Catnip and dogs

Last night I was at a friend’s house and she has cats. While there, she sprinkled a little loose catnip on a scratching post and the cats went nuts for it.

This got me to thinking about two things.

  1. What the heck is it? I’ve never had a cat, and I don’t know much about it. Looks like oregano, smells kind of good, but does it have any affect on the cats, positive or negative (I mean healthwise…obviously they enjoyed it). Is there any purpose to giving it to cats other than to make them happy?

  2. What if I sprinkled a little near my dog? Would it hurt him? Do dogs like it as much as cats, or at all? Anyone have any experience with this?