[EntrePrescott]

> Why are they called 'feral hogs' in America?

because they are domestic pigs gone feral, plus a minority of boar-pig hybrids resulting from the contact with wild boar.

> This is the original wild species of pigs (…) I think wild boar would be better

Feral hogs are not the same thing as wild boar. The latter are the ancestor species from which pigs descended, whereas the former are domestic pigs gone feral plus a minority of hybrids. Western wild boar have a chromosome count of 2n = 36, whereas pigs (including the majority of feral hogs that aren't hybrids) have a chromosome count of 2n = 38. Hybrids typically have 37 or 38 chromosomes.

> We also don't call wolves 'feral dogs,'

… because they aren't, just like wild boar aren't feral hogs. Wolves aren't domestic dogs who went feral but just wolves who stayed wolves. So the equivalent of the wolf in the porcine world would be the wild boar, not the feral hog, of which the equivalent in the canine world is… a feral dog.

[achow]

Also..

Although the domestic pig as we know it today took hundreds of years to breed, just a few months in the wild is enough to make a domestic pig turn feral. It will grow tusks, thick hair, and become more aggressive. https://mybosstools.com/fun-facts-domestic-pigs/