Hi Heather,
I am so sorry to hear about your pup. It is so hard when you cant get any answers from the vet. I have been going through a similar situation with my 16 1/2 year old pitbull.
Does your dog still have blood in the urine? If the blood is gone now, maybe the antibiotics took care of the problem. If there is still blood in the urine, you might want to ask your vet about doing a blood test that specifically tests for bladder cancer. I am not sure what the name of the test is but if your vet does not know about it maybe you should ask another vet if they have the test. I have been dealing with my dog acting totally normal for over a month with the exception of blood and blod clots in his urine. My vet just kept giving different antibiotics and doing regular blood and urinalysis tests as well as xrays. Nothing specific was found. My dog just kept having more frequent blood and then started having other bathroom problems (incontinence, leaking, urgency, straining). I saw all the information on this web site about bladder cancer in dogs and then talked to another vet who said it sounded like my dog did in fact have bladder cancer. I just recently saw his regular vet who finally offered up this bladder cancer test. I am supposed to get the relults Monday or Tuesday.
Anyway, for right now my dog is doing ok (as well as an old, old dog can be). And actually he is doing a little better over the past week.
You might want to take a look on this message board under the pet cancer section as well as this bladder cancer section on the last page (pg 11) under the heading canine bladder cancer (tcc). There are over 700 postings under this thread with a ton of information. It is really hard to read all of the stories as they are so heartbreaking. But there is alot of positive information there about what other people have been going through and what they are doing to make their pups' lives better (medicines, natural remedies, diets, etc.)
I hope it turns out that your pup is ok, but if not, please know that you are not alone and that there are alot of people going through the same thing and that there is hope.
Keep me posted,
Teresa (Porkys mom)