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Department of Veterinary Medicine

Cambridge Veterinary School

Brachycephalic Obstructive Airway Syndrome (BOAS)

“Brachycephalic” means “short-headed”

CT image of a Labrador retriever CT image of a pug 

The French bulldog, bulldog, pug, pekingese, shih tzu, Japanese chin, boxer and Boston terrier are all examples of brachycephalic breeds. The most distinctive feature of these breeds is their short muzzle. 

In recent decades, breeding selection for extreme brachycephalic features has resulted in dogs that are predisposed to upper airway tract obstruction and subsequent respiratory distress, among several other health issues. Although not all brachycephalic dogs show clinical signs, the incidence and severity of the respiratory disorders has increased. The respiratory disease related to brachycephalic conformation is called brachycephalic obstructive airway syndrome (BOAS).    


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