FLUTD (Feline Lower Urinary Tract Disease)

Jamie Lovejoy, DVM
By Jamie Lovejoy, DVM on Oct. 22, 2021

In This Article


What Is Feline Lower Urinary Tract Disease?

Feline lower urinary tract disease (FLUTD) is a term that refers to several conditions affecting your cat’s lower urinary tract, including the urethra (a thin tube that carries urine) and bladder. FLUTD can be frustrating for both pet owners and veterinarians because the underlying cause can be difficult to identify, and the illness can range in severity.

Most cases of FLUTD can be managed with a combination of medications, diet, and environmental changes.

FLUTD can occur in cats at any age, depending on the underlying cause. It is most often seen in young to middle-aged adult cats but has been diagnosed in kittens and even senior cats who have never shown urinary symptoms.

Types of FLUTD     

Currently, FLUTD is used as an umbrella term to describe the clinical signs of a few syndromes that can occur on their own or in combination. Some of the conditions that cause FLUTD include:

Urinary Tract Infection (UTI)

This is the most common cause of urinary symptoms in cats. UTIs are caused by bacteria colonizing the urethra or bladder, and they occur most commonly in female cats. Risk factors for UTIs include obesity, poor grooming, diseases (such as diabetes and kidney disease), or anatomical changes in the bladder or urethra.

Bladder Stones (Urolithiasis)

Bladder stones may occur in cats with UTIs. Stones not caused by infection are thought to result from a combination of diet and genetics. Bladder stones can range from being very uncomfortable to life-threatening. Cats with bladder stones are at risk for urethral obstruction, or the blocking of the exit for urine, which can cause death within hours.

Feline Idiopathic Cystitis (FIC)

In FIC, cats experience inflammation of the bladder not caused by bacteria or stones. Unfortunately, FIC is just as severe as other forms of FLUTD and can still cause urethral obstruction in male cats.

Cancer (Bladder or Urethra)

Cancer of the bladder or urethra is a rare cause of FLUTD, but it is a serious condition. To rule out cancer, a full workup is important in a cat with FLUTD, even if UTI, bladder stones, or FIC is suspected.

Cat Urinary Tract Anatomy


Health Tools

Not sure whether to see a vet?

Answer a few questions about your pet's symptom, and our vet-created Symptom Checker will give you the most likely causes and next steps.

Symptoms of Feline Lower Urinary Tract Disease

The most common symptom of FLUTD is your cat urinating outside the litter box (inappropriate urination). Inappropriate urination often occurs on clothes, bedding, and rugs. Some cats may choose one location, but others may urinate throughout the home.

Your cat may also make very frequent trips to the litter box but only pee small amounts at a time. Other symptoms include vocalizing while urinating and/or the presence of blood in the urine.

If you see your cat trying to use the litter box and producing no urine at all, or just a few small drops, bring them to the vet immediately. This may be a sign of the most severe FLUTD syndrome: urethral obstruction. This occurs more commonly in male cats but can occur in females as well.

Causes of Feline Lower Urinary Tract Disease

While anatomical changes, obesity, diet, and genetics can increase the risk of urinary tract infections and bladder stones in cats, feline idiopathic cystitis is a more complicated diagnosis.

Leading studies suggest there is a connection between FLUTD symptoms and stress or perceiving a threat in the environment. Common things that you may not see as stressors might cause a lot of stress for your cat, such as certain scents, noises, and even furniture changes. The source of stress may be more obvious, as well—stray cats outside, new babies, losing a family member, and so on. We’re still not sure exactly how these stress events and situations cause physical changes in a cat’s bladder.

Most, if not all, cases of FIC require some form of environmental management (making a change in your cat’s environment) and stress/anxiety relief to resolve the symptoms.

How Vets Diagnose FLUTD

Diagnosis of FLUTD can be tricky and often relies on a combination of physical exam findings, test results, and—most importantly—patient history. At minimum, your vet will perform a urinalysis to rule out a urinary tract infection. Some cases may require a urine culture if the infection is hard to find or does not respond to initial antibiotics.

