My rat, Kitty, is over two years old and she has been showing her age. She is less active and slower than my younger rats. She also lost her alpha status in the cage. What has been worrying me is that she is walking weird now. She isn't lifting her back legs up all the way and kinda dragging them. Is she hurt or is it normal for old rats to walk like that? Also her fur is less soft and, well, ratty. Is that also something old rats get her does she need something? What things do I have to do differently to care for a elderly rat?