Long Winter Hair Obscures Horse’s Actual Body Condition

Spring is more than two weeks ago, and many horse owners have noticed deterioration in their favorite mount’s body condition.

“Long winter hair can often give the false assumption that certain horses are fat when they are actually thin,” according to veterinarian Dr. Thomas R. Lenz.

Temperatures between 15 and 60 degrees F are considered energy neutral for horses. “Horses don’t need extra energy or calories to stay warm in that temperature range,” said the senior director of Equine Technical Services for Zoetis Animal Health.

However, this assumes that the wind is not blowing and the horse’s hair coat is not wet. “Both of these conditions increase the horse’s caloric needs,” Lenz added.

When it’s cold, horse owners are reminded to focus on providing plenty of long-stemmed hay, preferably free choice. “Unlike grains, additional hay can quickly be added to a horse’s diet without risk of colic or founder,” Lenz pointed out.

An idle horse in comfortable weather eats 3 percent of his body weight in feed daily. “At least half of that should be forage,” the veterinarian explained.

“Now toward winter’s end, give your horses a thorough going-over to make sure that the cold winter months have not taken a toll on body condition,” Lenz encouraged.

“Pay particular attention to very old or young horses,” he added.

Horses instinctively know when they need extra calories to increase body temperature and maintain weight, Lenz stated.

Horses instinctively know when they need extra calories to increase body temperature and maintain weight.

“Unfortunately, most horses are on a fixed diet,” the horse specialist verified. “When additional calories are required to maintain body weight, they’re at the mercy of their owner to adjust the feed ration.”

Don’t be deceived by woolly winter hair coats that can make a horse look fat, he reiterated.

“During cold weather, horses that are not receiving adequate rations first burn stored fat and then protein from muscle tissue to fuel daily activities,” Lenz said.

 Initially, fat reserves stored along the ribs, crest of the neck and rump are used. “Then the muscles in the neck, shoulder and hindquarters are sacrificed,” Lenz explained. “So when trying to assess body condition on a winter-coated horse, run your hands over the horse’s back, hips and ribs to determine if he is losing weight.

“If you are uncomfortable estimating weight loss through palpation, use a weight tape to check the horse’s weight,” Lenz advised.

“Keep in mind that hay, not grain, is the best feed to help a horse generate body heat,” Lenz said.

“The heat of digestion from five pounds of extra hay will raise the average horse’s core body temperature 1.2 degrees for nearly four hours,” Lenz detailed.

 Forage is digested in the horse’s large intestine through bacterial fermentation, which not only provides nutrients but also generates heat.

When faced with cold weather, many horse owners tend to keep their horses’ hay intake constant while increasing the grain portion of the diet.

“Although grains are very calorie dense and work well to fatten a horse, they are low in fiber and generate little heat,” Lenz said.

A pound of corn contains 1,800 calories, while a pound of oats contains 1,500. So, additional grain provided in the fall will add a layer of fat that serves to insulate the horse and does help him retain heat, Lenz pointed out.

Dr. Thomas R. Lenz, D.V.M., M.S., is a past president of the American Association of Equine Practitioners (AAEP) and has been a lifelong advocate for the welfare of the horse.

“Good-quality hay should be the foundation of any equine diet and the first component to be increased to generate heat or regain body condition,” Lenz emphasized.

“If a horse continues to lose weight on hay, add grain to increase the caloric supply,” the veterinarian advised.

“Remember that the sudden addition or increase of grain in a horse’s diet, especially of corn or barley, can cause colic or founder, so add grain slowly over several days,” Lenz concluded.