Consider the case of a middle-aged domestic shorthair cat. The owner reports the cat has started urinating on the living room rug. A purely medical approach might look for a urinary tract infection (UTI). But advanced recognizes differential diagnoses: Is it a UTI, or is it Idiopathic Cystitis triggered by the arrival of a new baby? Is it kidney stones, or is it territorial anxiety due to a neighbor’s outdoor cat?