If your male cat keeps going back to the litter box and straining but little or no urine comes out, he may have a urinary blockage. This is one of the most urgent emergencies a cat can have. This guide covers the signs of a urinary blockage in cats, why it’s so dangerous, what treatment involves, and how to lower the chance it happens again.
Quick Answer: A urinary blockage happens when a male cat’s narrow urethra gets plugged and he can’t pee. Toxins and potassium build up in the blood, and it can be fatal in as little as 24–48 hours. If your cat is straining with little or no urine, take him to a vet or emergency clinic right away.
What Is a Urinary Blockage?
The urethra is the tube that carries urine from the bladder out of the body. In male cats it’s long and very narrow, so it blocks easily. Female cats rarely get blocked.
According to International Cat Care, common causes include:
- Urethral plugs: a paste-like mix of protein, cells, crystals and debris that forms in the bladder
- Bladder stones that lodge in the urethra
- Swelling and muscle spasm caused by bladder inflammation, often from feline idiopathic cystitis (FIC), a stress-related bladder condition
When a cat can’t empty his bladder, waste products the kidneys normally remove build up in the blood. Potassium levels rise, which can disrupt the heart’s rhythm. The Cornell Feline Health Center warns that death can follow a complete blockage in less than 24 to 48 hours.
Signs of a Urinary Blockage in Cats
Many owners first think their cat is constipated, because both look like straining. Watch for:
- Frequent trips to the litter box with little or no urine
- Straining or squatting for a long time
- Crying or yowling while trying to pee
- Peeing outside the litter box
- Blood in the urine
- Licking the genital area a lot
- Hiding, restlessness or agitation
- Not eating, vomiting or lethargy. These often appear later, as toxins build up.
Check the litter box. Fewer or smaller clumps than usual, or none at all, is a key clue.
Which Cats Are Most at Risk?
Cornell lists several risk factors:
- Male cats, including neutered males
- Middle-aged cats
- Overweight cats that get little exercise
- Indoor cats that use a litter box
- Cats that drink little water
- Multi-cat homes and major changes in routine, such as a move
What Happens at the Vet
A blocked cat needs emergency treatment. Your vet will usually:
- Stabilize your cat with IV fluids and, if needed, medication to protect the heart from high potassium.
- Sedate or anesthetize him and pass a thin catheter to clear the blockage and empty the bladder.
- Leave the catheter in place for a day or more in many cases while the bladder recovers.
- Run tests such as bloodwork, a urine test and X-rays to look for stones and check kidney function.
- Send him home with pain relief and, often, medication to relax the urethra.
Some cats block again. For cats that block repeatedly, a vet may discuss a surgery called a perineal urethrostomy, which widens the opening.
How to Help Prevent a Urinary Blockage
Prevention focuses on more water, less stress and a healthy weight:
- Increase water intake. Wet food adds a lot of moisture. Try a water fountain or several bowls around the house.
- Feed a prescription urinary diet if your vet recommends one. These diets help dissolve or prevent certain crystals and stones. Don’t add urine acidifiers without your vet’s advice.
- Keep litter boxes clean and easy to reach. Cornell recommends one more box than the number of cats, in quiet, safe spots.
- Reduce stress. Keep routines steady and give each cat their own resources, such as food, water, beds and hiding places.
- Manage weight. Smaller, more frequent meals and daily play help.
For help with diet, see our guides on what to feed your cat and dry vs. canned food.
When to Call Your Vet
Go to an emergency vet now if your cat:
- Is straining in the litter box with little or no urine
- Cries while trying to pee
- Is vomiting, very lethargic or hiding along with any litter box changes
- Hasn’t produced any urine clumps in 12 hours or more
Book an appointment soon if:
- You see blood in the urine but your cat is still peeing normal amounts
- Your cat is peeing more often or outside the litter box
Urinary signs in a female cat are less likely to be a blockage, but they still need a vet visit.
Frequently Asked Questions
How long can a cat live with a urinary blockage?
Not long. A completely blocked cat can die within 24 to 48 hours, and sometimes sooner. Don’t wait overnight to see if he improves.
Is my cat constipated or blocked?
It can be hard to tell from straining alone. Check the litter box for urine clumps. If you’re not sure, assume it’s a blockage and call your vet, because it’s far more urgent.
Can female cats get urinary blockages?
It’s rare, because females have a shorter, wider urethra. Female cats can still get bladder inflammation, stones and infections.
Will my cat get blocked again?
Some cats do, especially in the first weeks after treatment. Follow your vet’s diet and medication plan, increase water intake and reduce stress to lower the risk.
This article is for general information only and isn’t a substitute for professional veterinary advice. If you’re worried about your pet’s health, contact your veterinarian or an emergency animal hospital.
