Based on the history you provided, it is likely that your dog suffers from lower urinary tract disease. Please read the article below about the different presentations of this disease, but bear in mind that blood in the urine is a sign of potentially serious disease. At this age, even cancer of the bladder must be considered as a possible cause. As such, as visit to a veterinarian is recommended ASAP. Should you wish to consult with a veterinarian 24 hours a day, 7 days a week, please visit our Ask the Vet page.