Equine asthma — formerly called heaves or recurrent airway obstruction — causes chronic breathing difficulty in horses and requires comprehensive environmental and medical management.
Equine asthma causes genuine respiratory distress that substantially impairs quality of life in affected horses. During exacerbations, horses experience the equivalent of severe asthma attacks — breathlessness, effort to ventilate, and exercise intolerance that prevents normal activity. The chronic nature of the condition means that inadequately managed horses live with intermittent severe respiratory episodes and reduced baseline respiratory function. Environmental management is the cornerstone of control: dust exposure from conventional hay and bedding is the primary trigger, and eliminating this exposure through soaked or haylage-form forage and dust-extracted bedding substantially reduces exacerbation frequency. Combined with inhaled corticosteroid therapy, horses with equine asthma can maintain good quality of life.