BAS is the upper airway obstruction present in brachycephalic dogs that results from the combination of narrowed nasal openings (also called stenotic nares), an elongated soft palate, and a small windpipe (also called the trachea). These dogs frequently develop secondary problems within their pharynx and larynx (voicebox). As a result of this upper airway narrowing, dogs with BAS suffer from noisy breathing, inability to exercise normally, and may even suffer collapse or death.

Dogs with BAS also have abnormalities within the nose, including an increase in nasal turbinates (small bones in the nose) and thickened soft tissues. The role of these tissues in causing the symptoms of BAS is not known. It is these nasal abnormalities that we hope to better understand with this study.