You must be a leader yourself if you plan to share your life with an Australian Cattle Dog. This is a smart and independent breed who can be a challenge to raise and live with. He has a reputation for being stubborn, but the corollary is that he never gives up when he puts his mind to something. The ACD is suspicious of strangers, making him an excellent watchdog who will be protective if necessary. The ACD has high energy levels and needs much more activity than a simple walk around the block. Choose this breed only if you are a high-energy person yourself who enjoys long periods of active daily exercise such as running, bicycling and hiking and can take your dog with you once he is physically mature. Remember that this breed is meant to be able to work long days herding unruly livestock (vetstreet.com).