Breathing Easy: Managing Horses with Asthma

Breathing Easy: Managing Horses with Asthma

Turning horses out when cleaning the barn and stalls, and waiting at least an hour after you're done before before bringing them back in is one simple step you can take to keep your horses breathing easy.

Photo: iStock

The latest on managing horses with equine asthma

It’s something that can be easy to forget. We neither inspect it daily for injuries or inconsistencies, as we do our horse’s body, nor do we watch it closely for subtle irregularities, as we do his gait. But it—the horse’s respiratory health—is vital. For our horses to thrive, much less be athletes, it must function properly, pumping massive amounts of air in and out of the body effortlessly.

A healthy horse at rest takes 10 to 14 breaths per minute, inhaling upwards of 150 liters of air in that time. But a horse diagnosed with asthma, just like his human counterpart, coughs, wheezes, and struggles to breathe. Airway inflammation and mucus accumulation associated with this condition make efficient performance nearly impossible for these horses.

Historically, we’ve known equine asthma better as inflammatory airway disease (IAD) and recurrent airway obstruction (RAO, or heaves), conditions that affect 25-80% of stabled horses in the United States, according to a 2006 paper by Tufts University’s Melissa Mazan, DVM, Dipl. ACVIM, and Andrew Hoffman, DVM, DVSc.

Since that paper was published, our perception of IAD and RAO has changed greatly. Because both of these diseases are characterized by airway inflammation and mucus accumulation, scientists are now labeling them equine asthma. A group of equine internal medicine specialists led by Laurent Couëtil, DVM, PhD, the section head of Large Animal Internal Medicine at Purdue University, in West Lafayette, Indiana, released a new consensus statement on the disease earlier this year (see

While a diagnosis of equine asthma can be devastating, there are many ways horse owners can help their animals, especially through management and environmental changes.

The Root of the Problem: Air Quality

Stables are full of tiny particulates that can infiltrate the equine respiratory system. Culprits include ammonia from urine; mold and fungi from hay, straw, sawdust, and shavings; dust from indoor arenas, rain, hay, and bedding; endotoxins from manure; and dander and hair from stablemates and companion animals.

“Organic dust exposure has been shown to result in long-term declines in respiratory function and increased prevalence of chronic lung diseases in humans—it is logical to expect that the same exposures will have similar effects on equine respiratory health,” says Mazan.

Dust particles, which can contain microorganisms such as bacteria and molds, and noxious compounds such as ammonia and toxins, exacerbate IAD and RAO, says Emmanuelle van Erck--Westergren, DVM, PhD, Dipl. ECEIM, founder and owner of Equine Sports Medicine Practice, a referral center in Waterloo, Belgium.

It’s difficult to visually assess barn air quality, though, because you’re dealing with microscopic particles, she says. All barns have some level of dust that can be inhaled, but the number, particulate composition, and size dictate whether or not they are harmful to horses (and people). Particles can reach the upper airways (which extend from the nostrils to the throat), trachea, and lower airways, (which include the lungs and the bronchi that supply them), and some are even small enough to dissipate throughout the body via the bloodstream.

Mazan says owners can rent air assessment equipment to check their stables. Some rental companies also analyze collected air samples. She says testing costs between $500 and $5,000, depending on the scope. If you don’t want to rent equipment, you can hire an environmental testing agency to do the analysis for you.

This article continues in the December 2016 issue of The Horse: Your Guide To Equine Health Care. Get expert advice on managing environmental triggers and medical treatments available to help horses with equine asthma when you subscribe now and get an immediate download of this issue.

About the Author

Sarah Evers Conrad

Sarah Evers Conrad has a bachelor’s of arts in journalism and equine science from Western Kentucky University. As a lifelong horse lover and equestrian, Conrad started her career at The Horse: Your Guide to Equine Health Care magazine. She has also worked for the United States Equestrian Federation as the managing editor of Equestrian magazine and director of e-communications and served as content manager/travel writer for a Caribbean travel agency. When she isn’t freelancing, Conrad spends her free time enjoying her family, reading, practicing photography, traveling, crocheting, and being around animals in her Lexington, Kentucky, home.

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