Some dog breeds may have trouble breathing because of a mutated gene

Norwich terriers don’t have flat snouts, but can suffer the same wheezing as bulldogs

Norwich terrier

DOG BREATH  Some Norwich terriers’ breathing troubles might rest on a mutated gene linked to swelling around airways, researchers suggest. The gene may also contribute to the labored breathing of dogs with flatter snouts, such as French and English bulldogs.  

Marcia A. Sessions

Dogs with flat faces aren’t alone in their struggle to breathe.