Blocked Bladder (Urethral Obstruction) in Cats
Blocked bladder in cats, also known as feline urethral obstruction, is a condition where your cat’s urinary tract becomes partially or completely obstructed, preventing them from urinating. It occurs mostly in male cats.
If you find your cat squatting over the litter box with little or no urine and showing obvious signs of discomfort, he may have a blocked bladder.
Complete urethral obstruction is an EMERGENCY and it can be fatal if not treated or resolved within 1-3 days. Therefore, knowing the signs of urethral obstruction in your cat can be life-saving.
A blocked bladder in your pet cat is a life-threatening emergency that requires immediate veterinary care to prevent pain, organ failure or even death.
What is a blocked bladder in cats?
The urethra is the part of the urinary tract which connects the bladder to the penis. It is a tube which helps transport urine from the bladder to the outside of the body. When the urethra becomes partially or fully obstructed, it affects urine outflow, which causes pain and discomfort, and may lead to the accumulation of toxic waste. When left untreated, a severely blocked bladder can cause bladder rupture, kidney failure, or even death. Symptoms such as frequent straining, pain or your cat’s complete inability to urinate is a veterinary emergency and requires a visit to the veterinarian immediately.
What causes blocked bladders in cats?
Blocked bladder occurs most commonly in male cats due to their narrow urethra as compared to female cats. As the urethra is extremely narrow, usually only 1-2mm in diameter, it can get easily obstructed.
Common causes of urethral obstruction in cats are:
- Idiopathic causes – In up to 50% of cases, there is no known cause for the blockage, often the obstruction can be caused by inflammatory swelling, but the cause for inflammation may not be exactly known.
- Urethral plugs – Urethral plugs are composed of a mixture of mucus, blood, crystals and sloughed tissues. Urethral plugs typically have a soft, malleable consistency, almost like a paste or jelly.
- Urolithiasis – Urolithiasis occurs when uroliths, or urinary stones block the urethra. Uroliths are different from urethral plugs by their composition and structure. Uroliths are mainly composed of crystalline minerals. Uroliths are also hard and rock-like.
- Strictures – Strictures refer to the abnormal narrowing of the urethra. Urethral strictures can be caused by chronic inflammation of the urethra (which could be part of a syndrome called Feline Lower Urinary Tract Disease), trauma to the urethra, or congenital abnormalities.
- Urethral spasms – Inflammation of the bladder and urethra causes pain and irritation. This can cause spasms of the muscles around the urethra which can lead to a urethral blockage.
Urethral obstruction in cats can develop slowly over time, especially in cases of urethral plugs and uroliths. Your cat may show initial signs of urinary discomfort or urinary tract inflammation.
What are the symptoms of blocked bladder in cats?
Understanding the signs and symptoms of a blocked bladder is crucial — it eases their suffering and prevents fatal outcomes. Getting early treatment for your cat can also minimise chances of complications and long-term issues like kidney damage or urinary tract scarring. Pay attention to your cat and look out for the following:
- Straining to urinate – Your cat may strain to urinate, but little to no urine is produced. This can sometimes be mistaken as straining to defecate
- Urgency to urinate – You may notice your cat going to the litter box more often than usual. Take note of the frequency of going to the litter box versus the amount of urine produced. Your cat may visit the litter box more often, but little to no urine is produced.
- Bloody urine – Blood in urine can indicate injury of the urethral lining. Bloody urine can also be caused by other causes such as stress or feline idiopathic cystitis (FIC). In general, bloody urine should prompt you to take your pet to the vet.
- Urinating outside of the litter box – Urinating outside the litter box (in the sink, bathtub, on the floor, etc) for no apparent reason may indicate urinary problems and urgency to urinate. Other than medical causes, behavioural issues can also contribute to this phenomenon.
- Behavioural changes – You may notice your cat becoming more irritable, aggressive, restless, and hide away from you. This can be due to your cat being in pain.
- Vocalisation – Your cat may become more vocal and cry a lot, due to being in pain.
- Loss of appetite – Loss of appetite is common in cats with urethral obstruction.
- Lethargy – Lethargy could be due to pain and discomfort, or due to electrolyte imbalance from being unable to urinate.
- Vomiting and diarrhoea – Vomiting and diarrhoea can be caused by metabolic toxins buildup in the body due to the inability of the kidneys to get rid of them through the urine.
- Coma – A comatose cat most likely has been suffering from a complete obstruction for 1 or 2 days, however, a few cats may be obstructed for only half a day. This condition is an emergency and requires immediate medical attention as it can be fatal. A cat in coma is unconscious and will not respond to strong external stimuli.
Urinary symptoms may not be easy to spot in cats, if you notice any concerning behaviour or changes in your pet, it is best to take your cat to the vet for a proper check-up or diagnosis.
What are the risk factors of a blocked bladder in cats
A blocked bladder can happen to any cat, but several risk factors can increase the risk of urethral obstruction. Among the risk factors include:
- Male cats – Male cats are at higher risk of urethral obstructions compared to female cats due to a narrower urethra.
- Overweight cats
- Dry food diet – Male cats which are on exclusively or mainly dry food diet have high incidences of urethral blockage as compared to those on a wet food diet.
- Neuter status – A recent study reported that intact male cats are more likely to suffer from early-onset urethral obstruction compared to neutered male cats [5].
