Lower Urinary Tract Disease in Cats (also known as FLUTD)

January 1, 2001 (published) | May 10, 2019 (revised)

The diseased lower urinary tract yields the same symptoms regardless of cause.

  • Bloody urine
  • Straining to urinate (can easily be mistaken for straining to defecate)
  • Urinating in unusual places
  • Urinary blockage (almost exclusively a male cat problem)
  • Licking the urinary opening (usually due to pain)

A cat with lower urinary tract disease may have some or even all of these signs.

The Trick is Determining the Cause

The urinary bladder, urethra, and urinary opening all constitute the lower urinary tract. It makes sense that effective treatment requires knowing the cause of the symptoms. The problem is that just about any inflammatory condition in the feline lower urinary tract creates the same collection of signs. Tumor, infection, bladder stone etc. all create the same clinical picture.

What are the Possible Causes?

It turns out that the age of the cat is tremendously relevant regarding which underlying causes are most likely. If we look at all cats with lower urinary tract symptoms, we find:

  • 50% will not have a cause that can be determined despite extensive testing (meaning they have what is called idiopathic cystitis.)

  • 20% will have bladder stones (females have a slightly higher incidence).

  • 20% will have a urethral blockage.

  • 1-5% will have a true urinary tract infection.

  • 1-5% will have a urinary tract cancer.

  • 1-5% will have had trauma to the urinary tract (i.e. have been hit by a car etc.)

  • 1-5% will have a combination of a bladder stone and an infection both.

  • The average age for symptoms is age 4 years. 

If we separate out the cats that are 10 years of age or older and only look at them, a different statistical picture emerges:

  • 50% will have true urinary tract infections.
  • 10% will have bladder stones.
  • 17% will have a combination of infection and bladder stone.
  • 7% will have urethral blockage.
  • 3% will have urinary tract cancer.
  • 5% will not have a cause that can be determined despite extensive testing.
  • 66% will be in some stage of kidney failure.
  • 5% will have urinary incontinence.

Sorting Out Causes

Testing is used to help sort patients into the correct group. A urinalysis is commonly performed. With a 50 percent incidence of infection in older cats, a urine culture would be extremely important for a cat age 10 or more but not as important for younger cats where infection is rare.  In younger cats, a urinalysis is helpful to look for the typical blood and crystals of idiopathic cystitis or to pick up the occasional bladder infection.

Radiographs (in cats young and old) to rule out bladder stones are a good idea as they will otherwise go undetected.

Notice the large percentage of young adult cats for whom no clear underlying cause can be identified. For these cats, there are many theories on how to proceed.

This syndrome has many causes. Use the links at the bottom of the page to guide you to other resources in these areas:

  • If your cat has a documented urinary tract infection.

  • If testing cannot reveal any specific cause or if your cat is a young adult.

  • If your cat has bladder stones.

  • If your cat has a urethral blockage or partial blockage.

  • If your cat seem to urinate in inappropriate locations for behavioral reasons.

  • If your cat has bladder cancer.

It is critical to note that lower urinary symptoms in a male cat can indicate a urinary blockage, which is an emergency situation.
If you are not sure if your cat is able to express urine,
assume it could be an emergency and call your veterinarian’s office at once.

See more about prevention.

FLUTD is a complex disease, so knowing the cause of the disease guides the treatment. In other words, there is no common treatment or management. Your best source of information will come from your veterinarian as they know you and your cat's circumstances.

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