The scratches have happened to me off and on all my life. My mom gets them too. She only get them on her back. I used to only get them there too, but lately on my face. Like you said, some are for a few days and some just disappear the same day they appear. I think its just one of those things that only people who experience this know that they arent doing it to themselves. I have experienced this in more than 3 different places that I have slept. I do know they happen in my sleep and all of the stories i have read about people who experience this say the same thing.
Hi
Welcome to the MedHelp forum!
What you have is probably a rash. Dog allergy can develop anytime during the course of your interaction with the dog. Take an anti allergic and sleep without the dog for a day and see. If it helps, then it is dog allergy and if you want to keep the pet, then you need to keep a HEPA filter, air the bedding and room regularly, wipe the dog with a wet cloth daily and give it bath twice a week.
Hope this helps. Take care!