title: Dynamic respiratory endoscopy of Standardbred racehorses during qualifying races.
abstract: BACKGROUND
  Examination of the equine upper airway during racing has not previously been documented.
  
  
  OBJECTIVE
  To describe the feasibility and appearance of the upper airways by overground respiratory endoscopic examination during racing conditions.
  
  
  METHODS
  Overground videoendoscopic examinations were performed on 46 Standardbred racehorses during qualifying races. Examined horses' speeds were recorded throughout the race with a portable GPS device.
  
  
  RESULTS
  The procedure did not interfere with performance as there were no significant differences in race times between races in which horses were examined with the endoscope in place and prior unexamined races. Airway obstructions during or after the race were documented in 21 horses. Most previously reported causes of upper airway obstruction were observed; surprisingly bilateral ventro-medial arytenoid displacement (VMAD; n = 5) was seen during exercise as frequently as dorsal displacement of the soft palate (DDSP). Although DDSP (n = 10) was the most common diagnosis made, many displacements (n = 5) occurred after the race. Horses that demonstrated DDSP after the race had slower speeds than unaffected horses during the race.
  
  
  CONCLUSIONS
  Racing endoscopy permits the diagnosis of upper airway obstructions without affecting performance. The occurrence of DDSP immediately after exercise may be clinically relevant. During racing VMAD may be an important anomaly.
  
  
  CONCLUSIONS
  Racing endoscopy could be used to correlate the sensitivity of diagnostic endoscopy during race-training or treadmill examination. The pathogenesis and significance of VMAD deserves further investigation.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Priest
authors.forename: J
authors.initials: J
authors.lastname: Cheetham
authors.forename: A L
authors.initials: AL
authors.lastname: Regner
authors.forename: L
authors.initials: L
authors.lastname: Mitchell
authors.forename: L V
authors.initials: LV
authors.lastname: Soderholm
authors.forename: Y
authors.initials: Y
authors.lastname: Tamzali
authors.forename: N G
authors.initials: NG
authors.lastname: Ducharme
mesh_terms: D000818:Animals; D004724:Endoscopy / Q000379:methods / Q000662:veterinary*; D005260:Female; D006736:Horses / Q000502:physiology*; D008297:Male; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000033:anatomy & histology*; D013177:Sports; D014741:Video Recording / Q000379:methods