how do i stop my cat peeing everywhere, the furniture, my sofa, the bathroom rug?!?

Posted under sofa furniture

My cat has started to pee all over the place! Especially the sofa and the bathroom rug. We only have the one cat, no other pets (apart from some sea-monkeys!) and she doesn't seem stressed. Shes been neutered. Its doing my nut in so please help as i can't afford another bloody sofa.

She might have cystitis.