Cat urinary blockage signs include straining in the litter box with little or no urine, repeated trips that produce nothing, crying, hiding, and vomiting or lethargy. A blocked cat is a medical emergency. If your cat, especially a male, is straining and passing little or no urine, go to a vet or emergency clinic now. Do not wait to see whether it passes, and do not stop to gather records.
What is a urinary blockage in cats?
A urinary blockage, or urethral obstruction, happens when something stops urine from leaving the bladder through the urethra. The cause is often inflammation, mucus plugs or urinary stones. Cornell's Feline Health Center calls urethral obstruction a true medical emergency and notes that the time from complete obstruction to death may be less than 24 to 48 hours.
Male cats face the highest risk because their urethra is longer and narrower. Females can be blocked too, though it is much less common. Any cat that strains and passes little or no urine needs a vet, whatever its sex, age or history.
What are the signs of a blocked cat?
The signs can look like other urinary problems or even constipation, which is one reason a vet has to sort them out. Treat the combination below as an emergency.
| What you may notice | What it can mean | What to do |
|---|---|---|
| Straining in the box with little or no urine | Possible obstruction | Go to a vet or emergency clinic now |
| Many trips to the box in a short time, with little produced | Possible obstruction or bladder inflammation | Go now if a male cat, or if little or no urine comes out |
| Crying, restlessness, hiding, licking the genital area | Pain or distress | Go now |
| Vomiting, weakness, loss of appetite, lethargy | The cat may be becoming seriously ill | Go now |
| Blood in the urine, or urinating outside the box | Urinary tract disease, which can progress to blockage | Call your vet the same day |
The American College of Veterinary Surgeons notes that cats may first show signs of inflammation, such as frequent urination, straining, blood in the urine and urinating outside the box, before a complete obstruction develops. That early stage is your chance to act.
How long can a cat go without urinating?
Use these thresholds and do not stretch them:
- Straining with little or no urine: emergency, leave for the clinic now, at any hour.
- No urine at all for 24 hours: call a vet the same day, even if the cat seems comfortable.
- Passing only a few drops: still counts as little urine. It does not rule out a blockage.
Our guide to how long a cat can go without peeing or pooping explains the reasoning.
For male cats, our page on the causes and emergency signs of urinary blockage in male cats covers the risks for males in more depth. The MSPCA-Angell's page on urethral obstruction in cats describes how quickly an untreated cat can decline.
What should you do right now?
- Call the nearest vet or emergency clinic and say your cat is straining with little or no urine.
- Put your cat in a carrier and leave. Do not wait for the next litter box visit.
- Do not press on the belly, and do not give human medicine.
- Bring a short timeline if you have it: when the signs started, recent diet changes, medications and past urinary problems. Never delay leaving to collect it.
The vet will confirm the cause and treat it. Treatment often means hospital care, and cats that have blocked once are at higher risk of blocking again, so follow the recheck and diet plan your vet gives you.
Which cats are at higher risk?
Urethral obstruction is more common in young to middle-aged male cats, according to the MSPCA-Angell clinical guide. Cats that have had lower urinary tract signs before, including bladder inflammation or stones, are more likely to have another episode. That does not mean other cats are safe. If you own a male cat with a urinary history, learn the signs above now, and keep your regular vet and an emergency clinic number where you can find them at night.
What will the vet do?
The vet will examine your cat and usually check the bladder and run tests. A blocked cat is stabilized first, often with intravenous fluids and medication for the imbalances a blockage causes. The vet then relieves the obstruction, typically with a urinary catheter that stays in place for a few days while swelling settles. Hospital stays vary from a few days to several weeks depending on how severe the blockage was and how long it lasted. Surgery is considered when a blockage cannot be relieved or keeps returning.
Ask the vet what to watch for at home afterward. Cats may continue to strain a little for a couple of days after treatment, but make sure your cat keeps passing urine, even in small amounts, and call the clinic if you are unsure.
What can the litter box show you?
The litter box is where most owners first notice something is wrong, and what you see there is worth acting on. Look for clumps that are missing or tiny, a cat that visits often with nothing to show, blood in the litter, or urine outside the box. Check clump size while you scoop, since visit counts alone do not confirm how much urine came out.
A litter box camera can add a dated record. LitterLens logs each cat's visit count, time in the box and urine clump events, and flags changes from that cat's own baseline, which takes about 7 days to build. Long or repeated visits are the closest signal it gives to straining. It does not see straining or posture, it does not measure clump size or urine volume, and it does not diagnose a blockage. Alerts and analysis need the Care+ subscription. The cat health monitoring collection shows what is available.
That record helps most in a home with several cats, where one cat's extra trips are easy to miss. The multi-cat health monitoring collection lists setups for two or more cats.
Read about how to monitor cat urinary frequency, or see whether a blockage can be silent.
How can you lower the risk of another blockage?
Your vet decides what prevents a repeat, and the answer depends on the cause. Common steps include a diet the vet recommends, encouraging water intake, keeping litter boxes clean and available, and reducing stress. Follow rechecks, and keep watching the litter box for the earliest sign that a pattern has changed. If the box shows a change that lasts more than a day, call your vet.
FAQs About Cat Urinary Blockage
Can a cat still be blocked if a little urine comes out?
Yes. A few drops do not rule out a partial or developing obstruction. Repeated straining, pain or very little urine needs urgent veterinary care.
Can female cats get a urinary blockage?
Yes, but it is much less common. Any cat that strains and passes little or no urine needs a vet.
Can urinary straining look like constipation?
Yes. The posture and repeated trips can look similar. If you are unsure whether urine is coming out, treat it as a possible blockage and call a vet. Our guide on when a cat can't pee or poop covers the difference.
Can LitterLens detect a urinary blockage?
No. It logs visits, duration, stool images and urine clump events. It cannot diagnose a blockage or measure urine output, so a change in the log is a reason to look closer and call a vet.
