I'm assuming that the defects they are talking about are breathing problems and joint problems that plague some breeds of bullies, but that breeders are getting past with hip x-rays on breeding stock and goals that are more geared towards function than show conformation points. Look at the physical difference between Irish setters from American show vs. Irish hunting lines. They aren't the same animal. The Amercian ones have way too short back legs to suit the intended purpose of flushing birds in a wide open field.