Dream: Not my dog

It was early in the middle of the night and I got up out of bed to let the dog outside. I walked by her as she slept in the dark hallway and noticed a terrible smell. Like something dead. I opened the front door and called to her. I heard her get up and saw this enormous black figure tromping towards the front door. It sounded like a horse galloping, which is strange because I have a miniature Australian shepherd that weighs 25 pounds. The dog blew by me and flew out the door and down the front steps. It was a massive black dog. It kept running down the front walk and leaped over the front gate and disappeared into the dark night.