Hmm maybe it's just me but I didn't actually think Disney were thinking of a Cavalier when they made Lady and the Tramp! I saw the similarities but I always thought it was more of a Cocker/Field spaniel of some kind, didn't she have a docked tail as well? I'm obviously looking into this a bit too much lol.
But I agree, very cute. I always fear when Cavaliers are put in adverts for anything though..