My neighbours had a small hunting terrier when i was a kid, forgot the name of the breed. Fucking asshole dog tried to bite me every time she saw me although i went in and out there every day. Also she killed everything that moved, cats, birds, hedgehogs, ...

Neighbour was a hunter and those fuckers were bred to follow badgers into their sett and kill them. Badgers can be quite nasty themselves so most animals stay away, but not this breed. Only chance the badger has is to kill the dog, even if half of its nose is bitten off, it doesn't give a shit.

So I'm a bit sceptical about the whole "aggression is not bred" theory.