Blood in dogs urine...vet has no answer.

My 3 year old pug first urinated blood last October during a long walk.  I immediately took him to the vet and the vet took a urine sample, the color was normal but tests yielded trace amounts of blood. The vet also did an ultrasound and could not find anything wrong. He prescribed anitbiotics. My dog didn't urinate blood again but I didn't take him on any long walks again either. When we flew on a plane from Germany to the states my dog was urinating blood after the plane ride. We took him to an emergency vet and they tested him for kidney stones and urinary tract infection. He had trace amounts of infection so he was prescribed antibiotics but my dog still urinates blood after running and after marking. I have taken him to the vet again and they cannot find an answer. He Ph levels are perfect, no kidney stones, and no infection. He is not in pain but urinating blood cannot be good. He will urinate normally and then when he is outside for a while and starts to mark on various things his urine changes from normal to bloody. The same result happens after he has been outside running. A few hours later he will urinate and the color is back to normal. PLEASE HELP!

[GSDgirl]

Is there a specialty near you?  Normally you need a referral to get an appt.  I am stumped but I am not a vet.  It sounds like you really care about your dog and have done more than a lot of people do.    Good luck

[Myown]

Years ago that happened to one of my dogs and it wound up it was something with the prostate if I remember.....the vet said the dog would need to be neutered. The only reason I hadn't neutered the dog is the type of breed it was does not always do well with anesthesia and I felt the neutering wasn't necessary. The vet told me that a male dog is more apt to cancer if they are not neutered. I didn't know that at the time or else I would have risked the chance of anesthesia.....but anyhow, it wasn't cancer or anything, the doc knew that prior to the neutering, and said once he is  neutered he would be fine and he was, never bled again. Sorry I wish I could remember exactly what the problem was with the prostate, but anyhow after the surgery - he never bled again.

Good luck,
MO