Identifying the causes of chronic unilateral nasal discharge in the horse

This article briefly reviews the causes of unilateral nasal discharge associated with sinonasal disease in the horse. Whilst, computed tomographic and radiographic imaging are often of great diagnostic value, clinical and nasal endoscopic examinations are the initial steps in investigating these disorders. This article reviews the use of oral examination and nasal endoscopy in the investigation of nasal discharge caused by sinonasal disease.