We don't get any infestations of fleas or ticks here so I've never had to use anything on my dogs and I'm so thankful for that. In all the years we've had dogs we had a case of fleas once and that was it. If I did need something I would mix my own with natural oils instead. I have a friend who is pretty heavily involved in that stuff and she seems to know what oils to mix for what. I know she made me up a batch of srtuff to repel flies and such from my horses .I only remember something about tea tree oil and lavender and it would be safe for my dogs if I ever needed something.