@Drogon @Max Hawk @Tropicalbri's
Kaiser doesn't lay on his back either and I thought all dogs did. I saw him roll over once...maybe in his first 2 weeks with us. I rubbed his belly thinking it was an invitation and then he got up. Never did it again as a small pup. As a grown pup I've seen him roll over in his crate a few times, but never where I could rub his belly. Maybe he does it at night when no one can see him? I assumed he wasn't comfortable enough, but even around us? Or am I mixing dog behavior with cats? The submission is an interesting point. I never see him roll over even with his doggy friends (dogs that are very familiar to him). As far as pack structure, I figured K is a middle of the pack kind of dog. Wouldn't that make him somewhat submissive? He plays well with older dogs and young pups.