Why Are Small Dogs So Aggressive?

It’s a common belief that small dogs are aggressive, misbehaved, angry, and are always trying to prove themselves to big dogs by barking, lunging, and sometimes even biting.

Photo Credit: Depositphotos/evdoha

Collectively, this behavior is often referred to little dog syndrome, small dog syndrome, or a “Napoleon Complex”.

But is it true? Are small dogs more aggressive?

And if so, why?

First, What Is Little Dog Syndrome?

Little dog syndrome is a broad term to describe collection of behaviors and actions that are – for lack of a better way to describe it – naughty or bratty.

Small dog behaviors that can be considered aggressive include:

  • Lunging or snapping at perceived threats
  • Growling at people or other dogs
  • Snarling or bearing their teeth
  • Standing rigidly and raising their hackles
  • Acting upset and frantic to the point that they “see red” and stop listening to the owner’s commands
  • reacting aggressively towards people and other dogs

There is a whole list of signs and symptoms of little dog syndrome but these are the most typical I see and have experienced.

Do note: many small dogs are full of energy but there is a difference between a small dog “being spunky” and one that is acting inappropriately and aggressively.

Don’t discourage your dog’s playfulness but the behavior needs to be addressed if it starts to get aggressive or possessive.

According to Animal Planet,

“There’s a big distinction between a typically spunky small dog and a dog with small dog syndrome. Symptoms of the syndrome include not following instructions, becoming territorial over areas of the house, toys, food or people, and even biting.

A small dog with spunk is ready to play when your grandchild crawls into your lap alongside him. A little guy with small dog syndrome will probably growl menacingly and may even try to bite.”

Are There Behavioral Differences Between Small and Large Dogs?

In a 2010 study led by Christine Arhant, University of Veterinary Medicine, Vienna titled Behaviour of Smaller and Larger Dogs: Effects of Training Methods, Inconsistency of Owner Behaviour and Level of Engagement in Activities with the Dog, it was confirmed that:

  • Smaller dogs were seen as less obedient (less likely to listen to their owner’s commands and/or perform a command consistently)
  • Smaller dogs were more aggressive and excitable (more likely to bark, growl, and lunge at strange people and other dogs)
  • Small dogs were more anxious and fearful (more likely to be scared of new situations or unfamiliar surroundings)

So, yes, the belief that small dogs are more aggressive and mean than big dogs is not totally unfounded.

But why is this? Why does little dog syndrome exist?

Are they born that way? In other words, are they genetically predisposed to this behavior?

Or is it something else?

Why Are Small Dogs More Aggressive, Anxious, and Misbehaved?

I understand that genetics plays a role in the base, or natural, personality of a dog.

I’ve read studies indicating some dogs are just born with more nervous and fearful personalities. However, this was true regardless of the dog’s size.

A large part of a dog’s behavior comes down to “nurture” – training, exposure to positive or negative experiences, the stability of their surroundings, etc.

In addition to the way a dog is raised, things like genetics and when and if they are neutered can affect their behavior. But these play a very small part.

There is even some evidence that early spay and neuter can cause a dog to be more anxious and aggressive.

In the study cited in the section above, the differences in behavior between small and large dogs came down to this:

Lack of Training for Small Dogs

Smaller dog owners reported being more inconsistent with, and engaging less in, training and play activities than larger dog owners.

In other words, small dog owners spend less time training their dog and engaging their dog’s brain.

This makes sense to me according to what I’ve seen.

When I see big dogs who bark or jump, or otherwise act act aggressively, the owners do something about it.

They have to because a large dog can do a lot of damage to another dog or person. A big dog acting that way is seen as scary and threatening.

The dog may even get reported to animal control if it’s bad enough or happens repeatedly.

When I see small dogs behaving the same way, usually nothing is done about it in regard to controlling the dog or situation.

The small dog owners usually just laugh nervously and apologize, thus enabling the behavior instead of correcting it.

Punishing a Small Dog Can Increase Fearfulness and Reactivity

Increased anxiety and fear was related to a more frequent use of punishment* in smaller but not in larger dogs.

Note: I combed the internet and was not able to determine what the definition of “punishment” was for the purpose of this study.

