Alar fold resection in 25 horses: Clinical findings and effect on racing performance and airway mechanics (1998-2013).
Authors: Strand Eric, Össurardóttir Saga, Wettre Kjersti B, Fjordbakk Cathrine T
Journal: Veterinary surgery : VS
Summary
# Alar Fold Resection in Racing Horses: Clinical Findings and Performance Outcomes Alar fold collapse (AFC)—characterised by abnormal expiratory flutter noise and false nostril distension during high-speed exercise—represents a treatable but often overlooked cause of poor performance in racehorses. This retrospective case series examined 25 horses (predominantly standardbred trotters) diagnosed with AFC via treadmill assessment and treated with complete bilateral alar fold resection, with nasopharyngeal pressure measurements taken in five cases to quantify the degree of airway obstruction. Horses with AFC demonstrated elevated expiratory nasopharyngeal pressures (10.8–21.8 cm H₂O) compared with normal reference values; surgical resection restored pressures to normal levels, and notably, 13 of 17 harness racehorses improved or established better racing time marks following intervention. Complicating the clinical picture, 12 of 21 standardbreds had concurrent dynamic airway disorders—intermittent dorsal soft palate displacement in 10 horses and nasopharyngeal roof collapse in 2—suggesting AFC may precipitate or exacerbate secondary obstructions. These findings support alar fold resection as an effective surgical intervention for performance-limiting AFC and propose nasopharyngeal pressure measurement as a diagnostic tool to confirm the condition's physiological significance, particularly where multiple dynamic airway disorders coexist.
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Practical Takeaways
- •Alar fold collapse should be considered in racehorses presenting with exercise-induced respiratory noise and/or poor performance; high-speed treadmill examination with temporary dorsal fixation can confirm diagnosis
- •Complete bilateral alar fold resection is an effective surgical treatment with most horses returning to competitive racing; nasopharyngeal pressure measurement can objectively confirm the diagnosis
- •Screen for concurrent airway disorders (dorsal displacement of soft palate, nasopharyngeal collapse) in horses diagnosed with alar fold collapse, as these were present in over half the standardbreds studied
Key Findings
- •Alar fold collapse caused mild to moderate expiratory obstruction with nasopharyngeal pressures elevated (10.8–21.8 cm H₂O) compared to normal values
- •Complete bilateral alar fold resection reduced expiratory nasopharyngeal pressures to normal levels
- •At mean 68-month follow-up, 20 of 25 horses competed after surgery and 13 of 17 harness racehorses established or improved their racing time marks
- •Secondary nasopharyngeal collapse was identified in 12 of 21 standardbreds, suggesting alar fold collapse may contribute to additional airway disorders