Try a Tuna based cat food with something else in the mix - Tuna with Shrimp or something like that. I feed my cats a variety of canned food each day. Chicken and this or just Chicken; Tuna and that or just Tuna etc... They eat dry kibble the rest of the day and both are old. Smokey is going on 21 (getting too that point though) and Missy (my mother's cat) is about 17.