"'a dog doesn't know how to fear a tiger' but that doesn't really mean anything in English" Nope, meaning 100% clear to this dog owner. It might not be a saying we use around here but I immediately understood it, because dogs are so very dumb around animals that might hurt them and if you've ever owned a dog in an area like I live in you tend to worry about how their dumb ass might charge off towards a bear or mountain lion or something.