Some people prefer little lapdogs and others enjoy the company of a large slobbering powerhouse. Every dog breed is different. There are mellow lazy breeds as well as very active and most aggressive dog breeds. All future pet owners and puppy adopters are encouraged to be careful in their choice, especially when it's the first time.

Any dog can become aggressive under specific circumstance. Certain dog breeds simply have a shorter fuse or a higher prey drive. Some may think these dog breeds are more dangerous, but it's not the case; understanding aggression in dogs is crucial. Thousands of people own these dogs or use them as working dogs without any aggression issues.

It's important to know which breeds tend to be more aggressive so you can handle the challenges that these breeds of dogs might present. Think about the qualities that you need in a pet and stick to breeds that are likely to have those qualities. Choose a breed that will be easy for you to handle based on your experience level.

Science on Aggression of Different Dog Breeds

Many previous studies have looked into a variety of behavioral traits among different breeds and how genetics determine them. For example, they've investigated obsessive compulsive behaviors among breeds (1, 2), behaviors like reactivity, adaptability, affability and wariness (3), trainability and boldness (4, 5), sociability (6) and more.

Aggression in different breeds is also highly genetic (7). And in one of the most ambitious attempts, geneticists in a 2016 study have managed to map out canine fear and aggression across several hundred breeds using genomewide association.

Scientists found that amygdala and hypothalamus are the two main parts of a dog's brain responsible for their aggression, fear, anxiety and prey drive. Using several genotype datasets, they found a few primary fear and aggression related traits that differed among breeds:

  • stranger-oriented fear
  • stranger-directed aggression
  • dog-directed aggression
  • owner-directed aggression
  • dog rivalry

Aggressive Dog Breeds

It was also discovered that there are many different genetic factors affecting the dog's fear and aggression traits, and the brain is just one of them. It was found that a dog's size and body-weight has a direct correlation to aggression (8), with medium and small breeds being most aggressive (9); a dog owner's personality was a determining factor with some breeds but not others (10), and breeds that are carriers of chr18 chondrodysplasia mutations were also found to be more fear-aggressive (11).

Dataset among most aggressive dog breeds
© Zapata, et al. 2016

While there were a lot more factors that scientists paid attention to, in conclusion, it seems that breed-specific aggression can be classified into four main categories: (a) development and environmental-malleability (12, 13), (b) molecular, biochemical, imaging factors showing up under stress (14), and (c) a dog's physiological and mental states (15, 16), and (d) a breed's ability to mitigate negative effects (17, 18).

What the Average Person Typically Means When Talking About Aggressive Dog Breeds

Aggressive Dog Breeds

With the technical definition of aggressive dog breeds out of the way, how does the average person typically use the term? They typically look at behaviors such as:

  • Barking
  • Lunging
  • Snarling
  • Biting
  • Charging at people
  • Showing teeth
  • Snapping 
  • Performing other aggressive behaviors

Common Reasons for Aggressive Behavior in Dogs

It is also important to note that most aggressive dog breeds will not be continuously aggressive. Instead, they will be aggressive in specific situations, such as when they are feeling sick, possessive, protective, afraid, in pain, frustrated, or have social aggression.

Aggressive Dog Breeds

20 Most Aggressive Dog Breeds

Wolf Hybrid as the most aggressive dog breeds1. Wolf Hybrid

The Wolf Hybrid is the most common wolf-type dog breed. It's a cross between a dog and, more often than not, the grey wolf (although other wolves can also be accounted for). It goes without saying that this breed will be unpredictable due to their high prey drive.

You won’t be able to have any smaller pets, because the Wolf Hybrid will most likely hunt them, hurt them and maybe even try to eat them due to his high prey drive. This breed needs someone who is a very skilled handler and won’t allow the dog to dominate.

2. Cane Corso

Cane Corso as the most aggressive dog breedsCane Corso already has an appearance of an aggressive dog, and many experts will certainly label this breed to be that. Today, they're becoming popular as police dogs.

This breed is a descendant of the Canis Pugnax, a dog that was used during the times of Roman warfare many centuries ago. It goes without saying that the Cane Corso has a tendency to be rather aggressive if not handled and trained well by an expert trainer.

3. Bull Terrier

Bull Terrier as the most aggressive dog breedsThe Bull Terrier has been a loyal family companion for a long time, but they're also one for the most aggressive dog breeds on the planet, and probably the smallest of them too. They're not great for first time owners, but can be fantastic companions for more experienced handlers.

Bull Terriers have a tendency to think that they’re lapdogs, even though they are pound for pound just lean muscle. Without the proper training and understanding of this dog breed, a Bull Terrier has the tendency to become aggressive and difficult to handle.

4. Rhodesian Ridgeback

Rhodesian Ridgeback as the most aggressive dog breedsOriginally from Africa, the Rhodesian Ridgeback is a large dog that was used to keep lions away from stock and guard farms. They've evolved to be constantly aware and ready for a fight should there be a need for this dog's help to protect.

