I wonder what neuroscientists will think of this:

As far as I know there are no reported cases of sleepwalking animals. It's very difficult to imagine what a sleepwalking dog might even look like. To be clear, I mean sleepwalking proper and not the acting out of dreams; that is, I mean behavior which exhibits coordinated sensorimotor functioning while asleep. I think that a sleepwalking dog, if one were to exist, would have to look just like a normally awake dog. It would roam around, sniff things, eat, maybe run in the yard -- all in all nothing observably out of the ordinary. The only thing that would be different in a sleepwalking dog, I'm forced to assume, would be that the brain activity would be different than if the dog were awake.

This is where neuroscience comes in. I wonder if it is feasible for a dog to exhibit exactly the same behavior, while possessing two very distinct brain states. In humans, for instance, the behavior of a sleepwalker is markedly different than that of a waking individual, thus exhibiting a behavioral difference to correspond to the difference in brain states. Is it possible, in the case of a dog, for two distinct brain states (one awake and the other asleep) to produce exactly the same behavior, namely walking about?

If this were impossible, do you think that it would prove the impossibility of sleepwalking in dogs?

The proof would look like this:

(1) If a sleepwalking dog were to exist, it would behave just like a waking dog.
(2) The only difference between the hypothetical sleepwalking dog and a waking dog would be a difference in brain activity.
(3) But it is impossible for such distinct brain activities to produce precisely the same behaviors.
(4) Therefore dogs must not be able to sleepwalk.

What do you think? Has it got any scientific weight?