If your pup lunges: If your dog is going after something while on a walk — another dog, a car, a skateboarder, for example, be proactive. Try to redirect his attention with a treat before he has a chance to lunge, and increase the space between your dog and the target. Stay alert and be prepared before the target of his frustration gets too close. This type of behavior may be more common in herding breeds, but any dog can be startled by something he’s not used to or finds exciting.
Just as a child needs a caring parent; an athletic team needs a coach; your puppy needs a leader and a clear social hierarchy. If you do not take up the role of leader, your dog will; and you will end up with an unruly, disobedient dog. Many people try to win their new puppy's love by letting the puppy always have its way. Buckets of affection is a wonderful thing for most puppies, but it must be tempered with respect.