"Urinary obstruction" refers to a condition where something blocks or restricts the flow of urine in the urinary system, like a clog in a pipe. Full definition
Over time, the malignant tumor grows and causes urinary obstruction, and spreads to the lymph nodes, lung, bones, and other areas of the body. (1800petmeds.com)
Cats with a complete obstruction need to be treated immediately as urinary obstruction is a medical emergency that can result in death if left untreated. (uvma.org)