Reccuring dream of me becoming a black dog

Okay basically for about a couple of years now I've been having this on and off recurring dream about me being a dog. A full black german Shepard. The last week I used to go into the dream and I was in this house I've never been in before. I used to search it. It was a nice bright house. Most decorative items were cream bache or White. I'd realise that I could stand up and when I did try to stand up like a normal person I'd just fall over. When I went to speak it would come out as a bark or growl. I would go up stairs and try and find a room with a mirror. Every time I found one I would look in it and realise I was a pitch black german Shepard type of dog. When I realised what I was I would bark in fear and then wake up! Sweating sometimes.

This week has been strange. In my dream I would usually be in that house like I described above or walking around barking at things such as people. But this weeks was the weirdest. My friend at college was assaulted by another student. My friend and myself didnt realise until after it was done what had happened. That night I dreamt I was that dog again but this time I was in the class room. I realised what was going on it was the scene of the assault and I went to go help my friend. As I imagined he was being hurt and I went in and bit the guys leg that was hurting him. Feeling his flesh in my teeth felt really good and I liked it.

Another instance was Ive been explaining to my friend about my dreams and he's really interested in them. That night I dreamt I was explaining to him on the bus. When I looked at my reflection in the window I was that black dog again.

It's really strange. It's been going on for years now. I've always felt an urge and sensation to want to be and feel what it's like to be a dog. All the way back to when I can remember I've wanted to be a dog.

What's going on? Is this normal?

Thanks. Sorry it's so long was really interested in hearing what you all thought.