PU/PD is an extremely common presenting complaint in small animal practice. Probably just as common are animals with polyuria and polydipsia that goes unnoticed by their owners. This is especially true of cats.
It is helpful to divide cats with FLUTD into obstructive and non-obstructive uropathy for treatment purposes. Obstructive uropathy is most commonly seen in male cats due to the small diameter of the male urethra. Typical clinical signs include dysuria, hematuria, frequent attempts to urinate, and licking at the penis or prepuce.