Choose a word or gesture to tell your dog to walk without pulling. For example, you can say “At the foot” or “Walk.” Be consistent in using this signal to avoid confusion.
Start training in a calm environment with no distractions. When your dog walks by your side without pulling, reward him with a treat and verbal congratulations.
If the dog tugs on the leash, Stop and wait for him to come back to you before continuing the walk. Repeat this exercise until your dog understands that pulling on a leash is not desirable.
As your dog progresses, increase the level of distractions by training in more stimulating environments, such as crossing paths with other dogs, or on streets with lots of distractions. Continue to reinforce the desired behavior by rewarding your dog every time he walks without pulling.
As with every apprenticeship, stay patient and be persistent.
Learning can take time, and each dog is unique. It's important to remain patient and not get discouraged if progress is slow. Perseverance and consistency are the key to success.
If your dog really doesn't learn to walk on a leash for various reasons, don't hesitate to contact a dog behaviorist.