Excessive urination (medical term polyuria [pah-lee-YOOR-ee-ah]; abbreviated as PU) is a sign of diabetes. It may also be a sign of other conditions. See the FDMB thread below for other reasons for dilute urine. Animals with high blood glucose levels urinate frequently and in large amounts to rid their bodies of excess glucose. With cats that use a litter box, excessive urination is an early but often overlooked sign of diabetes. The clumps in the litter box of an unregulated diabetic cat can be very large, numerous, and sticky.