You vet may also take a blood sample to look for systemic infection, diabetes, and kidney disease. These conditions may have similar symptoms to FLUTD. Stones in the bladder or urethra can usually be found on x-rays, though doctors with access to ultrasound may prefer using ultrasound to look for kidney changes or bladder abnormalities that wouldn’t show up on x-rays. Advanced imaging, such as MRI or CT, is rarely used.

Successful diagnosis and treatment of FLUTD often requires a lot of information about how a cat interacts with their environment at home. Recent behavior changes in your cat are an important part of the diagnosis. You may be asked to complete a detailed questionnaire about how and where your cat eats, sleeps, plays, and interacts with family members. These questionnaires can be just as helpful as regular lab tests because they can help identify stressors in your cat’s environment.

Treatment for FLUTD

Treatment of FLUTD is very individual and based on the specific syndrome. Some common treatments include increasing water consumption (feeding wet food or tempting cats with a water fountain), giving your cat more litter box options, and weight loss in overweight cats. Some cats require a combination of therapies or a “multimodal” approach.

Here are some more specific treatments your vet may use based on the underlying cause.

Urinary Tract Infections

Bacterial infections are an uncommon cause of FLUTD (only present in 5-15% of cases), but if urinalysis or urine culture discovers bacteria in your cat’s bladder, your vet will likely prescribe antibiotics.

Bladder Stones

Bladder stones often require surgery, especially in male cats who are at risk of a dangerous urethral obstruction. Some stones can be dissolved using prescription diets, but this approach must be used with caution, as it can take weeks. Once a stone is removed from the urinary system, your cat will likely be put on a prescription diet to reduce the risk of new stones forming.


FIC is perhaps the most difficult syndrome to control. Treatment of FIC in cats often involves a combination of pain medications, a prescription diet, anti-spasmodic medications, and environmental management. Treatment often includes behavioral elements, such as:

  • Determining and eliminating sources of stress or anxiety for your cat

  • Ensuring easy access to food, water, and litter boxes

  • Allowing your cat as much freedom as possible to express normal behaviors

You can use pheromone diffusers, food puzzles, cat trees, and water fountains to reduce stress and promote your cat’s happiness. Extreme cases may require anti-anxiety medications, but these are often a last resort.

Recovery and Management of FLUTD

Though improvement of symptoms can occur within days, it is common for FLUTD to come back, so active management will be a lifelong commitment. Medications may only be used long-term in severe cases. Cats that respond well to prescription diets should stay on them indefinitely. You will work with your veterinarian to adjust treatment accordingly.

Sudden changes in your cat’s environment make it much more likely for symptoms to return. You will need to try to anticipate stressful situations for your cat, such as moving or adding new pets or family members to the household.

While many cats with FLUTD can live a long and happy life, it is not uncommon for treatment to fail. Unfortunately, euthanasia may be considered for cats with pain and anxiety that cannot be controlled.

FLUTD (Feline Lower Urinary Tract Disease) FAQs

How long can a cat live with FLUTD?

Your cat will have a normal life span if the disease can be managed well. That said, management can be difficult, and some pet parents may need to choose humane euthanasia or try rehoming their pet.

How do I know if my cat has FLUTD?

Cats with FLUTD show any or all of the following clinical signs: urinating outside the litter box, visiting the litter box frequently, straining to urinate, and blood in the urine. Male cats with severe complications may exhibit vomiting, decreased appetite, and/or hiding—sometimes, with no known urinary symptoms.

How long does it take for FLUTD to go away?

The time frame depends on the specific type of FLUTD. Urinary infections may clear up in a few days, while FIC may take weeks to months to manage appropriately.

What do you feed a cat with FLUTD?

There are multiple prescription diets available to help manage FLUTD in cats. These diets are created to increase thirst/water intake, change the pH of the urine, reduce the risk of bladder stones, and even help with behavioral management. For situations where a prescription diet is not practical, cats with FLUTD benefit from a diet based on canned food to help increase water intake.


Image Credit: iStock/Lightspruch

Jamie Lovejoy, DVM


Jamie Lovejoy, DVM


Dr. Jamie Lovejoy graduated from Tufts Cummings School of Veterinary Medicine in 2012 after an undergraduate degree in Marine Biology. ...

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health