Are you sure "its" getting bigger - or is he just getting bigger and therefore, the spot growing w/ him? Check to see if he got shots in this area. My Wylie had the same thing happen w/ a shot - and then a bald spot.
As for the allergies and paw biting - could be food related or seasonal right now. Have you eliminated ALL chicken for 6 weeks yet? That would be a good thing to try. After that, I would then try Raw Frozen.
