>>91637129It opens with Fievel waking up and trying to tell his parents about a dream he had where they went west and there were cowboys and gunfights and shit, and it's just waved away with a "that's nice dear, but that is a dream you had that totally never happened." I guess you could say it's possible they could still go west later and place the third movie in between one and two and the dream was just a coincidence, but you could also look at it like the whole second movie was the dream and doesn't actually happen.
Or you could ignore it entirely, that too. Even though I like the second movie, I actually prefer to not count it as canon to the first even, myself.