However, when people talk about punishment in dog training, often they mean adding something to make the likelihood of a behavior go down (positive punishment), such as using leash jerks, alpha rolls, or hitting the dog.

I’m assuming that is also what they mean in this study but acknowledge that I can’t be sure and could be wrong.

In other words, if a small dog owner used punishment, it was more likely to scare a dog and make them anxious.

It seems logical to me that a small dog who is more scared and anxious is more likely to act out negatively.

So I’m not saying it’s impossible for a small dog to be genetically predisposed to anxiety, poor behavior, and aggression.

BUT that is just as likely to affect large dogs so the behavior difference seems to come down to that nurture thing I was talking about.

Why is A Small Dog Misbehaving and Acting Aggressive A Big Deal?

Aggression in small dogs is not something to shrug off or easily dismiss as “just the way they are”.

Small dogs, because they are short and are easy to control physically, often get away with shockingly inappropriate behavior.

People often see small dogs acting out as funny and harmless.

The problem is, it’s is not harmless.

Any dog acting aggressively is not funny, no matter what size they are.

First, if the aggressive and nuisance behaviors can be difficult to change, or or positively influence through training, if they are allowed to go on for too long.

Once you have a mean small dog, it can be very difficult to change that if it’s not corrected right away.

But it’s also a big deal for these reasons……

Dogs Are More Comfortable with Structure and Clear Expectations

If a small dog acts out because they are nervous and fearful, and the owner does nothing to control this, dogs can get messages like:

  • Lashing out is appropriate behavior
  • However he or she wants to act is ok so it’s fine to react the same way next time
  • The world is scary so they have to defend themselves because their people aren’t going to protect them

All dogs want to feel safe. They want to know that they don’t always have to defend or advocate for themselves.

They don’t want to always live in a state of fear, be anxious all of the time, and be on the lookout dangers.

If you, as a dog owner, can consistently control the situation (like not putting them in situations that you know they find scary), and teach them how to properly interact with the world through training, your dog will live a happier, less stressful, life.

It’s Not Fair to Other Dogs

It can be frustrating for owners of big dogs to put up with small aggressive dogs.

The general public expects larger dogs to behave but I see, time and time again, small dogs acting inappropirately and getting away with it.

Imagine if a Pitbull or German Shepherd lashed out at another dog or human? Or bit them?

The dog would be labeled as aggressive and, depending on the severity and frequency, may be reported to animal control and potentially be euthanized.

One time, I watched a guy with a Pitbill cross the street. A woman with a Toy Poodle was coming the other way.

As they passed each other, the small dog started to snarl, bark, and leap at the larger dog.

It looked like the only thing keeping this little dog from confronting the big dog was the leash.

Photo Credit: Depositphotos/balakatie

The Pitbull looked curious and a bit disturbed to me.

I watched the owner of the Pitbull look down at the small yapping dog and laugh (or was it a nervous chuckle?)

What if that small dog had upset the big dog so much that a dog fight ensued?

I can bet most, or all, of the repercussions would have fallen on the large dog because it would likely do more damage.

And because, in this particular case, the large dog was a breed that is stereotyped as “dangerous”.

It’s important to teach your small dog to act appropriately with other dogs, or learn how to manage the situation, so interactions like this can be avoided and no one gets hurt.

It’s Frustrating or Embarrassing to You

Although plenty of small dog owners allow their small dogs to lash out and act inappropriately towards other dogs, I almost always see owners of dogs displaying small dog syndrome acting or verbally being apologetic.

Based on my own experience, I can say it’s no fun when I’m walking along having a nice day and all of a sudden my small dog yanks on my arm and causes a scene.

I don’t believe that any small owner PREFERS that their small dog act mean by growling, barking, or lunging at other dogs or people.

My suspicion is that these owners just don’t know what to do.

They don’t understand dog body language (their own dog and others approaching) enough to know how to avoid negative situations.

They don’t understand how to teach their small dog to stop barking and lunging.

Or maybe they have tried one or two techniques that didn’t work so they gave up.

But is the situation hopeless?

How to Stop Small Dog Aggression Toward Other Dogs

The good news is that aggressive behaviors associated with small dog syndrome have less to do with the size of the dog than it does with the way most owners treat little dogs.

Here are some ways you can help prevent, or correct/manage, your small dog’s behavior issues.

