I have an uncommonly sweet and docile toller. She loves strangers and will pester them until she is pet.
The postman refuses to come to our door because he says she bared her teeth at him. We dismissed him as a lunatic, but today she approached a stranger and opened her mouth showing her teeth. She didn't curl her lips back or anything, and was definitely friendly, but it did seem to be a display of some sort. The guy she did it at says his dog also "smiles" at strangers. If I didn't know better I might have thought it was hostile; so maybe the postman wasn't a lunatic.
Is that a common diplay; opening the mouth to be friendly?
I have an uncommonly sweet and docile toller. She loves strangers and will pester them until she is pet. The ... was hostile; so maybe the postman wasn't a lunatic. Is that a common diplay; opening the mouth to be friendly?

As a youngster I knew someone who had a rather scary looking Doberman, who was really very sweet, and would smile. Of course there is scant difference between a smiling show of teeth, to an impending bite warning. So one day his neighbors were having a cookout and "Smiley" went over to investigate the yummy smells. When he smiled at them, they freaked out, and I think "Smiley" got the Mother Lode of a reward in the form of steaks, burgers, and other treats, while the terrified picnicers cowered behind the door.

AFAIK, dogs do not have many facial muscles, so a smile may be hard to distinguish from an aggressive expression. However, I think there are usually other signs, such as growling and body posture. Beware the C-shape! )
I think a relaxed, partly open mouth indicates a smile. Baring the front teeth may possibly be attempting to mimic the owner's smile.

Paul and Muttley (Smiling?)
I have an uncommonly sweet and docile toller. She loves strangers and will pester them until she is pet. The ... was hostile; so maybe the postman wasn't a lunatic. Is that a common diplay; opening the mouth to be friendly?

I don't know how common it is. But our Dalmation smiles a bit. And we had a rescue dog here who would bare his front teeth. It didn't look like a bite warning at all. What it mostly looked was weird. But he was "smiling."
flick 100785
Is that a common diplay; opening the mouth to be friendly?

You bet and some breeds (Chessies for instance) tend to do it more often than others. My Flatcoat learned to do it after spening 10 days with 100's of other Flatcoats. He saved it for a special few people initially, but has become a smiling fool. With his intense body wiggling, it would be hard to mistake it for aggression!

Janet Boss
www.bestfriendsdogobedience.com
I don't know how common it is. But our Dalmation smiles a bit. And we had a rescue dog here who would bare his front teeth. It didn't look like a bite warning at all. What it mostly looked was weird. But he was "smiling."

Showing teeth is a well-known (or maybe not) submission signal.

Melinda Shore - Software longa, hardware brevis - (Email Removed)

Prouder than ever to be a member of the reality-based community
Is that a common diplay; opening the mouth to be friendly?

A friend of mine had an Irish Setter who grinned all the time; not a small Mona Lisa smile but a great big toothy grin. It looked a little odd but it was definitely not something that could be interpreted as anything but friendly. She was a real sweet dog with a great big grin. George
Is that a common diplay; opening the mouth to be friendly?

You bet and some breeds (Chessies for instance) tend to do it more often than others. My Flatcoat learned to ... a smiling fool. With his intense body wiggling, it would be hard to mistake it for aggression! Janet Bosswww.bestfriendsdogobedience.com

It's also common in some Aussie lines. It can be disconcerting to naive people who haven't seen it before. I know of an Aussie that was shot because the smile was mistaken for aggression.