Exercising videoendoscopic evaluation of 45 horses with respiratory noise and/or poor performance after laryngoplasty.
Authors: Davidson Elizabeth J, Martin Benson B, Rieger Randall H, Parente Eric J
Journal: Veterinary surgery : VS
Summary
# Editorial Summary When horses continue to perform poorly or make abnormal respiratory noise despite laryngoplasty, determining the underlying cause requires careful assessment of what's happening during exercise, not just at rest. Davidson and colleagues reviewed 45 post-laryngoplasty cases using resting and exercising videoendoscopy to explore whether the degree of arytenoid abduction achieved during surgery could predict dynamic collapse during work, and to characterise other upper airway obstructions contributing to poor performance. Dynamic collapse of the left arytenoid was likely only in horses showing no postsurgical abduction, whilst those achieving grade 3 or 4 abduction did not develop this specific problem—though this finding alone was insufficient to explain ongoing clinical signs, as most horses displayed multiple concurrent obstructions including vocal fold billowing, right-sided involvement, soft palate displacement, and pharyngeal collapse. These data highlight a critical clinical reality: post-laryngoplasty complications are rarely single-issue problems, and post-operative resting endoscopy grading of abduction has limited predictive value for exercising dysfunction. Practitioners investigating underperformance after laryngoplasty should pursue dynamic (exercising) endoscopic assessment to identify the full spectrum of airway abnormalities and avoid anchoring diagnoses to resting findings alone.
Read the full abstract on PubMed
Practical Takeaways
- •If a horse has no visible arytenoid abduction at rest after laryngoplasty, expect dynamic collapse during exercise; however, grade 3-4 resting abduction does not guarantee normal upper airway function during work.
- •Exercise endoscopy is necessary to fully assess post-laryngoplasty patients with ongoing poor performance, as resting exams miss critical dynamic obstructions involving multiple structures.
- •Respiratory noise alone cannot diagnose the cause of upper airway dysfunction—look for concurrent vocal fold billowing, soft palate displacement, and pharyngeal involvement to explain poor performance.
Key Findings
- •Dynamic collapse of the left arytenoid cartilage was probable in horses with no postsurgical abduction but could not be predicted in horses with grade 3 or 4 abduction.
- •Most horses with a left vocal fold after laryngoplasty demonstrated billowing of the fold during exercise.
- •Complex obstructions involving multiple upper airway structures were observed in most examinations and in all horses with exercising collapse of the left arytenoid cartilage.
- •Respiratory noise was associated with upper airway obstruction but was not specific for arytenoid collapse alone.