Inc. It's normal for dogs to urinate when they want to demonstrate submission. Even a dog that is otherwise housetrained may leave dribbles and puddles of urine at your feet and on the floor when greeting you.
Submissive urination is the ultimate show of respect and deference for higher rank.
It occurs frequently with young puppies who have not yet learned and perfected other social skills and means of showing respect. Overly sensitive or mistreated dogs submissively urinate because they feel the need to constantly apologize. This state is often caused by excessive or delayed punishment which frightens and confuses the dog without teaching him how to make amends. The dog resorts to the only way he knows to show respect and fear, by urinating. When your dog urinates in this manner, it is best to just ignore him.