Oslo seems to be well within lynx territory, whom I am sure would be glad to snack on a housecat. Norway also has wolverines and in a few areas, wolves and bears.

Norwegian cats eat lynx.

https://en.m.wikipedia.org/wiki/Norwegian_Forest_cat

More seriously - biggest danger is probably cars.

Wow that is one big house cat! Beautiful.

That's just what the coyotes and raccoons want you to think!