Equine asthma, formerly called COPD or RAO, causes chronic breathing difficulty in horses. Environmental management is the cornerstone of welfare-focused treatment.
A horse with severe equine asthma working to breathe at rest is in constant respiratory distress - every breath requires effort and the sensation is comparable to breathing through a constricted airway. The welfare response is environmental: moving to field conditions, soaking hay, using paper or rubber-crumb bedding instead of straw, and improving stable ventilation. Medical management with bronchodilators and corticosteroids reduces airway inflammation, but without environmental change the triggers remain. Outdoor living is often the single most effective welfare intervention.