Dynamic ventrorostral displacement of the dorsal laryngeal mucosa in horses.
Authors: Pollock P J, Kelly P G, Reardon R J M, Kelly G M
Journal: The Veterinary record
Summary
# Editorial Summary: Dynamic Ventrorostral Displacement of the Dorsal Laryngeal Mucosa Pollock and colleagues reviewed 600 dynamic endoscopic examinations of the equine upper airway to characterise a poorly understood condition in which the dorsal laryngeal mucosa progressively obscures critical laryngeal landmarks—the interarytenoid notch and dorsoaxial corniculate processes—during high-speed exercise. Among their cohort, twelve Thoroughbreds presented with this ventrorostral displacement of dorsal laryngeal mucosa (VRDDLM), many of whom exhibited concurrent upper airway obstructions including aryepiglottic fold deviation, vocal cord prolapse, and arytenoid luxation. Whilst the clinical significance of isolated VRDDLM remains uncertain, its frequent co-occurrence with other obstructive airway pathologies suggests it may contribute to poor performance and abnormal respiratory noise in affected horses. For practitioners investigating performance problems or exercise-induced respiratory distress, recognition of VRDDLM during dynamic endoscopy warrants careful assessment for concurrent airway abnormalities, as the combination of lesions rather than isolated VRDDLM may explain clinical signs. Further work is needed to establish whether VRDDLM itself requires intervention or functions primarily as a marker of more clinically significant airway disease.
Read the full abstract on PubMed
Practical Takeaways
- •Dynamic endoscopic examination during high-speed exercise is essential for diagnosing VRDDLM, as the condition may not be visible at rest
- •When VRDDLM is identified, thoroughly investigate for concurrent upper airway pathologies (vocal cord prolapse, soft palate displacement) as these frequently coexist and may be more clinically significant
- •The clinical relevance of VRDDLM alone remains unclear; focus diagnostic and treatment efforts on concurrent obstructive lesions that are better understood
Key Findings
- •VRDDLM was identified in 12 of 600 dynamic endoscopic examinations (2% prevalence) in Thoroughbreds presented for poor performance or abnormal respiratory noise
- •The condition involves progressive obscuration of the interarytenoid notch and dorsoaxial arytenoid cartilage portions during high-speed exercise
- •Eight of twelve horses (67%) with VRDDLM had concurrent upper airway abnormalities including vocal cord prolapse and soft palate displacement
- •VRDDLM is a rare condition of unknown clinical significance that may contribute to respiratory noise and poor performance when present with other obstructive airway diseases