Mother Nature equipped our horses with highly effective "clothing" to keep them warm and comfortable in even the coldest, snowiest winter weather. The long hairs of their winter coats stand on end to create an insulating layer of warm air around their bodies. When a layer of snow accumulates on their backs, their coats' natural oils and thick hair prevent the moisture from reaching the skin.
Horses even have a built-in wicking system: When their coats get wet, their body heat pushes the moisture out toward the tips of the hairs where it then evaporates into the air. When the air temperature is below freezing, this moisture may even form icicles on the tips of the hairs, still a comfortable distance from the skin.
For those of us who choose to work with this incredible system rather than replace it with body clipping and blanketing, one of the biggest challenges we face is drying off our horses when they get too wet. Whether your horse is sweaty from a hard ride or "soaked to the bone" by rain, his wet coat temporarily loses its ability to create a warming air space around him. Throwing him into his stall or, even worse, turning him out on a brisk, cold day (temperatures below 40 F and/or windy conditions) without drying him off first may cause him to become chilled and burn extra energy trying to keep warm. But that doesn't mean you have to spend hours towel drying him or leaving him under fancy heat lamps. The simple wicking technique I'll share in this article requires very little time and a minimal budget.
The only essential equipment you'll need is a wool or polar fleece cooler. Both are excellent wicking materials designed to create an air space around your horse. His body heat warms up this air space, which then draws the moisture away from his skin to the outer surface of the blanket. When you see moisture droplets beading on the outside of your horse's cooler, that means it's working.
Heavyweight wool coolers are handy for extremely cold days but, if you're on a budget, one lightweight one will do the job for most conditions. In my experience, polar fleece doesn't wick quite as effectively as wool, but it is more durable and easier to work with because it's machine washable and moth-resistant. Coolers are also now available in various types of high-tech synthetic wicking materials. These work well, too.
Cotton, on the other hand, is not a good wicking material. It holds moisture against your horse's skin, making him clammy. (If you know any hikers, you may have heard the saying, "Cotton kills.") So, although Irish-knit coolers have been used on horses for years, and they're fine for warm, sunny days, I'd avoid putting one on a damp horse in cooler weather.
Here's how to use your cooler.
Drying a Warm Horse
After a winter day's ride, your unclipped horse may be damp with sweat even after he has cooled out--that is, his body temperature has returned to normal. The key to helping him dry is to enhance, rather than interfere with, the coat's natural wicking process I described above without making him so warm that he begins to sweat again. It's very common for riders to pile too many blankets on their horses after a workout, thinking that their mounts are cooling off as quickly as they are themselves. But equine body temperatures don't drop as quickly as humans' do. A horse's just-worked muscles can easily heat up again to the point where he "re-sweats" if you cover him with blankets, particularly if he is unfit or his workout was harder than usual.
To prevent this from happening, end your ride with 5 to 10 minutes of walking, either under saddle or by hand, to bring your horse's breathing and skin temperature back to normal. Watch his nostrils or sides to monitor his breathing and feel his neck and shoulders with a bare hand to check his temperature. There is usually no need for him to wear a cooler while you walk him under saddle; you can add a rump rug or quarter sheet for the last few minutes of your ride if it's especially windy or cold. (If you cover your horse before his body temperature returns to normal, he may become too warm and break out in a "second sweat.")
After you've cooled him out, dismounted and untacked, give him a quick brushing to "straighten" any hairs that were matted or mussed by sweat and tack, then dress him in your lightweight cooler. Secure it well enough to keep it from shifting as he moves around in his stall. Some coolers come fitted with chest and belly straps for this purpose. More traditional, square coolers need to be closed in the front with a blanket clip--a large metal utility-type clip--and held in place with an elastic surcingle. (Both are available through tack stores and online catalogs.)
If you plan to turn out your horse after your ride, cover the cooler with a lightweight, water-resistant, breathable turnout sheet. This will protect the cooler from rips and tears and help hold it in place. Things tend to slip around more when horses are turned out, so fitted, secured coolers are best in this case. The turnout sheet also will provide some defense against the elements while your horse's natural "weatherproofing" system is being restored to normal. But it won't prevent your horse from drying off thoroughly. (On the other hand, if you put on just a turnout sheet without a cooler underneath, you'll lose that valuable air space above the skin and slow the wicking substantially. I would only recommend doing this with a horse that is just slightly damp in the flank area, for instance.) Some manufacturers now make breathable, water-resistant turnout sheets with mesh linings that create the air space necessary for wicking moisture. These can be used on damp horses without a cooler underneath.
With this clothing secured in place, you can leave your horse to dry off on his own, so long as you're sure he's completely cooled down and not overblanketed. (To check this, slip a hand under his cooler to feel his chest and flank areas. They shouldn't be any warmer than your own skin. The first few times you use the cooler, you may want to check him again after half an hour or so.) Depending on how wet your horse is, it may take him an hour or more to dry off completely after a ride.
I often go back to work after a midday ride, leaving my horse's cooler on until I get home in the evening. If you ride late in the day and need to turn out your horse for the night, it's OK to leave a cooler and turnout sheet on overnight. When you do remove his clothing, "fluff" up any matted or flattened hair with a stiff brush to restore its normal texture. (Like wet hair, matted hair loses its ability to trap warm air around the horse's body.)
Additional Drying Tips
On most days, the process I described above should dry your horse sufficiently. However, if he's extremely wet, you may want to do a little manual drying before applying a cooler. I've had the best success with a household-cleaning product called Micro Fiber Miracle Cloth. It is made of super-absorbent fabric that holds many times its weight in moisture. You can rub it over your horse's dampest areas, such as the saddle and girth area, ears and flank, wring it out when it's saturated and rub some more.
In rare cases, an extremely wet horse may saturate a cooler with sweat before he's completely dry. This will slow down the drying process. You'll know it has happened when the cooler feels wringing wet. Leaving a saturated wool or polar fleece cooler on your horse is still better than exposing his damp body to wind and cold. However, if you have more than one cooler, replacing the saturated cooler with a dry one will speed things up.
Placing handfuls of hay or straw underneath your horse's cooler or between two coolers can enhance the wicking even further. Not only does the hay or straw absorb some of the moisture, it adds an extra layer of air space around your horse, helping to draw the water droplets to the outer layer of clothing where it can then evaporate. Be sure to put hay in front of your horse as well, so he's not tempted to reach around and eat what's under his cooler. It's usually not a good idea to try this on horses turned out together, as it encourages them to nibble at each other's coolers.
Drying a Cold Horse
All of the above techniques also work for drying a horse brought in soaking wet from rain. However, if the weather has chilled your horse, too, he won't have the added benefit of body heat to drive the moisture away from his skin. So to keep him from getting too cold and to speed up the drying process, you may need to use a heavier cooler or an additional blanket layered over the cooler. A little extra rubbing with the Magic Cloth will help, too. As your horse dries, be sure to monitor his temperature carefully, feeling his chest and flanks for overheating and watching for shivering that would indicate he's too cold. In the latter case, you may need to replace the first cooler with a dry one or add more layers to warm him up again.
Dr. Heather Hoyns is an equine veterinarian with her own practice, Evergreen Equine, in West Windsor, Vermont. She also has competed in trail and endurance riding since the late 1970s. Down-to-earth stable management techniques help her make time for conditioning two horses for 50- and 100-mile rides, in addition to working a full-time job.
She explains, "I'm a fan of the KISS principle--Keep It Simple!" Among other recent successes, she and her 14-year-old partner, Just Bill, won the second day of the 2006 Mustang Memorial 50/50-mile ride in the Pine Barrens of New Jersey.