Endoscopic examination of the upper respiratory tract and oesophagus in small ruminants: technique and normal appearance.

The aim of this study was to describe the technique of rhinolaryngotracheobronchoscopy and oesophagoscopy in small ruminants and to report the normal endoscopic appearance of the structures of the upper respiratory tract and oesophagus. Thirty sheep and 30 goats, all clinically normal, underwent rhinolaryngotracheobronchoscopy and oesophagoscopy using a flexible endoscope (length 100 cm; diameter 4 mm). The anatomical features of the structures and the appearance of the mucosa were investigated. The degree of mucosal pigmentation varied between breeds. The appearance of the pharyngeal tonsil and the shape of the trachea in cross-section showed most individual variation. The technique was easily performed and sedation was necessary in only a few cases. No major complications were encountered. It was concluded that the procedure facilitated more accurate diagnosis and prognosis of conditions of the upper respiratory tract and oesophagus.