What is feline lower urinary tract disease?

Feline lower urinary tract disease (FLUTD) is a general term for conditions affecting the urinary bladder and urethra. Different diseases can cause very similar signs, so further testing may be needed to determine the underlying cause.

The most common diagnosis in young and middle-aged cats is feline idiopathic cystitis (FIC), which means inflammation of the bladder without an identifiable infection, stone or other structural cause. FIC is painful and is strongly influenced by the cat’s stress response, environment and water intake.

Common signs
• Frequent trips to the litter tray
• Straining or taking a long time to urinate
• Passing only small amounts of urine
• Blood-tinged urine
• Crying, restlessness or other signs of discomfort when urinating
• Urinating outside the litter tray
• Excessive licking around the genital area

Straining to urinate can look like constipation. Cats may repeatedly squat, remain in the litter tray for a long time or produce little to no visible urine. If you are unsure whether your cat is passing urine, seek veterinary advice promptly.

What causes FLUTD?

Possible causes include:
• Feline idiopathic cystitis (FIC)
• Bladder or urethral stones
• Urethral plugs
• Bacterial urinary tract infection – uncommon in young, otherwise healthy cats, but more likely in older cats or cats with other medical conditions
• Anatomical abnormalities, trauma or, less commonly, tumours

How can FLUTD lead to urethral obstruction?

Inflammation, urethral spasm, mucus, crystals, a urethral plug or a stone can block the urethra and prevent urine from leaving the bladder. This occurs most commonly in male cats because their urethra is longer and narrower.

A cat with non-obstructive FLUTD is still able to pass urine, although often in small amounts. An obstructed cat produces no urine or only a few drops despite repeated attempts. Owners cannot reliably distinguish the two conditions at home.

Why is urethral obstruction dangerous?

When urine cannot leave the bladder, pressure builds within the urinary tract and waste products and potassium accumulate in the bloodstream. This can cause severe pain, kidney injury, dangerous heart rhythm abnormalities, bladder damage and death.

Signs that may indicate an obstruction
• Repeated, unproductive trips to the litter tray
• Straining with no urine produced, or only a few drops
• Crying, agitation, hiding or obvious discomfort
• Vomiting, reduced appetite or profound lethargy
• Weakness, wobbliness, collapse or reduced responsiveness
• A tense or painful abdomen

Do not wait until the next day. If your cat is repeatedly straining and you cannot confirm a normal urine stream, seek emergency veterinary care immediately.

How is the cause investigated?

Your veterinarian may recommend one or more of the following:
• Physical examination, including assessment of the bladder
• Urinalysis to assess urine concentration, blood, inflammation and crystals
• Urine culture when infection is suspected or needs to be ruled out
• Blood tests, particularly in older, unwell or obstructed cats
• Electrocardiogram monitoring when high potassium is a concern
• Abdominal radiographs or ultrasound to look for stones and other abnormalities

Crystals in a urine sample do not always mean that crystals are the cause of the signs. Results must be interpreted together with the cat’s history, examination and imaging.

Treatment for non-obstructive FLUTD

Treatment is tailored to the cause and to your cat’s level of pain and illness. For cats with FIC, treatment commonly focuses on pain relief, improving water intake and reducing stress. Antibiotics do not treat FIC and are only prescribed when a bacterial infection is confirmed or considered likely.
• Pain relief and other medications as prescribed
• Wet food or another strategy to increase water intake
• A veterinary urinary diet when specifically recommended for your cat
• Environmental changes to reduce stress and improve access to key resources

Treatment for urethral obstruction

An obstructed cat requires urgent hospital treatment, which may include:
• Pain relief, sedation or general anaesthesia
• Placement of a urinary catheter to relieve the obstruction and flush the urethra
• Intravenous fluid therapy and correction of electrolyte abnormalities
• Close monitoring of urine production, kidney function and heart rhythm
• Urinalysis, urine culture and imaging when indicated

A urinary catheter is often left in place temporarily while inflammation settles and urine production is monitored. After the catheter is removed, your cat is observed to ensure they can urinate independently before discharge.

How long will an obstructed cat be hospitalised?

Hospitalisation commonly lasts approximately two to three days, but this varies. Cats with severe electrolyte abnormalities, kidney injury, very high urine output after relief of the blockage, difficult catheterisation or other complications may require longer and more intensive treatment.

Possible complications of obstruction

• Re-obstruction after the catheter is removed or after discharge
• High urine output after relief of the blockage, causing dehydration or electrolyte changes
• Kidney injury
• Bladder weakness or, rarely, bladder rupture
• Urinary tract infection associated with catheterisation
• Urethral injury or narrowing

Helping your cat at home

Environmental management is an important part of FIC treatment and may reduce the frequency or severity of future episodes. These measures are also recommended after an obstruction, alongside any individual medication or dietary plan.

• Provide one litter tray per cat, plus one extra, in separate quiet locations
• Use large, clean trays with a litter type your cat prefers; remove waste at least daily
• Ensure each cat has easy access to separate food, water, resting, hiding and toileting areas
• Provide safe hiding places, elevated resting areas and regular play
• Increase water intake using wet food, multiple water bowls or a fountain according to your cat’s preferences
• Reduce conflict between cats; competition may be subtle even when cats do not visibly fight
• Give all medications exactly as directed
• Follow the recommended feeding plan and use a prescription urinary diet only if advised

Some straining, frequent urination or blood-tinged urine may continue briefly after treatment because the bladder and urethra remain inflamed. However, you must continue to confirm that urine is being produced.

Can obstruction happen again?

Yes. Re-obstruction is most likely during the early recovery period and is another emergency. Cats with repeated obstruction despite appropriate management may be referred for perineal urethrostomy surgery. This surgery widens the urinary opening and reduces the risk of future obstruction, but it does not prevent bladder inflammation or all urinary signs.

Seek urgent veterinary care if:
• Your cat is repeatedly straining but produces no urine, or only a few drops
• You cannot confirm that your cat has passed urine
• Your cat becomes weak, very quiet, collapses or appears severely painful
• Your cat vomits, stops eating or develops a tense or painful abdomen
• Signs are worsening or are not improving as expected