Make sure the horse has plenty of fresh, cool water. A bucket hanging on a fence will get warm, too warm to be appealing. Left long enough, it will also become stagnant and unhealthy. If the horse has access to clean, cool water and doesn’t seem to be drinking, encourage it by providing a salt block, or even misting hay with salt water.
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.
If the 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.
If the horse is sweating a great deal, water laced with electrolytes can help keep its body in balance. Whenever offering electrolytes, however, be sure to offer fresh water as well. Too many electrolytes can be harmful.
Within the parameters of keeping it cool, try to stay as close as possible to his normal schedule. Too much change at one time can be an invitation to colic.
If the horse 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.
Don’t think that because your horse has been working intensely at 1 p.m. every day that it can take the heat when the temperature tops 90 degrees. 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 the horse is breathing.
Fans are a great way to help keep the air moving in the barn, but use them wisely. The horse will benefit most if the fan is pulling the hot air out of the stall, not pushing air into the stall. Always ensure the horse can’t reach cords and plugs.
As the moisture is absorbed from the 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.
This is important, especially for 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.