Feline Idiopathic Cystitis (FIC) in Cats: Symptoms and Treatment

What Is Feline Idiopathic Cystitis (FIC) in Cats?

Urinary issues in cats are frequently lumped under the blanket term “feline lower urinary tract disease” (FLUTD). Common symptoms of FLUTD—typically referred to as lower urinary tract signs or LUTS—include changes in the following:

• More frequent urination
• Increased urine volume
• Urine that has an abnormal color or appearance

Signs of FLUTD may also include abnormal behaviors a cat exhibits while peeing, such as straining to urinate or crying out while doing so.

When a disease or cluster of symptoms can’t be linked to a specific cause, the condition is considered to be idiopathic—as is the case with feline idiopathic cystitis. Raymond Spragley, DVM, a veterinarian at Zen Dog Veterinary Care in Tuckahoe, New York, describes feline idiopathic cystitis as “a lower urinary tract disease that causes inflammation in a cat’s bladder.”

In other words, FIC is a term used to describe bladder inflammation in cats that has no identifiable cause.

Idiopathic Cystitis vs. Interstitial Cystitis

Like many feline health problems, idiopathic cystitis is known by several other names. According to the Merck Veterinary Manual, it can also be called “idiopathic feline lower urinary tract disease” (iFLUTD).

Some vets also use the term “Pandora syndrome.” “Pandora syndrome,” like FLUTD, is a catch-all term used when multiple organ systems are implicated but none can be identified as the underlying cause of a cat’s symptoms. This term also takes into account non-biological contributing factors such as environmental stressors.

In scientific studies conducted prior to the 2010s, the word “interstitial” was often used instead of “idiopathic” due to similarities between FIC and interstitial cystitis (IC) in humans. In humans, interstitial cystitis is a chronic, painful bladder condition often mistaken for urinary tract infection (UTI).

Like many vets, Sarah Wooten, DVM, CVJ, veterinarian in Silverthorne, Colorado, suggests the terms “feline idiopathic cystitis” and “feline interstitial cystitis” can be used interchangeably. She defines FIC as “a stress disorder that manifests in bladder inflammation.”

Dr. Spragley agrees that the two terms can be used interchangeably but offers one point of clarification in terminology. “‘Interstitial’ refers to the inflammation being present between the cells of the bladder,” he says, “while ‘idiopathic’ refers to the disease not having a definitive known cause.”

What Causes Feline Idiopathic Cystitis in Cats?

By definition, FIC has no known cause—that’s where the term “idiopathic” comes in. More specifically, it’s an exclusionary diagnosis. Vets use the term “FIC” for cases of FLUTD where affected cats experience bladder inflammation, but common urinary issues have all been ruled out.

Some common causes of FLUTD in cats include:

• Bacterial infection
• Bladder stones, aka urinary blockage
• Trauma
• Neurologic disorders, aka disorders of the nervous system
• Anatomical abnormalities
• Tumors

When a veterinarian has ruled out all of the above issues, as well as any other underlying cause, it generally leads to a diagnosis of FIC.

Feline Idiopathic Cystitis (FIC) Symptoms

While any cat can develop idiopathic cystitis, the issue is most common in young to middle-aged cats. Symptoms vary but often include litter box problems such as:

• Frequent urination
• Peeing in inappropriate locations
• Straining to urinate
• Vocalizing while urinating

Many cats exhibit non-urinary symptoms such as lethargy, loss of appetite, increased aggression, or hiding behavior, as well.

Despite how it manifests, at its core, FIC can more accurately be described as a stress disorder rather than a urinary one.

In many cats with idiopathic cystitis, symptoms come and go. According to the Merck Veterinary Manual, symptoms typically resolve in two to seven days but about half of cats with FIC will experience another incidence within 12 months. The recurrent nature of FIC is a major clue that the condition is linked to a stress response in cats.

Let’s take a closer look at some of the most common signs of FIC in cats.

Pollakiuria (Frequent Urination)

Many cats with FIC experience an increased urge to urinate, often without increased water intake. The result is frequent release of small amounts of highly concentrated urine.

Hematuria (Blood in the Urine)

Blood in the urine can result from a wide array of issues, including urinary tract infections, bladder stones, and bladder cancer. In male cats with FIC, hematuria can also be related to urinary tract obstruction, which can be a medical emergency.

Urinating in Inappropriate Locations

Cats avoid the litter box for many reasons, but outside of medical causes like urinary tract infections, stress is a common link. In multi-cat households, peeing outside the litter box can be a form of territorial marking. It can also be an indicator that the cat doesn’t like something about the litter box—the type of litter, the size or shape of the box itself, or its lack of cleanliness.

Straining or Crying While Urinating

Crying out while urinating often indicates that a cat is experiencing painful urination, or dysuria. If your cat is visiting the litter box more often than usual, check to see whether they’re peeing or not. Straining to urinate may indicate bladder inflammation or a dangerous obstruction.

Inability To Urinate

If your cat is unable to urinate, consider it a medical emergency. This is often caused by urinary obstructions like bladder stones or urinary crystals but can also be related to neurological or anatomical issues. See your vet immediately if your cat is not peeing.

Behavioral Changes

When urinary symptoms can’t be linked to an underlying medical cause, cat parents should look for changes in their cat’s behavior—especially those that might indicate a response to stress. When stressed or anxious, cats may hide more often than usual, respond aggressively, or show less interest in food.

Diagnosing FIC in Cats

When a cat stops using the litter box, inexperienced cat parents can be quick to assume it is a behavioral issue. In fact, litter box avoidance is often cited as a primary reason for euthanasia and abandonment of cats. In reality, inappropriate soiling is often a stress reaction and, in such cases, can be resolved by reducing or eliminating stressors in the cat’s environment.

Though the condition is usually triggered by stress, diagnosing FIC involves first eliminating medical causes for a cat’s urinary concerns.

“Generally speaking, vets will use an oral history from the [cat parent], a physical examination, a urinalysis, a urine culture, radiographs (X-rays), and an abdominal ultrasound,” says Dr. Wooten.

If your veterinarian cannot identify a medical cause for your cat’s urinary issues, it’s time to shift the focus to environmental triggers. Significant changes to their routine or environment can be incredibly stressful for cats, and that stress often manifests through behavioral issues, litter box problems, and changes in appetite.

Treatment of Idiopathic Cystitis in Cats

Because the cause of FIC is unknown, the Merck Veterinary Manual suggests, “The goal of treatment is to reduce the severity and frequency of episodes.” This may require a two-pronged approach of treating the cat’s physical symptoms and making changes to the environment to mitigate stress and prevent future episodes of FIC.

“Treatment of FIC typically starts with pain relief,” says Dr. Spragley. Depending on the cat’s level of pain, he typically recommends analgesics like gabapentin or buprenorphine. While gabapentin is not an FDA-approved veterinary medication, veterinarians can prescribe some human drugs for animals in certain circumstances. This is called extra-label drug use, and it is legal. Your veterinarian will determine which medication is right for your pet.

Some cats may also benefit from non-steroidal anti-inflammatory drugs (NSAIDs) to decrease inflammation in the bladder or anxiolytic drugs to manage acute anxiety.

Making changes to your cat’s environment, routine or diet may also help alleviate the pain and stress associated with FIC. Veterinary experts often recommend the following steps for cats with FIC—but before making any major changes to your cat's diet, including supplements, talk to your vet. They'll have the best insight into what your unique kitty needs.

• If your cat eats dry food, switch to wet/canned food. Increasing your cat’s moisture intake may help improve urinary health and help prevent issues like bladder stones.