Hi. Sorry to hear about your dog. I went thru the same thing with months of wrong diagnosis, wrong treatment, & lots of wasted money. Save yourself time & money & have your vet run the canine vbat bladder cancer test. That's what finally diagnsosed my dog correctly. It cost me $100 & was well worth the money. It uses a urine sample that needs to be more urine volume than the standard urine analysis test. After the positive result on that screening test, my vet referred me to the Colorado State Animal Cancer Center for review by an oncologist. The oncologist recommended against doing the biopsy because the positive vbat test & appearance of the abnormal cells in the urine, along with ultrasound results, confirmed tcc diagnsosis.
Here's a link to the website that gives info on what the test is & how to order it:
http://www.btastat.com/veterinary_bta.html
Good Luck.
Joy & JJ