Glossary

Urinary blockage

A life-threatening emergency in which the urethra is plugged so a cat cannot pass urine, most often in male cats.

Also called: urethral obstruction, blocked cat, blocked bladder, urinary obstruction

A urinary blockage happens when the urethra, the narrow tube that carries urine out of the bladder, becomes plugged. The plug may be made of crystals, mucus, cells or a small stone. Male cats are at far greater risk, because their urethra is longer and narrower. Neutered cats are not immune, and indoor cats on dry food and with little water intake are commonly affected.

A blocked cat visits the litter box again and again, strains, cries, licks its genitals and produces little or no urine. It may hide, vomit, stop eating, become weak or collapse. The bladder fills, the kidneys cannot clear waste and potassium builds up in the blood, which can stop the heart. Without treatment, a complete blockage can be fatal within a day or two.

Go to a vet or an emergency clinic at once. Do not wait to see whether it passes. The vet usually sedates or anesthetizes the cat, passes a catheter to clear the blockage, runs blood tests and gives intravenous fluids, often with a stay in hospital. Some cats block again. A surgery called perineal urethrostomy is an option for repeat cases, and your vet can explain the risks. Ask about diet and ways to increase water intake afterward.

Last reviewed November 7, 2026

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Related terms

FLUTD An umbrella term for the conditions that cause pain, straining and bloody urine in a cat's bladder and urethra. Bladder crystals Microscopic mineral particles in urine that can clump into stones and irritate or block a cat's urinary tract. Cystitis Inflammation of the bladder, which in cats is often stress-linked and has no infection or stone behind it. Anesthesia The medically controlled loss of consciousness and pain sensation that lets a vet perform surgery, dental work or imaging safely. Blood panel A set of blood tests that counts cells and measures chemicals to show how a cat's organs are working. Neuter The surgery that removes a male cat's testicles so he cannot father kittens, with fewer urges to roam, fight and spray.

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