Low-intensity exercise may ease airway resistance in severe equine asthma

Version 1

A new Equine Veterinary Journal study suggests that low-intensity, field-applicable exercise may temporarily improve airflow in horses with severe equine asthma. In the study, led by Sophie Mainguy-Seers, Sarah-Maude Grondin, and Jean-Pierre Lavoie, pulmonary resistance fell by about 50% after submaximal aerobic exercise, from 2.6 to 1.3 cm H2O/L/s, while a turnout control intervention did not change resistance. The authors say that degree of bronchodilation was comparable to bronchodilator therapy, raising the possibility that carefully managed exercise could have therapeutic value in some horses with severe asthma. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinarians, the finding adds nuance to a disease area where environmental management remains the foundation of care, and where bronchodilators help airway spasm but don’t address underlying inflammation. Severe equine asthma is strongly linked to inhaled barn and hay allergens, and experts continue to stress low-dust management, turnout, ventilation, and forage changes as first-line strategies. That context matters because a bronchodilation signal from exercise is intriguing, but it shouldn’t be read as a substitute for controlling dust exposure or for anti-inflammatory treatment when indicated. Recent work on steamed hay also underscores how difficult nonpharmacologic management can be: in a 2025 crossover study, steamed hay still produced mild but significant worsening in lung function and airway inflammation, with no significant advantage over dry hay under the study conditions. (thehorse.com)

What to watch: The next question is whether repeat low-intensity exercise can deliver durable clinical benefit in real-world cases, and how it might fit alongside standard medical therapy and environmental control. (pubmed.ncbi.nlm.nih.gov)