Interesting question plowline! Made me think about the sad story of the twisted Alabama football fan that poisened the VERY OLD live oaks at Toomers corner in Auburn. :( If it's possible to save your tree, you may be able to get info on how it can be done from reading some of the stuff online about how the Auburn trees have been treated. Still dont know if they're going to survive or not. :( but the content may lead you to your answer! Good luck! Live Oaks are such beautiful old trees with so much character!! :)
You cant, if the whole is on the main trunk and its big you should consider taking it down with a tree company. If its small you might want to fertilize the tree so it stays healthy. Consult a tree company tho.