Feline idiopathic cystitis

Feline idiopathic cystitis (FIC) or feline interstitial cystitis or cystitis in cats, is one of the most frequently observed forms of feline lower urinary tract disease (FLUTD). Feline cystitis means "inflammation of the bladder in cats". The term idiopathic means unknown cause; however, certain behaviours have been known to aggravate the illness once it has been initiated. It can affect both males and females of any breed of cat. It is more commonly found in female cats; however, when males do exhibit cystitis, it is usually more dangerous.

Despite the shared terminology, cases of feline idiopathic cystitis, as opposed to human cystitis episodes, are sterile. In other words, they do not involve a primary bacterial infection. If upon investigation the inflammation of the feline bladder is in fact found to be the result of an infection, then it is described as a feline urinary tract infection (UTI) or less commonly, feline bacterial cystitis. In cats under the age of 10 years old, FIC is the most common urinary disease seen in cats and UTIs are very rarely encountered. However, in cats over 10 years of age, UTIs are much more common and idiopathic cases are much less frequently observed. On the other hand, FIC does show several similarities to an analogous disease in humans called bladder pain syndrome.