This dog breed is aloof towards people they don’t know and can be very sensitive. Using positive reinforcement is the only way forward with this type of dog, and you must consult with a professional trainer on how to handle this breed moving forward.

5. Dogo Argentino

Dogo Argentino as the most aggressive dog breeds

Dogo Argentino is a white, muscular dog breed from Argentina that has been banned from being owned in the UK as well as many other countries due to its aggression.

This dog was bred for big game hunting such as puma and boar. They are really beautiful canines, but tend to be a bit on the wild side for a family living in the suburbs. Dogo Argentino is a great and powerful hunting dog, but needs a handler with experience.

6. Boerboel

Boerboel is one of the most aggressive dogs

Boerboel dog breed originates from South Africa where it was bred to guard farms and livestock from lions and leopards. It was also used to track wounded animals and keep them safe until their owner arrived. The Boerboel is a very loyal and large dog.

They are extremely protective of their families and properties, which is what puts them on the list of the most aggressive dog breeds. This dog is still used on farms in South Africa today.

A farm lifestyle is the perfect environment for Boerboels, seeing as they work with the farmers and are very skilled in protecting the farms from unwanted intruders.

7. Basenji

Basenji as the most aggressive dog breeds

Sometimes it's difficult to believe how certain canines that look small and cute can be put on the list of most aggressive dogs, but it all comes down to breeding history and genes.

Originating from Central Africa, the Basenji is a sight hound. This means any movement from a small animal will put their hunting instinct into overdrive and they won't stop.

The Basenji is one of the least trainable dogs that there is. They are reserved and aloof towards strangers and tend to have only one master. If you think about adopting a Basenji dog, it's best you speak with an experience dog trainer who's dealt with them before.

8. Saint Bernard

Saint Bernard as the most aggressive dog breedsEven though they are known for their good deeds in movies and reality, are one of the best rescue dogs, Saint Bernards actually have high levels of aggression.

This large working and talented breed derives from the Swiss and Italian Alps. For centuries this breed was used for rescuing people caught in avalanches. Known as one of the best rescue breeds ever, these dogs are used for working and thrive when used for a purpose.

It's absolutely essential that a Saint Bernard is socialized and trained from puppyhood to prevent (to an extent) this dog from becoming one of the most aggressive dog breeds.

9. American Bulldog

American Bulldog as the most aggressive dog breedsThe American Bulldog is a very heavy set dog that is actually very friendly and loyal.

That said, American Bulldogs have a tendency to be overconfident and very stubborn, which makes them difficult to train and handle. They can be great house family dogs with the proper training, but without it they could be one of the most aggressive dog breeds.

10. Akita Inu

Akita Inu as the most aggressive dog breedsThe spitz breed from Japan is a gorgeous medium sized dog. There are two variations of this breed – one being the Akita Inu from Japan and the other the Akita from America.

Both of these dog breeds are strong and dominant types of animals with high prey drive. They are extremely affectionate towards their family, but standoffish and territorial when it comes to strangers, and will often be extremely aggressive.

11. Chow Chow

Chow Chow as the most aggressive dog breedsDistant and fiercely independent, The Chow Chow breed needs a lot of attention as well as proper and regular training. Socialization is extremely important for the Chow Chow, because they don’t like strangers and are very protective of their owners.

They are known as one of the most aggressive dog breeds, which means recorded bites for this breed are higher than many others. Chow Chows also require plenty of exercise or they can become unpredictable, aggressive and dangerous.

12. Doberman Pinscher

Doberman Pinscher as the most aggressive dog breedsDoberman Pinscher is a very loyal and alert breed is one of the best guard dogs around. They only attack when provoked, and are aggressive towards other dogs and strangers.

That said, Doberman experts who love this breed are well-aware of their tendency to be extremely aggressive. Because they are known as one of the most aggressive dog breeds, do not adopt a Doberman Pinscher unless you are an experienced owner.

13. Alaskan Malamute

Alaskan Malamute as the most aggressive dog breedsAnother wolf-like dog, Alaskan Malamute is related to the famous Siberian Husky dog breed but is much larger in size as well as personality. They are also much more aggressive than Huskies and most dog owners will have trouble with this breed.

Without daily exercise these dogs become bored and therefore destructive. Alaskan Malamutes are extremely difficult to train and are very unreliable watchdogs. With a high prey drive, they do not do well with most other small pets.

14. Rottweiler

Rottweiler as the most aggressive dog breedsThe Rottweiler is a strong dog that was bred for herding and guarding. To this day, they are ranked as one of the most scary dogs on the planet due to dog bite statistics.

This working breed can become very aggressive very quickly, particularly from neglect, abuse and irresponsible pet ownership. Socialization at an early age is important to make sure your Rottie gets on with other dogs, people and pets, but caution is also needed.

