Clinical Experiences With Axial Deviation of the Aryepiglottic Folds in 52 Racehorses


  • Presented at the Seventh Annual Symposium of the American College of Veterinary Surgeons, Orlando, FL, October, 1997.

  • Address reprint request to D.S. King, DVM, Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Drive West, Madison, WI 53706.


Objective— To describe the clinical findings in 52 racehorses with axial deviation of the aryepiglottic folds (ADAF) and to report outcome in 33 of these horses after either rest or transendoscopic laser excision of aryepiglottic fold tissue.

Study Design— Retrospective study.

Animal or Sample Population— Racehorses admitted for high-speed treadmill (HST) evaluation of poor performance.

Methods— Medical records and videotapes of resting and exercising videoendoscopic examinations were reviewed. Racing performance records and owner or trainer interviews, at least 1 year after HST examination, were used to compare results after either surgical management or rest in 33 horses with ADAF and no other upper-airway abnormalities.

Results— ADAF occurred in 6% of horses evaluated for poor performance. No breed or gender predisposition existed, but horses with ADAF were younger than the overall population evaluated on the HST. Of 52 horses with ADAF, 19 horses had at least one other upper-airway abnormality. There was no apparent association between ADAF and other causes of dynamic upper-respiratory obstruction. Surgical correction was successfully performed in standing or anesthetized horses without complications. When ADAF was the only upper-airway obstruction, 75% of horses that had surgery and 50% of rested horses had objective improvement in performance. Owners and trainers also perceived greater improvement in performance in horses that had surgery.

Conclusions— Whereas surgical management of ADAF is recommended, clinical experience indicated that it is not required to resolve ADAF in all horses. However, owners and trainers of horses that had surgery were more satisfied with outcome than those with horses managed conservatively.

Clinical Relevance— Diagnosis of ADAF can only be made by videoendoscopic evaluation during high-speed exercise. Transendoscopic laser excision of the collapsing portion of the aryepiglottic folds can be performed safely in standing horses and results in resolution of airway obstruction and rapid return to training.