Ventroaxial luxation of the apex of the corniculate process of the arytenoid cartilage in resting horses during induced swallowing or nasal occlusion.
Authors: Barakzai S Z, Es Cert, Milne E M, Dixon Padraic
Journal: Veterinary surgery : VS
Summary
# Ventroaxial Luxation of the Arytenoid Corniculate Process in Horses Researchers at the Royal Veterinary College documented an unusual laryngeal condition in horses whereby the apex of one arytenoid's corniculate process shifts ventromedially beneath the contralateral process—a luxation that remained invisible during quiet breathing but became apparent when horses swallowed or had their nostrils occluded. Among 133 Clydesdales surveyed endoscopically, 7 animals (5.2%) exhibited this finding, and notably, one Thoroughbred showed progressive luxation during high-speed treadmill exercise accompanied by abnormal respiratory noise. Post-mortem examination of an affected Clydesdale revealed a pathologically enlarged transverse arytenoid ligament measuring 10 mm across, compared with normal cadaver larynges where the arytenoid apices could not be separated manually, suggesting mechanical laxity as the underlying cause. Whilst the clinical significance of this condition in resting horses remains uncertain, the association between ligamentous laxity and exercise-induced luxation warrants further investigation, particularly in performance horses presenting with unexplained respiratory obstruction or exercise intolerance, and may represent another anatomical contributor to dynamic airway obstruction worthy of consideration during endoscopic evaluation.
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Practical Takeaways
- •This condition may be clinically silent at rest but could contribute to poor performance or respiratory noise during exercise; high-speed treadmill endoscopy may be needed to detect it during work
- •Prevalence in Clydesdales (5.2%) suggests breed predisposition; consider laryngeal pathology in draft horses with unexplained poor performance
- •Clinical significance remains unclear from this case series; further investigation needed to determine whether intervention is warranted
Key Findings
- •Ventroaxial luxation of arytenoid cartilage apex occurred in 5.2% (7/133) of Clydesdale horses during induced swallowing or nasal occlusion but not during quiet breathing
- •Affected Thoroughbred exhibited progressive luxation during high-speed treadmill exercise with associated abnormal respiratory noise
- •Necropsy revealed excessively wide transverse arytenoid ligament (10 mm) in affected horse compared to normal cadaver larynges where apices could not be separated