There is a tea tree oil ointment available. I bought it at my local coop and use it to keep the dogs from licking ointment off. I have also mixed a small amount of tea tree oil into neosporin to keep them from licking.
Also, a heads up, Nicky ran his feet raw when he was about 14 months old and had gotten free chasing a cat. His feet healed up fine in about a week but his pads have always been more tender than the girls.