Train Your Small Dog Focusing on Positive Reinforcement

The amount and type of training matters.

Small dogs deserve the same amount of training and effort that big dogs do.

If we take the flip side of the findings in the above study – lack of training for small Dogs and punishment likely increasing fear and reactivity – the answer would seem simple.

Train your small dog.

Do it using positive reinforcement techniques.

It’s not that simple though.

Assuming only training, and only positive reinforcement, will correct this issue feels like blaming the owner for all misbehaved small dogs.

Sometimes other factors do limit the effectiveness of training and using training techniques from other operant conditioning quadrants work better for some dogs.

However, there could be significant improvement in obedience and desirable behavior through training using positive reinforcement.

As a side note, I am guilty of not training my small dog either. Or at least I used to be.

I didn’t train my first Dachshund at all. I didn’t know anything about owning a dog and he was chill and friendly so there was no urgent need.

But my second Dachshund was a hot mess when I adopted her.

She taught me a lot about reactive dogs and training.

I used what I learned to “start right” with my third Dachshund, whom I got as a puppy.

I’m not a great dog trainer, and I could be more consistent, but she is a pretty well trained small dog I think.

If you want to get started with training your small dog, check out these articles:

If you feel like you need support and insight from a dog trainer, I highly suggest online dog training classes from my friend Kama at Club Doggie.

She’s very knowledgable (she is actually a well-known dog agility trainer), is non-judgemental, and speaks to you in plain English instead of complicated dog training terminology.

She helped me a lot with my Dachshund puppy (virtually… so know online dog training can be highly effective).

A well trained small dog is unlikely to display aggressive and defensive behavior toward other dogs and people.

Implement Structure at Home

This is an extension of the section above but a lot of people think that training a dog to react appropriately to other dogs is something that only happens out in the world and has to involve another dog.

In reality, training behavior and expectations starts at home.

But teaching self control, and teaching your dog to self sooth, at home can greatly impact the way your dog reacts to stimulus in the outside world.

Some great training exercises that can help in a multitude of situations, including those with strange dogs and people, are:

  • The place command – teaching your dog to stand or sit where you want them to, and to relax there, can help when you need your dog to step aside to let others pass.
  • Leave it – Teaching your dog to leave a piece of kibble can eventually translate into teaching your dog to ignore potentially upsetting stimuli like another dog coming toward you.

Teach Your Dog to Be Comfortable In Strange Situations

Socializing your dog (from an early age if possible) is also important.

I might argue it’s one of THE most important things that will determine your dog’s future behavior toward new dogs and people.

Socialization is more than just putting your dog in a room with other dogs and letting them work it out.

The term socialization brings to mind meeting a lot of dogs and people but socialization is really so much more than that. In reality, meeting a lot of dogs and other people is a privilege a well socialized dog earns.

When you “socialize” your dog, you are exposing them to different stimuli – be it new people, new dogs, new situations, new environments, or new experiences – at their pace teaching them how to act/respond appropriately to these things.

Note: Dog parks are not good socialization tools for your dog. Your small dog should not visit a dog park until after they are properly socialized.

A well socialized dog is more confident.

If you raise a confident dog, they are less likely to develop small dogs syndrome.

Not everyone has the privilege of raising a puppy – of having control over their dog’s socialization process, foundation training, and life experiences – though.

Sometimes people (generously) adopt an older dog that may or may not have existing anxiety, anger, and behavior issues.

What do you do if that is your situaiton?

Learn How to Manage the Situation

Sometimes all the training in the world won’t eliminate small dog syndrome behavior.

My Dachshund Gretel is always anxious.

She had a rough start to life so, although she has come a long way in 10 years, she is still on edge all the time and defensive.

At this point, that ain’t changing and I’m ok with it.

We still do things calm, relaxed dogs do though.

We’re able to navigate the word without much incident because we work as a team and I control our interactions with other dog and people.

I’ve learned her signs that she is getting ready to react and that she needs more space to remain calm.

I give it to her.

  • We may cross the street
  • We may turn and walk the other way
  • We may out-run children that want to pet her (seriously, I have done this. Ha, ha)
  • We step aside on the trail when we are hiking and I keep her attention on me
  • I tell strangers who ask that they can’t pet her if I see her being uneasy

In a pinch, if there is nowhere for us to go that gives her more space, I pick her up and hurry by.

