Conscientious attention to winter nutrition can prevent colic, laminitis, and a loss of condition.  Feed high quality feeds on a regular schedule and ensure adequate water intake by checking a horse's water source twice daily.  Horses can only last for three days without water.   Horses drink between eight and twelve gallons of water a day.  Although during the winter months, intake will be at the low end of the range, the effects of dehydration can easily go unnoticed during winter months.  Forcing horses to produce moisture by eating snow is counter-productive.  In addition to the fact that six times as much snow must be eaten to provide an equivalent amount of water, horses must use precious body heat to melt the snow.  This requires them to use up calories that could be used for warmth just to satisfy their thirst.

Offering horses warm water late in the morning (during the "heat of the day") after they have eaten roughage, usually assures they will drink.  Breaking the ice on a trough or creek at 6 AM or 8 PM is usually a waste of time.  Not too many horses will drink during these coldest times of the day.  Automatic waterers are convenient but you must check them daily to be sure they are functioning.  There should be a back-up watering system in the event of a power failure.  When using automatic waterers, it is nearly impossible for an owner to tell if and how much a horse is drinking.

If a horse's flank appears "drawn up", he may not be getting adequate water.  Being familiar with a horse's normal fecal consistency and checking it routinely during the winter will give you an additional indication of the state of the horse's dehydration.  Performing the pinch test on the neck gives an even better assessment of body fluid level.  Grasp a fold of skin between the thumb and forefinger.  Raise it above the muscle for one second and then let go.  It should return to its flattened position on the neck within a second or two.  A "standing tent" of a longer duration indicates dehydration. 

During winter, as well as other times of the year, a horse's ration should be formulated to satisfy the requirements for age (stage of growth), phase of pregnancy (or lactation), and level of work.  In addition, the ration will need to be adjusted to compensate for weather stresses.          For every ten degrees Fahrenheit below freezing, the hay ration should be increased 10%.  When it is twelve degrees above zero Fahrenheit (twenty degrees below freezing), the normal 20 pound hay ration of a 1200 pound horse may be increased to 24 pounds per day (a 20% increase).  Horses fed less than is necessary to combat cold and wind will burn fat and muscle tissue by shivering to keep warm and will lose weight.

Contrary to popular belief, feeding grain will NOT appreciably increase a horse's body warmth, but feeding increased roughage will.  The heat of digestion (in terms of calories) is greater and lasts longer from hay than from concentrates.  It is most beneficial to feed a horse several hours in advance of a storm rather than during it.  Immediately after a large meal, blood is concentrated around and in the digestive tract rather than in the muscles where it is needed for warmth.

Because of winter's snows and sunny thaws, feeds can spoil easily.  Damp hay, pellets, or grain can become fermented or moldy in a matter of a few hours in the sun.  Check feed over carefully during daylight hours, then offer an amount that will be cleaned up in one feeding, and remove what is left.