 "Form-driven selective breeding has changed the shape of well-known breeds away from the norm of 50 to 100 years ago by exaggerating specific features considered particularly characteristic of the breed" and in many cases, this has had a negative impact on welfare.In some cases, selection for specific characteristics written in breed standards "can be demonstrated to be directly threatening to health and welfare".To the outsider, it seems incomprehensible that anyone should admire, let alone acquire, an animal that has difficulty in breathing or walking.