Why “It’s the Breed” Is Not Enough to Explain Dog Behaviour Problems

Many people want a simple explanation for a dog’s behaviour problem. A Border Collie chases cars because it is a Border Collie. A German Shepherd barks at strangers because it is protective. A Labrador steals food because Labradors love food. A mixed-breed dog is reactive because someone thinks they can see a certain breed in its face. These explanations are tempting because they feel clear, but they are incomplete. Breed and genetics matter, but breed alone is never enough to explain an individual dog’s behaviour.

A dog is not only a breed label. A dog is a mammal, a canine, a domestic dog, a member of a breed or breed mix, and, most importantly, an individual animal with its own genetics, development, learning history, health, environment, and daily routine. At the broadest level, dogs share mammalian systems involved in fear, reward, attachment, arousal, stress, pain, motivation, and learning. As canines, they have inherited capacities for chasing, hunting, social interaction, territorial behaviour, and communication. As domestic dogs, they have also been shaped to live closely with people, read human cues, and form social relationships in environments controlled largely by humans.

Breed adds another layer. Selective breeding has shaped tendencies such as herding, retrieving, guarding, tracking, sound sensitivity, responsiveness to people, and working motivation. Those tendencies can affect risk. They can help explain why certain triggers are powerful for certain dogs. However, they do not diagnose the dog in front of you. Two dogs from the same breed can have completely different thresholds, fears, motivations, medical problems, and learning histories. When someone says, “It’s the breed,” the more accurate answer is, “Maybe, partly, but that is not a diagnosis.”

Research supports this distinction. In 2019, MacLean et al. studied behavioural data from more than 14,000 dogs across 101 breeds. They found that breeds differed, on average, across traits such as trainability, chasing, fear, aggression, attachment-related behaviour, and energy level. They also found genetic associations linked to some breed-level behavioural differences. This matters because it shows that breed is relevant. The key phrase, however, is “on average.” The study describes population-level patterns. It does not show that every dog in a breed behaves the same way, and it does not make breed a reliable stand-alone explanation for an individual behaviour problem.

In 2022, Morrill et al. published a major study in Science examining dog genetics and behaviour. They found that breed explained only about 9 percent of behavioural variation in individual dogs. That number is clinically important. Breed is not meaningless, but it is a weak predictor for the individual dog standing in front of the owner, trainer, veterinarian, or behaviour professional. Breed background can shift probabilities, but most of an individual dog’s behaviour reflects a combination of genetics, development, learning, health, and environment.

Consider a Border Collie that chases cars, bicycles, or running children. Movement sensitivity may fit the breed background. The dog may be more visually triggered by motion than many other dogs. That information is useful, but it is not the whole case. The problem still depends on arousal, anxiety, frustration, repeated rehearsal, access to safe outlets, reinforcement history, leash handling, sleep, exercise, and the environment. If the dog lunges at traffic every day and the behaviour is repeatedly practised, the pattern becomes stronger. The breed gives a clue. It does not provide the full explanation.

Now consider a German Shepherd that barks, growls, or lunges at strangers. Owners often describe this as protection. That label can be misleading and sometimes dangerous. The behaviour may reflect fear, poor early social exposure, repeated exposure beyond the dog’s threshold, frustration, pain, or learning. If barking and lunging make people move away, the behaviour may be repeated because it works. Calling it “the breed” or “protection” can hide the real problem and may even make owners proud of behaviour that is unsafe and distressing for the dog.

A Labrador that steals food, jumps on visitors, or grabs items provides another example. Food motivation may be relevant, but it is not the full case. Feeding routines, reinforcement, impulse control, frustration tolerance, household management, owner responses, and health factors that affect appetite or arousal still matter. A dog that receives attention, food, chasing games, or conflict after stealing items may keep doing it because the behaviour has been reinforced. Again, breed may explain part of the tendency. It does not explain the individual problem.

This is where many people confuse correlation with destiny. A breed tendency means that a behaviour may be more likely in a given breed. It does not mean that the behaviour is guaranteed, fixed, untreatable, or irrelevant to welfare. That distinction matters because behaviour problems are not just personality quirks. They involve emotion, learning, physiology, environment, safety, and health. When owners believe behaviour is fixed by breed, help is often delayed. Problems are tolerated too long. Punishment may be used because the dog is labelled stubborn, dominant, protective, or difficult. In some cases, dogs are given up when they could have improved with proper assessment and a realistic plan.

