Mew, mew mew, nyanyan, mew, merow, mew mew mew, meow, mew-meow, purrrRRrr, moew, mow, meow, moow, reow, meow moew. *Bows and takes leave.*
<It seems to relate purely physically. Dogs are thought of as 'built', solid, and essentially a brute-ish creature. Cats are seen as sleek, dexterous, and compact. I think the whole idea entirely builds around the line of thought of such a theme. ---Personality wise, I don't think that there's much at all a comparison even remotely attempted. I guess maybe people just look at women and men much the way Princess of Hearts thinks about cats/dogs, though...That's just my opinion.>
(Edit: add)
*From distance "RREEWOOR!"*
<Oh, and btw, I say as well that it's just a silly metaphor. XD >