Epiglottic Entrapment in Horses
Epiglottic entrapment is a less common cause of respiratory noise and exercise intolerance. In this condition, the aryepiglottic fold completely envelops the apex and lateral margins of the epiglottis. The general shape of the epiglottis is visible, and the position (dorsal to the soft palate) is appropriate. However, the distinct serrated margins of the epiglottis and the dorsal epiglottic vascular pattern are obscured by a fold of aryepiglottic mucosa. Clinical signs of epiglottic entrapment include inspiratory and expiratory respiratory noise during exercise and poor exercise performance. Less common signs include cough, nasal discharge, and headshaking. In mature nonracehorses, cough is the most consistent presenting complaint. Diagnosis is determined by endoscopic examination. Surgical correction of epiglottic entrapment is axial division of the aryepiglottic fold to free the epiglottis. Axial transection of the aryepiglottic fold may be performed by transendoscopic contact Nd:YAG laser, transnasal or transoral transection via curved bistoury, or direct excision through a laryngotomy or pharyngotomy. Surgical transection is generally curative, with a relapse rate of 5%. Some affected horses can race successfully with the condition.