We had adopted a puppy at 7 weeks old Aussie mix. She started showing signs of aggression towards certain dogs and people at about 7 months old. We did not want the liability if she would hurt one of our other dogs or a person. We enrolled her in the 3 weeks course . After just one week upon our first visit to see her progress we could not believe the change in her. She use to be very hyper active out of control and leash aggressive towards other dogs. She is calmer and stays put while other dogs walking by her. No pulling on the leash or wining. Well worth the investment. Andrew and the staff are doing an excellent job.