Note: contrary to popular belief, picking up your small dog to help them feel safe on occasion won’t ruin them.

Make Sure Your Dog is Getting Enough Exercise

Remember, small dogs need exercise too.

Some, like Dachshunds, were bred to be athletic hunters and can handle as much as a big dog can.

Make sure that you are giving your small dog an outlet for their energy through regular activity.

Small dogs that don’t get enough exercise can have a lot of pent-up energy and are more likely to act out.

Read This: Signs Your Small Dog Isn’t Getting Enough Exercise

Also, if a dog is getting inadequate exercise, it’s follows that they are likely not being taken outside for a walk often.

A dog that isn’t regularly exposed to new situations, and stimulation of the outside world, is more likely to be fearful of things and act defensively.


Aggressive behaviors associated with small dog syndrome primarily occur because of the way a small dog is raised.

Small dogs are often not properly socialized and small dog owners spend less time (none in many cases) training them.

This lack of structure and training can result in a small dog who is fearful and always acting defensively toward unfamiliar dogs and people.

This puts undue stress on your small dog and it’s not fair that other people and dogs have to tolerate your dog’s (mis)behaivor.

The bottom line is that ALL dogs deserve to be treated the same regardless of size.

Raising a well-adjusted and trained small dog will help ensure that both you and your dog enjoy a happy, stress free life together.

Read More: 25 Dachshund Facts Every Owner Should Know

About the Author

Hi, I’m Jessica. I’ve been studying the Dachshund breed since 2007, owned 3 of my own, and shared in the lives of thousands of others through their owner’s stories. When I’m not sharing what I know on this blog, you can find me hiking, camping, and traveling with my adventurous wiener dogs.


  1. This post is so wonderful, Jessica! There are so many things I’ve never thought about – and you are right – at first glance, seeing a small dog act too big for his britches is funny (there are MILLIONS of videos of this online). But it quickly turns to tragedy for everyone involved so quickly.

    Back when I dog-sat professionally, one of my clients lived across the street from a home of six small dogs (at least two Dachshunds) and they terrorized everyone walking past. I had to CARRY the Lhasa Apso past that house just to take her on a walk (she melted in my arms – I wouldn’t have forced the issue otherwise). How sad is that?! A dog couldn’t go on a walk just because she didn’t want to walk past ONE house!

    Even worse, a different neighbor’s son brought his pit bull over to visit – and the pit bull got loose – trying to run past the house with the aggressive small dogs. He panicked though – at the aggressiveness of the small dogs – and turned around and bit one of the Dachshunds (unfortunately, very seriously injured). The kicker of the whole thing was that the pit bull had been abused (not by the neighbor’s son) – and had no history of aggression – he was even petrified of cats!

    I never heard what happened to that pit bull – but animal control got involved and the last I heard, they were considering putting him down. I saw the whole thing and I told everyone – whether they wanted to listen or not – what happened. All these years, I was bitter toward Dachshunds – but you are ABSOLUTELY right – the owners were to blame by letting the problem behavior continue. Thank you for shining light on this topic – and giving me a new perspective on something that’s long weighed on my heart.

    1. Hi there. Good to hear from you! I do want to make the distinction that a protective dog will always protect their house so it shouldn’t be expected that they won’t. What I am referring to is when they are away from their home being walked on a leash. But I 100% get that experience about having to carry the dog. There are some houses where dogs have scared Gretel and she will pull at the leash to cross the street as soon as she see’s we’re getting close. That’s such a sad case about the PitBull. Although not exactly the same scenario, that’s what I mean when I said small dogs, even if they’re just being “cute yappy” can escalate the situation quickly and it can scare or intimidate the other dog. I sure hope Animal Control saw the situation for what it was and there were no repercussions for the PitBull.

  2. Very thorough and great read! It’s definitely the owners who let it happen. My aunt used to have a Chihuahua that I feared so much and had some sort of bias towards small dogs growing up. After being around Toy Poodles and eventually owning one, I have come to love our smaller friends. It’s all about how they are raised. Now I don’t believe there is such thing as a bad breed. It’s just bad training.

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