My guess is, blood is probably coming from his kidneys or bladder if is in his urine ... That could be a sign of somethng very serious. He needs to see a vet ASAP.
My dog is leaking blood from its penis. Its been going on for 2 days and a lot of blood has came out. What do I do?
Take him to the vet; he could have an injury in the penis or an infection; either way, he needs treatment.