Selective breeding for extreme physical traits in dogs causes widespread suffering. Brachycephalic breeds including bulldogs and pugs experience chronic breathing difficulties as a direct result of breeding for flat faces.
Brachycephalic breeds suffer from conformation-related health problems that are inherent to their breeding standard, not incidental. Chronic breathing difficulty causes reduced exercise tolerance, sleep disruption from obstructive sleep apnoea, and risk of acute respiratory crisis in warm weather. Many dogs live their entire lives with compromised breathing that causes ongoing discomfort. Eye problems including corneal ulceration, skin fold infections, and spinal disorders are additional welfare costs of extreme breeding. The normalisation of these conditions by owners and breed enthusiasts means suffering continues largely unrecognised. Regulatory intervention including breeding standard reform and veterinary certification requirements before breeding is gaining traction internationally.