He growls whenever a stranger stares at him or attempting to pet him. He bit his Vet Doctor and my sons friend, don't know what to do.
That must be so stressful. The first thing you need to do is figure out some reasons he might be acting this way. One thing to note is whether this behavior suddenly started or has been ongoing for awhile or building over an extended period of time. Here are some possible reasons your dog may be acting aggressively towards people:
Bad experiences being approached or petted, including being petted when the pooch did not want to be.
Physical pain. It's important to rule out physical pain as a cause of your dog's aggression. If you feel comfortable and safe, do a physical exam to test for pain by putting moderate pressure on each area of your dog's body to test for pain (watch for flinching or whining). Note whether your dog has acted differently lately - excessively licking or scratching himself, dragging his butt across the floor, shaking his head or tilting it to one side (possibly indicating ear pain), looking at part of his body and whining, or whining in general without a noticeable reason.
Lack of socialization with people. If your dog has not had much interaction with people, especially when he was young, this may create aggressive tendencies. Trainers often suggest exposing puppies to LOTS of different people - different scents, clothes (hats, sunglasses, jackets, etc), skin colors, heights, etc in order to get dogs accustomed to identifying people and associating them with positive or neutral emotions.
Activities to try:
Do NOT allow people to pet your dog until you can clearly read your dog's body language and tell whether he would like pets or not. People are used to seeing a dog, walking straight up to it, and petting it on top of the head, when really this is the worst way to approach a dog.
Learn your dog's warning signals. Dogs typically give off signals that they do not want to be approached/pet/etc even before they start growling - watch for intense eye contact, leaning away from people reaching out, tightening of the jaw, changing position of the ears, hackles going up, body tensing, changes in tail movement or height (either increase or decrease - tail wagging is not always a sign of a happy dog, tail tucked=nervous, tail high=dominance/trying to look larger), freezing in place, yawning or licking his lips to relieve stress and tension, and so forth. Knowing your dogs signals will help you pinpoint when exactly he is getting stressed and will allow you to intervene earlier to prevent bites.
Help your dog build a positive association with people. There are many ways that people can signal that they mean your dog no harm - most notably is turning to the side or away from your dog and not making eye contact. Eye contact can signal aggressive intentions or a warning signal in the dog world, so it sounds like your dog is interpreting people's eye contact as bad intentions. Kneeling down (while also facing to ...
Wow, sounds like you got your hands full and good on you for looking for ahelp. But before we declare him a proper Cujo, the cause of this severe aggression should be established. Is it medical, is purely lack of training, is it genetic? What age, breed, sex is your dog, what were is formative weeks like, what is his history? So many things to consider before we can know how to approach this, what ,methods or treatments would be effective.
So I would strongly recommend quickly making an appointment with a behaviorist veterinarian, not a GP vet. This vet will do a bunch of medical and temperamental tests, ask you a million questions and be able to give you a proper diagnostic for your dog. When you know what is going on, you will be able to establish a treatment and/or training plan that will help you with this.
Good luck with it all and don't give her on the little terror just yet, with the proper personalized approach, the can and will surprise you.
Many dogs do NOT like when strangers stare at them or grab them/pet them. They perceive it as a threat. You should tell strangers not to approach and tell them to stop staring in your dogs eyes.