10/29/2026
THE DOGS BEHIND THE FENCE
Are they Aggressive, Poorly Trained, or Simply Being a Dog?
Before we blame the dog—or the person who owns him—we need to understand what is actually happening.
Recently, I came across a discussion in a Facebook community that caught my attention.
A woman was walking her senior dog along a public road when she passed a property where two older German Shepherds regularly ran along the fence.
The dogs reacted as she passed, running the fence line and apparently displaying territorial behavior.
What happened next was interesting.
The woman was criticized by members of the community for walking her dog past the property. She was eventually asked to walk on the opposite side of the road.
She agreed.
But even from across the street, the German Shepherds continued running along their fence.
Her own dog, incidentally, completely ignored them.
She then asked a very reasonable question:
“Are these dogs performing some kind of security task? Why do they behave this way?”
I believe this situation deserves an explanation, because what many people immediately interpret as aggression, poor training, or irresponsible ownership may involve something much more complex.
And after more than five decades breeding, raising, training, and evaluating German Shepherds, I have seen this behavior countless times.
THE FENCE IS MORE THAN A PHYSICAL BARRIER
We have to understand thst Dogs do not understand property boundaries the way humans do.
But they certainly recognize familiar territory.
Their home, their yard, the places they patrol, the sounds they recognize, and the movements they observe every day become part of their established environment and they become protective
For a breed like the German Shepherd, selectively developed for vigilance, responsiveness, and protective working abilities, movement near that familiar territory can trigger an immediate response.
A person walking past.
Another dog approaching.
A bicycle moving along the road.
Sometimes, even a familiar neighbor.
The dog notices the movement, becomes alert, and follows it along the boundary.
Depending on the individual dog, that response may be different, involve barking, running, heightened excitement, frustration, or territorial motivation.
But here is something important: Not every dog running along a fence is displaying aggression.
And not every dog that barks at a passerby is trying to attack.
Behavior must be interpreted in context.
WHY DOES THE DOG KEEP RUNNING THE FENCE?
This is where canine behavioral science becomes particularly interesting.
Imagine a German Shepherd standing in his yard.
He sees another dog approaching.
He becomes alert.
He runs toward the fence, barks, and follows the passing dog.
Eventually, the other dog disappears down the road.
From the resident dog’s perspective, something significant has happened.
He reacted.
The approaching animal moved away.
And his territory remained undisturbed.
Whether the passing dog intended to leave all along is irrelevant to what the resident dog may learn from that experience.
Through a process known as operant conditioning, the behavior can become reinforced.
The dog may learn that barking and running are followed by the disappearance of the approaching animal.
And the next time someone passes?
He does it again.
With repetition, the behavior may become increasingly automatic.
This is one reason fence running can continue for years, even in dogs that are otherwise obedient, sociable, and well-mannered.
The behavior has become part of their established response to activity outside the property.
BUT ISN’T THIS A TRAINING PROBLEM?
Not necessarily.
And this is where I believe we need to stop making sweeping judgments about dogs and their owners.
A dog can have excellent obedience training, a stable temperament, and years of appropriate socialization and still react to movement along his property boundary.
Why?
Because obedience, emotional responses, territorial motivation, and learned behavioral patterns are not identical things.
Training influences behavior.
It does not erase every inherited tendency, emotional response, or instinctive motivation.
However, we must also recognize the other side of this discussion.
Just because a behavior has a natural foundation does not mean it should be encouraged or left unmanaged.
Repeated fence running can become excessive and frustrating to neighbors!
Some dogs experience considerable frustration or arousal when they cannot physically approach what they see beyond the barrier.
Others may become so accustomed to reacting that even ordinary movement triggers an exaggerated response.
And in senior dogs, repeated intense running may place unnecessary physical demands on aging joints and bodies.
Responsible management matters.
Visual barriers, supervision, appropriate training, and preventing constant rehearsal of the behavior can make a considerable difference.
ARE THESE GERMAN SHEPHERDS ACTUALLY PROVIDING SECURITY?
There is an important distinction between a dog displaying territorial vigilance and a professionally trained security dog.
A German Shepherd that barks and patrols his fence may be exhibiting natural watchdog behavior.
That does not establish that he has received professional protection training.
Nor does it mean that he is capable of making appropriate decisions in a genuine security situation.
Barking at everything that moves is not the definition of a reliable protection dog.
A properly trained protection dog requires discrimination, emotional stability, responsiveness to the handler, and control.
The ability to recognize a potential threat without reacting indiscriminately is far more valuable than simply making noise behind a fence.
And this distinction matters enormously in a breed as intelligent and capable as the German Shepherd.
NOW, WHAT ABOUT THE WOMAN WALKING HER DOG?
She was walking her senior dog along a public road.
Her dog remained calm.
She even agreed to cross to the opposite side to accommodate the situation.
Yet the resident dogs continued their behavior.
That tells us something important.
Increasing the distance did not eliminate whatever was motivating those dogs to react.
And while walking farther away may sometimes reduce a dog’s response, it does not necessarily change an established territorial or barrier-related behavior.
The woman should not automatically be blamed for simply walking past a property.
Likewise, we cannot determine from this brief account whether the owners have failed to train their dogs.
We do not know their training history, their management practices, or the emotional motivation behind their behavior.
What we can say is that the responsibility for safely managing dogs within a property belongs to the people responsible for those dogs.
And consideration between neighbors should work both ways.
WHAT 52 YEARS WITH GERMAN SHEPHERDS HAVE TAUGHT ME
Over the decades, I have worked with German Shepherds displaying very different responses to their surroundings.
Some will quietly observe a stranger passing their territory.
Others will stand alert and bark once or twice.
Some will follow movement along the fence with considerable enthusiasm.
And others will barely lift their heads.
These differences remind us that breed tendencies do not produce identical individuals.
Genetics matters.
Temperament matters.
Early experiences matter.
Learning history matters.
And the environment in which the dog lives matters.
We cannot evaluate an entire dog’s temperament from a few seconds of behavior behind a fence.
Nor should we automatically diagnose aggression simply because a dog is vocal, alert, or territorial.
But we should never use the word instinct as an excuse to ignore behavior that is becoming excessive, stressful, or unsafe.
MY FINAL THOUGHT
We have become very quick to judge dogs.
A dog barks, and someone calls him aggressive.
A dog runs along a fence, and someone declares that his owner never trained him.
A German Shepherd displays territorial vigilance, and suddenly people assume he is dangerous.
Yet canine behavior is rarely that simple.
The real question should not always be, “How do we stop this dog from behaving this way?”
Sometimes the first question needs to be:
“Why is this dog behaving this way, and what is reinforcing it?”
Because understanding behavior is where responsible training begins.
And after a lifetime working with dogs, I remain convinced of one thing:
Before we judge the dog, we owe him the courtesy of understanding the behavior.
— Maria Cecilia Martinez
Founder, Southernwind Kennels LLC
German Shepherd Breeder, Trainer, Judge & Canine Development Educator
Since 1974
Southernwind Kennels — Where experience meets understanding.
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