THE RAPID AND EFFECTIVE ADMINISTRATION OF A BETA-2-AGONIST TO HORSES WITH HEAVES USING A COMPACT INHALATION DEVICE AND METERED-DOSE INHALERS

The purpose of the study was to administer therapeutic aerosol generat ed by metered-dose inhalers to horses exhibiting clinical signs of hea ves using a compact inhalation device developed for human medicine. It was fitted to a custom face mask in order to study the effect of an i nhaled beta2-agonist, fenoterol. Pulmonary function testing was perfor med on six horses following an acute exacerbation of heaves, character ized by tachypnea, wheezes, crackles, and spasmodic cough. Horses inha led fenoterol in 1 mg increments administered as one 200 mug puff ever y 5-10 s with the recording of data 5 min after the cessation of drug inhalation. A significant effect of fenoterol was shown for maximum ch ange in transpulmonary pressure, dynamic compliance, lung resistance, and work of breathing, and the wheezes and crackles disappeared when a uscultation was performed at the end of the test. This study demonstra tes a novel, highly effective method for the rapid administration of i nhaled medication in horses.