Breed Standards-Part or All of the Problem?

Veterinary school has started back up again but my interest in tough questions pertaining to the health and welfare of breeding dogs still remain...

Deleterious traits exist in mixed breed, purebred, pedigree, and unknown origin dogs. Often with pedigree dogs, breed standards are frequently blamed for the existence of deleterious traits in breeding dogs.

As this Wall Street Journal video states, there are traits of certain breeds, such as the bulldog, that lead to poor health outcomes.  At the end they mention that revisions to breed standards may include how color can negatively impact a dog’s welfare.

“A genetic assessment of the English bulldog” by Niels Peterson revealed that bulldogs have low genetic diversity and has brought about much discussion on the welfare of the breed. An opinion piece by David Sargan at the University of Cambridge suggests the “best way of breeding back to a less extreme skull shape would be to introduce dogs from outside the current breed registers.”

The question then becomes, do traits like color or others, such as the degree of brachycephaly, have more of a welfare impact? Are breed standards to blame? What else influences a breed’s health and welfare?

In addition, how do we categorize which changes would make more of an impact?

Should it be based on animal’s affected or severity of disease?