Yes. I have a two year old rescued Lab/Shepherd mix who I got when he was 1 1/2 years old. He was horrible! He chased our cats continually. He ran away several times. I enrolled him in basic obedience class that uses the reward-only training and I found out that he is very intelligent. But I couldn't trust him. He had to be on leash 24/7 unless he was in our back yard. After completing basic training I hired a professional trainer that uses the Dogtra e-collar. The turnaround was nothing short of amazing! Within just one lesson he was no longer trying to chase the cats, he knew his "place" and would stay until released. As the lessons progressed he learned more and more. Just the other day we were out in the front yard for hours--I was planting flowers and my husband and son were in and out moving furniture. He never strayed from the yard. He comes when he's called. He and (most) of our cats are, well not best buddies, but they get along. Also, I've found that he actually heels better off leash than on--and we don't use the collar any longer. We only used it for the training part. He listens and obeys.