At the pet store, you may have noticed the range of cat food options, each targeting a specific ailment or stage of your cat’s life. There’s kitten food, which is nutrient-rich to help kitties grow healthy and strong. There’s adult food, which offers a balanced mix of nutrients. There’s even specialized food for cats with food intolerances, allergies, hairballs and urinary tract issues. And then there’s senior cat food—but what does that do?