Me and My Husband did something really stupid

We have a pond in our backyard and My Husband was at the pond store and he got some tadpoles to put in our pond. The guy at the pond store told him they are bullfrog tadpoles. We put them in our pond and then I looked them up and it says they can secret toxins that can poison a dog. Does anyone have experience with these frogs? Can they poison a dog so bad that it dies? I am just so concerned and there is no way for me to remove them now. I could try to catch them once they are frogs. I am so upset