Recurrent airway obstruction (RAO), formerly called heaves, is a common chronic inflammatory lung condition in horses requiring lifelong management to maintain breathing comfort and performance.
RAO causes ongoing respiratory discomfort that impairs quality of life significantly, particularly in severe cases where horses struggle to breathe at rest. The chronic nature of the condition means affected horses experience recurring distress over years or decades without a cure. Well-managed horses can maintain reasonable quality of life, but management is intensive — hay must be soaked or replaced with alternative forage, bedding must be dust-free, and stabling minimized. These requirements create challenges in traditional management systems. Horses that develop the characteristic heave line are already in chronic respiratory distress, indicating prolonged inadequate management. Early intervention with dust reduction measures is the most important welfare action, potentially preventing the chronic irreversible changes that come with long-standing disease.