An essential veterinary guide to urinary blockages in cats, by Dr. Rocío Cromstedt Lavigne at TINAVET Marbella.
There is something particularly heartbreaking about seeing a cat in pain.
By Dr. Rocío Cromstedt Lavigne, MRCVS
Veterinary Surgeon & Co-Founder of TINAVET Marbella
Cats are extraordinary animals. They are affectionate, independent, curious and sometimes wonderfully mysterious. But they also have a remarkable ability to hide when something is wrong.
A cat who is suffering may not cry for help. They may simply become quieter, hide under the bed or visit their litter tray more often than usual.
And sometimes, what looks like a small change in their behaviour can be the beginning of a life-threatening emergency.
As a veterinary surgeon, one of the situations I want every cat owner to recognise is a cat struggling to urinate.
It is especially frightening because the first signs can be so easy to misunderstand.
You might think your cat is constipated.
You might assume they have a mild urinary infection.
You might decide to wait until tomorrow to see whether they improve.
But if your cat is trying to urinate and cannot, waiting could put their life at risk.
During our years working as veterinarians in Birmingham, my husband Alberto and I learned how important it is to recognise these early warning signs.
That experience is one of the reasons we founded TINAVET Marbella: to help families understand their pets' health, make informed decisions and recognise when urgent veterinary attention is needed.
Today, I want to explain a condition that every cat owner should know about.
Not to frighten you.
But because recognising the problem early could save your cat's life.
A cat struggling to urinate may have a life-threatening urinary blockage. Recognising the warning signs and seeking immediate veterinary attention can save lives.
My cat can't pee. Is it an emergency?
Yes. If your cat is repeatedly trying to urinate but produces no urine, or only a few drops, you should treat it as an emergency and seek veterinary care immediately.
Your cat may have a urinary blockage, also called a urethral obstruction.
This happens when urine cannot pass normally from the bladder through the urethra to the outside of the body.
Without treatment, urine accumulates inside the bladder, pressure increases, the kidneys become affected and dangerous changes can develop in the bloodstream.
Some cats develop life-threatening complications within 24–48 hours of a complete obstruction.
Do not wait until tomorrow. Do not wait for your cat to stop eating or become weak. Seek veterinary attention as soon as you notice the problem.
What is a urinary blockage in cats?
To understand what happens, imagine your cat's urinary system as a simple drainage system.
The kidneys produce urine.
The urine travels to the bladder, where it is stored.
When your cat urinates, the urine leaves the bladder through a narrow tube called the urethra.
A urinary blockage occurs when something prevents urine from flowing through that tube.
This may be caused by inflammatory material, mucus, urinary crystals, stones, swelling or other problems affecting the urethra.
When the urethra becomes blocked, the bladder continues filling.
Your cat feels the need to urinate but cannot empty it.
The result is increasing discomfort, pain and potentially serious damage to the body.
This is not simply a problem with the litter tray.
It is a genuine medical emergency.
Why are male cats more likely to develop urinary blockages?
Although both male and female cats can suffer urinary problems, complete urethral obstruction is much more common in male cats.
The reason is anatomical.
Male cats have a longer and narrower urethra, particularly towards the end of the penis.
This means even a small amount of inflammatory material or urinary debris can block urine flow.
Both neutered and unneutered male cats can develop urinary obstruction.
However, female cats can also suffer painful and potentially serious urinary conditions.
Every cat showing signs of difficulty urinating deserves prompt veterinary assessment.
Seven warning signs that your cat may have a urinary blockage
Some cats show several symptoms. Others only show one or two.
Please pay special attention to these changes.
1. Repeated visits to the litter tray
Your cat goes into the litter tray, stays there for a while, comes out and returns again a few minutes later.
You may notice this happening repeatedly.
It can look as though your cat urgently needs to urinate but cannot get comfortable.
This is one of the most important warning signs.
2. Straining without producing urine
Your cat adopts their normal urinating position and pushes, but little or nothing comes out.
