To blanket or not to blanket? That is the question facing many horse lovers as cold winter weather approaches. There is, of course, no simple answer.
A Hairy Situation
Like many mammals, horses are better adapted to cold weather than to extreme hot weather. Horses have excellent thermoregulatory abilities for cold weather and possess reasonably thick skin, which helps to retain their body heat. As daylight hours shorten, horses start to grow their coats with not only more, but thicker hair. Obviously horses in northern climates grow more hair than horses living in warm areas, but all horses change their hair coats to some extent.
Along with having more hair, horses can adjust how their hair lies. Piloerection is the term used to describe the movement of hair via muscles to stand and increase the insulating ability of the coat. A normal, ungroomed coat will also accumulate some oils, which help to repel rain and snow, keeping your horse fairly dry right next to the skin.
Horses also depend on their body fat layer to provide some insulation. Thin horses may grow longer coats to compensate for their low fat levels. Ponies, who have a greater surface area ratio than big horses do, tend to grow very thick coats.
One of the major ways horses stay warm in cold weather is via their diet. Horses are designed to graze or eat much of the time (as opposed to ruminants like cows, who eat, then lie down and chew their cuds), as digesting and metabolizing fiber generates heat. A horse that goes outside and is not blanketed may need some extra calories to stay warm and comfortable during a cold winter. Ideally those calories should be top-quality hay, not concentrates.
Moving around while grazing or playing generates heat from muscle activity. Horses will also take advantage of cold, sunny days by soaking up those warm rays. On cold days when it is wet or windy, horses will seek shelter to stay warm and dry or will stand with their tail to the wind, using their rear muscles and body bulk to block the worst effects. Horses can stay comfortable in temperatures that are quite low when sheltered to avoid rain and wind. Healthy, fit horses can generally withstand the cold, unless temperatures fall below 10°F and stay that way for multiple days.
If horses adapt to cold weather so well, why blanket? If you wish to work your horse during cold temperatures, whether it’s for pleasure or competition, you will probably do some sort of body clip. Otherwise, your horse may sweat when worked and a wet horse has a much harder time maintaining body heat.
A horse that will be outside much of the time may need a blanket even without a clip if he does not have good shelter from wind and rain. Horses that are not in prime physical condition—young, old, thin or with chronic health conditions—may also need a blanket to supplement their own thermoregulatory system.
Here are some guidelines to follow if your horse will be wearing a blanket this winter:
- Make sure the blanket fits properly. Ideally you should remove the blanket daily, groom your horse thoroughly and replace the blanket. Check straps daily for twisting or breakage. Look for any tears in the fabric.
- Do not share blankets between horses without thoroughly washing and cleaning the blanket first. Sharing could lead to the spread of skin irritations.
- Use the correct blanket for your horse’s situation. If stabled outside, the blanket should be waterproof. The weight of the blanket will vary with your climate; true heavyweight blankets are only necessary in severe cold. Fly sheets really don’t provide any warmth and should be used mainly in the summer.
- Never put a blanket on a wet horse—including wet from sweat, not just rain or snow. You may need to have two blankets to swap out. If your blanket gets soaked-through, you will need a substitute while the first one dries.
Most horses do not need blankets during the winter months as long as they have shelter from wind, rain or snow plus plenty of good feed, especially forage. If you plan to work or show your horse during the winter months, you may want to consider some sort of body clip plus the use of a blanket.