Why can't my cat pee?  The emergency blocked bladder

Your cat is spending a long time in the litter tray without passing anything more than a few drips of urine.  Why can't my cat pee?  What's the matter and will it get better by itself?  They may have had cystitis in the past but is this just a repeat?  Well a blocked bladder might be the cause and this is a true cat emergency.


Let me start by saying that if at this very minute you have a male cat who is currently struggling or straining to pee, and if he appears in any form of discomfort, pain or distress, or is in any way unwell you should stop reading and contact your vet straight away.  Untreated bladder obstruction kills quickly and rapid treatment is needed.  Don't finish reading this, call your vet.  Seriously.

Why can't my cat pee?

For those of you still here let me go into more detail.  First of all, there are several things that can cause a cat to stop urinating.  These include:

  • "simple" cystitis, feline lower urinary tract disease, idiopathic cystitis - different names for the same condition

  • bladder stones

  • bladder infection

  • bladder tumour

  • nerve damage

  • damaged pelvis, tail or spine

  • urethral obstruction or blocked bladder

Cystitis in cats is by far the most common cause.  Cystitis and bladder disease are discussed in a separate article but right now how can we tell if the bladder is blocked and that our cat is suffering a genuine emergency?

Is my cat at risk?

First of all, this is almost always a disease of male cats. 

This is because the urethra (the tube between the bladder and the outside world) is longer and more narrow in male compared to female cats.  If your cat is a girl then the chance of their bladder being blocked is very remote.  Other factors that increase the risk of your cat developing an obstruction include:

risk factors for blocked bladder in cats as a reason for why they cant pee
  • Obesity

fat cats have been shown to more likely to develop a blockage than healthy weight cats.  Read about the other risks of being fat in cats here

  • Previous history of cystitis or obstruction

If your cat has had urinary issues in the past even if they have never obstructed before then they are at a greater risk.  We know that once a cat has had cystitis, this is a condition that will need to be managed long term.

  • Dry rather than wet food diet

Cats are poor drinkers and so will have a very concentrated urine if they are fed dry food.  This means they need to empty their bladder less often.  If there is any sludge, debris or crystals in the urine then they are more likely to build up in the bladder and so are more likely to cause an obstruction.  A cat with a larger water intake will have their bladder flushed more regularly, reducing the risk of a plug forming.

  • Stress-prone cat in a stressful situation

Stress is a big cause of cystitis.  This might be building work or renovations, firework season, visitors to the house, a new baby or even a new cat on the street.  If you know that a stressful situation is coming up then be extra vigilant and definitely speak to your vet if your cat has had issues before.

  • Neutered/castrated and/or indoor only cats

In isolation these factors are unlikely to increase risk.  What these do mean though is that your cat is more likely to be overweight and therefore be at a higher risk of developing a blocked bladder

Do I need to call my vet?

Your cat may tick a couple of these boxes, but the disease can also happen in those who don't fit the stereotype.  What symptoms might they be showing that means a bladder obstruction could be developing?

Very often there will be a build-up of a few days where your cat may appear a little uncomfortable, they may not eat or drink as well as normal.  You might just feel that they are a bit off.

Sometimes though there may be no warning.  They go from normal to emergency in the blink of an eye.

Blocked Bladder Symptoms

If you notice any of the following then a trip to your vet should be arranged straight away:

  • frequent trips to the litter tray

  • spending more time squatting without producing any urine

  • red tinged urine

  • crying or vocalising, especially when urinating (or attempting to)

  • increased agitation and restlessness

  • licking their back end frequently

  • pain when picked up under their abdomen

As the disease progresses, your cat may start to vomit, they may collapse, they may become comatosed and ultimately they will die.

How to Treat a Blocked Bladder

When you take your cat to the vet, and if an obstruction is confirmed, several things will happen.  They will need to be hospitalised and the blockage will be cleared by passing a urinary catheter under heavy sedation or anesthesia.  An xray may be taken to see if there is any clear underlying problem and blood testing run to check the kidneys and general body health.  Once cleared, the bladder will be flushed to remove all of the debris that has collected and the catheter will be stitched in place and maintained while your cat recovers.  Intravenous fluids are also essential to support your cats recovery.

blocked bladder repeat obstruction rate

Typically after a day or two the bladder catheter will be removed and your cat will be discharge on several different medications and management strategies to try and prevent the risk of the blockage recurring.  Medications are likely to include anti-spasmodics such as prazosin (these stop the urethra from spasming and becoming even narrower), as well as pain killers and possible antibiotics. 

This is important because we know that within 24 hours 10% of cats will re-obstruct.  This increases to 20% after 30 days.  1-in-4 cats suffering a repeat bladder obstruction within 2 years.

There are some medical strategies to treat these cats without catheterisation but they are definitely sub-optimal and carry a higher risk of death.  Also, in some instances when either the obstruction can't be cleared or an individual suffers from multiple episodes of obstruction an operation known as a perineal urethrostomy may be required.  This involved removal of the penis, where the urethra is at its most narrow, and creating a new hole for a cat to urinate through.

Environmental management, medication and dietary changes can all reduce this risk of repeat obstruction.  These are discussed in my separate article on the treatment of cystitis in cats.

Briefly though, some of the main cystitis home prevention strategies to reduce stress and getting your cat to drink more water include:

  • resource management - litter trays, water and food bowls

  • providing a 3D space

  • securing the home - this might require a microchip cat flap (amazon link)

  • anti-stress medication such as the pheromone Feliway

  • changing to a wet diet or adding water to the food and feeding a special prescription urinary diet that come in wet and dry forms

  • using a cat water fountain

  • add tuna juice to the water for flavor

I hope these tips help your cat get the treatment they need, or kick starts some strategies such as weight loss to prevent it in the first place.

If you have any questions or stories you would like to share then please leave a comment below.  I would love to hear from you.  Also sign up to my newsletter to access the Knowledge Vault and to make sure you don't miss out on future articles and allow me to continue to help you and your pet live healthier, happier lives.

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