Hi Cherish, long time. No advice on the antibiotics but in one of the insulin specific forums there was a thread about members using either bottled/filtered water and/or a cat water fountain and/or a pretty basic supplement that ended their UTI problems forever. I know it's frustrating, Marco and Andy go through this on an annual basis.
I often wonder about the water we get from our taps, stinks like bleach but is actually too much chlorine. Our water bowls sit on the floor where all the crap in the house settles, disgusting.
I'll try and find that thread, I might have bookmarked it. Won't help now but maybe in the future. Does anyone else remember this thread?