No. Actually he doesn’t. Dogs do not seem to recognize themselves. Ever. It’s just not part of how their brain works. To them, another dog suddenly appears out of nowhere. Imagine how you would react if you came around the corner and there was a stranger in the bedroom or kitchen!
Now imagine that stranger has no body and, importantly to your puppy, no smell. It is there but it isn’t there. It is, for all intents and purposes, a ghost. A dog ghost appearing in their home before their very eyes!
Bark? You bet they bark! Wouldn’t you?
From this perspective, I don’t ask why puppies bark at their reflection, I’m impressed that they stop barking. I don’t know how long I would have to live with a ghost in my home before I stopped reacting with a shout (at least).
If you like this, you’ll love my most recent book: My Smart Puppy Guide: How to Train Your Dog to Come.