When you spend a lot of your time in reactive dog forums, it doesn't take long before you hear either of these two questions:

"What are the most aggressive dog breeds?"


"What are the least aggressive dog breeds?"

As a dog owner, it's natural to have concerns about your furry friend's behaviour and temperament, especially regarding reactivity. If you Google the most reactive dog breeds, you will find countless articles listing specific breeds as "reactive" and often under the label of "most aggressive dog breeds" or "aggressive dogs to avoid". The truth is that any dog, regardless of breed, has the potential to exhibit reactive behaviour or, worse still, become an aggressive dog.

This article aims to shed light on the reality of reactive dog breeds and examine the factors contributing to dogs' reactivity. Whether you already own a reactive dog or are considering bringing a new pup into your home, this article will provide valuable insights and guidance.

The Complexity of Reactivity

Reactivity in dogs refers to an exaggerated response to certain stimuli, such as other dogs, unfamiliar people, another animal or loud noises. It can manifest as barking, lunging, growling, or even aggressive behaviour. While some breeds may be more prone to certain behavioural traits due to their genetic predispositions or historical roles, it is essential to understand that reactivity is not exclusive to specific breeds and not dependent upon breed alone.

Is a Reactive Dog an Aggressive Dog?

It's crucial to recognise the difference between dog reactivity and dog aggression. Despite seeming similar, reactivity and aggression are distinct behaviours stemming from different emotional states. Reactive dogs often exhibit behaviours such as barking or lunging out of fear, anxiety, or over-excitement. It’s their way of communicating discomfort or that they feel threatened and is often misinterpreted as aggressive behaviour.

On the other hand, dog aggression generally involves more serious behaviours like biting or snapping with the intent to harm. It's often driven by a desire to assert dominance or control. Understanding the difference helps us respond more appropriately to our dogs' behaviours, ensuring we're meeting their emotional needs effectively.

Genetic Factors vs. Individual Variation

While genetics play a role in shaping a dog's temperament and behaviour tendencies, it is crucial to remember that, like other animals, every dog is an individual. We cannot simply label particular dog breeds as reactive dog breeds or aggressive dog breeds. Even within a particular dog breed known for its calmness or sociability, there can be significant variations in individual dogs' personalities and reactions.

For example, Golden Retrievers are generally considered friendly, easygoing and great with other dogs. However, there may be instances where a Golden Retriever will exhibit a reactive response due to any number of factors, such as lack of socialisation, another dog's behaviour, lack of dog training as a pup or previous traumatic experiences.

The Role of Early Socialisation and Training

Early socialisation and obedience training are vital for fostering well-rounded and confident dogs. Properly exposing puppies to various stimuli at an early age helps them develop positive associations with different environments and situations. This exposure aids in reducing the likelihood of dog reactivity later in life.

Regardless of dog breed, inadequate socialisation and dog training can lead to fear, anxiety, and reactive behaviours. Responsible dog owners understand the importance of investing time and effort into proper socialisation and training for their four-legged companions.

Exploring Breed Nuances

While it is essential to acknowledge that reactivity is not exclusive to specific breeds, we cannot ignore that some breeds have garnered a reputation for being more prone to reactive behaviour. It's crucial to approach these breed stereotypes with an open mind and remember that individual variation plays a significant role.

Breeds Often Associated with Reactivity

  1. German Shepherds: German Shepherds are known for their versatility and being intelligent dogs. However, due to their protective instincts and intense loyalty, some individual dogs may display reactive behaviour if not adequately socialised or trained from an early age.
  2. Border Collies: Known for their exceptional intelligence and agility, the Border Collie is a dog breed that thrives on tasks and mental stimulation. As herding dogs, their 'eye' and focus can sometimes translate into reactive behaviour, especially if they aren't given a job to do or if their environment lacks mental and physical stimulation.
  3. Australian Shepherds: Similar to Border Collies, the Australian Shepherd is often associated with reactivity due to its natural instincts as a herding dog. This intelligent breed has an intense focus and control over herds, but this can sometimes be misunderstood as reactive behaviour. Adequate training, exercise, and mental stimulation are crucial for channelling their energy. As with all other dog breeds, each Australian Shepherd is unique and should not be judged based on just breed alone.
  4. Pit Bulls: Pit Bulls are often unfairly stereotyped due to misconceptions surrounding their temperament. While some individuals within this breed may exhibit reactive tendencies, responsible ownership, proper training, and positive socialisation can help them become well-adjusted and friendly companions.
  5. Australian Cattle Dog: Another intelligent breed, the Australian Cattle Dog is renowned for its hardiness and intelligence. They can be headstrong at times and may exhibit reactive behaviours if not given proper dog training and early socialisation. However, as working dogs, with consistent training and a stimulating environment, reactivity can be addressed early.
  6. Chihuahuas: Despite their small size, Chihuahuas can be prone to reactive behaviours such as excessive barking or aggression towards unfamiliar people or dogs. Without early socialisation and consistent training they can often become anxious and territorial.

