Do Aggressive Dog Breeds Exist?

Written by: Macey Wolfer

There’s a lot of debate about the existence of aggressive dog breeds vs behavior that stems from the environment. Before I jump into it, I want to remind my readers that this is not professional or medical advice. If you’re concerned about a potentially aggressive dog situation, it’s a good idea to seek professional help, especially if there are real safety concerns. 

So, do aggressive dog breeds exist? It’s a complicated question requiring us to consider breed tendencies as well as environmental factors. Breed can lead to behavioral predispositions, but training and socializing play a huge role in aggression outcomes, too. 

What the science says about aggressive dog breeds

A study published in 2025 by the Department of Veterinary Sciences at the University of Turin looked at the origins of aggressive dog behavior to see if it’s more influenced by genetics or environment. The authors analyzed 19 different studies across the last two decades to see how aggression was measured, the genetics involved, and what role factors like age, gender, and environment play into the equation. 

The authors concluded that aggression stems from multiple factors. It is influenced by genes, but it’s not caused by a single source. But the authors also noted that the studies they examined were small and unclear about their aggression measurements, making it difficult to come to a clear understanding. To conclude, the authors stated that more research is needed to better understand aggression across breeds. 

A 2022 study published in Science examined the genes of more than 2,000 dogs in tandem with 200,000 survey answers from dog owners. They found that breed accounted for just about 9% of behavioral variation in individual dogs, with zero traits unique to a single dog breed.  

The researchers suggested that much of the variations between dogs comes down to individual experiences, training, and other environmental factors. 

That’s not to say there weren’t clear differences between breed-specific behaviors, but the researchers noted that the variations were largely related to functional behaviors. Bloodhounds and beagles are much more likely to howl while herding breeds tend to be more easily trained and playful with toys. 

Why are there lists of aggressive dog breeds, then?

Some people own dog breeds that are considered aggressive, barring them from living in certain apartment complexes or neighborhoods. But given the information the above studies provide, how can HOAs and apartment owners determine what is considered an aggressive breed?

It’s true that some dog breeds can have statistically different behavioral predispositions that can lead to aggressive behavior. In a 2008 study of breed differences in canine aggression, researchers found that eight breeds ranked similarly for aggression towards strangers, dogs, and owners. These eight breeds included Dachshunds, English Spring Spaniels, Golden Retrievers, Labrador Retrievers, Poodles, Rottweilers, Shetland Sheepdogs, and Siberian Huskies. 

Breeds that showed the greatest percentage of serious aggression toward humans (bites and attempted bites) were Dachshunds, Chihuahuas, and Jack Russell Terriers. Akitas, Jack Russell Terriers, and Pit Bull Terriers tended to display the most aggression toward unfamiliar dogs. 

All of this is to say, the list of aggressive dog breeds often include bigger dogs like Rottweilers, Pit Bulls, German Shepherds, and Akitas. But the science doesn’t always back these breeds up as inherently aggressive. 

Places with breed restrictions are often viewing things through an insurance point of view. They see Dobermans, Rottweilers, and Pit Bulls as high risk and don’t want to deal with the perceived liability, even if the data doesn’t back it up. 

Aggression is complex and greatly influenced by environment, training, socialization, health, and other factors. 

What’s the difference between an aggressive and reactive dog?

Reactive dogs and aggressive dogs can look similar at first. You might see barking, growling, lunging, and other sometimes scary behavior. But the key differentiator is the motivation and intent behind the behavior.

Aggression is behavior that aims to threaten, harm, or control other dogs or people. Reactivity is an overreaction to a trigger. 

But if a dog’s reactivity is poorly managed and they face repeated contact with their trigger, they can begin to display aggressive behavior. It’s why it’s so important to work on desensitizing your reactive dog.

If you’re dealing with dog behavior that feels like it’s heading toward aggression, it may be time to bring in a professional if you’ve exhausted your at-home training work. Know that most reactive dogs can get better, but you will likely need to adjust your expectations and exercise a lot of patience. 

Working on your dog’s reactivity? Don’t Worry, He’s Friendly helps reactive dogs in urban spaces thrive.  Check out our other articles to learn more dog reactivity tips. 

About the author:

Macey is a freelance writer from Seattle. She wants to see more confident dogs and owners with a lower rate of shelter surrenders.

This content is for educational purposes only and is not a substitute for professional veterinary, behavioral, or training advice.