Started when I got back from a weekend away two weeks ago. Took the most likely culprit to the vet who said it was anxiety and prescribed cystophan. Doesn't seem to be cystitis as she's not in pain and it's a whole bladder full. In the same place and similar time every day. She's still using her litter tray and no change of litter. Now swapped her to zykelene and treating them both. They are very chilled but it's still happening. Any advice?!