I'm glad (not happy for your suffering but happy in another way) that someone else experiences these problems. I have often seen my cat in ridiculous places that I know she couldn't be, like on top of the fridge or on the ceiling fan. Other times, I see her and reach out to pet her only to touch thin air. Once, I heard a woman being raped on my roof and actually walked outside and screamed that I'd call the cops if they didn't stop. Another time I heard my friend in a neighbor's house making fun of me in a way I'd never heard her do to my face. I tried to approach the situation by banging on the neighbor's door and ended up in the psychiatric ward. I firmly do not believe this is nicotine withdrawal because I rarely smoke cigarettes; but I'm also not convinced it's schizophrenia.
I'm not entirely sure what causes this, but they're called "delusions" or "psychotic breaks" from reality. There are techniques I've taught myself (not foolproof) that can help you figure out what's real and what's not. First, think if it's rational. You're talking about hearing your dog walk around, which is pretty realistic, so you have to go to step number two. Next, realize these things happen sometimes and make yourself okay with the fact it might not be real; this makes it much easier to handle if you find out it's not real. If you live with someone who doesn't have this problem, ask them what actually happened. Of course, you have to be able to trust this person or that won't work, but we usually don't live with people we don't trust at all. Finally, realize there are legal limits that must be obeyed, not because they're morally correct but because it is the law. If you ever go looking for the dogs barking you'll likely end up in the looney bin like I did, so try to let it go. I know that's tough but it's better than a 302.
Now... I have also been looking for an answer to what has caused all of this craziness, so I'm curious to know if you've had experience with other drugs besides nicotine. Sometimes I think it was my year and a half on strong Crystal, but the flaw in that theory is that it happened a few times before I ever met Crystal. Sometimes I think it's just a buildup of drugs over a thirty-four year lifetime, but there's no proof for that so I'm not sure.
It may very well be a mental issue of its own, but again I can't be sure. It may be my OBSESSION with "truth" and my philosophical skepticism (meaning I doubt the actual reality of what I see, smell, hear and touch). You can read DesCartes and Hume if you don't understand this concept.
Maybe you can help me understand this better or we can help each other.