Dynamic respiratory videoendoscopy in ridden sport horses: Effect of head flexion, riding and airway inflammation in 129 cases
Article first published online: 15 NOV 2011
© 2011 EVJ Ltd
Equine Veterinary Journal
Special Issue: 57th Annual Convention of the American Association of Equine Practitioners
Volume 43, Issue Supplement s40, pages 18–24, November 2011
How to Cite
VAN ERCK, E. (2011), Dynamic respiratory videoendoscopy in ridden sport horses: Effect of head flexion, riding and airway inflammation in 129 cases. Equine Veterinary Journal, 43: 18–24. doi: 10.1111/j.2042-3306.2011.00492.x
- Issue published online: 15 NOV 2011
- Article first published online: 15 NOV 2011
- [Paper received for publication 15.03.11; Accepted 04.08.11]
- ridden exercise;
- overground endoscopy;
- head flexion;
- upper respiratory obstruction;
Reasons for performing study: Dynamic upper airway obstruction (UAO) is a cause of respiratory noise and sometimes poor performance in sport horses. Riding, head flexion and airway inflammation may impact upper respiratory tract stability during exercise.
Objectives: To evaluate upper airway mechanical behaviour in ridden sport horses using overground endoscopy and the effect of head flexion, rider intervention and underlying airway inflammation on the pharynx and larynx.
Methods: Resting and exercising videoendoscopic recordings during ridden exercise were obtained in 129 sport horses referred mainly for respiratory noise, poor performance or routine evaluation. The rider modified poll flexion and way of riding during the test and associated changes in UAO were recorded. Presence of upper and lower airway inflammation was also assessed.
Results: Dynamic UAO was diagnosed in 91% (64/70) of the horses referred for respiratory noise and in 71% (29/41) of horses referred for poor performance. Pharyngeal instability was the most frequently diagnosed problem. However, differences were observed between dressage horses and showjumpers. Rider interaction and head flexion exacerbated upper airway instability and promoted the occurrence of complex UAO. Both lower airway inflammation and pharyngeal lymphoid hyperplasia were associated with pharyngeal instability, but not with any other UAO.
Conclusions: Rider intervention during ridden exercise (i.e. the various movements a horse might be asked to perform) influences upper airway morphology and function and, in cases of upper airway dynamic obstruction, can contribute to increasing laryngeal and/or pharyngeal instability in sport horses.
Potential relevance: As these are changes that would not usually be seen with treadmill videoendoscopy, ridden videoendoscopy should be the preferred method for evaluation of the upper airway in sport horses.