Endoscopic examination of the equine paranasal sinuses

THE majority of horses which present with a unilateral nasal discharge will have a disorder of the paranasal sinuses. The history and results of a physical clinical examination are often insufficient for providing a definitive diagnosis of the cause of sinusitis and further evaluation is therefore necessary. At present, radiography, nasal endoscopy and sinocentesis are the most commonly used diagnostic techniques. Recently, the use of direct endoscopic examination of the paranasal sinuses or ‘sinuscopy’ has become a useful adjunct in the evaluation of equine sinus disorders. This article discusses the technique of sinuscopy, using either an arthroscope or flexible endoscope, as well as describing the normal sinus structures and sampling/postoperative options.