[Mumps]

If I'm reading your meaning correctly, about lifespans, I think the comparison isn't quite correct?

lifespan seems to be more strongly correlated by size, not squashed-nosed-ness.

Consider chihuahua, shitzu's (and crosses: bichon-shitzu, ...), poodle crosses, heck lagotto (lagotti?). All can live well past 15.

Versus GSPs, great danes, Irish wolfhounds, and so on, coming in closer to say 6-10 years.

I've never really heard argument on lifespan of pugs et al versus other dogs, though. More around (perceived) ugliness/prettiness, and their breathing issues.