Pigs aren't suitable pets outside a farm. They're too big, too strong, and far too intelligent. Remember watching a BBC documentary where they discussed how pigs are more intelligent than small children. They escape constantly exactly because they're incredibly intelligent. Feral pigs are also dangerous and cause untold damage.
Neither are cows. Cows are much like dogs. They like playing fetch, playing football, listening to music, cuddling, etc. But they're far too big and strong to keep as pets for most people.
To be clear, I'm not arguing that it's more moral to eat a pig, dog or cow.
I'm arguing that people are more able to lie to themselves that eating a cow or pig is less bad, because they have less experience interacting with them. Just like the kid who died mining ore in a Congolese mine, that makes it easier to ignore their suffering.
e: here's a short fragment from a BBC documentary about pigs: