Professor of Surgery University of Pennsylvania Philadelphia, Pennsylvania
Nasopharyngeal Collapse in Brachycephalic Dogs: Severity and Effect of Corrective Airway Surgery. Holt D, Clarke D, Reetz J, Drobatz K. University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA.
Brachycephalic dogs are frequently presented for stertor, snoring, difficulty breathing when exercising, and collapse. Traditional evaluation of these dogs has largely focused on abnormal anatomy, including stenotic nares, overlong soft palate, and hypoplastic trachea. However, this neglects the potential role of functional airway abnormalities in this condition. The objectives of this study were to determine the severity of nasopharyngeal collapse in symptomatic brachycephalic dogs and to determine the effect of corrective upper airway surgery on nasopharyngeal collapse. Symptomatic brachycephalic dogs presenting for upper airway evaluation and corrective surgery and a control population of mesocephalic dogs had fluoroscopy performed in a standing position. Fluoroscopy was also performed postoperatively in a cohort of brachycephalic dogs. Median nasopharyngeal collapse was calculated from five breath cycles and compared between brachycephalic and mesocephalic (control) dogs. Nasopharyngeal collapse was similarly compared before and after corrective upper airway surgery. Median collapse was significantly greater in brachycephalic dogs (P = 0.0001). Corrective surgery did not improve collapse significantly. The results of this study suggest that nasopharyngeal collapse is a common and often severe component of brachycephalic airway disease. The lack of improvement of nasopharyngal collapse postoperatively suggests that either: 1) Standard corrective surgery for brachycephalic dogs does not reduce upper airway resistance adequately; or 2) Nasopharyngeal collapse is either a somewhat independent or separate functional abnormality in brachycephalic airway disease.