Funny, the dog is just not able to deal with the new reality, and I have run into some people who react much in the same way, when something fundamental changes in their lives, they just do not know how to change.
Vaughn - Yours is a boxer so a natural comic. I had two and there were so many instances in which you could see them playing tricks/jokes on each other. Only dogs I have ever owned with a visible sense of humour.