Recurrent Airway Obstruction in Horses: Welfare Management

Equine RAO causes chronic and episodic breathing difficulty in horses exposed to hay dust and mould, causing significant welfare impacts manageable through environmental change.

Key Facts

Recurrent airway obstruction (formerly called heaves or COPD) affects 10-14% of horses in temperate climates
RAO results from hypersensitivity to dust, mould spores, and other particles in hay and bedding
Affected horses show chronic cough, nasal discharge, and flared nostrils when breathing
Severe episodes cause laboured breathing with visible abdominal effort at rest
Management through soaking hay, using haylage, and improving stable ventilation significantly reduces signs

Welfare Considerations

Horses with RAO experience chronic respiratory effort and episodic crises of severe breathing difficulty. Severe episodes cause visible distress from laboured breathing, anxiety, and exhaustion from the effort of breathing. Chronic mild RAO causes persistent subclinical discomfort and reduced exercise tolerance. The good news is that environmental management dramatically improves welfare: transitioning from dry hay to soaked hay or haylage, improving stable ventilation, and using dust-free bedding reduces antigen exposure and allergen load causing significant clinical improvement.

What You Can Do

Soak hay for 30 minutes or use haylage for horses with RAO
Improve stable ventilation by opening windows and using ridge ventilation
Use dust-free bedding such as paper, cardboard, or rubber matting
Avoid storing hay above the stable where dust falls through
Use inhaled bronchodilators and corticosteroids as prescribed by your vet during acute episodes