Sure, you can watch an exercising horse’s airways with an endoscope while he’s on a treadmill, but this technique does not account for travel over varying terrain or for the influences of rider intervention on his respiratory efficiency. At the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio, Texas, Emmanuelle van Erck-Westergren, DVM, PhD, Dipl. ECEIM, of Equine Sports Medicine Practice in Belgium, presented a study on upper airway function using videoendoscopy on ridden horses.

She explained that in racehorses and sport horses, duplication of the circumstances in which upper airway problems occur is important for establishing a diagnosis and proposing an appropriate treatment to maximize a horse’s performance. Respiratory noise occurs as a result of upper airway obstruction (UAO), which might lead to decreased performance and reduction in the horse’s commercial value. But this noise has rarely been examined in horses that are exercising off the treadmill and with riders.

Van Erck-Westergren investigated the effect of head flexion and rider interference on the upper airways. The study involved 129 show jumpers and dressage horses with an average age of 6 ½ years. Owner complaints ranged from respiratory noise, poor performance, and cough to epistaxis (nose bleeds) and headshaking. The ridden exercise test was performed at the walk, trot, and canter on both leads for 15 minutes or until each horse showed signs of fatigue or displayed typical clinical signs. Each horse, ridden by his usually rider, was asked to work with the head free, then with increasing poll flexion with rider contact and skill sets.