Left, static endoscopic image of an 18-year-old Percheron with respiratory distress. Note the marked enlargement of the right arytenoid cartilage and narrow to absent airway. Note the marked edema of the adjacent aryepiglottic folds as they curl around the epiglottis. Right: Endoscopic image of the same horse after 10 days of medical therapy consisting of anti-inflammatory medication and broad-spectrum antimicrobials. Note the reduction in size of the right arytenoid and some improvement in the size of the airway opening.