I have two very sweet cats with two different health issues. Nym is a fluffy black cat and Snow White is a chubby white cat. Nym has trouble with hair balls. I have been bathing and brushing her since she was a kitten, but I noticed that certain foods clear up her hair balls altogether. Snow White was rescued last year, and I very quickly discovered that she has a sensitive tummy. I can't find a food that satisfies both girls, and I can't really separate them. Purina indoor upset Snow's tummy, Friskies indoor brought Nym's hair balls back, and neither of them liked the Meow Mix. Any suggestions? I want both of my girls healthy again.