I read that article and starting watching my dog, who tends to do his business while walking. It's not true for my dog at least. There really is no rhyme or reason though he will tend to go parallel to a path if there is one.

So I'm not convinced on the north/south axis thing, and not just because of my anecdata, but because it sounds like one of those internet facts like duck quacks don't echo.

It's a bit off topic, but having raised ducks, I think I know the reason for that "fact."

Duck quacks have an odd sound sometimes, almost like an echo in itself. I've only noticed it when they're on the ground; in the air they seem to quack differently. Anyway, with a quack that already sounds a bit like an echo, I could see a case where the quack was actually echoing against a hard surface, but not sounding any different from the "normal" quack.

My ducks flew away years ago, so I can't do any scientific testing now...