Our dog , in the last few months , taken to sleeping on her back , she must be very comfortable ,and I can assure this is not a set up, she appears to smile
Yes, I looked it up on google once, and a vet had answered when dogs are happy they relax their jaw muscles so their mouth goes floppy which gives them the appearance of smiling. ‘
Dog owner : Look he's so cute, he's smiling at you, he must be happy! Non-dog owner : Oh my God, he's as angry as hell and is going to bite my face off! Dog - It's hot in here, wish I could sweat