Before assuming this is a behavior problem, have your dog examined by your veterinarian. Anything that is making your dog uncomfortable or irritable, such as an abscessed tooth or ear infection, can lower his threshold for threats and aggression. So can certain medications and other medical problems.

The most common reason dogs are threatening and aggressive to people they don’t know is because they are afraid. This is particularly true for children your dog doesn’t know well. Often, dogs are afraid or anxious when children reach out to pet them, and they snap or growl to make the child go away.

Some dogs may appear quite threatening at the door or from behind a fence, but are quite friendly once visitors actually enter your home. This is likely a manifestation of territorial threatening behavior.

Do not believe the popular media and television trainers that your dog’s behavior is all about “dominance”. It’s nothing of the sort and if you try to change your dog’s behavior based on that starting point you will not be successful and will likely end up with a worse problem.

Most dogs (there are notable exceptions) don’t want to injure people, but want to warn them to go away or stop what they are doing. Aggression – biting and other behaviors that harm – is different from threatening behaviors – growling, lunging, snapping without injury, etc.

Some dogs who snap, growl, and show other threatening behaviors never bite. Others do. You should assume your dog will, and seek help before this happens.

Your immediate goal is to keep people, especially children, safe from your dog. Until you get help, avoid situations in which your dog is likely to bite. Don’t rationalize this problem as your dog having a bad day, or perhaps he was startled, or the person looked or smelled odd.

Your dog is more dangerous if he is inconsistent in his behavior. In other words, sometimes he may allow visitors or strangers to pet him and sometimes he won’t. Just because he is “OK” one time, do NOT allow this to lull you into a false sense of security that he’s “over” his problem. He is not. If he’s growled or snapped even once, unless you take steps to change his behavior, he will do it again.

We do not recommend confrontational techniques such as leash and collar corrections, alpha rolls and scruff shakes. Your dog will not learn to be friendly to people with these procedures, and they put you at great risk of being bitten.

Threats and aggression are serious problems. You will likely need to seek additional professional help.   Be sure and read our Guidelines for choosing a behavior consultant. Private “obedience” lessons will not help this problem. Your dog may sit, lie down and come when called quite readily and still growl at people or try to bite them.