I have a male doberman and every few month he drips blood from his penis. I was wondering if anyone knew why he would be doing this.

You really need to take your dog to the vet, If his penis is bleeding he has to be in pain.

Yes, the vet. It could be many things. Even if somebody here knew what it was, you still might have to see the vet.

Blood dripping from the penis might be a sign of a urinary tract infection or something more serious. Without being able to examine him online and run tests, no one here can give you a definite answer. Please follow the direction other posters have already given you. Make an appointment with your vet. I hope it is a simple UTI that can be treated with medication. Please let us know how he is doing.