Keeping Horse Airways Healthy During Winter
Take a look around your barn, what do you see? Horses in their half-mucked stalls with straw or shavings and a wheelbarrow and pitchfork right outside; the tractor running at the barn door; hay bales piled outside stalls and at the end of the shedrow; a fan on the floor; piles of blankets, coolers, slinkies, bandages, and wraps; dusty shelves covered with medications and first aid supplies; a tack room “graveyard” of retired equipment; sunbeams struggling to shine through dirt-covered windows with dust motes dancing in the light.

“Barns are inherently difficult to keep clean, but dusty barns can wreak havoc on some horse’s respiratory health,” said Melissa Millerick-May, MSc, PhD, assistant professor of medicine in Michigan State University’s Division of Occupational and Environmental Medicine, in East Lansing. “This can result in airway inflammation in both young and older horses and exacerbate symptoms in horses previously diagnosed with heaves (or recurrent airway obstruction, also called equine asthma).”

Millerick-May has shown via research that air particles measuring 10 microns in diameter—which is smaller than the human eye can detect—or less can reach horses’ lower airways and cause problems, including inflammation and mucus accumulation. Those small particles tend to travel with larger particles, which are inhaled and irritate the upper airways. This means that if we can see dust motes in the barn, we need to consider the small particles moving with them as a potential hazard for airway health in our horses and ourselves.

“There are several easily implemented management strategies designed to reduce dust and other respiratory irritants to help minimize inflammation in your horses’ airways, which are known to negatively affect performance,” Millerick-May said. “These practices should be established even if your horse hasn’t developed overt signs of respiratory disease, as in most cases of IAD (inflammatory airway disease, a less severe type of equine asthma). These horses may be characterized as not meeting performance expectations, resistant (to work), not able to maintain a level of ‘effort’ that shouldn’t be a problem given their training schedule, etc.”

Millerick-May also noted that such small particles can also affect human airway health: “By implementing low-dust control methods, we’re likely to improve our own health as well.”

Consider these tips to help protect your horse’s breathing zone (the 2-foot sphere around the horse’s nose from where he draws his breath) and most effectively achieve optimal respiratory health:

  • House your horse outside as often as possible, even during the winter. Barns are home to countless motes, mites, and molds, and many horses have no trouble being maintained outdoors almost year-round.
  • However, avoid simply throwing a round bale in the paddock or pasture. Horses often dig their noses into the bale, all the while inhaling dust, mold, and other particles buried deep within the hay. This, of course, negates the benefits of living on pasture. If you need to supplement with round bales, store them elsewhere and place measured amounts of hay in the pastures to be fully consumed daily.
  • Consider soaking or steaming hay to minimize inhalation of dust and mold; feed hay off the floor to promote mucus drainage from the airways; or use low-dust hay alternatives such as haylage, complete pelleted feeds, or alfalfa cubes. If you must use a haynet, use a slow feeder to prevent the horse from burying his nose in the hay, also making it more difficult to grab hay within the net and shake it.
  • If your horse must be stabled frequently during winter, use good-quality, low-dust bedding.
  • Always turn horses out before mucking out, sweeping, or cleaning the barn, and leave them out for a while afterwards. It takes several hours for the dust to settle.
  • Consider using an agent designed to reduce ammonia levels in stalls.
  • Don’t leave vehicles/tractors running near horses.
  • Avoid storing potentially dusty hay or bedding materials near horses.
  • Leave doors and windows open, even during winter, to promote air circulation and promote ventilation.

“If you see dust, you can be confident that there are particles capable of reaching the lower airways, putting the horse at risk for the development of respiratory issues,” Millerick-May concluded. “Every change an owner adopts will ultimately benefit the horses’ respiratory tract. These changes need not be difficult to implement or expensive in order to make a big difference.”