Dogs, much like their wolf ancestors, are territorial animals. They use various methods to show others who might intrude on their domain who is the boss. Scent marking with urine is one of those ways.
Around six to twelve months of age, male dogs experience a hormonal spike and will start to lift one of their hind legs to urinate. This scent marking is a bit different from normal urination, in that the dog will actively seek out an object, such as a tree or the corner of a house or even a car tire, then purposefully sniff it before lifting his leg to urinate on it.
Many times, if your male dog is neutered early, he won’t lift his leg to urinate at all and that’s totally ok. There is nothing wrong with him, it’s just that he does not feel the need to mark his territory.
But a male dog doesn’t necessarily have to be neutered. Some dogs, neutered or not, just never display the behavior. There are some dogs who add a sort of “scratching off” behavior after they urinate, as this throws the scent of their urine onto an even wider area.
Male dogs that are placed in a high stress situation, just as a shelter, may revert to the more juvenile leaning forward position to urinate. One study found that dogs who were in the shelter and did revert to the juvenile posture, did over time revert to leg lifiting as they got used to their new environment.
Sometimes when your pup reaches adolescence and begins lifting his leg to urinate, he may suddenly start to do this in the house as well, even though before this, he was throughly housebroken.
Ways to stop this behavior include having him neutered, if he is not already. Immediately clean urine odors from places he has marked using a odor neutralizer solution. Reward him when he urinate appropriately outside. Also, make sure there is no underlying medical problem, such as a urinary tract infection. Consult with your veterinarian if the problem continues.