Sadly, every year thousands of dogs are sent to their deaths at animal
shelters because of their aggressive behavior towards people. Although
dogs are instinctively aggressive creatures, the overly aggressive or
vicious behavior some dogs exhibit can be prevented if you take a
proactive approach.

In nature, aggression comes in handy and is in fact necessary.
Descending from wolves, dogs needed to defend themselves against other
animals, had to hunt and protect resources and of course find a mate.
Lets face it-dogs are well adapted to do some serious physical harm-
take a look at your dog’s teeth! Some of a dog’s aggressive nature has
been minimized through selective breeding but you can’t change the fact
that dogs are hunters and had to be aggressive to survive.

The easiest way way to stop aggressive behavior in dogs is to not let
it form in the first place. Count yourself lucky if you are reading
this while your furry friend is still a puppy because really all you
have to do is what I call diverse socialization. Let your puppy see and
play with a wide variety of people: babies and toddlers, old people,
young boys and girls, men with beards, other animals and even the
mailman.(Don’t laugh-according to the US Postal Service every year
2,851 mail carriers get bitten by dogs)

Your dog depends on you to broaden his social horizons. If you give him
many positive socialization experiences with a wide variety of people
and animals he will feel more relaxed when he encounters a stranger or
unfamiliar situation. He has learned that new people and situations are
fun and interesting, not scary. He has to learn this through experience
and the earlier you start him on this “socialization training” the
better. It is not enough to put your adult dog in a room full of
strange people and tell him to “Relax, settle down Rufus, it’s
alright”. He has to learn this himself. If you don’t have time to do
this yourself there are “puppy preschools” that encourage socialization
with other dogs and their owners. The environment is safe and
controlled and your dog will get exposure to wide variety of different,
friendly faces and other dogs. This way he will learn that he doesn’t
need to fear new faces.

It is best to continue with a dog’s socialization as an ongoing
lifetime effort. If he looks like he is being overwhelmed just back off
the training a little bit until he can build up his tolerance.
Aggression Towards Your Family Members

In some situations an adult dog will show aggression to someone in your
own family. This type of aggression is usually a behavior that dogs
exhibit when they are trying to guard a resource from what they
perceive as a threat. He may be guarding his food, or his territory
from a perceived threat-you or another family member. Some dogs will
growl if you approach them while they are eating or may give you a
“staredown” if you try to take anything away from them such as a toy.
This behavior is commonplace and it relates to the social behavior of
dogs. Dogs are pack animals and live in a structured, hierarchal
society. Each individual in their society has a certain status or rank.
The highest ranking dog, the alpha, is the leader of the pack and gets
his choice of food and mates. Each dog knows his rank, or dominance in
relation to every other dog. So he would know which dog he can easily
push away, which ones he can muscle in on, and which ones he must back
away from in a confrontation.

Your dog also lives in a pack-your family. Your dog already has
everyone ranked in the family in his social schema. The problem that
can occur here is that if he thinks that he has a higher rank than you
or another family member he may act aggressively. This aggressive or
dominant type behavior is the “right” of a higher ranking animal. Only
a higher status or dominant dog would act aggressively this way.
In other words, if your dog understood that he was not the alpha dog in
this situation he would never aggressively try to prevent you from
taking his food or toy. A lower staus or ranking dog would simply go
along with what the higher ranking dog (you or your family) does
without a fight.

The best way to stop this is with some obedience training which will
make him understand that you and your family are the leader of the pack
and not him. Don’t take this to mean you have to beat your dog if he
disobeys-this can lead to fear biting and other problems. It’s better
if you spend a couple of short sessions a day-say 10-15 minutes and
reward him with praise and food treats for following your commands and
putting him in isolation when he disobeys. Your dog wants to be an
accepted part of the pack.

Some dogs, especially dogs that have been abused and abandoned in
shelters may be especially aggressive and fearful. He may be too much
to handle for you. If you have the heart there are professional dog
trainers that can help train very aggressive dogs.