Your dog always barks at other dogs when walking?

This is because your dog wants to say hi and play. If you want to stop this behavior, then i would invest in a gentle leader. Whenever you go on walks, have your dog wear the gentle leader. When your dog barks, give the leash a sharp tug and say no. Once your dog stops barking, give your dog a treat and some praise. The first time you dogs sees another dog and doesnt bark make a big deal out of it and give him lots of treats and lots of praise, so he knows what he did was exactly what you wanted.