Wow! Randi, thanks for the info. yes, I do recall that our dear Fister had all kinds of bladder problems. I've heard that males become blocked more frequently, but that females can be too...

also it's interesting the part about "boredom". The first time Ritz had one of these, the vet said they are often caused by stress - at the time she was going through her first heat, and the vet felt that was likely the cause. This was the time that the vet told us that black and white kitties, particularly Tuxedos, are a bit more highly strung and "tightly wound" than other kitties, and that she may be prone to them throughout her life.

That was 2 1/2 years ago and there has been no recurrence until a few nights ago. We play with her regularly, so I don't think it's boredom...but who knows what a cat thinks?

We remain on "litter patrol" for the time being she's eating well, drinking water and eliminating other waste without problems, so time will tell.....thanks again for the input.