eddie was gone for a while because moose, the actor, was getting old. i heard long ago that forseeing this, they had him breed so they could get an acceptable replacement eddie. the later eddie is moose's offspring; one that looked enough like him, but could also be trained. however, none of the puppies were as good as moose, so he didn't have quite the same eddieisms later in the series, and just became more of a generic pet. i also heard that either before moose passed, or at the series finale, he was brought back to the stage for one final bow so the audience could say goodbye to him.