Abstract: A device and method are provided for convenient, patient compliant inhalation therapy of equine species. The device can be used to deliver any drug or other pharmaceutical agent which can be adapted for inhalation directly into the nasal passages of a horse and thereby provide inhalation therapy with minimal discomfort. The device can be used to treat any of a number of conditions including, EIPH, infections and allergies, e.g., asthma or heaves. In one embodiment, the invention provides a method for the treatment or prevention of EIPH, utilizing a composition adapted for inhalant therapy comprised of sildenafil citrate alone or in combination other agents.