By: Cate Burnette

Our cats, whether they live inside our homes or inhabit our back yards and gardens, are subject to Feline Lower Urinary Tract Disease (FLUTD). FLUTD can be caused by any number of reasons, including cystitis, urethral obstruction and bladder stones. Overweight, middle-aged and older cats of either sex are prone to this condition.

Because the encompassing tract disorder always involves the urinary bladder (the organ that holds urine), the ureters (tubes that carry urine from the kidneys to the bladder), and the urethra (the tube leading to the outside of the body that dispenses urine), many of the causal symptoms are similar. Extra care and diagnostic texts may be needed to come to a correct diagnosis.

Several possible categories and origins of FLUTD are detailed below.

Feline Interstitial Cystitis (FIC)

Also called “feline idiopathic cystitis,” this inflammation of the urinary bladder causes the symptoms commonly seen in other urinary tract diseases, but a definitive cause for the illness cannot be identified. This chronic condition can be seen in both female and male cats and is very difficult to treat effectively.

Symptoms of FIC typically include:

  • Frequent attempts to urinate
  • Inappropriate urination in the house
  • Straining to urinate
  • Crying out while attempting to eliminate
  • Blood in the urine

Though the cause of FIC may not be fully determined, veterinarians believe stress and the body’s reaction to it may play a large part in the formation of the disease. Studies show that stress also causes abnormalities in a cat’s cardiovascular, endocrine and nervous systems. Why some cats develop symptoms of cystitis and others do not is unknown at this time.

A veterinary diagnosis relies mainly on ruling out the causes of other diseases that may be causing the same symptoms, including crystals in the urine, bladder stones and a urethral obstruction. The same diagnostic tests (urinalysis, bloodwork, radiographs) are commonly recommended for all feline urinary diseases including suspected cystitis.

Treatment for your cat diagnosed with FIC consists of reducing environmental stress, medicating for pain, changing your pet’s diet and possibly administering meds (namely the antidepressants amitriptyline, fluoxetine, or clomipramine) that calm your cat’s mental state. Aerosol pheromones, such as Feliway, may be suggested to reduce your cat’s stress levels.

The PetMd website recommends using the MEMO System to provide for all of your cat’s basic needs. Litter box management, proper feeding and watering, and other environmental factors are the cornerstones of this program.

Feline Urolithiasis

Uroliths are stones that form in your cat’s urinary tract secondary to genetics, urinary infection and dietary influences. Uroliths vary in size and numbers and can form in any part of the urinary system including the kidney, the bladder, the ureters and the urethra.

Oversaturation of urine with various types of crystals is the largest factor in the formation of stones. This can be caused by concentrated urine in the kidneys, increased excretion of crystals in the urine, and changes in urine pH triggered by diet, genetic predisposition, certain medications, urinary tract infection and inflammation. The crystals begin to form around a central foreign body (bacteria, white blood cells or organ cells) then continue adhering to the center as more and more crystals pass by the stone.

As in other urinary tract diseases, symptoms of urinary stones include blood in the urine, urethral obstruction, a decrease and/or absence of urination and inappropriate elimination outside of the litter box.

According to the Merck Veterinary Manual, only 10 percent of feline uroliths can be detected by abdominal palpation of the bladder, so x-rays, urine cultures, urinalysis and ultrasonography may be required to differentiate this disease from other urinary tract issues. Because most uroliths under 3mm cannot be seen on regular x-rays, your vet may recommend testing with double-contrast radiography in order to detect the more common, smaller uroliths. Typical veterinary treatment for bladder stones includes surgical removal where applicable, followed by dietary therapy to reduce the incidence of reoccurrence. The type of veterinary food recommended depends on the category of stones and crystals distinguished during the diagnostic process.

Veterinarians commonly find two types of uroliths in felines: calcium oxalate stones and struvites.

