My sister has a pet pig (a 150+-lb https://en.wikipedia.org/wiki/Vietnamese_Pot-bellied); it lives in the house with everybody else and forages in the backyard. I can't say I'd ever thought of keeping a pig as a pet, but it's a perfectly fine creature, gentle when it's not being provoking, and intelligent and quite communicative.

I can't see it being "man's best friend" (dogs have a bunch of special abilities that pigs don't) but both pigs and goats play an important enough role to call them "man's best helpers"

Arbitrary standard gets drawn and then pigs get condemned to failing to meet it

Pigs don’t pull sleds. They don’t hunt. They don’t play with children. They can’t manoeuvre a flock of sheep. They won’t even try to ward off a bear. They’re bad at sniffing truffles, because they eat them. They won’t run ahead of a fire engine, clearing the way. And they most certainly won’t cuddle up in camp.

Dogs are extremely versatile and have helped humans over thousands of years. Pigs, on the other hand, are tasty.

It’s not that arbitrary.

It's arbitrary because of how human-centric it all is.

You're make my point.

Isn't that life? Or society at least.

I didn't say there was any logic or deep meaning to it, just that someone being willing to sacrifice pigs but not dogs for scientific research doesn't surprise me at all. In mine, even vegetarians generally find the idea of those in others eating dogs (more so than pigs et al.) abhorrent.