Since you don't explain the scale further, I can't tell if you're asking about fellow owners of dogs, or owners of fellow dogs
Discussion
The former. How hard do you let your dog go to the mouth?
None because I hear dogs do that as a sign of submission and this is an anarchist household
I've heard such reasoning, but have my doubts. My theory, at least with this dog, is it's her way of checking your health out in the morning, and/or a gesture of affection her limited means of communication allow her.
So I don't have time heart to stop her