Tea Tree Oil is safe to use on dogs skin as long as you dilute the Tea Tree Oil with some water before applying it to the dogs skin.
If you don't dilute the Tea Tree Oil before applying it to the dogs skin then it can cause burns and irritation to the dogs skin.
But when diluted with some water the Tea Tree Oil is very safe for dogs skin.
I've used Tea Tree Oil diluted to get rid of fleas and ticks on my dog and it worked great and even better than flea and tick treatment for the dog.
The tea tree oil is a more natural way of getting rid of ticks and fleas than regular flea and tick treatment chemicals.