Endoscopic appearance of the glossoepiglottic fold of normal horses

Abstract

The objective was to characterize the endoscopic appearance of the glossoepiglottic fold (GEF) in normal horses. Six clinically normal adult Quarter Horses between 5 and 7 years of age were used and ranged from 480 to 520 kg body weight. Prior to oropharyngeal endoscopic examination, all horses had demonstrated normal function of the upper respiratory tract during high-speed treadmill examination. The horses were cantered at between 6.5 and 8.0 m s− 1 on a high-speed treadmill until fatigued and unable to maintain position on the treadmill. All horses were able to canter for at least 5 min. Oropharyngeal endoscopy was performed under intravenous general anaesthesia. The ventral aspect of the epiglottis and the GEF were examined with the aid of a specially designed epiglottic elevator. The endoscopic appearance of the oropharynx was documented using digital image capture technology Karl Storz AIDA™ Vet compact data archiving system (Karl Storz Veterinary Endoscopy America Inc., Goleta, CA, USA). In all horses, the GEF attached to the most caudo ventral aspect of the base of the epiglottis. The mucosa of the GEF was consistently plicated in the transverse plane, and in no horse, was there plication in the sagittal plane only. The clinical relevance included malformations of the GEF, which have been implicated in the etiopathogenesis of dorsal displacement of the soft palate. The results of this study may facilitate the differentiation of normal oropharyngeal anatomy from malformations (frenula) that may contribute to upper airway dysfunction.