Selective breeding has created many dog breeds with serious, lifelong health problems built into their genetics. Understanding the welfare implications helps consumers and breeders make better choices.
Breed-specific health problems represent systemic welfare failure encoded into genetics. A French Bulldog that cannot breathe normally during play, that cannot cool itself through panting effectively, and that may require multiple surgeries to function - is experiencing welfare compromise that is completely predictable from the day of birth. The welfare harm is not incidental but inherent to the breed standard. A Cavalier King Charles Spaniel with syringomyelia - where the brain is literally too large for the skull, causing the equivalent of a constant migraine - is in chronic pain from a condition caused by human breeding decisions. Consumer demand drives the breeding of dogs with these conditions, and changing consumer preferences - away from extreme breed types toward healthier conformation - is the most powerful lever available.