20 Dog Breeds That Are Prone To Aggression – What You Should Know Before Bringing Them Home
Before we begin, it's important to emphasize that no dog breed is inherently "bad." Every breed listed here can grow into a happy, healthy, and well-balanced family pet with the right care.
As the saying goes, “There are no bad dogs, only bad owners.” Proper training and early socialization with both people and other animals are key to helping dogs thrive. However, for some breeds, this early groundwork is especially important, as their strong instincts may present more challenges if not thoughtfully managed.
Coton De Tulear
The Coton De Tulear may not look intimidating, but it does little to dispel the notion that small dogs can sometimes be more aggressive than larger ones.
Although it's not considered one of the most dangerous or aggressive breeds overall, a 2021 study published in Scientific Reports found that it ranks fairly high in terms of aggressive tendencies—landing it among the top ten breeds most prone to such behavior, according to the researchers.
Bullmastiff
Similar to Rottweilers, Bullmastiffs are not typically a threat to their own families. In fact, they're valued for their loyalty and fearless instinct to protect the people they live with.
That said, this protective nature underscores the importance of proper training and early socialization. Without it, a Bullmastiff might mistakenly see an innocent person as a threat—potentially leading to serious consequences. According to Herbert Trial Law, Bullmastiffs were involved in 3.2% of fatal dog attacks during a 13-year study period.
Doberman Pinscher
Doberman Pinschers have long carried a fierce reputation, partly due to the power and speed their lean, muscular frames can unleash when they feel threatened. That intensity has made them a popular and dependable choice for guard dog roles.
Given that the breed was developed for protection work—the term "pinscher" even implies a tendency to bite—it's not shocking that they’re often labeled as aggressive. However, that image may be somewhat exaggerated. According to Herbert Trial Law, Dobermans were linked to six fatalities over a 13-year period. While any loss is serious, those six incidents account for just over 1% of the total cases in the study.
Wheaten Terrier
Terriers are typically recognized for their determined and stubborn personalities. While some breeds like the Cesky Terrier are generally more easygoing, all terriers share a distinctive streak of independence.
This characteristic is especially evident in the Wheaten Terrier. A 2021 study published in Scientific Reports placed this breed among the top ten most likely to exhibit aggressive behavior. Although their aggression may not result in serious harm, it remains an important consideration for prospective owners.
Rough Collie
At first, this might seem shocking. Collies are widely known as reliable family dogs—intelligent, affectionate, and brave enough to protect their family's most vulnerable members. While all of this is true, it also highlights just how crucial training and socialization are.
After all, protection means recognizing and responding to real threats. If a Collie has trouble telling friends from foes, that can lead to serious issues. In fact, a 2021 study published in Scientific Reports, analyzing behavior data from 13,715 dogs, found that Rough Collies had the highest likelihood of exhibiting aggressive behavior.
Rottweiler
Though Rottweilers often carry a tough reputation, the reality of their aggressive behavior is more complex than the idea that they'll attack anyone, anytime, and for no reason. Still, Herbert Trial Law discovered that research spanning 13 years of fatal dog attacks showed that Rottweilers were responsible for 10% of those incidents.
While many Rottweilers are deeply affectionate and highly protective of their families, they sometimes struggle to understand that they don’t need to be on guard against familiar visitors.
Siberian Husky
While Siberian Huskies are often affectionate dogs that simply require plenty of exercise, their powerful survival instincts can sometimes backfire if those needs aren't fulfilled. This can happen even in dogs without any prior aggressive behavior.
Herbert Trial Law reports that Siberian Huskies accounted for 3% of fatal dog attacks during the 13-year study period. Despite their loving nature, they deserve careful handling and understanding.
Akita
While Herbert Trial Law pointed out that Akitas weren't among the top breeds involved in fatal dog attacks, the firm still highlighted convincing evidence that this breed can become aggressive quickly. Known for their strong protective nature, Akitas also tend to be stubborn and may have conflicts with other dogs, making caution important when around them.
Referring to a 32-year study by Animals 24-7, Herbert Trial Law noted that Akitas rank as the third most likely breed to bite without provocation. This reputation has led some states to enact laws restricting ownership of Akitas.
American Bulldog
While British and French Bulldogs are famous for their affectionate nature (as well as the health issues linked to generations of selective breeding), the American Bulldog usually has a different reputation. They're often seen as strong, hardworking dogs—but that strength can sometimes be a double-edged sword.
According to Herbert Trial Law, fatal attacks involving American Bulldogs have been less common than with some other breeds, yet they still accounted for 3.5% of fatal dog attacks during the 13-year study period.
Chinese Crested
When a dog is small, charming, and show-quality—like the Chinese Crested pictured here—it's easy to want one right away. While it’s not fair to say owners will regret the choice, many do wish they had been better prepared.
