Epiglottic entrapment by arytenoepiglottic folds in the horse.

An abnormality of the epiglottis and arytenoepiglottic folds that caused epiglottic entrapment was diagnosed in 21 horses. Until recently, this entrapment was poorly understood. Definitive diagnosis of epiglottic entrapment can be made only by endoscopic examination of the epiglottis, arytenoepiglottic folds, and soft palate to differentiate the abnormality from dorsal displacement of the soft palate. Dorsal displacement of the soft palate is often associated with entrapped epiglottis. Epiglottic deformity, especially hypoplasia, is often associated with the entrapment. The abnormality was detected in horses 1 to 16 years old. Because of the relatively large number of young animals (11 being less than or equal to 2 years old), a congenital predisposition was suggested. This suggestion was strengthened by the fact that many of the horses had deformities of the epiglottis that were considered congenital. Because some of the horses had trained and raced satisfactorily before signs of upper airway obstruction developed, it was assumed that the abnormality may be a sequel to epiglottic injury.