I agree with Stenograsaurus. Perry is a pretty good size for a mini schnauzer, maybe 26 pounds and he is very protective of us and anyone coming into our yard. We realize this and have to be very careful, if someone comes to the front door, we have to put him outside in a fenced patio. He is so loving with us, you would never know he had this in him, but he does. He is also aggresive towards children and other dogs so we exercise him in our lower yard which is pretty big and fenced and when taking him out, he always has a harness on him and always, always on a leash. We have taken him to a dog behaviorist but it really didn't help, so we are very careful with him since we know his tendencies.