Are we as a society ethically obligated to euthanize all these brachycephalic dogs immediately to end that suffering? If not, why not?
I blame dog breeders for knowing better and breeding the dogs anyway.
Never say "ethically obligated" and "euthanasia" in the same sentence. That is asking the wrong question - but for the record the answer is no. Obviously. In addition to such a thing being impossible, there are easier ways forward. :-)
On suffering, the fact of the matter is that the dogs really have no idea that they're suffering. They just exist. They know nothing more than what they are exposed to, and what they perceive.
I feel that if we are obligated to do anything, it is simply to change how and for what purpose we breed animals. Deciding that the pug can still exist - with a longer nose - or that the Dalmatian can exist after they breed out their uric acid problem is attainable. It just takes work. And support, from pet owners and breed lovers, to guide people and to vote with their money.
I'd say it's probably unethical to breed more brachycephalic dogs, and by extension unethical to purchase those dogs from breeders (unless maybe the breeders have ceased to breed these dogs).
With that stipulated:
If the benefit a dog obtains from living outweighs --- in all but the most extreme cases --- the suffering that dog will have due to its genetic defects, AND people are entitled to make a rational decision not own a dog, are they not ethically entitled to select any breed they want? How would it be more ethical to create no benefits for any dogs than to create compromised but net-positive benefit for some dogs?
Were no dog available that could reliably provide those attributes, our choice would certainly have been not to acquire a second dog.
But I also think, for what it's worth, that it's still ethically tricky to dispose of the question of whether it's unethical to select dogs for appearance. I think you can predict the argument I'd make there.
a) Given existence: significant suffering, but not enough to justify ending the existence
b) Given no existence: creating an existence knowing you'll create the same amount of suffering as in (a)
Something meaningful is created by the very fact of existence. Or, should I say, already existing matters a lot.
People have known for a long time that brachycephalic breeds have many health problems, but just like people: why shouldn't they have a chance to live their life? I don't think it's fair to say that society as a whole has a responsibility to completely remove a type of animal from the world by force.
Instead: it would be great if more people were educated about this stuff. The more dog owners that know about this, the better. When I first heard about this I told myself that if I ever had a brachycephalic dog I'd ensure they were fixed, and didn't reproduce. That way I can take care of something and ensure it has a good life, but also prevent future generations from pain.
Dogs are great companion animals. If anything, we have a responsibility to help them out as much as we can and reduce suffering long term through education.
Just my two cents.
But in choosing a dog to bring into the world, (a) and (b) have no weight, so (c) wins
For instance, to refine the point: some decent number of brachy purebred dogs are currently in shelters (usually, specialized shelters). Those dogs have no owners and the human emotional pain that would be inflicted by euthanizing them is minimal. Should those dogs be put down, rather than rehomed? Bear in mind that it's actually pretty difficult to acquire a homeless purebred brachycephalic dog; they're in demand.
(We tried; our older dog is a rescue and we'd hoped to rescue an older purebred as well).
I think the pug will suffer so much that its life is not worth living. But if the pug feels differently then to some degree I should respect that.
I guess my view is shaped by my empathy for the dog. How would I feel in his situation? Similarly, if I end up in a hospital bed racked with pain, do I want the doctor to make a cost-benefit analysis without regard for my own feelings?
We own a rescue mutt and a brachy purebred, and while I can't get inside the heads of either of my dogs, I would have absolutely no trouble telling you which of the two dogs is enjoying its life more. :)