Horse Tales: How does your horse keep warm?
‘Tis the season for winter’s cold and chill! Indoors, we’re able to throw another log on the fire, cozy up with some hot cocoa or tea and wear warm layers. When we go out and brave the frigid temperatures, we add a warm coat, hat, scarf, mittens and boots. But what about our horses?
Many people use blankets on horses that are very young, aged, thin, ill or in poor condition. Blankets are used especially on horses being shown during winter that have been clipped in order to manage sweating and drying more rapidly during cold temperatures.
In addition to blanketing and a warm barn, one of the most important things we can do for our horses is make sure they have plenty of hay or other roughage to eat. It’s the digestion of this high-fiber food, not that of concentrated feeds or grain, that activates the horse’s “indoor furnace.” It creates heat through the process of fermentation or microbial breakdown of the roughage in the horse’s hindgut (the cecum and large intestine), which acts as a natural internal heater.
The hay or roughage provides a continuously slow-burning source of energy that keeps the horse warm even at night. It is also extremely necessary to provide plenty of fresh ice-free water at all times.
Water is needed for the proper breakdown of the roughage and to ensure that the horse is able to eat all they need to keep warm.
But what about those horses that don’t have access to blankets or warm barns?
Fortunately, Mother Nature has equipped the horse with a sophisticated heating system in their own bodies.
The blunt shape of the horse’s muzzle has long nasal passages that have a lot of blood flow, which warm up cold air significantly before it enters the lungs, thus preventing the horse from losing body heat while breathing.
The horse’s beautiful, thick eyelashes protect its eyes from wind and cold temperatures.
The long legs of the horse enable it to keep its body raised out of the snow and cold mud that would remove heat from its core. The horse can also restrict blood flow to its legs and hooves, conserving core heat by minimizing the amount of blood moving through the less insulated parts of its body. (Horses’ hooves also have specialized blood circulation.)
No doubt you’ve noticed that horses will turn their backs to the cold and wind, actually fanning out the hairs on the dock (the fleshy, upper part of the horse’s tail). The skin and hair located on the horse’s rump and back are actually thicker and can better withstand the wind.
Horse skin is made of three layers: the epidermis, the dermis and the hypodermis. The epidermis (the top layer) has several waterproof layers. It contains specialized skin cells which migrate upward and continually replace sloughed skin cells. Other cells include the pigment-producing cells that give the skin and hair its color, and the specialized Langerhans cells that help fight infection (an important role in the immune system of the skin).
Although hair follicles pass through the epidermis, they are rooted in the layer just beneath, the dermis. This layer nurtures the epidermis. When the horse grows its winter coat, this coarser hair is set at an angle, with a fine layer of soft, downy hair underneath. Pockets of air are trapped between these layers of hair which can retain heat and provide an insulating layer, creating an effective windbreak. (For horses that are kept predominantly outdoors and are not covered with a blanket in cold weather, the winter coat will grow thicker than that of a horse that is stabled and blanketed.) The downward tilt of the haircoat serves to deflect raindrops and snowflakes before they reach the skin; the longer the haircoat, the more effective.
It’s important to provide shelter from the rain, whether a shed or run-in, to prevent horses from becoming wet, resulting in their coats laying down flat and eliminating that insulating layer of air. The dermis makes up the bulk of the skin, containing blood vessels, nerves, hair, sweat glands and sebaceous (oil) glands. The oils contained in the horse’s skin, called sebum, are produced by the sebaceous glands to keep the skin soft and moisturize the hair, providing a healthy, shiny coat in addition to creating a natural, slightly waterproof barrier – important in the cold and wet weather of winter to help keep the coat dry. The sebum also reduces water loss and is antimicrobial – it offers physical and chemical protection against infections.
The hypodermis is the final layer of skin, located beneath the dermis. It contains fat, blood vessels, nerves and muscles. The “twitch” muscles enable horses to discourage insects from landing on their skin. In addition, muscle movement, such as shivering, helps generate heat in the horse through muscle activity.
The hairs on the horse’s skin can actually move up and down to help regulate heating and cooling. This phenomenon is called piloerection. The elevation of the hair is due to contraction of the tiny muscles that lift the hair follicles above the rest of the skin, moving the hair vertically, giving the appearance of hair “standing on end.” This is what traps air in the hair next to the body, creating an insulating layer.
Whether or not to bathe your horse during winter depends on how often the horse is used. Of course it’s necessary to remove dried sweat, dirt and debris, especially after riding, as this foreign material can lead to all sorts of discomfort, including skin irritation, pain and infection. However, bathing too often can remove the protective layer of sebum in the horse’s coat and can cause flaky skin, itchiness, dandruff and even allergic reactions. Careful grooming (but not overgrooming) can remove such debris and will also alert you to any cuts, abrasions or changes in your horse’s skin.
Providing your horse with adequate free-range hay or roughage day and night, along with plenty of clean, ice-free water and a shelter to serve as a windbreak and place to get out of the rain and snow will enable the horse to use its abilities to stay warm in winter’s chill.
by Judy Van Put
