I've been having a lot of problems with food with my Guinny, and she will only be a year old tomorrow. She will refuse to eat pate one day, and will only eat gravy foods. So I buy her special gravy food, and then she decides she wants the pate. She would not touch the dry salmon food I have for her, so I went out and bought a slightly more expensive chicken brand which she loved. Now she won't touch that at all, and is back on the salmon. Oh its been quite the experience with her. Even when she does switch to a different food, she doesn't eat much. Anyway, I've noticed whenever she starts acting weird with food though, shortly after (sometimes it takes days) she will hack up a giant hairball. Obviously its caused her to become finicky either because she is full from fur or not feeling well. Could this be the issue with yours? Mine won't take the hairball treatment I've bought, but I brush her with a deshedder a lot lately, and it seems to be helping.