Oct 12, 2017
Dr Megan Rice

Idiopathic Sterile Cystitis

A disease of cats that is characterised by the painful and/or frequent urination of small amounts.

Male cats suffering from FIC are at risk of developing a “blocked bladder”.

Idiopathic sterile cystitis is a disease of cats that is characterised by the painful and/or frequent urination of small amounts, often with blood and white blood cells in the urine.  The same symptoms can be caused by bacterial infection of the bladder and bladder stones and it is important to rule these conditions out prior to making a firm diagnosis of FIC (Feline Idiopathic Cystitis).

Most cats with idiopathic sterile cystitis have their first episode between the ages of 2 and 6 years.  Older cats are more likely to have another cause of their symptoms. There is no known cause and no definitive treatment. A leading theory now is that in genetically predisposed individuals stressful events will have effects on the bladder creating inflammation.  Urinary retention (not emptying the bladder frequently)  will often initiate or worsen signs. This means that managing FIC will involve: 1) reducing stress in the cat’s life; 2) litter box management to discourage urinary retention; and 3) decreasing the concentration of urine (increasing fluid intake).

Reducing Stress: Each cat’s environment and lifestyle must be evaluated since each cat will have different stressors. Does the cat have enough time alone? Does it have enough interaction with people? Are other house cats picking on him/her? Does it have its own food bowl? Does it live in an extremely noisy environment? Do the household children pester it?

The following website has many excellent suggestions for reducing stress in anxious cats: www.facebook.com/Indoor-Cat-Initiative-119746471371455/

Feliway is a synthetic pheromone (chemical messenger) made to mimic the feline cheek gland pheromone which cats use to mark boundaries and promote emotional stability.  In a number of studies Feliway has been shown to support the reduction of urinary marking and anxiety.  It may be helpful in minimising stress and reducing the frequency of flare-ups of FIC.

Hills “C/D stress” and Royal Canin “Calm” are diets designed with naturally calming additives such as tryptophan and Milk protein hydrolysate which have been found to reduce anxiety-related behaviours (such as FIC).

Litter Box Management: Is there at least 1 litter box per cat? Is the litter box cleaned daily? Are litter boxes with this cat’s favourite substrate available (clay, clumping, paper, etc.)? Does this cat prefer a covered or non-covered box? Is the litter box always accessible or is it sometimes behind closed doors? Is the litter box large enough to be used comfortably?

In cats that prefer toileting outdoors make sure they have easy and safe access at all times the day and night. Consider the presence of other animals, or bad weather outside that may change or prevent the cats normal toileting behaviours.  Would a safe clean indoor alternative be appreciated?

Increasing Water Consumption: This may require some creativity on the owner’s part. Try a fountain with constantly running water. Liquid treats such as tuna water or chicken broth can be made into ice cubes and added to water (which must then be changed frequently). Switching to a canned diet or adding water to a dry diet may be a reasonable option.  Cats who have crystals in their urine or who cannot eat a mostly wet food diet often do best on a prescription urinary diet.

Even if all these measures are undertaken, most cats will still have occasional flare-ups. During flare-ups, we may prescribe a pain reliever to alleviate bladder/urethral pain. For cats that continue to have frequent flare-ups, we may also recommend higher level diagnostic tests. In a very few cases, an anti-anxiety medication may be prescribed.


Male cats suffering from FIC are at risk of developing a “blocked bladder”.  This is a life threatening and extremely painful condition where inflammatory cells +/- urinary crystals form a plug in the cat’s urethra blocking their ability to urinate.  If you see any of the following signs it is important to seek immediate veterinary attention, day or night!

  • Unproductive straining to toilet (even if it looks like your cat is trying to poo),
  • Discomfort during toileting or when being picked up,
  • Crying out, restlessness or hiding away,
  • Excessive licking around the penis,
  • Acting unwell e.g. off food, vomiting, lethargy etc., especially in conjunction with recent urinary signs

Idiopathic sterile cystitis can be a very frustrating disease, and owners should be aware that it is a chronic disease, however most cats can be managed and have an excellent quality of life with only very occasional flare-ups.


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