I think it would be best for a vet to tell you what is causing this, you really need to get the pup there as fast as you can considering his age. This is a very old age for a dog. Hope this helps, good luck to you and the pup.
I would lean on my Vet, to investigate, the cause of this. Perhaps you can pull something up off the computer. Follow through until you get a serious answer.
I have to agree with the other answer here....your old feller is maybe beginning to show his age...I have a 17 year old that day in and day out she worries me....but blood in the urine is something you need to see a vet for.....be aware the vet will likely tell you that his/her age may warrant bad news! Good Luck!!
I see this has happened to your dog eleven months ago, but my boxer that is 7 years old and a male is going through the exact same thing. He urinates the blood and some clots and sometimes can't hold it. He never cries in pain. I took him to the vet and they did a scan and did not find anything in his urine or kidneys. What was the outcome for your dog?
This may be due to the disease which is known as "Bladder Stones" which usually occurs in dog's urinary baldder. They can be in various sizes either can be like the grains of sand or sometimes as as large as the size of fist of a normal young man. Their occurance in urinary bladder cause difficulty and sometimes painful urination and can often result in blood in the urine. So I think that could be the cause of blood in your dog's urine.
The cause of it would be you have to get him or her spayed or natured.
My dog is 16 urinates blood with clot ,first I noticed frequent urinates then he wanted to vomit hes been resting more but slowly coming back maybe he ate something bad