Hello, I have an approximately 2 year old male Lhasa apso. He weighs about 20 pounds, and is not neutered. I was given him about a month ago by someone who could no longer care for him properly. At first he was perfectly friendly, if a bit shy. But recently he has become aggressive. He bit my sister when she came over, and then he started claiming certain areas of the house as his (primarily under my desk). When I tried to make him move, he bit me. Last night he refused to go to bed in his normal spot, and bit me when I got near him. And I don't mean a little warning bite, I mean he charged me in a frenzy. I am afraid that he will try to bite my other dog, a Lhasa apso/ Shih tzu mix. As of now he leaves my other dog alone, but he is only get more aggressive.