We had exactly the same symptoms in our cat he was a boy so it caused other problems with a blockage and we lost him eventually through complications. He was put on a special Hill dried food diet. Our vet told me that if you feed cheap dried food as in kitty kat and whiskas this can cause problems but if you buy the Royal Canin/hill type (in other words the expensive brands
) and feed it to them for up 70% of there diet and give them fresh meat/eggs/fish for the other part you will have no problems. I have 2 very spoiled cats who eat fresh fish everyday mainly because they go and cadge it off the fisherman at the end of the street when he is sat out gutting his fish
other than that I would rather spend 18€ a fortnight on dried food than have 100€ vets bills