I worried about that too, but watched them after I put it on, one lick and they didn't go back. They didn't get enough in that one lick to hurt them, just enough to say "yuck". I can use it now, and they won't even try chewing, I think the smell reminds them not to chew.
Just make sure to watch them after you put it on. If they still chew, clean it off, I'm sure if they got alot, it would make them sick.
