Horse Respiratory Health: Recurrent Airway Obstruction

Recurrent Airway Obstruction (RAO/heaves) is a common, debilitating respiratory condition in horses closely linked to stable management and bedding choices.

Key Facts

RAO (equine asthma) affects an estimated 10-15% of horses in temperate climates
The condition is triggered by allergens including dust, fungal spores, and endotoxins in hay and bedding
Straw bedding and conventional hay are the most common triggers in stabled horses
Horses with RAO show labored breathing, mucus, coughing, and reduced exercise tolerance
Moving affected horses to pasture or using soaked hay and dust-free bedding dramatically improves symptoms

Welfare Considerations

RAO causes chronic respiratory distress that significantly impairs quality of life. Horses with poorly managed RAO breathe with visible effort even at rest, and exercise causes oxygen deficit and distress. The good news is that environmental management dramatically improves most cases: soaking or steaming hay removes 90% of respirable particles; dust-free bedding materials (paper, rubber mats, cardboard) eliminate the primary trigger. Medication (bronchodilators, corticosteroids) provides additional relief but works best alongside environmental changes.

What You Can Do

Soak hay for 30-60 minutes or use steamed/haylage for horses with respiratory issues
Switch from straw to dust-free bedding (paper, hemp, rubber) for affected horses
Ensure maximum ventilation in stables — air changes reduce allergen concentration dramatically
Avoid sweeping or mucking out while horses are stabled; move them out first
Consult a vet about bronchodilator and corticosteroid treatment for clinically affected horses