So sorry to hear Sunny isn't getting better. Unfortunately the only time "I" had a UTI that didn't respond to antibiotics it was because Peanut had a tumor. I sure hope that's not the case with Sunny.

I know Tigris (Barbara) went through an, I think she called it "idiopathic" UTI, meaning they really couldn't find a reason for it. Hopefully she'll respond here with some tips, or maybe if you search the Health section...