Sometimes, owners believe their cat is trying to pass faeces.
This confusion is common because the posture may look similar.
If you cannot confirm that your cat is passing urine normally, do not assume they are constipated. Seek urgent veterinary advice.
3. Crying or showing discomfort
Some cats vocalise when trying to urinate.
Others become restless, change position repeatedly or appear uncomfortable.
A cat in pain may also become unusually defensive or avoid being touched.
4. Licking their genital area excessively
Cats naturally groom themselves, but repeated or intense licking around the penis or vulva may indicate discomfort or inflammation.
In male cats, this can be associated with urinary problems.
5. Blood or very small amounts of urine
You may notice pink or red urine, tiny spots of urine in the litter tray or unusually small clumps.
These signs can occur with several urinary conditions.
Importantly, passing a few drops of urine does not prove that your cat is safe from an obstruction.
6. Hiding, loss of appetite or vomiting
As the condition progresses, your cat may become less interactive.
They might hide, refuse food, vomit or appear unusually tired.
These symptoms are especially concerning because they can indicate that the urinary problem is affecting the rest of the body.
7. Weakness, collapse or severe lethargy
These are advanced warning signs.
A cat who becomes very weak, unresponsive or unable to stand may already be critically ill.
Do not wait for symptoms to reach this stage.
Why is a blocked bladder so dangerous?
This is the part I most want cat owners to understand.
The bladder is designed to store urine temporarily, not indefinitely.
When urine cannot escape, several serious problems can develop.
Kidney damage
The increased pressure can interfere with normal kidney function.
Waste products that should leave the body in urine begin accumulating in the bloodstream.
Dangerous potassium levels
A blocked urinary system can cause potassium levels in the blood to rise dangerously.
This is called hyperkalaemia.
Potassium is essential for normal muscle and nerve function, including the heart.
When potassium becomes too high, it can cause dangerous heart rhythm abnormalities.
Severe pain and distress
A bladder that continues filling without emptying can become extremely uncomfortable.
Cats may suffer considerable pain even when they are not obviously vocalising.
Bladder damage or rupture
In severe cases, the bladder wall may become damaged, and occasionally the bladder may rupture.
Shock and death
Without urgent treatment, the combination of urinary retention, kidney dysfunction and electrolyte abnormalities can become fatal.
That is why veterinary professionals consider a suspected urinary blockage an absolute emergency.
Is my cat constipated or unable to urinate?
This is a very common question.
Both conditions can cause a cat to spend longer than usual in the litter tray and strain.
The problem is that owners cannot always distinguish between them by watching.
A cat who appears to be constipated may actually have a blocked urethra.
Clues suggesting a urinary problem include:
Frequent attempts to urinate
Little or no urine in the litter tray
Repeated genital licking
Crying while trying to urinate
Blood in the urine
Pain or discomfort
However, these signs do not confirm a diagnosis.
If your cat is straining and you are unsure whether they are passing urine, it is safest to treat the situation as urgent.
What causes urinary problems in cats?
Not every cat with urinary symptoms has a complete blockage.
Veterinarians use the term Feline Lower Urinary Tract Disease (FLUTD) to describe several conditions affecting the bladder and urethra.
The underlying causes can include:
Feline idiopathic cystitis (FIC)
This is one of the most common causes of lower urinary tract symptoms in cats.
It involves inflammation of the bladder without an identifiable cause such as a urinary stone or bacterial infection.
Stress and a cat's individual response to its environment can play an important role.
Affected cats may experience painful urination, frequent litter tray visits, blood in the urine or urination outside the tray.
Some cases can contribute to urethral obstruction.
Urinary crystals
Crystals may form in urine under certain conditions.
Crystals do not always cause symptoms, and their presence does not automatically mean the urethra is blocked.
However, they can be associated with urinary stones or inflammatory plugs.
Bladder stones
Mineral deposits can develop inside the bladder.
