I was also going to share the same advice that Chrissy did. I have a great "pocket pet vet," though I know some areas don't have one expereinced in treating small critters. Alfalfa hay is a great source of extra calories, but you don't want to feed him that as a steady hay diet. You might want to buy one of those little scales so that you can monitor his weight, just to make sure he's not losing!