Hi all, My pup of 9 weeks has just started going a bit crazy and chewing his back left paw like mad. He can't leave it alone, and when he does stop chewing, it twitches like it's really irritating him and then he'll start chewing it again. I've tried to have a look at it and I can't see anything at all wrong with it, any ideas? I'm worried he's gonna hurt himself if he keeps chewing it the way he is. He hasn't been de-flead, but he's generally not an itchy dog and I've never seen a flea on him so I don't think it can be fleas.