Some stones cause irritation and discomfort. Others may move into the urethra and obstruct urine flow.
Urethral plugs
A mixture of mucus, inflammatory cells and mineral material can form a plug that prevents urine from passing.
This is an important cause of obstruction in male cats.
Urinary tract infections
Bacterial urinary infections can cause similar symptoms, although they are less common in otherwise healthy younger adult cats than many owners assume.
A veterinary examination and appropriate testing are needed to determine whether infection is present.
This is why antibiotics are not automatically the right treatment for every cat with urinary symptoms.
Other less common causes
Anatomical abnormalities, urethral narrowing, trauma and occasionally tumours may also affect urine flow.
The important message is that urinary symptoms can look very similar even when the underlying causes are different.
What should I do immediately if my cat cannot urinate?
If you suspect your cat has a urinary blockage, follow these steps.
1. Seek emergency veterinary attention immediately
Do not wait for a routine appointment.
Do not wait until the following morning.
If your normal veterinary clinic is closed, contact an available emergency veterinary service.
2. Keep your cat calm
Place your cat gently inside a secure, comfortable carrier.
Minimise noise and unnecessary handling.
A painful cat may become distressed when touched or moved.
3. Do not press on your cat's abdomen
Never attempt to squeeze the bladder or force urine out.
This can cause severe pain and potentially serious injury.
4. Do not give medication or home remedies
Do not give human painkillers, antibiotics, diuretics, laxatives or other treatments without veterinary instructions.
Do not attempt to insert anything into your cat's urinary opening.
5. Take useful information with you
If possible, tell your vet:
When you last saw your cat urinate normally
Whether any urine has been produced
Whether there is blood in the urine
Whether your cat is vomiting
Whether they are eating and drinking
Whether they have experienced urinary problems before
Whether they are taking any medication
But do not delay leaving for the clinic simply to collect this information.
The most important thing is getting your cat examined without delay.
What happens at the veterinary clinic?
When a cat arrives with suspected urinary obstruction, the priority is to assess how seriously the condition is affecting the animal.
The veterinary team may begin by checking the cat's heart rate, circulation, hydration, temperature, pain level and bladder.
Blood tests
Blood tests can help assess kidney function and detect dangerous electrolyte abnormalities, particularly high potassium levels.
Urine testing
Once it is safe to obtain a sample, urine testing may help identify crystals, inflammation, blood or infection.
Ultrasound or X-rays
Diagnostic imaging may be recommended to examine the bladder and identify stones or other abnormalities.
Emergency stabilisation
Depending on the cat's condition, treatment may include intravenous fluids, pain relief, monitoring of the heart and correction of dangerous electrolyte imbalances.
Urinary catheterisation
In many cases, the veterinarian needs to relieve the obstruction by carefully passing a urinary catheter through the urethra.
This is usually performed under appropriate sedation or anaesthesia.
The catheter allows the bladder to drain and may remain in place while inflammation and swelling settle.
Hospitalisation
Many cats require hospital monitoring after the blockage has been relieved.
The veterinary team may monitor urine production, kidney function, electrolyte levels, pain and the ability to urinate normally.
The length of hospitalisation depends on the severity of the condition and the cat's recovery.
Will my cat need surgery?
Not every blocked cat needs surgery.
Many obstructions can be relieved through catheterisation and supportive treatment.
However, surgery may be required if there are bladder stones that cannot be managed appropriately by other methods, or if obstruction repeatedly recurs despite careful treatment and investigation.
In selected cases of severe recurrent obstruction, a procedure called perineal urethrostomy may be considered.
This surgery creates a wider urinary opening to reduce the risk of future blockage.
It is not appropriate for every cat and does not cure all underlying bladder diseases.
The decision must be made after a thorough veterinary assessment.
Can a cat survive a urinary blockage?
Yes. Many cats recover well when treatment is started promptly.
