Use of successive dynamic videoendoscopic evaluations to identify progression of recurrent laryngeal neuropathy in three horses

CASE DESCRIPTION: 3 racehorses were evaluated because of poor performance or abnormal noise originating from the upper portion of the respiratory tract. CLINICAL FINDINGS: During maximal exercise, initial dynamic videoendoscopy of the upper respiratory tract revealed complete arytenoid cartilage abduction in 2 horses and incomplete but adequate abduction of the left arytenoid cartilage in 1 horse. Subsequent exercising endoscopic evaluation revealed severe dynamic collapse of the left arytenoid cartilage and vocal fold in all 3 horses. TREATMENT AND OUTCOME: 2 horses were treated with prosthetic left laryngoplasty and raced successfully. One horse was retired from racing. CLINICAL RELEVANCE: Idiopathic laryngeal hemiplegia can be a progressive disease. Successive dynamic videoendoscopic upper airway evaluations were used to confirm progression of left laryngeal hemiplegia in these 3 horses. Videoendoscopy of the upper respiratory tract during exercise should be considered as part of the clinical evaluation of horses with signs of upper respiratory tract dysfunction.