I'm the one that fostered Katie who had four large stones in her bladder. her original owner did not give her proper medication when it was first a uti, and did not have her on a rx diet, she was feeding her Beneful!
She was peeing straight red not even pink. The day after I picked her up I took her in to the vet. They had to have her on IVs and have her system flushed out for three days before they could operate, her white blood cell count was so high, and red down, she was anemic. She did great after her surgery, and she felt so great afterwards. Imagine living with that kind of pain for 2 years!
Having the stones or crystals in the bladder cut into the lining of the bladder, a perfect spot for bacteria to thrive. Which makes it practially impossible for the body to heal itself. Katie also developed a growth in her bladder, her body trying to cushion the stones from the bladder, kind of like how an oyster makes a pearl.
It's very important to feed a high quality too too. I'm sure it attributed to it. i had a cat when i was younger and I fed him cheap food and he always had uti problems.
since she is only 6 months and already has developed stones, you will need to have her checked every few months for crystals.
here is a pic of Katies stones.
eta: agree with the others, pre op bloodwork is not an option. that's how the dr found her WBC count so high and RBC so low, along with a lot of other things way out of whack and not in the normal range.