Walking the dog in heel (with an in-motion leash pass off) would be an excellent place to start. Getting the dog to recall to the new person (perhaps with a ball) is another good option.
If you ever encounter a dog and he or she starts to exhibit aggressive body language, stop your approach, move slowly, and appear non-threatening. In addition, avoid eye contact, look away, and remain calm and confident. DO NOT run away!
In most cases, the best way to get a reactive dog ready for socializing is to slowly expose them to their triggers in a controlled environment and reward them with natural dog treats until they no longer react so strongly.
While it is never too late to socialize your dog, the sooner you start, the better. Socializing your dog is very important at any stage in their life. It's especially crucial as they get older.
Dogs of any age can start training to improve their reactivity. You do need to keep in mind that the longer a behavior has been ingrained, the longer it will take to retrain the dog. Whether or not the dog will be “cured” in the sense of being completely fine in the presence of his triggers cannot be predicted.
Don't put yourself directly in the dog's face, but keep in mind that you'll be less threatening if you're not towering above. You can squat or sit down close to the dog. For extremely fearful dogs, you may even want to lie down a little distance away to begin making it more comfortable with your presence.
Among humans, eye contact is a way to connect with other people and show that you're paying attention. Among dogs, staring is a threat. When a dog holds their body very still and stares at you, avert your gaze and turn your head to show that you mean no harm. Hold very still to avoid escalating the situation to a bite.
Attempting to punish or physically restrain a reactive dog may cause him to escalate his behavior and is likely to result in a bite or a severe attack. Do not pull back on the leash when your dog is reacting.
Territorial barking or leash reactivity, such as when your dog is barking at the UPS driver when they deliver a package to your front door, are not behaviors you should ignore either, as these can make other people uncomfortable or put them in danger.
Start on neutral territory where you have plenty of space, like a park, open field, or quiet street. Start on opposite sides of your space walking the same direction. When one dog looks at the other one, they get a treat. Keep walking until they are no longer focused on each other.
Should you socialize your reactive dog? Whether and how this is done will depend on your individual dog and his specific behaviors. A dog that is leash-reactive might get along well with other dogs off-leash. In that case you can definitely let him play and socialize with doggy friends.
Stay calm – Don't scream and don't run – It's important to stay calm in a dog attack. Your body language should tell the dog that you are not a threat, and it will be less likely to attack you. Do not run away or scream in a panicked way if you can help it as it will incite the prey drive of the attacking dog.
Stop or Block the Dog's Approach
There are a few ways you can try to stop a dog in their tracks as they are coming towards you. Tell the dog in a loud, firm voice to "Go Home!" or ask for another basic behavior like "Sit." Step forward and put your hand out in a stop motion.
This kind of work can take anywhere from two to 12 months, as that's how long it takes for a dog to learn a new behavior.
The most challenging time of raising a puppy is the adolescent period. Dogs become “teenagers” and seem to forget everything they have ever been taught. This period is individual to each dog, but it may begin when he's about eight months old and continue until he's two years old.
It's never too late to start dog training
In fact - as your dog ages it's important for his or her physical and mental health that they have good manners.
The time it takes to calm a reactive dog depends on many factors so there is not a definitive answer. Fearful and over reactive behavior will not go away on its own. The dog will not grow out of it. Left untreated, both the frequency and the intensity of the problems will increase.
Puppies also usually become much calmer and mature between 1 and 2 years old. While many puppy habits eventually subside, reactivity unfortunately is not one of those.
Dogs will only display their true feelings with people and at places where they feel safe. So when a friend takes your leash, or the vet, or anyone else, and your dog doesn't react it is not because they behave better with someone else. It is because they do not feel safe with that person. They feel safer with you!