15. German Shepherd

German Shepherd as the most aggressive dog breedsThe German Shepherd Dog is a fearless, confident and extremely intelligent dog breed. They are the most commonly used canine in the military as well as the police force. This breed of dog is very trainable, which is why they’re mostly used as working dogs.

GSDs are very territorial and fiercely overprotective of their families. They need early socialization and someone who understands the German Shepherd needs well. Without the proper tools and dog training, they can become destructive and very aggressive.

16. Boxer

Boxer as the most aggressive dog breedsBoxers are headstrong and lean dogs who have very high energy, and they're often ranked as one of the most aggressive breeds for that particular reason. They were bred as hunting dogs and also used during World War 1 for guarding.

The Boxer is another protective breed and will thrive when trained and exercised properly. The bite of a boxer can cause serious injury, which is why they need ample exercise and something to keep them busy with all the time.

17. Great Dane

Great Dane as the most aggressive dog breedsOn the lower end of the spectrum in terms of dog aggression, Great Danes are generally known as gentle giants and they're even highly recommended as best apartment dogs.

But that's only when your Great Dane is trained properly. Without an understanding of these extra-large canines, they can become one of the most aggressive dog breeds. Often, the Great Dane is seen as dangerous due to their large size but they are unlikely to bite.

18. Bull Mastiff

Bull Mastiff is one of the most aggressive dogs

Bull Mastiff is a very large and strong breed that's extremely loyal to his family. This is yet another type of dog that needs an experienced handler who knows what they’re doing.

If not, your house will be run by a giant breed of dog who can cause havoc by just running through your kitchen. Socialization and training is very important when adopting a Bull Mastiff in order to avoid this canine turning into one of the most aggressive dogs.

19. Siberian Husky

Siberian Husky as the most aggressive dog breedsSiberian Huskies are one of the most popular dog breeds on the planet and many view them as gentle pets. But experts say that they're one of the most aggressive dogs.

Huskies closely resemble the Alaskan Malamute discussed above, but they are a little bit smaller in stature and calmer. They require a ton of exercise and stimulation.

A temperament of a Husky is very close to that of the wolf, which can make them unpredictable. Stubborn and dominant are two other characteristics this breed is known for. This is a very difficult dog to control and keep from getting bored.

20. Pit Bulls

Pit Bulls are the most aggressive dog breedsAs the dog stereotypes go, no list of most aggressive dog breeds can go without Pit Bulls.

Pitbull is a name for a large variety of dogs, all of whom are closely related but are not the same dog breed. The American Pit Bull Terrier, American Staffordshire Terrier, the Bull Terrier and the Staffordshire Pit Bull Terrier all fall into this category.

Originally, the Pitbull was bred to bait and pull down bulls and bears. This group of dogs is the breed most often used for dog fighting to this day, which adds to the stigma of them being one of the most aggressive dogs by nature.

Honorable Mentions

In addition to the above most aggressive dog breeds, there are some other breeds that are occasionally part of similar lists. These include: 

  • Australian Shepherd
  • Chihuahuas
  • Collie
  • Dalmatians
  • Jack Russel Terriers
  • Kangal
  • Labrador Retriever
  • Perro de Presa Canario (Canary Mastiff)
  • Tosa Inu

FAQs About Aggressive Dog Breeds

We’ve gathered the most common questions about aggressive dog breeds to help you get a clearer image of which breeds are most likely to be aggressive or dangerous. 

What Is the Most Aggressive Dog?

The Wolf Hybrid is the most aggressive dog breed, followed by the Cane Corso. 

What Is the Most Dangerous Dog?

According to the Humane Society, the American Veterinary Association, and the CDC, the most dangerous dogs are the Pit Bull Terrier, Rottweiler, and German shepherd. 

What Is Considered the Most Aggressive Dog?

While the Wolf Hybrid is the most aggressive dog, other dog breeds commonly labeled as the most aggressive include the Cane Corso, Rottweiler, Doberman Pinscher, Chow Chow, Siberian Husky, Pit Bull Terrier, and other breeds mentioned above. 

Which Dog Is Very Aggressive?

Pit Bulls, Dobermans, Rottweilers, Wolf hybrids, Akitas, and German shepherds are all commonly considered aggressive. Chihuahuas are also notably aggressive, but they rarely cause injury due to their size. 

Which Dog Can Kill a Lion?

The Rhodesian Ridgeback, which is from Southern Africa, can reportedly kill a lion. 

Which Dog Has Killed the Most Humans?

Pit Bulls have killed the most people in the United States. As of 2018, research indicated they accounted for 66% of deaths but 6.5% of the dog population in the country. 

Remember That Training Addresses Aggression

While all of the above are typically considered aggressive dog breeds, it is important to remember that a significant amount of canine behavior comes down to behavior. With the right training, many of the breeds on this list can be non-aggressive and peaceful. Many on the list will also not be aggressive to their family members but show aggression to strangers. Training is the key in most cases.

READ NEXT: How To Deal with Dog Aggression Without Training Collars

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20 Most Aggressive Dog Breeds