Fence aggression is a very common trait in dogs. Mail carriers, delivery men, newspaper boys, they all may have a story to tell. It basically, stems from a territorial nature, in other words, most likely if the dog could talk its barking would simply translate into ''Get out of my property''.

Of course, dogs do not know where their property exactly ends, so they will work on barking at anything over the fence, because either they think they own property over the fence or because simply they do not want anybody too close to their territory.

These deterrent qualities are often appreciated by those owners that want a dog to guard a property, however, fence aggression can turn out being a big ordeal if the dog cannot be properly contained.

Indeed, some dogs can be so fence aggressive that they eventually make it through the fence. It may happen suddenly, out of the blue, that dogs jump over the fence or squeeze through it or gradually, day after day, the fence may weaken in certain spots, until it eventually breaks up. For this reason owners of fence aggressive dogs should inspect their fencing routinely to identify some weakened spots. An ounce of prevention is certainly worth a pound of cure!

But what makes the difference between a fence aggressive dog and a guard dog? They are ultimately both behaviors stemming from the same purpose: protecting property. However, fence aggressive dogs are particularly focused on the fence area more than other areas. They are almost obsessed with guarding the fence more than the whole property.

Fence aggressive dogs are often frustrated by the barrier because it prevents them from getting to the other side. Often these dogs are found aggressively trying to manage ways to make their way through the fence. This frustration causes the dog to pace back and forth barking out of anger.

A main trigger of fence aggression is boredom. Dogs will often resort to barking at people and animals at the other side for the main purpose of entertaining themselves. They particularly get a kick out of scaring people away. Or at least that is what they think they are doing...

For instance, a dog barks at passer byers. Because these are people going from point A to point B, after a few seconds, they will  eventually leave. In a dog's eyes these people are not leaving because they were simply passing by the property, rather, they are leaving because they have heard him claim his territory. This even is enforced more by people jogging, trucks driving quickly by and cyclists. They simply think everything is leaving because of his barking. What a great confidence boost, indeed!

This is perhaps why mail personnel are so targeted by dogs, these people come and go every day and the dog is frustrated by their behavior, sort of ''I told you already so many time to stay away from my property!''

What can owners do however, to keep dogs from becoming fence aggressive?

A good way is to limit exposure to the outdoors. The more the dog is exposed to the fence, the more he will feel the need to protect the area from outdoor intruders. A privacy fence may help in some ways, because it takes away the dog's chance of seeing beyond the fence. However, sounds and smells still may abound.

Fence aggression, should be treated as any other form of aggression: a serious matter that may turn tragic if the dog is left unsupervised. It is better to be safe than sorry and discourage obsessive fence guarding behaviors before they settle in becoming more difficult to manage.