Idiopathic (Sterile) Cystitis
(Inflammation of the bladder of unidentifiable cause)
First, you must understand that the cause of Idiopathic (Sterile) Cystitis (inflammation of the bladder) is not very clear and there is no known definitive treatment. In 50 years, since the initial identification of the disease, we haven’t figured this out. A leading theory now is that it involves, in some measure, stress effects on the bladder made worse when concentrated urine is retained in the bladder. It is of paramount importance for the cat to be able to get to and use the litter box whenever they want and not to ever be stuck not getting there because human guests are around or because the other cat has used it, etc. This is difficult because no one really wants to have lots of giant litter boxes displacing the normal flow of the house. Bigger, cleaner litter boxes with the preferred litter type and depth and in the right location can go a long way in helping cats with this condition.
Housemates (feline, canine, human, or others) can cause the cat stress. If there are housemates, make sure the cat has enough alone time, its own feeding bowl, and opportunities for getting away from it all, such as a cat tree or the top of a tall bookcase. You should also consider whether the cat is getting enough play time with the owner. These things may not cost you anything, but they do require effort, energy and commitment.
The next challenge is getting the fluid intake up. Cats aren’t by nature big drinkers. We need to get the water intake up to promote dilute urine, so they void more often. Running water fountains or cat fountains can be helpful to stimulate thirst. Turn on the faucet if your cat likes that. Your cat may prefer the taste of certain bottled water. Liquid treats like lactose-free cat milk, cream, tuna water, and chicken broth may all stimulate more water intake (and are ok as long as they don’t cause digestive tract upset). Feeding canned food only with water added is also recommended. Periodic checking of the cat’s urine concentration by the veterinarian will ensure that these measures are actually working.
Special diets are sometimes recommended to dilute the urine or to prevent crystals from forming. You should still continue with the necessary interventions, including liquid treat foods, to get the water intake up and more frequent urine voiding. SQ fluids (fluids periodically injected under the skin) are another option to dilute the urine and increase urine voiding, especially during active disease when obstruction is a risk; however, many cats will find the injections quite stressful.
Although this is not a disease that can be treated with a pill alone, if the problem recurs despite all of the above efforts, the next phase of treatment is to add a polysulfated glycosaminoglycans (such as Cosequin) to the regimen and possibly amitryptiline or another tricyclic anti-depressant. Prior to starting these medications we will recommend some baseline lab work, a urine culture, and radiographs or ultrasound (if that was not already done) to be sure that the diagnosis is correct and that no other concurrent problems exist.
Bladder biopsy is rarely recommended (unless everything else has failed) because it is usually not very helpful. Special cultures for a bacteria called ureaplasma are sometimes needed (it won’t grow on a conventional culture), but it is considered fairly uncommon in cats.