My dog, Barnum, frequently licks and nibbles at his front paws. I thought it might be arthritis (he's 7 1/2), but none of the info I find online about canine arthritis says anything about licking joints. Mostly it talks about a decline in activity or willingness to play, which doesn't seem to be an issue with him. Any thoughts about what it might be? Or if it is arthritis, is there anything I can do that doesn't involve liver-damaging (and expensive) Rimadyl?