The prognosis depends on factors such as:
How long the obstruction has been present
The cat's general health
Whether kidney function is affected
Whether dangerous electrolyte abnormalities have developed
The underlying cause
Whether complications occur
Early treatment substantially improves the chances of a good outcome.
But recovery from one episode does not guarantee that another blockage will never occur.
Some cats develop recurrent urinary problems and need ongoing management.
What happens after my cat comes home?
Once your cat has recovered enough to leave the veterinary hospital, follow-up care becomes extremely important.
Your vet may recommend medication, dietary adjustments, additional tests or changes to the home environment.
Monitor your cat's urination carefully.
Check that they are passing normal amounts of urine and behaving comfortably.
If they begin straining again, return repeatedly to the litter tray or stop producing urine, seek urgent veterinary care.
A recurrence can happen, particularly in the period following treatment.
How can I help prevent urinary problems in my cat?
Not every urinary blockage can be prevented.
However, there are several important ways to support urinary health and reduce the risk of recurrent problems.
1. Encourage your cat to drink more water
Adequate water intake helps produce less concentrated urine.
Practical ideas include:
Providing several fresh water bowls
Trying a cat water fountain
Offering wet food when appropriate
Keeping water bowls clean
Placing water away from noisy or stressful areas
Some cats prefer wide bowls, moving water or particular locations.
2. Consider wet food as part of the diet
Wet food can help increase total water intake.
However, no single diet is suitable for every urinary condition.
For cats with certain urinary crystals or stones, your vet may recommend a specific therapeutic diet.
Do not start a prescription urinary diet without understanding the diagnosis.
3. Reduce stress at home
Cats are sensitive to changes in their environment.
Moving house, introducing another pet, changes in routine, conflict between cats or lack of safe resting spaces may contribute to stress.
For cats with feline idiopathic cystitis, improving the environment is a central part of long-term management.
Provide predictable routines, comfortable hiding places, opportunities to climb and regular interactive play.
4. Improve litter tray arrangements
A useful starting point is one litter tray per cat, plus one extra, ideally in different quiet locations.
For example, two cats should usually have access to three litter trays.
Keep them clean, accessible and away from noisy areas.
Choose a litter your cat feels comfortable using.
5. Maintain a healthy weight
Obesity is associated with an increased risk of some lower urinary tract problems.
Maintaining a healthy body condition and encouraging daily activity can be helpful.
6. Recognise changes early
Pay attention to how often your cat urinates, the size of the urine clumps, and any changes in behaviour around the litter tray.
A cat urinating outside the tray is not necessarily being naughty.
They may be in pain.
Never punish a cat for urinary accidents.
7. Follow your vet's recommendations
Cats with recurrent urinary problems may need individualised dietary, environmental or medical management.
Regular follow-up helps us adapt the plan to the cat's needs.
A special message for cat owners in Marbella
Whether you live in Marbella, San Pedro de Alcántara, Guadalmina, Nueva Andalucía, Puerto Banús or elsewhere on the Costa del Sol, urinary blockages deserve the same urgent attention.
Some cats live indoors in apartments.
Others spend time outside in gardens or terraces.
For indoor cats, regularly checking the litter tray can help identify changes in urination.
For cats who usually urinate outdoors, recognising a problem may be more difficult.
This makes changes in behaviour especially important.
If an outdoor cat suddenly starts visiting an indoor litter tray repeatedly, appears uncomfortable, hides or stops eating, do not ignore it.
Marbella's climate also makes access to fresh water particularly important during warmer periods, although urinary obstruction is not simply caused by hot weather.
A personal message from Rocío
One of the things I love most about cats is their quiet way of communicating.
They do not always demand attention.
Sometimes they simply sit beside us, follow us from room to room or choose to sleep close to the people they trust.
And when they are unwell, that quietness can make it difficult to understand how much they are suffering.
As veterinarians, Alberto and I know that many serious conditions do not begin with dramatic symptoms.
Sometimes they begin with a small change.
A cat visiting the litter tray more often.
