Emily Decker, DVM

December 2005

The chilly winter months in Minnesota can make playing and working outdoors fairly unpleasant, to say the least.  In most cases, this includes riding.  Although your horse may not mind the decreased work during these months, it does not mean that he or she requires less care 

During the winter months, most horse’s nutritional needs do not change dramatically.  Although horses do use slightly more energy to keep warm during cold days, they are often much less active and therefore do not require extra calories.  Many horses do very well on hay alone over the winter and don’t require extra grain.  In fact, studies have shown that the slower digestion of hay in a horse’s gastrointestinal system produces more heat than digestion of grain with similar energy contents.  Some horses will require supplementation with grain but a horse’s diet should consist of at least 50% hay.  At any time of the year, a diet higher in forages decreases boredom and promotes good gastrointestinal health. 

In the winter, however, horses do not have pasture available to supplement the quality of their hay and it is therefore very important to provide quality forage for your horse during this time.  Most feed mills will analyze the quality of your hay for a very small fee.  Another quick way to determine quality of hay is to feel the hay.  Good quality hay should be soft:  your hand should not hurt if you plunge your fist into the middle of a bale.  In addition, the hay should not be dusty or moldy.  Although they may be cheaper, round bales are notorious for containing mold.  Mold and dust can cause chronic respiratory irritation or allergic reactions, which can lead to a disease known as recurrent airway obstruction or heaves.  Heaves can be a lifelong and career-ending condition for horses, and its treatment can be considerably more expensive than the extra cost of square bales.

Finding good quality hay takes time and effort.  Often, it is easiest and most economical to buy larger quantities of hay during the growing season (late summer and fall) to last throughout the winter.  It is equally important to keep your hay in good shape throughout the winter.  Even the best hay can become moldy and lose important nutrients if it becomes wet.  Hay should be stored off the ground in a dry building or under a waterproof canvas (plastic can be punctured and can even trap water inside).  Although haylofts above stalls are great for preserving the quality of hay, they unfortunately create a constant stream of small dust and hay particles that rain down over your horse’s head.  This constant irritation, even from quality hay, can also predispose horses to heaves. 

Some older horses may have difficulty digesting hay.  There are complete feeds available that provide all required nutrients and roughage in a pelleted, easy-to-digest form.  Speak with your veterinarian to determine if this type of feed could benefit your horse. 

As the weather begins to change and your horse’s coat grows longer, it is much more difficult to identify weight loss.  As with any time of year, you should be able to just barely feel your horse’s ribs, underneath his heavy hair coat.  In addition, using a weight tape to determine your horse’s weight is an accurate and cost effective way to watch your horses weight over the winter months.

When temperatures drop, we often want to bundle up ourselves and our horses.  However, when dry, horses are very comfortable at temperatures down to 18⁰F, and can tolerate temperatures down 0⁰F very well with an adequate hair coat. Extra blankets and heating at these temperatures can actually make a horse uncomfortably warm!  When temperatures drop below 0⁰F or if your horse has a poor winter hair coat, a winter blanket is a great option for keeping outdoor horses comfortable.  Wet hair coats and wind decrease a horse’s cold tolerance dramatically, though; so it is important to provide shelter for your animals during our winter season and to change wet blankets if you choose to use them.  An adequate shelter can be as simple as a covered, three-sided run-in shed.  If you decide to stable your horse this winter, it is essential to use a barn with good ventilation.  Poor ventilation can lead to excess dust and ammonia in the air, which predisposes horses to respiratory diseases such as heaves and pneumonia.  While a run-in shed or open doors and windows may be uncomfortable for you during cold days, they are a very comfortable and healthy situation for your horse. 

Whether you keep your horses inside or out water that is fresh and not frozen is essential during winter months.  Snow and ice do provide some water to horses, but require more energy to convert to water and are not sufficient to provide proper hydration for your horse.  Dehydrated horses are at a much higher risk for developing colic, choke, and many other diseases.  Therefore, it is important to check and replenish fresh water daily in the winter to ensure that the water has not frozen.  Tank heaters can be purchased and are wonderful for preventing freezing; however, daily checks are still necessary.  Heaters can occasionally break or even electrify a water tank.  They can also melt a plastic tank – tank guards can be easily purchased and prevent this from happening. 

Intestinal parasites such as bots, large and small stronglyes, and pinworms don’t survive well in cold weather, and when the weather turns cold, they look for a place to stay warm over the winter.  That “place” is your horse.  In addition, although dewormers are very effective at killing most life stages of parasite larvae, a few stages are resistant and will continue to grow in your horses even after a deworming.  Therefore, you should continue your deworming schedule throughout the winter months to prevent a large build-up of parasites in the spring.

Just as for people, winter can be a very slippery time of year for your horse.  It is best to remove shoes during the winter for better traction.  Many horses that require shoes during the summer are ridden less during the winter and do very well unshod.  However, if your horse is uncomfortable without them, shoes with studs have been designed to give better traction for your horse.  With or without shoes, regular trimmings are just as important during the winter as in the summer.  The hard, frozen ground increases the risk for hoof cracks, chips and other injuries.  A well-trimmed foot is the best prevention for these ailments.  The concave shape of a horse’s sole creates a perfect environment for ice and snow to collect and form an “ice ball”.  These balls can create painful and slippery conditions for your horse.  To prevent their formation, it is best to pick your horse’s feet daily during cold, snowy periods.

Although horse care can be somewhat tiresome on those cold, Minnesota winter days, it is very important for the health of your horse.  We owe it to our equine friends to provide good care year-round and also to ensure that our horses have many more summers to enjoy with us.