Exercising upper respiratory videoendoscopic evaluation of 100 nonracing performance horses with abnormal respiratory noise and/or poor performance.
Authors: Davidson E J, Martin B B, Boston R C, Parente E J
Journal: Equine veterinary journal
Summary
# Editorial Summary Dynamic upper airway obstruction is substantially more prevalent in nonracing performance horses than previously documented in the literature, with exercising videoendoscopy revealing pathology in 72% of 100 horses presenting with abnormal respiratory noise or performance issues. Davidson and colleagues performed resting and exercising endoscopic examinations on their cohort, with particular attention to how exercise intensity and head-neck positioning influenced airway collapse patterns; notably, head and neck flexion was required to elicit a diagnosis in 21 cases, suggesting that standard endoscopic positioning may miss clinically significant abnormalities. Pharyngeal wall collapse emerged as the single most common finding (31% of cases), whilst 27% of horses exhibited multiple concurrent airway problems, yet perhaps most striking was the poor correlation between resting and exercising observations—54% of examinations showed different findings between these states, and horses with resting dorsal displacement of the soft palate demonstrated exercise-induced obstruction in only 7.7% of cases. These findings underline a critical gap in practice: resting endoscopy alone provides limited predictive value for dynamic airway function except in cases of recurrent laryngeal neuropathy, making exercising videoendoscopy essential for accurate diagnosis and informed treatment planning in performance horses with respiratory or performance complaints.
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Practical Takeaways
- •Resting endoscopy alone is insufficient for diagnosing dynamic upper airway problems in performance horses—exercising videoendoscopy is essential for accurate assessment
- •Pharyngeal wall collapse is the most common finding in nonracing horses with respiratory complaints; consider this when investigating poor performance or abnormal breathing
- •Head and neck position during exercise significantly affects airway visualization—horses may require flexion positioning during endoscopy to reveal obstructions that affect performance
Key Findings
- •Dynamic upper airway obstructions were observed in 72% of nonracing performance horses with abnormal respiratory noise and/or poor performance
- •Pharyngeal wall collapse was the most prevalent abnormality at 31%, with complex abnormalities noted in 27% of cases
- •Head and neck flexion was necessary to obtain a diagnosis in 21 horses (21%), demonstrating importance of exercise conditions
- •Exercising endoscopic findings differed from resting observations in 54% of examinations, with only 7.7% probability of detecting DDSP during exercise in horses with resting DDSP