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Top 10 Most Aggressive Dog Breeds in the World (With Pictures)

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By Nicole Cosgrove

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Dr. Paola Cuevas

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When shopping around for a new best friend, one of the most common questions asked by prospective dog owners is: how aggressive is my chosen breed? Wanting to know the answer to this question is understandable, especially if you have small children or other pets. Unfortunately, it’s also far from straightforward.

Before we can look at which breeds have the highest likelihood of being aggressive, we need to agree on the definition of “aggression.”

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What Is Aggression in Dogs?

To the detriment of many dog breeds and their owners, determining whether an entire breed is aggressive or not is largely subjective. There’s also a big difference between aggression and behavioral traits like reactivity and prey drive, both of which can be mistaken for the former.

In the simplest terms possible, aggression is a display of dangerous behavior, generally toward another dog or a person. While most people equate aggression with biting, it involves a full spectrum of behaviors. Other examples of aggression can include barking, growling, and lunging.

What Is Reactivity?

Meanwhile, reactivity refers to dogs that become overstimulated in certain situations and can present as lunging, growling, and barking. Some dogs become reactive around men, other dogs, or even just while on a leash. Although special care and training are required to manage reactive behavior, these dogs generally aren’t dangerous.

Prey Drive vs. Aggression

Prey drive can also be confused with aggression. While aggression is normally triggered by fear, a dog’s prey drive is simply an extension of its natural hunting instincts. Prey drive can lead to dangerous behavior toward small animals, including cats and other dogs, but doesn’t make a dog inherently unsafe.

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The 10 of the Most Aggressive Dog Breeds According to Real Research

For our list of the most aggressive dog breeds, we turned to research from the American Temperament Test Society (ATTS). The ATTS conducts testing to see how different dog breeds perform in a variety of scenarios, including interacting with strangers, noise stimuli, visual stimuli, and more.

While it’s impossible to definitely label any dog breed as aggressive or not, the results of the ATTS testing give us a pretty good idea of which breeds are more likely to display aggressive tendencies.

1. Chihuahua

Image credit: Regenwolke0, Pixabay

They might be tiny, but the Chihuahua routinely scores quite low on temperament tests. However, few can agree on whether the Chihuahua is prone to aggression because of its genetic makeup or because many Chihuahuas receive inadequate training and socializing.

Their small size means that even the most aggressive Chihuahua won’t do much damage. Still, if you have a Chihuahua, then it’s your responsibility to ensure they get proper training, socialization, and aren’t allowed to roam free in environments where aggression could be triggered.

2. Dachshund

dachshund on grass
Image Credit: James Player, Shutterstock

Another aggressive dog breed, at least according to temperament studies, is the adorable Dachshund. This breed, more often known as a “wiener dog,” presents the same issues as the Chihuahua. While they’re small and won’t pack much of a bite, they’re often aggressive toward strangers.

While it’s tempting to treat your Dachshund like a spoiled lap dog, routine training and socialization are crucial. Don’t underestimate the effectiveness of professional training if your Dachshund shows signs of aggression.

3. Chow Chow

Chow chow
Image: cr-pix, Pixabay

While the Chow Chow looks like a big, fluffy teddy bear, the breed is well-known for its aggressive tendencies. However, this behavior presents in very predictable ways.

The Chow Chow tends to show aggression toward strangers and other dogs if not socialized from a young age. At the same time, the breed also has a high prey drive which is often mistaken for even more aggression. With the right training protocol, though, it’s entirely possible to raise a calm and well-adjusted Chow Chow.

4. Doberman Pinscher

Doberman Pinscher
Image Credit: patstatic, pixabay

A well-trained Doberman Pinscher can make an excellent companion, but they are still one of the more aggressive breeds out there. Plus, even the calmest Doberman can strike fear with its intimidating size, speed, and strength.

Most Doberman Pinschers that display aggression actually do so out of fear. Because of this, it’s important to manage your dog’s anxiety and teach them to be confident around strangers and in new environments.

5. Dalmatian

Image Credit: Dalmatian by aljonushka, Pixabay

According to ATTS testing, the wholesome Dalmatian is actually at risk for aggressive behavior. Many experts believe this is because of the breed’s history as a guard dog, which required them to treat all strangers as threats.

While the breed’s popularity has dropped since the release of Disney’s 101 Dalmatians, they’re still one of the most recognizable dogs in the world. However, you shouldn’t bring home a Dalmatian just because you’re a fan of the iconic spots. Remember that these dogs require thorough training and socialization to live happy, safe lives.

6. Rottweiler

rottweiler standing
Image Credit: Ricantimages, Shutterstock

After the pit bull breeds, the Rottweiler probably has the worst reputation in popular culture. While it’s true that Rottweilers rank high on the list of aggressive breeds, most are well-adjusted, loving companion animals.

Since Rottweilers tend to struggle with being territorial, other dogs are their most common trigger. Also, since they have a higher prey drive, the breed isn’t the best option for households with cats or small dogs. With lots of socialization from puppyhood and the right environment, though, Rottweilers make great pets.

7. Jack Russell Terrier

Jack Russell Terrier
Image Credit: Alexas_Fotos, Pixabay

Now, let’s go back to the small breeds. While not many people would think of the Jack Russell Terrier as aggressive, the breed is known for being stubborn and having a strong prey drive despite its size.

First and foremost, the Jack Russell Terrier is high-energy and requires lots of exercise and stimulation. The breed is prone to biting if neglected or undersocialized. Although their bite is nothing compared to that of a larger breed, it’s extremely important to set your Jack Russell Terrier up for success with proper training.

8. German Shepherd

aggressive dog
Image Credit: christels, pixabay

Despite being one of the most popular family dogs of today, it shouldn’t come as a surprise that the German Shepherd ranks high on our list of most vicious dogs. After all, the breed is known for its work as a police and military dog, among other jobs.

Often, a German Shepherd’s aggressive side will come out when it feels its family is in danger. To prevent potential issues, it’s extremely important to provide proper socialization to your dog from a young age. If they know strangers are friends rather than foes, the risk of aggressive behavior will be significantly reduced.

9. American Pit Bull Terrier

red nose American pitbull terrier
Image Credit: KruBeer Photo, Shutterstock

If you’ve seen the stats about pit bull bites, then you might be surprised to see the American Pit Bull Terrier so far down on this list. But you need to keep something very important in mind.

While most sources report on pit bull aggression, the term “pit bull” actually encompasses several different breeds, including many mixed breed dogs. When you break this grouping into its individual breeds, temperament testing actually shows that the American Pit Bull Terrier and other bully breeds are far from the most aggressive dogs out there.

10. Siberian Husky

Siberian Husky standing outdoor
Image Credit: BARBARA808, Pixabay

Unlike many other dogs on this list, the Siberian Husky isn’t normally aggressive because it’s protective or anxious. Instead, this breed’s aggression is often a result of poor training and socialization.

Because Huskies are extremely headstrong, they’re a difficult challenge for even the most experienced dog owners. They also have a high prey drive, which can often be mistaken for pure aggression. In general, Siberian Huskies need a stern hand and enriching environment to thrive.

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Final Thoughts

If you see one of your favorite breeds on this list, don’t fret. While it’s true that these breeds show the highest rate of aggressive behavior, the likelihood of any one dog acting out is still extremely low. For example, the Doberman Pinscher is fourth on our list, but close to 80 percent of tested dogs still passed the ATTS testing with flying colors. With the right training, your favorite breed will make a great pet!

Featured Image Credit: Piotr Wawrzyniuk, Shutterstock

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