  • Calcium Oxalate stones are the most common feline uroliths, although the cause of their formation is unknown. Surgery is the primary means for removing the stones, however, some oxalate stones – particularly those found in the kidneys – may not show clinical signs until the disease is fairly advanced. Recurrence of these stones is a common problem. Recommended diets include those foods that acidify the urine, avoid mineral supplementation, and keep Vitamins C and D to the minimum. Water consumption is critical to the resolution of these stones.
  • Struvite stones may be the result of certain dietary restrictions, chronic urinary tract infections and inflammation, or large quantities of cellular material in the urine. Treatment of struvites revolves around making the urine more acidic and feeding magnesium-restricted diets. Additionally, your vet may recommend re-checking the size of the struvites every 4 weeks using radiographs or ultrasonography and urinalysis. Adhering to veterinary dietary recommendations can completely dissolve this type of urolith.
  • Other types of stones include ammonium urate, calcium phosphate, uric acid and cystine uroliths that account for less than 6 percent of all feline uroliths. While the cause of these stones remains mostly unknown, highly acidic and concentrated urine in conjunction with diets high in acidic organic compounds appear to be risk factors. Surgery remains the most common method of removal.

“Blocked TomCat” Syndrome

A blocked urethra – the tube that drains urine from the bladder out of the penis – is a fairly common condition of male cats between the ages of 1 to 10 years. Plugs of inflammatory material, mucus (also called “Feline Urologic Syndrome”), crystals, or small stones that have formed in the kidneys and traveled into the urinary bladder can be the cause of the obstruction. The American College of Veterinary Surgeons states that diet, cancer, traumatic scarring and viral infections may play a role in the initial inflammation, however, early neutering of cats won’t result in the urethral narrowing seen in other animals.

A cat in this condition is unable to urinate properly, and may not use his litter box or may find inappropriate places in the house to eliminate. In the beginning, a blocked cat may have frequent urination, blood in the urine, may vocalize due to pain, and show straining to urinate. Without treatment, your cat can become completely blocked – a life threatening development that can cause death within 3 to 6 days. These poor cats may cry, travel restlessly from room to room, attempt to hide because of pain and discomfort, may vomit during straining, may have a very distended bladder palpable by hand, and will eventually lose all appetite and become extremely lethargic.

Risk factors for male cats with this disease include being kept indoors, living in a stressful and/or a multi-cat household and eating a strict dry-food diet. According to veterinary statistics, the incidence of blocked tomcats occurs more often during winter months.

If your cat has a urethral obstruction, emergency treatment is needed. Your vet will probably either sedate or anesthetize your cat in order to place a catheter into the urethra to flush out the plug or force a stone back into the urinary bladder. The bladder is flushed through the catheter to eliminate any small stones and sediment. Your vet may recommend surgery to remove any stones left behind. The urinary catheter is typically left in place until swelling subsides and the cat is able to urinate on its own. Pain medication, antibiotics and a diet change to decrease the formation of crystals may be prescribed.

This condition is known to reoccur frequently in some male cats, and those animals with chronic plugs may need a surgical procedure called a “perineal urethrostomy” to widen the urethral opening so that obstruction is no longer an issue.

Veterinary Diagnosis and Treatment of FLUTD

According to the American Association of Feline Practitioners, your veterinarian will probably recommend several diagnostic tests to determine a correct treatment protocol. Those tests may include a complete urinalysis (including a bacterial culture and sensitivity test), a Complete Blood Count with serum chemistry and thyroid assay tests, and either radiographs (x-rays) or an ultrasound looking for bladder or urethral stones.

Treatment depends on your vet’s diagnosis. Commonly, antibiotics are recommended to clear up any bacterial infections causing your cat’s symptoms. If a blockage or uroliths are seen during the initial examination, surgical intervention may be necessary in order to remove these objects and resolve the disease.

Aftercare typically includes follow-up visits with additional urine testing to assess the dissolution of any crystals or stones and the destruction of bacteria. You will probably be asked to place your cat on a specific veterinary diet pH-balanced to halt the body’s further manufacture of more uroliths. Constant free-fed water and scrupulously clean litter boxes may also be suggested. To learn more about how to help your cat remain healthy while continuing to use her litter box, please read our blog “Why Your Cat Stops Using The Litter Box.”


Cate Burnette is a semi-retired registered veterinary technician with clinical experience in small and large animal medicine. With 30-plus years of journalism experience, she went back to school after 9/11 to work with her first love: animals. The pet parent of four cats, three dogs and one ex-racehorse, Cate is a certified rescue volunteer with the American Humane Association’s Red Star Emergency Services and served with the group in New Orleans doing animal search and rescue after Hurricane Katrina. She is also a horse safety and horse management expert, and has volunteered with US Pony Clubs as a district commissioner and horse management judge.

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