Will A German Shepherd Attack an Intruder Untrained? 

When we hear of a GSD “attacking an intruder” we immediately think that the dog must have been previously trained; how could he have known how to do that? Your GSD may have attacked the intruder simply because he (or you) felt unsafe or was startled – he may have done his “job” without being trained to.

German Shepherds were originally bred for herding work but have since been bred for many other types of protection responsibilities like police work and military/warfare.  Due to this careful breeding, GSDs tend to be able to detect potential danger and will respond accordingly, regardless of formal training – a GSD will typically protect the people/person he has formed a relationship with.

The GSD is a highly intelligent working breed that will attack an intruder untrained – but do we want to rely solely on genetics to perform such a dangerous and important job?  Your GSD thrives on instruction and purpose which makes training so important.

Will A German Shepherd Attack an Intruder Untrained?

The short answer is yes – a GSD is capable of attacking an intruder untrained.  I have worked with lovely GSDs who have a strong relationship with their owner/family and when they detect a threat, they will respond accordingly and attempt to remove that threat in a controlled and confident manner. 

However, their reaction to an intruder may be out of fear or due to simply being startled.  The result is quite different, where the removal of the threat is not controlled and confident – rather it’s erratic and emotionally charged due to anxiety or insecurity.  

Are German Shepherds Good Protectors?

Most of the GSDs I’ve worked with have been very good about protecting their family from threats, with appropriate, controlled warnings – they understand cues at the moment like “come” or “sit” when a stranger appears and can follow those instructions without hesitancy or stress. 

These German Shepherds are typically trained to follow these cues so that when situations like this arise, they know exactly what to do when asked. He will trust that you have control of the situation.

Can a German Shepherd Still Attack an Intruder if He’s Afraid?

A fearful GSD is a much more dangerous one – he reacts out of fear rather than confidence and will offer very little (if any) low-level stress signs before escalating to using his body or his teeth to attempt to remove an intruder.  I’ve learned to always let people know before I approach their fence or gate if I’m coming over!

What Could Happen When an Untrained German Shepherd Attacks an Intruder?

When an untrained GSD attacks an intruder, the risk of injury to the intruder and to the dog is high.  An untrained GSD, even if controlled and confident, may struggle with appropriate bite force and with knowing when to release.  If the intruder is injured, he can sue for damages – your GSD could also be injured.

Unfortunately, most areas still consider animals as property so the law may not be on your side.

Will My Untrained German Shepherd Be Ok After Attacking an Intruder?

I’ve worked with many untrained GSDs who were not able to recover after attacking an intruder – in one case, she began to patrol the area more frequently under stress, became more sensitive to noises, shadows and lights, and was much more easily startled even by her family. 

An appropriately trained GSD will ward off intruders confidently and under control and will be able to return to their normal, bouncy self much faster.

Why bother training my GSD to attack if it’s built-in?

Without appropriate training, the risk of trauma to your dog is high.  He may seem to recover after an incident like that but they often require help to learn how to cope with day-to-day life after an attack, sometimes requiring anti-anxiety medication to help them to feel safe again. 

Appropriate training can prevent this as well as give you the confidence that he’s going to do his job properly and without stress.  A German Shepherd has great instincts to protect and attack, but with proper training, he could be even better at it.

Can I Train My GSD to Attack an Intruder on My Own? 

Sure you can!  Just be prepared to be kind, consistent and fair.  You’re not looking to make your GSD aggressive – you’re looking to teach him how to hone in on those skills he was born to use.

  • Expose your GSD puppy to as many people/dogs/environments as possible, being sure to not overwhelm or flood him
  • Enroll in a Force Free obedience/manners class that uses positive reinforcement methods rather than fear and punishment
  • Teach your GSD to “speak” and to “quiet” on cue (see video demo below)
  • Encourage barking at strangers on your property to alert you of their presence
  • Regularly take your GSD on leashed perimeter walks around your property if they’re not doing it on their own (see a real-life example below)

If I Hire a Trainer, What Kind of Questions Should I Ask Before Starting? 

The dog training industry is completely unregulated – that means that anyone can claim to be the next “expert” without any kind of proof of quality education or experience applying that education. 

Anyone who makes the recommendation that you should be the “alpha”, “pack leader” or “the dominant one” is practicing debunked theories from decades ago and is not qualified to help you.

My GSD Comes from Very Strong Protection Lines, Can I Just Trust His Genetics Instead of Training?

Your GSD’s behavior is comprised of 4 very important components – Learning History, Genetics, Environment, and Self.  This means that his genetics play a role, but they are not everything.  

  • His learning history – was he trained with fear and intimidation (shock collars, prong collars, choke chains, yelling/hitting) or with positive reinforcement. 
  • His environment – is he living in a stressful space with multiple threats and triggers to manage each day or are his needs being met appropriately.  
  • Then we have to factor in his unique self – who is HE.  Is he a goofball or a warrior? Would he prefer to lay on the couch or patrol his space?  Does he go outside into the yard to sunbathe or to watch the gate for intruders?   Just because your last GSD was a gladiator, doesn’t necessarily mean that this one will be.  Even littermates will be entirely different from each other because genetics only play a role in behavior.  It is not everything and we shouldn’t be relying on them alone.

Will My Already Trained GSD Train My New GSD Puppy to Attack an Intruder? 

Your GSD puppy is probably mirroring (or mimicking) all kinds of things that your adult GSD is doing.  According to a study in the Wires Cognitive Science Journal“ emotional contagion involves matching the perceived emotion of a nearby individual, positive or negative.

It is found in all sorts of social species suggesting its importance as a mechanism of coordination” which simply means, monkey see, monkey do. Your GSD puppy can learn to alert you and even attack an intruder if he follows his big brother (or sister).

How Will I Know That My GSD Will Attack an Intruder if Not Trained To?

We won’t always know for sure, but there are some signs to watch for:

  • Careful and confident scanning of the perimeter, regularly 
  • He is able to bark to alert you of a strange sound or unfamiliar person and also be able to be “quiet” when cued
  • His manners and obedience skills are exemplary
  • He is able to respond to your cues and will watch for you to provide the next one
  • He is comfortable around any human or dog until you let him know that there is in fact a threat


In conclusion, a GSD will attack an intruder untrained to do so, however, relying on genetics only will come at a risk.  It is best to seek out a qualified professional to help you to train him properly, such as Denise Fenzi of the Fenzi Dog Sports Academy.

Further Questions

Should I Just Purchase an Already Protection Trained GSD? 

Having a GSD that already has the obedience and other important skills intact can be helpful, however, the bond that you create with your German Shepherd will ultimately determine his success. He is a sentient being with needs that must be met outside of his job.

I Just Adopted an Adult GSD, Will He Attack an Intruder Without Training? 

A newly adopted GSD may have a significant history that neither you nor the rescue organization knows anything about.  Since learning history plays a significant role in behavior, it’s best that he be trained to do this very special job – yet understanding that he may just want to live a more relaxed life.

Will My Mixed Breed German Shepherd Attack an Intruder?

A mixed-breed GSD is capable of attacking an intruder – but regardless of what genes are most dominant in the mix of breeds, he may be attacking the intruder out of fear rather than the desire to protect.  Each dog is unique and should be managed accordingly.

Written by Sheila Gunston

Sheila Gunston holds a Canine Behavior Science and Technology Diploma, is an Accredited Professional Canine Behavior Consultant with the PPAB, and a Doggone Safe “Be a Tree” Presenter.  Sheila specializes in aggression and other complex behaviors and continues to further her education regularly.