Equine recurrent laryngeal neuropathy (RLN) has long been recognized in larger breeds of horses as a cause of laryngeal airway obstruction with production of abnormal respiratory noise during work and with variable levels of reduced athletic performance. Methods employed in the assessment of laryngeal function include listening to the horse's respiratory noise during exercise, palpation of the muscular process of the arytenoid cartilage to assess laryngeal muscle atrophy, and digital, endoscopic and electromyographic assessment of the laryngeal adductor reflex, laryngeal ultrasonography, and endoscopy, the latter of which has been the most commonly used technique for the past three decades. Resting endoscopic assessment is currently the most common technique used to evaluate laryngeal function and indeed forms the mainstay of all upper airway assessments.
- Equine recurrent laryngeal neuropathy (RLN)
- Laryngeal ultrasonography
- Resting endoscopic grading
- Upper airway abnormalities