Here is the info on Dr. Lisa website, a good read and tells the only way the vet can know with certainty if there is bacteria causing the cystitis is to do a Culture and Sensitivity ( C& S) If you go this route and no bacteria, and inappropriate urinating is still happening, I would go the route of a little bit of either blueberry powder or cranberry powder. I got my organic blueberry powder online. Wellness wet cat food puts cranberry in their food for just this reason. Below is from Dr Lisa's website.
A very important note on
antibiotic usage in these cases: Most cases of cystitis are sterile.
In other words, they are not the result of an infection and the patient should not be placed on antibiotics.
Only ~1% of cats with cystitis that are under 10 years of age have a urinary tract infection, yet many veterinarians place these patients on antibiotics when these drugs are
not warranted. Most cats under 10 years of age produce a very concentrated urine (USG greater than 1.035) and bacteria do not grow well in concentrated urine.
In cats over 10 years of age, infections are more common but that still does not mean that older cats with cystitis should automatically be put on antibiotics. The reason that an older cat is more prone to urinary tract infections is because kidney disease is more common in this age group and so these cats will have a more dilute urine which is not as hostile to bacterial growth.
Diabetes and hyperthyroidism are also more common in cats over 10 years of age and both disease render the patient more prone to urinary tract infections.
That said, only ~20% – or less – of all older cats that present with lower urinary tract signs (see Feline Urinary Tract Health – Cystitis) actually have an infection so ~80% of this age group exhibiting these clinical signs do
not need to be put on antibiotics.
A urine
culture and sensitivity (C & S) should be run to check for an infection, especially if the patient has a low urine specific gravity or is diabetic. It must be kept in mind that even with a low USG,
most cases of cystitis are not due to an infection. This is why it is important to run a C & S before placing the patient on antibiotics.
Antibiotics are NOT harmless drugs and they need to be used with more critical thought than is currently happening in both human and veterinary medicine.
This is especially true of
Convenia. Please do not allow that drug to be injected into your cat without reading my Convenia webpage first.
A C & S test identifies the bacteria (if present) and tells the veterinarian which antibiotic is appropriate. The urine for a C & S needs to be obtained by way of cystocentesis which involves using a syringe and needle to obtain urine directly from the bladder.
This is not a painful procedure for the cat and this method is the only way to obtain a sample for accurate information in order to properly treat with antibiotics. One problem, however, is that a sample may be difficult to obtain without waiting a couple of hours since cats with cystitis urinate frequently and often do not have enough urine in their bladder to get a good sample.
To get around this problem, your veterinarian can give the your cat a dose of subcutaneous (just under the skin) fluids. The patient is then put into a cage without a litter box. Within a couple of hours (or less), the bladder is usually full enough to obtain a urine sample via cystocentesis.
We have to stop treating all cases of cystitis with antibiotics without supporting evidence of an infection!
Cystitis will often recur in these patients and this painful health problem can be very frustrating to deal with. On a good note, most cats will have their clinical signs spontaneously resolve even without any treatment. In fact, it has often been said, jokingly, that a cat with cystitis will often stop exhibiting clinical signs within seven days with antibiotics and in one week without antibiotics.
Unfortunately, when people don’t understand this issue, antibiotics often get the credit when they had nothing to do with the patient’s improvement. When this happens, the abuse of antibiotics continues.
ETA:
Treatments for sterile cystitis include:
- Pain medication;
- increasing water consumption with a canned food diet, etc.;
- decrease the patient’s stress – not always easy since cats can be very ‘silent’ in their stress and we may not always be aware of what is bothering them;
- glucosamine/chondroitin sulfate/hyaluronic acid products such as Cosequin or Trixsyn may help but studies have not supported them as being beneficial. That said, they don’t seem to have any downsides and may be worth a try.
. I also heard cranberry is good for helping UTI crystals? Anyone else heard this?
When Forrest started this behavior, we were renovating and painting, redoing hard wood floors and there was lots of noxious odors. He told my Animal Communicator that "this place stinks!" and it was upsetting him. 
