Feline Idiopathic Lower Urinary Tract Disease

What is feline idiopathic urinary tract disease?
Feline Lower Urinary Tract Disease (FLUTD) is a term used to describe a set of clinical signs associated with abnormal urination in cats. When the condition has no identifiable cause, it is called Feline Idiopathic Lower Urinary Tract Disease (iFLUTD) to indicate that this is an exclusionary diagnosis.
It is important to understand the difference between iFLUTD and Feline Urologic Syndrome or FUS. FUS is simply a description of the syndrome manifested by straining to urinate, frequent attempts at urination, and a partial or complete urethral obstruction. FUS is not a diagnosis but a term used to describe the cat's condition, just as you would say a cat is itchy or is vomiting. iFLUTD is the exclusionary diagnosis made once all of the common or known causes of the clinical signs have been eliminated.
What are the clinical signs of feline idiopathic lower urinary tract disease?
The most common clinical signs of iFLUTD are the same as those of FUS:
  • Straining to urinate
  • Bloody or discolored urine
  • Frequent urinations
  • Urinating in unusual locations
  • Urethral obstruction or the inability to urinate
What causes feline idiopathic lower urinary tract disease?
By definition, in cases of Feline Idiopathic Lower Urinary Tract Disease there is no known cause. The conditions that should be ruled out include:
  • Bladder stones and urethral plugs
  • Bladder infections
  • Trauma
  • Neurologic disorders that alter normal urination by affecting the nerves and muscles of the bladder
  • Anatomic abnormalities such as urethral strictures
  • Neoplasia (cancer or benign tumors of the urinary tract)
Once all of the common causes of abnormal urination have been eliminated, a diagnosis of Feline Idiopathic Lower Urinary Tract Disease may be made.
How is iFLUTD diagnosed?
iFLUTD is diagnosed by performing tests to eliminate the known causes of abnormal urination. These tests include any or all of the following:
  • Thorough medical history and physical examination - especially pay attention to any changes in environment, feeding, stress, etc.
  • Blood tests - complete blood cell count (CBC) and serum chemistries
  • Complete urinalysis
  • Urine culture and antibiotic sensitivity tests
  • Abdominal radiographs, which may include contrast radiographic studies
  • Abdominal ultrasound
  • Cystoscopy or endoscopic examination of the urethra and bladder
  • Bladder biopsy
Your veterinarian will formulate a diagnostic plan based on your cat's specific clinical symptoms.
What is the treatment for FLUTD?
This depends on the underlying cause. For example:
  • Bacterial infections of the lower urinary tract usually respond well to antibiotic therapy.
  • If a cat develops a blocked urethra, emergency treatment is required to remove the blockage. Usually the cat will be given a short-acting general anesthetic/sedation and the urethra will be flushed or catheterized. Urethral obstruction occurs almost exclusively in male cats.
  • If bladder stones or uroliths are present, they will have to be removed. Depending on their type, they may be able to be dissolved by using a special diet or dietary additive, or they may require surgical removal. In some cases, this can be determined by the results of a urinalysis.
There is no universal treatment for FLUTD. Each case has to be investigated to determine the underlying cause, and then the treatment has to be tailored to the individual cat. Sometimes despite appropriate tests and treatment, clinical signs may still recur, requiring further therapy.
How can FLUTD be prevented?
It is impossible to completely prevent diseases of the lower urinary tract from occurring. However, FLUTD is more common in cats that have low water consumption and in cats that are inactive and obese. All these factors may relate, at least in part, to the frequency with which a cat urinates. Weight control and encouraging exercise may be of some help in preventing FLUTD.
If urinary calculi or crystals caused the symptoms of FLUTD, the feeding of special diets may help prevent recurrence.


This client information sheet is based on material written by: Ernest Ward, DVM
© Copyright 2009 Lifelearn Inc. Used and/or modified with permission under license
Alta Vista Veterinary Hospital is a Central Phoenix Animal Hospital.