Trouble is a male German Shepherd Dog who is owned by Arnie. He only appears on walks and sometimes appears in competitions in the original Nintendogs games and does not appear in Nintendogs + Cats. He doesn't get along well with other dogs, causing him to fight. In some games, however, he will be friendly toward the player's dog. Trouble is also the type of neighbor that brings discs and chewable toys back. It is possible that Arnie and Trouble could be nintendogs masters because Trouble can flip when he catches a disc.