My mouse Toby has had a respiratory infection for a long time, it seems to be improving slightly but he's still scratching. I've tried mite treatment multiple times and I've changed his bedding from megazorb to fleece. He doesn't have any peanuts/sunflower seeds etc. I'm sure it's compulsive and it's breaking my heart because he's so gentle and had a bad start in life.
His ear is torn and he has lots of sore patches. I will update in a few days with photos.