Heidi is 12 1/2 years old and she has always had a stubborn streak. Lately I have been noticing that her stubbornness seems to be increasing and I have commented that she won't do anything if it isn't her idea. For instance, she stands outside in the middle of the yard, no matter how cold it is (and it is REALLY cold today) and she refuses to come in. When I get my shoes on and go outside and get her, she lets herself be led in very docilely. I thought today that it is almost as if she doesn't remember what to do. Does dementia even really exist in dogs? Does this sound like Heidi could be in early stages of it? If so, what is she experiencing and how can I help her?