I haven't had any experience with UTI's but I have with switching vets. My thoughts are that if the vet isn't doing what you feel should be done find one that will. In searching for an answer to Daisy's problems we've been through about 7 vets. They were great vets they just weren't as proactive as we would have liked and some just kind of gave up. I also got to the point where I did my own research and then would call the vet and ask about the possibility of various causes. I would say doing your research can be nothing but helpful. Vets aren't perfect, but finding one that you feel is right for you is really important.