I've been giving it to both my dogs, with excellent results. The small min-pin gets 1 in a cheese ball, while my 3 legged, Lucky gets 2. Not a flea all year and it used to be a big problem. I guess they would have to be allergic to make them sick, as I've been using this over chemical treatments for the season, after someone came into my store and bought a bottle and told me what it was for. The Vet business wouldn't want you doing this for obvious rea$ons. For my guys, it's a great cure. I haven't seen a flea all year, I check them all the time, they always find a way to wake up in our bed come morning
and it doesn't make them sick. If you look at a can of dog food, garlic is in it.