Just wanted to say a quick thank-you for the feedback! I'm reading up all I can on her condition, so the link was greatly appreciated. I'll obviously consult my vet before I try to change anything drastically in her diet.

In the meantime, I'm moving my youngest cat over to wet food in an attempt to avoid the same thing happening to her. She's not keen... It took about six hours of putting bowls of wet food out and taking them away again whenever she gave me a "You must be joking!" kind of look instead of tucking in. Eventually she seemed to realise it was that or nothing, although the tough love approach doesn't come naturally to me!