially important when the humidity is high, contributing to the poor quality of the air he is breathing.
8. Stick to a schedule. Within the parameters of keeping him cool, try to stay as close as possible to his normal schedule. Too much change at one time can be an invitation to colic.
9. White out! Horses, especially white horses, can suffer from sunburn. Even those with white socks and blazes, pink noses or even hairless patches from scarring can be problematic. Using a fly scrim can help; applying sunblock to small, particularly vulnerable areas can also be effective. Staying out of the sun’s harmful rays will, of course, be best.  (Also be aware: if a horse has excessive sunburn it could indicate a rare, underlying liver disease)
10. Clipping horses with longer hair coats is important … especially those with Cushing’s disease. While some coat can provide protection from the sun and insulation, a long, thick coat tends to hold heat in and make it difficult for the horse to cool down.