- Previous incidences of urethral obstruction – Your cat may be at higher risk of urethral obstruction if your cat has had a previous incidence of bladder blockage. You may want to talk to your vet about changing your cat’s diet or other therapeutic options that can prevent future occurrences of urethral obstruction.
- Stress – Stress can often cause FIC, which may lead to inflammation and the likelihood of a blocked bladder. Common sources of stress for your cat may include multi-cat households, construction or renovation, visitors, unclean litter box, or lack of enrichment/boredom.
How is a feline blocked bladder diagnosed?
When you take your cat to the vet for urinary issues, the vet will often conduct the following tests to diagnose a blocked bladder:
- Physical examination – Physical examination of your cat often starts with taking symptoms and medical history. Inform your vet of your cat’s symptoms, when they first started, and previous incidences of blocked bladder. Your vet will palpate your cat’s bladder to diagnose for urethral obstruction, a hard and firm bladder is an indicator of urethral obstruction.
- Abdominal x-ray – Abdominal x-rays can help the vet see the size of your cat’s bladder in cases where palpation is difficult, such as in obese cats. Bladder or urethral stones can be detected via xrays.
- Abdominal ultrasound – Abdominal ultrasounds can be useful to check for the presence of other masses that may contribute to the obstruction.
- Lab tests – Lab tests such as blood tests and urinalysis are often done for further evaluation, such as to assess kidney function, detect the presence of infections, or to analyse the composition of uroliths found.
A cat getting an ultrasound done to check for bladder growths.
How is a feline blocked bladder treated?
Treatment for feline urethral obstruction has to be done in a veterinary clinic or hospital, medical treatment at home is not possible. Most likely, your cat will have to stay in the hospital for several days.
- Urinary catheter – The most common treatment for feline urethral obstruction is clearing the blockage by use of a urethral catheter. Your cat may need to be sedated or put under anaesthesia for the vet to insert the catheter. The catheter is left in the urethra for several days until the bladder is thoroughly flushed or cleared of the blockage. During this time, your cat will be hospitalised and kept on intravenous fluids and pain medication.
- Urethral stone removal — If the obstruction is caused by urethral stones, the stone removal is typically done by flushing the stone back into the bladder followed by cystotomy for removal or dissolution of the stone. In cases where the stone cannot be flushed, a perineal urethrotomy (see next point) is advisable.
- Perineal urethrostomy (PU) – PU is a reconstructive surgical procedure to create a wider opening of the urethra, and is commonly performed in cases of recurrent urethral obstruction.
Post-treatment care
Most cases of urethral obstruction in cats can be treated successfully. After being discharged, monitor your cat closely for the next 1 to 2 days to ensure they are able to urinate normally. It is also important to continue monitoring your cat’s urinary health to prevent future occurrences of blocked bladder.
Your vet may recommend a change in diet to prevent future occurrences of blocked bladder in your pet. Your cat may need to be put on a prescription diet (urinary care line of cat food) for the rest of their life, which helps reduce the risk of crystal formation, and regulate urine pH. Additionally, increased water intake with the use of a drinking fountain, or incorporation of wet foods, can improve your cat’s urinary health.
Summary
Understanding the signs of a blockage in your cat’s bladder or urinary tract and acting immediately can make a difference between life and death. This condition isn’t just painful — it is a ticking clock, and getting immediate veterinary care can prevent your cat from irreversible damage, giving them the best chance to recover and thrive.
Dr Paws Vet Care is dedicated to providing the best possible care for your pets, and when it comes to emergencies like a blocked bladder, we understand how important every moment is. Schedule a consultation with our veterinary experts today for a comprehensive diagnosis and personalised treatment for your pet.
Frequently Asked Questions
References
- Bartges JW, Finco DR, Polzin DJ, Osborne CA, Barsanti JA, Brown SA. Pathophysiology of urethral obstruction. Vet Clin North Am Small Anim Pract. 1996 Mar;26(2):255-64. PMID: 8711861.
- Cosford KL, Koo ST. In-hospital medical management of feline urethral obstruction: A review of recent clinical research. Can Vet J. 2020 Jun;61(6):595-604. PMID: 32675811; PMCID: PMC7236633.
- Osborne CA, Lulich JP, Kruger JM, Ulrich LK, Bird KA, Koehler LA. Feline urethral plugs. Etiology and pathophysiology. Vet Clin North Am Small Anim Pract. 1996 Mar;26(2):233-53. PMID: 8711860.
- Hadar EN, Morgan MJ, Morgan OD. Use of a self-expanding metallic stent for the treatment of a urethral stricture in a young cat. J Feline Med Surg. 2011 Aug;13(8):597-601. doi: 10.1016/j.jfms.2011.03.001. Epub 2011 May 6. PMID: 21530344; PMCID: PMC10822414.
- Sampaio KO, Silva-Junior VAD, de Sousa-Filho RP, Aleixo GAS, Mori da Cunha MGMC, da Silva ECB. Neutering is not associated with early-onset urethral obstruction in cats. J Feline Med Surg. 2022 Dec;24(12):e611-e617. doi: 10.1177/1098612X221128781. Epub 2022 Dec 1. PMID: 36453601; PMCID: PMC10812360.
- Conway DS, Rozanski EA, Wayne AS. Prazosin administration increases the rate of recurrent urethral obstruction in cats: 388 cases. J Am Vet Med Assoc. 2022 May 21;260(S2):S7-S11. doi: 10.2460/javma.21.10.0469. PMID: 35290210.