The "Dog's Theme" Box is an exclusive item in Nintendogs Dachshund & Friends. It is a brown colored music box with silver turning handle. When turned, the box plays the game's theme music. It is rarely found on walks and can be sold for $20 at the Secondhand Shop. It is also one of the four collectable music boxes.
DS: "This song sounds oddly familiar... Rotate the handle to play it."