My 14 year old female cat has used litter box for years (even after spending all day outside). Always used Tidy Cats clumping litter. Did try the Breeze litter system prior to being diagnosed diabetic (a little over month ago) and stopped after poop was continuously runny (seems to be switching back to normal). Is this normal for litter to be like mud instead of clumping as before? I have gone through 3 containers in just over 2 weeks. Am cleaning weekly litter box (washing).