Equine asthma, including both mild-moderate and severe forms (previously called heaves or RAO), causes chronic respiratory difficulty requiring management of both the acute condition and underlying triggers.
Equine asthma causes suffering that ranges from chronic mild discomfort to severe respiratory distress. Horses with severe asthma exhibit visible effort breathing at rest - the heave line of hypertrophied abdominal muscles is visible on inspection. This represents significant welfare compromise affecting the horse's ability to exercise, rest comfortably, and engage normally with its environment. Even mild-moderate asthma causes subclinical compromise of performance and comfort. The encouraging news is that environmental management - particularly hay steaming, dust-free bedding, and maximizing outdoor time - can produce dramatic clinical improvement without reliance on long-term medication.