Recurrent Airway Obstruction in Horses: Asthma Management
Recurrent airway obstruction (RAO/equine asthma) causes chronic airway inflammation and bronchoconstriction in horses, significantly compromising respiratory welfare and exercise ability.
Key Facts
- RAO is triggered by inhaled allergens, primarily fungal spores in hay and bedding
- Affected horses show nasal discharge, cough, labored breathing at rest in severe cases
- Management centers on reducing inhaled allergen load through hay and bedding changes
- Bronchodilators and corticosteroids provide relief during acute exacerbations
- Outdoor living on pasture is often the most effective welfare intervention
Welfare Considerations
RAO welfare management requires fundamental changes to how affected horses are housed and fed. The primary welfare intervention — reducing allergen exposure — conflicts with traditional stable management practices using dry hay and straw bedding. Soaking or steaming hay, using haylage, switching to paper or rubber bedding, and maximizing outdoor time can dramatically reduce allergen load. Horses with severe RAO struggle to breathe at rest during exacerbations, showing increased respiratory rate, abdominal effort in breathing, and flared nostrils. Prompt bronchodilator treatment during acute episodes provides important welfare relief.
What You Can Do
- Move horses with RAO to outdoor living on pasture where possible
- Switch from dry hay to soaked, steamed hay, or haylage
- Change bedding from straw to dust-free alternatives
- Maximize ventilation in any stable housing for affected horses
- Work with your vet on a bronchodilator protocol for acute exacerbations