Equine Epiglottic Entrapment Study Guide

Overview and Clinical Importance

Epiglottic entrapment (EE) is a common upper respiratory tract disorder affecting athletic horses, particularly Thoroughbreds and Standardbreds. In this condition, the aryepiglottic fold (subepiglottic tissue) becomes abnormally positioned and envelops the dorsal surface of the epiglottis, obscuring its normal serrated margins and vascular pattern. The condition has a reported incidence of 0.9-5% in racehorses and represents a significant cause of poor performance and abnormal respiratory noise during exercise.

Understanding epiglottic entrapment is essential for the NAVLE because it tests knowledge of equine upper airway anatomy, diagnostic endoscopy interpretation, and surgical treatment options commonly encountered in equine practice.

Anatomy and Pathophysiology

Normal Laryngeal Anatomy

The epiglottis is a triangular, leaf-shaped elastic cartilage that forms the rostral boundary of the larynx. In horses, the epiglottis normally rests dorsal to the soft palate and is essential for maintaining obligate nasal breathing and protecting the lower airways during swallowing. The epiglottis is covered by well-vascularized mucous membrane that is closely adherent to the cartilage on both its dorsal and ventral (lingual) surfaces.