Is a Smiling Dog a Happy Dog?

Dogs don't have muscular control of their lips, so it's not an actual smile. Licking around the mouth seems to be the cue that stimulates her to vomit up some nicely partially digested meat. Researchers of wild canids report that puppies lick the face and muzzle of their mother when she returns from a hunt in order to get her to regurgitate for them. The kisses feel affectionate to me, but are they gestures of affection to the dog? I confess that i treat pumps licks as sign of affection. How disappointed pump must be that not a single time have you regurgitated half eaten rabbit flesh....