Hey all, I have a book that can be bought at dogyeast.com which is all about a guy who has cured his dogs with natural remedies. I've used this and it works! One thing in the book is that it recommends tea tree for external treatment, but warns against internal use as there have been no long term tests on its safety. The author uses it and thinks it's fine, but is just telling it as it is and says to be aware of the unknown long term effects. I don't think I'd use it for internal use. ... View related article.