Sometimes it is all the shots they have to have that brings on the allergies. Our little Chihauhau has the problem. We use the Advantage III on her, best one and plus she gets baths with dawn and bacon grease helps a bit. Use flea comb on her too. Dawn does not keep fleas off, it is just a good soap to use because it dissolves the oils on the fleas and they drown, otherwise they can float around tub in little bubble of air and hitch a ride back on your pet. With all the stuff in food now days, as many have said, could be the diet too. Poor animals, we love them so much and work hard to keep them comfortable, hate to see them suffer.