one year male doberman pee on other dogs

Question
why does he pee on other dog's ? also when is the best time to stud by dog? He has once peed on someone's foot?

Answer
Never.  He is showing signs of being excessively dominant, intolerable in a Doberman.  Much of our problems with dogs come from breeding such unsuitable ones.  Get him neutered, the sooner the better. As he matures, he could expand his dominance to people.  The Doberman world does not need another aggressive male passing on his defects.