This breed can display aggressive behaviors if not properly trained. In fact, a 2021 study published in Scientific Reports found that Chinese Cresteds have aggression levels comparable to breeds like German Shepherds, Lagottos, and Spanish Water Dogs.
Lagotto
The Lagotto is a perfect example of how a fluffy, cute appearance doesn't always guarantee a friendly nature. While they can be very loving with their families and other dogs, they possess more strength than they might seem to.
It’s common for a dog’s physical power to be linked with a tendency toward aggression, and the Lagotto fits this pattern. A 2021 study published in Scientific Reports found that this breed ranks high in the likelihood of aggressive behavior, placing it alongside breeds like German Shepherds and Spanish Water Dogs.
Boxer
Similar to Bullmastiffs and Rottweilers, Boxers are affectionate family dogs that can make young children feel wonderfully safe. However, like these other breeds, early training and socialization play a crucial role in shaping how Boxers behave around others.
According to Herbert Trial Law, Boxers accounted for about 1% of fatal dog attacks during a 13-year study, but there are many more recorded cases of non-fatal bites. Their muscular build and protective instincts are strong, which can sometimes lead to issues when their guarding becomes overly intense.
Cairn Terrier
While several dog breeds featured in the 2021 Scientific Reports study rank high for the likelihood of aggressive behavior, a few fall closer to the middle ground between aggression and calmness.
Cairn Terriers, for example, aren't the most aggressive dogs, but it would be misleading to describe them as completely relaxed either. Compared to other terriers like the Jack Russell, American Staffordshire, and Cesky Terriers, which are known for being more easygoing, Cairn Terriers tend to be more spirited.
Miniature Poodle
The case of the Miniature Poodle illustrates why the difference between a potentially dangerous dog breed and an aggressive dog breed matters. Although a Saint Bernard is physically strong enough to cause some serious damage if it wanted to, that sort of behavior would be incredibly atypical for the breed.
On the flip side, a miniature poodle isn't likely to do life-changing damage when it gets aggressive, but that won't necessarily stop that aggression from becoming an issue. Since the 2021 study in Scientific Reports considered the Miniature Poodle a breed with one of the highest probabilities of aggressive behavior they studied, early training is important to a stress-free life with one.
Pembroke Welsh Corgi
Considering how important they are to the British Royal Family and how happy they always look, it's fair to say that Pembroke Welsh Corgis are hardly the first dog anybody thinks of when aggressive breeds come to mind. In fairness to them, that's partially because they aren't considered the most aggressive breed out there.
However, that doesn't suddenly mean they're easygoing. According to the 2021 study in Scientific Reports, this breed is on the higher end in terms of probability for aggressive behavior. There's just a great deal of variation in how they behave depending on their level of training.
Miniature Schnauzer
Small dogs are often thought to be more aggressive than larger breeds, partly because they can display these behaviors without the same level of danger if things go wrong. While the Miniature Schnauzer is a lovable companion, especially with kids, it certainly fits this stereotype.
The 2021 study published in Scientific Reports found that the Miniature Schnauzer ranked third in terms of likelihood for aggression. While this is more likely to lead to frustration than serious harm, it's still something to keep in mind.
German Shepherd
Considering how often German shepherds are employed as police dogs and military combatants, it's perhaps not the most surprising revelation to learn how aggressive they can be. With the right training, those aggressive tendencies can be channelled into constructive purposes.
However, there doesn't seem to be any denying them. The 2021 study in Scientific Reports put German shepherds in the top five of breeds considered the most likely to show aggressive tendencies.
Spanish Water Dog
Spanish Water Dogs are shaggy, fluffy, and very cute, but looks can be deceiving if they haven't been appropriately socialized. As it turns out, this dog can get surprisingly aggressive when its most problematic traits are left to fester.
That's why the 2021 study in Scientific Reports put them in the top five for probability of aggression. In some ways, the Spanish Water Dog can be even more aggressive than the German Shepherd despite their respective reputations.
Mittelspitz
Also known as a German Spitz Mittel, this dog is a specific variant of the wider Spitz umbrella, which often features breeds that appear in larger sizes. As the size changes, so do the common personality traits, as these larger Spitzes are often considered pretty docile.
The same cannot necessarily be said for the Mittelspitz, though. According to the 2021 study in Scientific Reports, this breed is in the top ten for probability of aggressive behavior. Although they don't tend to be as aggressive as German Shepherds or Chinese Crested dogs, they're still on the high end.
Border Collie
Although that's not the reason for its name, the Border Collie is appropriately on the borderline between laid-back and aggressive dogs, as the 2021 study in Scientific Reports ranked them similarly to Cairn Terriers. Much like Rough Collies, this dog can be one of the best breeds a family could want with proper training and socialization.
However, it can share the Rough Collie's tendency of being overprotective and too quick to consider visitors intruders if that training doesn't occur. While the research shows that this is true to a lesser extent than the Rough Collie, it's still wise not to neglect a proper regimen with Border Collies.
