I have been walking Lacy on my left because that is how the trainer taught me in her puppy class when she was younger. The other day while walking our dogs with my neighbors my friend's husband said no you need to train her to walk on right side. She should be able to walk on left or right and that is how he trained his lab. I really don't know if it makes a difference my husband kinda hinted the same thing but since I'm the one who walks her I've always put her to my left. Does any one know why that is done in training and the reason for it. Also, do you think it would be better for Lacy to learn both ways. I have no idea.