Well, wolfsbane is a poison even for humans, but that doesn't mean that maybe it could be used to heal too. I've seen that happen, in my 'world'. He was shot with a bullet filled with wolfsbane, and then burned the wolfsbane from another bullet, and then shoved those ashes into the bullet hole, which...somehow...healed him. Painfully.
I wonder why you can't do it whenever you want. Like, the claws and the fangs and the eyes thing. Different sub-species, I guess?
Say that turning into a dog isn't an option, because you are a pathetic human being with no supernatural or magicalness. Is there anything else that helps?