You go out for a walk and your normally loving pup lunges and barks at everyone or everything he sees! Not only is this embarrassing, it’s dangerous. Your dog could pull away from you and get lost or run into traffic, he could run afoul of another bigger, meaner dog, or he could pull you over. Some dogs express their lack of socialization by retreating or hiding. This can also lead to a dog that runs away from a social situation, and into trouble. Your dog is not happy, you're not happy, and no one the two of you encounter is likely to enjoy your dog’s company very much either.
Dogs are naturally social creatures. Think about a pack of your dog's wild cousins, their survival depends on being part of a social group. Your dog definitely wants to be social, but depending on his past experiences, he just might not know how. If you have a dog that has come from a situation in which they were isolated, neglected, or abused, or where a transition occurred which may have caused emotional stress to your dog, you may need to help him to develop his social skills! Most of us require our dogs to be social with other people and with other animals, so if your dog needs help with his social skills, you will have to give him some guidance.
Never use punishment to redirect an antisocial dog, as this just creates a negative experience associated with the social situation and will make existing antisocial behavior much worse. If your dog has acted up before in a social environment, do not give into that memory and tense up or be nervous about his behavior, as this will make your dog nervous and tense. You want to teach and encourage your dog to see other people and animals as friends, pack members, and have a positive, rewarding experience. You should be calm and confident in social experiences to provide your dog with the guidance he needs.
You will need a leash, treats to reward appropriate behavior, and lots of friends, both furry and otherwise, to assist you. If your dog is prone to be aggressive or bite, you may want to use a basket muzzle to ensure everyone is safe during training.