It's interesting that the fact that a pyr will just "shut down" was mentioned. I think this is a trait of a lot of large dog breeds. All of mine will do it if I repeat things with them, like sitting more than twice in a row, trying to get them to sit, when I stop walking, etc. Jake will do it if he feels that something you want is stupid or just doesn't care. He can be sitting right in front of you but becomes totally deaf and won't even look at you. Max was described by our trainer as being an ADHD dog. He just shut down on her. He laid down and stayed there, wouldn't move. Done. Cody does it as well, when the mood strikes him. They will respond to me if speak normally, and continually change up what we are doing, but if I raise my voice for anything other than calling them to me, or saying no, they won't even look at me. I just cease to exist in their world.
Kathy