HORSE HEALTH
The Case for
CLEAN AIR by Kim F. Miller
52 SUMMER ISSUE 2022
Perform dust-producing barn chores—like cleaning stalls and sweeping or blowing out barn aisles— while horses are outside.
PHOTO: VPROTASTCHIK/STOCK.ADOBE.COM
Hay and bedding are two major sources of respirable dust, but there are steps you can take to reduce dust—which can also help prevent or manage equine asthma.
A veterinary education would have been helpful to absorb every bit of information conveyed in the “Respiratory Diseases in Horses” session at last December’s American Association of Equine Practitioners convention in Nashville, Tenn. However, common sense was enough to get the main takeaway for horse owners: reducing respirable dust in the horse’s environment is critical to preventing or managing conditions on the equine asthma spectrum. The spectrum is broad, starting with mild and moderate asthma cases that are usually reversible. Severe equine asthma sits at the other end. It can cause remodeling of the airways and usually can only be managed, not cured. Inflammation in the airway causes all grades of equine asthma, and the main cause is respirable dust. Throughout the four-hour AAEP session, veterinarians were urged to help their owners recognize and reduce respirable dust in their horse’s living spaces. “Dust” might sound simple, but in the equine world it is a complex mixture of organic and inorganic matter. Bacteria, endotoxins, mites, mold, and fungal spores are common components. Myriad other particles in dust can activate the horse’s inflammatory and allergic responses. Triggers lurk everywhere, observed Dr. Renaud Léguillette of the University of Calgary Veterinary Medicine faculty. “Horses are shipped in trailers, live in stalls, and are fed inside stables,” he said. Even when these dust sources are identified, sustained owner compliance can be difficult. In a 2020 study1 of 49 horses with severe equine asthma, only six owners were described as “good” in following dust management recommendations. “For the six who did comply, the measures worked very well,” Léguillette noted. Clinical signs including breathing effort and coughing were much improved. “It’s frustrating, because even for those who do all these efforts, if there is one mistake in the chain—say, the owner is on holiday—it is not forgiven with asthma,” Léguillette said. “Doing a good job most of the time is not enough.” While that’s discouraging news, it’s also powerful inspiration to recognize and reduce respiratory risks before problems arise or progress to extremes.
PHOTOS: COURTESY HAYGAIN, SHELLEY PAULSON PHOTOGRAPHY
Recognizing and reducing respirable risks is critical to our horses’ respiratory health.
