This is what it looks like on ultrasound when I’m flushing a cat’s bladder after placing a urinary catheter to relieve a urinary obstruction. All those little specks floating around? That’s debris — a mix of crystals, mucus, inflammatory cells, gritty sediment, and sometimes even tiny urinary stones swirling around in the bladder. When this debris becomes dense enough it can clump together and block the urethra, especially in male cats where the urinary tube (urethra) is naturally very narrow. T