I know this is a LATE reply to this post, but just because something is all natural does NOT mean your dog won't react badly to it. Humans and Animals can have different reactions to all natural and/or organic things the same as they can to non-natural things. I try to go all natural with everything that I can for me and my furbabies. Unfortuantely, sometimes it just isn't an option
Hopefully you can find something on the internet to help you find another more natural alternative to the more common flea and tick treatments out there that are LOADED with chemicals. For now, add crushed garlic cloves to their food. It helps a lot. Just make sure you put the right amount. Too much is not good for them.