Most dogs lives are going to be lots of internal battles between its non-physical brain and its physical dog.
For those dogs that take a different route, for whatever reason, there will be times when the dog’s non-physical mind will come into play. The non-physical mind is, frankly, the ugly parts of Nature that Nature had to program into every wild animal, and every wild dog. It was and is the parts of the wild She had to figure out and put into every dog’s programming millions of years ago in order for there to be what we refer to as “the wild.”
It’s not pretty sometimes. We don’t like talking about it. We don’t want to admit it most of the time. It remains an elephant in the room.
The mind (the non-physical mind) is the part of the dog package that keeps dogs dozing; it prevents dogs from genuinely sleeping. Dogs in the wild will typically sleep on their bellies, dozing for a split second, and waking up to check in on things to keep themselves safe and alive. Being on their bellies, they can immediately get up to defend themselves if needed.
Dogs whose brains have vetted their surroundings as safe environments will sleep on their sides. A relaxed dog that is in a safe environment will sleep on its side. Sleeping on its side is risky in the wild because two things have to be done to protect itself: 1) the dog has to right itself, and 2) it needs to get up. The split second it needs to do (1) could be the difference between life and death. The behavior of laying on its side is the dog’s communication that it’s trusting its leader.