Will Peanut be boarding at the vet's while you are away? If not, I highly recommend it, especially since there are questions unanswered. You will feel better knowing she is there, and her caregiver (if not the vet) will have less worry placed on her.

I know a vet can palpate a bladder to feel if it is full or not, I wonder if they'd be able to feel any tumors?

Was the urine tested for crystals as well as infection?

Also, diarrhea, caused by the antibiotic, could casue some irritation and therefore bleeding.

(sorry my thought seem all messed up here. I hope they all make sense to you)

{{{{{{{{HUGS}}}}}}}}