ok here is the background...
female american bulldog/french mastiff mix. dob 9/2/2009.i had gotten her, Chaise, when she was 8 weeks old. she was from a litter of 13. at around 3-4 months she started to have blood in her urine. everything else was fine, eating sleeping, playing all fine. took her to vet, said twice it was just a uti. she was on antibiotics for 4 weeks and nothing helped clear it up. switched vets and the new vets ran many more tests including; xrays, cultures, cbc, liver functions, kidney function, clotting test, ultrasound, and finally exploritive surgery which she also got spayed. still nothing. all the test came back fine. and the surgery all they could say was that there was some blood in her bladder but they could not determine from where. they did take out a small piece of "extra" growth or something but tested it and it came back fine too. this peeing blood went on for about 5 months. then one day out of the blue it just stopped. i was thinking the the surgery fixed it and it just took a while for her to heal. i was wrong. it started back up this november. same as before, blood in the urine but not showing any other symptoms. took her to the vet hoping it was a uti this time but after being on antibiotics for 3 weeks it hasnt' cleared up. all the vet said this time was "hmm isn't this funny, maybe it's an allergy or something". i don't know what to do. i can't keep bringing her to the vet for the same tests as before (which ran me about $4000+) and the vet not even being able to give me any help or answers. is there anything you can suggest?
This is an extremely unusual situation, and I'm sure you are very frustrated by a lack of answers. However, I can't see that this is a problem with your vet based on what you've described. My first thought would be a urinary infection, but obviously this has been ruled out. The second possibility would be bladder stones, which should have been noticed on x-rays or during the bladder surgery; this would also be extremely unusual on such a young dog. The next possibility would be a mass of some sort. If it was in the bladder this would likely have been noticed during the surgery. Honestly, all of the steps taken were appropriate.
There is one more thing I would consider at this point. There would be a possibility that the bleeding is from the vagina and not the bladder. Did your vet do a thorough vaginal exam? This should be done under heavy sedation or light anesthesia, as it can be painful. Without the proper speculum it might be a little more difficult, but can be done with an otoscope. If the vet can't see all of the way to a cervix, it might be necessary to be referred to somewhere with an endoscope. A vaginal mass would be rare, but could explain the lack of efficacy of the antibiotics and the inability to find it in the bladder. Removing a vaginal mass would be difficult and may require a specialist, but could be curative.
If it's not in the vagina, I would strongly recommend referral to a multi-discipline specialty practice or a veterinary college. There may be tests (such as a CT scan or urethrogram) that could identify the problem and aren't readily available in general practice. At a clinic or college with several kinds of specialists they can work together to cover all possibilities. Going to a specialist would likely cost another several hundreds or even thousands of dollars, but if your vet can't find the problem, it may be the only way to figure out what is going on.