A cat hiding in a different room.
A cat who is no longer interested in breakfast.
These little changes matter.
When we created TINAVET Marbella, we wanted to build a veterinary clinic where families could ask questions, feel listened to and understand what their pets were trying to tell them.
Because I believe that good veterinary medicine is not only about treating an illness.
It is about helping families recognise problems early enough to make a difference.
If you remember only one thing from this article, please let it be this:
A cat who is trying to urinate and cannot is asking for help, even if they cannot tell you in words.
Please listen.
Please act quickly.
And please never wait until tomorrow when a urinary blockage is possible.
Your cat is depending on you.
How TINAVET Marbella can help
At TINAVET Marbella, Alberto and I are committed to compassionate, evidence-based veterinary care for dogs and cats.
Our veterinary services include consultations, laboratory investigations, diagnostic imaging, preventive medicine and follow-up care, according to clinical needs and availability.
We are based in San Pedro de Alcántara, serving pet owners from Marbella, Guadalmina, Nueva Andalucía, Puerto Banús and surrounding areas.
We offer communication in English and Spanish, helping local and international families understand their pets' health and treatment options.
Important: If your cat is unable to urinate, seek emergency veterinary care immediately. Do not rely on an online contact form or routine appointment request.
For non-urgent urinary concerns, follow-up appointments or general veterinary information, you can contact TINAVET Marbella.
Because your cat deserves to be understood.
And because recognising a warning sign at the right moment can save a life.
Frequently Asked Questions About Urinary Blockages in Cats
Is it an emergency if my cat cannot pee?
Yes. A cat who is trying to urinate but cannot may have a urethral obstruction. This is a potentially life-threatening emergency requiring immediate veterinary attention.
How long can a cat survive without urinating?
A complete urinary obstruction can cause dangerous complications within 24–48 hours, sometimes sooner. Do not wait for a specific number of hours. Seek emergency veterinary care immediately.
Why does my male cat keep going to the litter tray but nothing comes out?
He may have a urinary blockage, bladder inflammation or another lower urinary tract condition. Because a blockage can be fatal, he needs urgent veterinary assessment.
Can a female cat have a blocked bladder?
Yes, although complete urethral obstruction is much less common in female cats than in males. Any cat with difficulty urinating needs prompt veterinary attention.
Can a cat be blocked and still pass a few drops of urine?
Yes. Passing a few drops does not rule out a serious partial obstruction or other urgent urinary problem. Veterinary examination is necessary.
How can I tell if my cat is constipated or unable to urinate?
The signs can look very similar. If your cat is repeatedly straining and you cannot confirm normal urination, treat it as a possible urinary emergency.
Can a urinary blockage go away on its own?
You should never assume that it will. A suspected blockage requires immediate veterinary care, and home monitoring can be dangerous.
Does my cat need antibiotics for urinary problems?
Not necessarily. Many feline urinary problems are not caused by bacterial infections. Treatment depends on veterinary examination and appropriate testing.
Can urinary blockages happen again?
Yes. Some cats experience recurrent urinary obstructions or other lower urinary tract problems. Follow-up care, appropriate nutrition, hydration and environmental management can help reduce risk.
How can I reduce my cat's risk of urinary problems?
Encourage water intake, provide clean litter trays, maintain a healthy weight, reduce environmental stress and follow any individual dietary or medical recommendations from your veterinarian.
Related veterinary advice
You may also find these articles helpful:
What to Do If Your Dog or Cat Swallows Something They Shouldn't
Meet Dr. Rocío Cromstedt Lavigne and Dr. Alberto Fernández Jiménez
Veterinary references
This article is informed by the following professional sources:
2025 iCatCare Consensus Guidelines on Feline Lower Urinary Tract Diseases
American College of Veterinary Surgeons — Urinary Obstruction in Male Cats
This article provides general veterinary education and does not replace an individual clinical examination or diagnosis. If your cat cannot urinate, seek immediate veterinary assistance.