Remember that these examples are common stereotypes and by no means definitive proof that every dog of these breeds will become reactive or aggressive dogs. It merely highlights the need for responsible ownership practices regardless of the breed you choose.

Other Factors Influencing Reactivity

It's important to note that various factors beyond genetics influence a dog's reactivity or breed stereotypes. Environmental factors such as upbringing, past experiences or trauma,  can all contribute significantly to a dog's reactivity levels.

Understanding these underlying factors helps shift our focus from blaming specific breeds towards promoting responsible ownership practices that prioritise socialisation, training, and positive reinforcement.

Nurturing a Well-Balanced Dog

Regardless of your dog's breed or background, there are several steps you can take to help nurture a well-balanced and non-reactive companion:

  1. Early Socialisation: Introduce your puppy to various environments, people, and animals positively during those critical early months (typically between 3 to 14 weeks). This helps them develop confidence and reduces the likelihood of dog reactivity later in life.
  2. Positive Reinforcement Training: Utilise rewards-based training methods to teach your dog appropriate behaviours and reinforce positive responses. Avoid punitive techniques that can exacerbate fear or anxiety.
  3. Consistent Experiences: Provide consistent experiences for your dog by exposing them to different situations regularly. This includes walks in diverse environments, meeting new people and dogs (other breeds) and experiencing various stimuli such as noises or vehicles.
  4. Seek Professional Help: If you are already dealing with a reactive dog or need guidance on preventing reactivity in your future companion, consider consulting with a professional dog trainer or behaviourist who specialises in positive reinforcement techniques.
  5. Patience and Understanding: Nurturing a well-balanced dog takes time, patience, and understanding. Each dog is unique and may require individual approaches to address their needs.


In conclusion, while certain breeds may have gained reputations for being prone to reactive behaviours or even regarded as being aggressive dog breeds, it's essential to understand that any dog can exhibit reactivity regardless of breed.

Rather than focusing solely on breed stereotypes, responsible ownership practices such as early socialisation, positive reinforcement training, consistency in experiences, and seeking professional help when needed play vital roles in fostering well-rounded dogs.

By prioritising these factors and treating each dog as an individual with unique needs, we can break free from the constraints of breed stereotypes and promote a more informed understanding of reactivity in dogs. Collectively, we can help ensure all dogs receive the love, care, and support they deserve to be the best version of themselves.



Q: Can small dogs be reactive too?

A: Hell yes! Reactivity is not limited to specific breeds or sizes of dogs. Any dog can exhibit reactive behaviours.

Q: Should I use scold or punish my dog to address her reactivity?

A: Hell no! Research has shown that positive reinforcement techniques are the most effective and humane way to address reactivity in dogs. Punishment-based methods can worsen reactive behaviours and damage the trust between you and your dog. It is best to seek guidance from a professional specialising in positive reinforcement training techniques.

Q: Can I prevent my dog from becoming reactive?

A: While genetics may play a role in a dog's temperament, early socialisation, consistent positive experiences, and positive reinforcement training can significantly reduce the likelihood of reactivity developing. However, any dog can exhibit reactive behaviours, so it's essential to continue practising responsible ownership even with a well-socialised dog. 

Q: Is reactivity considered aggressive behaviour?

A: Reactivity is often misunderstood and mislabeled as aggression. Reactivity is typically a fear-based response to certain stimuli, such as other dogs or people, whereas aggression is intentional and directed towards causing harm. It's important to seek professional guidance to assess and address your dog's behaviour properly. 

Q: Can reactivity be cured?

A: Reactivity can be managed and improved through proper training, but it may never be fully "cured." As with any behaviour, it's important to understand and work with your dog's individual personality and needs. With consistency and patience, reactivity can be significantly reduced, allowing for a happier and more confident dog. So keep hope - there is always room for improvement! Please remember to continue using positive reinforcement techniques and seek help from a professional trainer if you need it. Your pupper will thank you for it!