Equine asthma (formerly heaves/RAO) affects a significant proportion of horses causing breathing difficulty that substantially impairs welfare and performance capacity.
Equine asthma causes significant ongoing discomfort and reduced quality of life — affected horses expend considerable effort on each breath during exacerbations and experience exercise intolerance that prevents normal activity. Severe cases involve labored breathing at rest with visible abdominal effort. The good news is that environmental management dramatically reduces disease burden: soaking hay, using dust-extracted bedding such as rubber matting or dust-free shavings, maximizing turnout time, and improving stable ventilation can achieve remarkable improvement even without medication. Horses managed in inappropriate high-dust environments suffer unnecessarily when effective prevention is available. Regular monitoring of respiratory rate and effort enables early detection of exacerbations.