From what you posted about her symptoms she could have a variety of problems. Get your hands on her and do a good physical exam-especially her butt. Clean all fecal matter from back there-wash her and blow dry her. She might possibly have egg peritonitis or some other reproductive problem...
Some of my Jersey Giants legs look like that. They are perfectly healthy for being 7 years old this Spring. It might be an age related thing like humans and their hair turning grey.