I have 7 cats inside. My 2 year old ragdoll has developed a UTI. Symptoms started late September and she has seen our regular vet. She started out with Amoxicillin and responded ok with them, seemed to clear up, and meds were stopped. About a week later, we had to take her back to the vet as she was exhibiting symptoms again…. We now have her on Baytril once per day and Centrine (1/2 pill per day). Her frequency has decreased and her bladder has been empty each time she has seen the vet. How long can a UTI persist until cleared up?
Are you sure your cat has a urinary tract infection? Her symptoms and background sound more consistent with feline lower urinary tract disease (FLUTD, also known as feline urologic syndrome/FUS and sterile cystitis).
Cats with FLUTD display symptoms identical to cats with bladder infections. They may strain to urinate, urinate frequently, or urinate outside of the litter box. Their bladders are irritated, but not infected.
In young cats FLUTD occurs more commonly than urinary tract infections. FLUTD is especially common in households with more than 2 cats.
FLUTD tends to run in cycles. Cats will feel bad for a few days, then feel better for several days. Then the cycle repeats. The apparent initial response to amoxicillin may have been nothing more than a coincidence.
A urinalysis and urine culture can differentiate between the two syndromes. I very strongly recommend this as the next step for your cat.
Owners of male cats should take special notice: FLUTD can lead to a catastrophically life-threatening syndrome called urinary obstruction in males. Urinary obstruction is essentially unheard of in female cats.