Horses can lose a significant amount of weight during a hard winter. It takes a lot of energy to stay warm in severe weather, and owners may not notice their horses losing condition if the process if gradual. Many horses wear blankets that can mask the appearance of ribs, and thick, wooly winter hair can make any horse look fatter than he actually is
To keep this problem to a minimum, start in the fall by weighing each horse or estimating weight by using a tape. Continue weighing about every two weeks and record the numbers. If a horse begins to lose weight, you can take steps to reverse the process before it becomes extreme.
Be sure all horses have plenty of hay. This serves several purposes: preventing boredom, providing calories, and fueling fermentation in the hindgut, the main source of a horse’s body heat. You may also need to provide more grain to prevent weight loss. If you are providing more than four or five pounds of concentrate, split this into two or three feedings to avoid overloading the horse’s relatively small stomach.
To get the most benefit from feed and hay, a horse’s teeth need to be in good condition. Having a veterinarian or equine dentist smooth out sharp points will allow the horse to chew comfortably, so this care should be scheduled at least once or twice every year.
Very old horses, very young horses, and those that have been sick or injured may tend to lose weight more easily than horses in prime condition. Thoroughbreds, Arabians, and other similar breeds are also more subject to weight loss than their stockier cousins like Quarter Horses and pony breeds. Because of these individual differences, consider the needs of each horse and work out a feeding program that meets his requirements. To allow the horse’s digestive tract to adapt safely, plan to make gradual changes to feed amounts and schedules.
Courtesy of Kentucky Equine Research