What everyone is saying, it’s all on the temperament of the dog. Had a pair of dachshunds years ago, the female would run right through screaming all the way when she wanted to chase a bird, bee, wasp or helicopter. She ended up getting out and run over. The male dog was so scared of it he wouldn’t leave it even when he didn’t have his collar on. Just put up a wireless system for our new mini schnauzer and she is training real well to it.