The equine inhaler is a device specifically developed to accurately administer Medicines to horses suffering from inflammatory respiratory diseases, including chronic obstructive pulmonary disease (recurrent airway obstruction - RAO). The equine inhaler is considered a convenient means to administer all types of metered-dose inhalers (MDI) available for horses. The MDI delivers the medication in an appropriate particle size (< 5 microns) for direct distribution to the small airways. The equine inhaler was developed in Denmark and tested at the Equine Studies Center, Animal Health Trust, Newmarket, UK. Documented studies show that the medication is distributed to the small airway system.