My cat, Stinkie, seems to losing a lot of his fur. This is not only summer shedding. His fur has thinned out A LOT. I can see his skin in several places. He has dermatitis. Could that have something to do with it? Or, is he missing some kind of vitamin? I know he needs vitamins that he isn't getting because I've noticed some unusual things he does lately, but could his fur loss have anything to with that? We were going to buy vitamins for him today, but Wal-mart did not have any for cats and the pet shop was closed for the holiday weekend. It won't be open again until Monday. I'm not sure of anyone else that sells vitamins for cats, because we live in a small town. The major pet stores aren't available to us. I don't what to do. Could this be serious?