Mixed-breed dogs make breed-based thinking even weaker. People often guess breed from appearance, but visual breed identification is unreliable. In 2018, Gunter et al. compared shelter-breed labels with DNA-based breed-heritage testing and found poor agreement between visual labels and genetic results. In 2009, Voith et al. also found that adoption agencies identified at least one breed detected by DNA testing in only 7 of 20 mixed-breed dogs. This matters because labels change interpretation. A dog called a shepherd mix may be treated as protective when the issue is fear. A dog called a terrier mix may be dismissed as stubborn when the issue is confusion, poor reinforcement, or an unsuitable environment.

Even physical structure can correlate with behaviour. In 2013, McGreevy et al. used C-BARQ data, a large owner-completed behavioural questionnaire, and found associations between behaviour, height, body weight, and skull shape across breeds. That is useful because selective breeding for appearance and function can affect behaviour. However, correlation is not certainty. Skull shape, body type, breed category, and visual labels cannot diagnose a dog’s learning history, emotional state, health status, pain level, household routine, or daily pressure. The individual assessment still matters most.

The better question is not only, “What breed is this dog?” The better question is, “Why is this individual dog behaving this way?” That question forces a broader assessment. It includes genetics, early development, social exposure, health, pain, sleep, fear, frustration, reinforcement, owner behaviour, household structure, training history, environmental pressure, and recovery time. These factors are not secondary. They govern behaviour alongside genetics. That is why two dogs from the same breed, and even from the same line, can behave very differently. One may be confident, resilient, and quick to recover. Another may be fearful, easily overwhelmed, slow to settle, and in need of a much more structured treatment plan.

Working lines and show lines add another layer. Two dogs with the same breed name may have been selected for different traits for generations. A dog bred for field work, herding work, or protection work may not have the same behavioural profile as a dog bred mainly for appearance or companionship. Line can provide more information than breed alone, but even line is not enough. The individual dog still matters more.

The correct use of breed is practical, not fatalistic. Breed information can support prevention, early socialization, activity choices, trigger awareness, management, risk assessment, training plans, and realistic expectations. It may tell us where to look first and why certain triggers are powerful. However, it should never be used to say that nothing can be done. Behaviour comes from the interaction between genetics and experience. That includes canine genetics, domestic dog genetics, breed genetics, individual genetics, development, learning, health, and daily life.

Breed matters, but it does not explain the whole dog. It can influence risk, tendency, and likely challenges. It can help guide assessment. It can help owners set realistic expectations. But it does not replace assessment of the individual dog, and it does not decide the outcome. When a dog is aggressive, fearful, reactive, compulsive, noise-sensitive, unable to settle, or getting worse, “it’s the breed” is not enough. The dog needs a formulation based on the individual, not a stereotype.

References

Gunter, L. M., Barber, R. T., and Wynne, C. D. L. 2018. A canine identity crisis: Genetic breed heritage testing of shelter dogs. PLOS ONE, 13(8), e0202633. https://doi.org/10.1371/journal.pone.0202633

MacLean, E. L., Snyder-Mackler, N., vonHoldt, B. M., and Serpell, J. A. 2019. Highly heritable and functionally relevant breed differences in dog behaviour. Proceedings of the Royal Society B, 286, 20190716. https://doi.org/10.1098/rspb.2019.0716

McGreevy, P. D., Georgevsky, D., Carrasco, J., Valenzuela, M., Duffy, D. L., and Serpell, J. A. 2013. Dog behavior co-varies with height, bodyweight and skull shape. PLOS ONE, 8(12), e80529. https://doi.org/10.1371/journal.pone.0080529

Morrill, K., Hekman, J., Li, X., McClure, J., Logan, B., Goodman, L., et al. 2022. Ancestry-inclusive dog genomics challenges popular breed stereotypes. Science, 376(6592), eabk0639. https://doi.org/10.1126/science.abk0639

Voith, V. L., Ingram, E., Mitsouras, K., and Irizarry, K. 2009. Comparison of adoption agency breed identification and DNA breed identification of dogs. Journal of Applied Animal Welfare Science, 12(3), 253–262. https://doi.org/10.1080/10888700902956151