I can't provide an answer to the question, but I would like to offer an anecdote.
This song was extremely popular in my house when I was growing up. We were a houseful of well-educated Californians, by the way, and my father was a loved and respected college professor.
But when we look back on our childhoods, my brother and I remember an incident, not entirely unlike the one in the song, that actually happened to our sister at our parents' hands. And it horrifies us that we let it happen, even though we were both younger than our sister and probably couldn't have done much to stop it.
Would it have made any difference in our parents' behavior -- or in our willingness to tolerate that behavior -- if that song hadn't been an accepted part of the family culture? Maybe not. But although I'll defend anyone's right to sing it, "Slap Her Down Again, Paw" is one song I doubt anyone in my family will ever sing -- or want to hear -- again.