we have a shelty dog in our home who bit our 22 month old son on the hand, it was not deep, just scratched the skin. Our dog stays in the house most days when he is out, he is in a fenced in yard in a community developement. He has not been updated his shots in over two years now. We noticed that our sons hand has like a boil or blister on it now, is this reason for concern or any recommendations to put on his finger?