What Neuroscience Tells Us About Stress in Dogs

Stress in dogs is often misunderstood, minimised, or mislabelled as "disobedience" or bad behaviour. Neuroscience, however, gives us a far clearer and more compassionate picture. When we understand what happens inside a dog's brain and nervous system during stress, it becomes evident that stress can substantially alter the behavioural options available to a dog, making flexible decision-making and learning more difficult. Behaviour under stress is, in large part, a biological response to perceived safety or threat.

At the centre of stress responses is the dog's autonomic nervous system, which regulates survival functions. When a dog perceives danger, whether that danger is real or simply felt, the nervous system mobilises a defensive response, commonly described as fight, flight or freeze. Heart rate increases, digestion slows, muscles tense, and stress hormones flood the body (Sapolsky, 2004). Research in dogs has found that aversive stimuli produce measurable rises in salivary cortisol and heart rate alongside changes in posture and behaviour (Beerda et al., 1998). From a neurological perspective, this state prioritises survival over learning, decision-making, or social engagement.

Crucially, stress does not require overt fear or aggression to be present. The brain's threat systems respond to perceived threat, not objective reality (LeDoux, 1996). A dog may find social pressure, restraint, unpredictable handling, loud environments, or even repeated training demands stressful, despite appearing calm on the surface. In many cases, dogs enter a state of behavioural inhibition rather than relaxation. Research in dogs subjected to social and spatial restriction found reduced activity and lowered posture accompanied by elevated cortisol, indicating that a quiet, inhibited dog can be a highly stressed one (Beerda et al., 1999a; Beerda et al., 1999b; Beerda et al., 2000). This is often mistaken for good behaviour, when in fact the nervous system is overwhelmed.

Chronic stress is particularly damaging. Across mammalian research, prolonged exposure to stress mediators such as cortisol can affect brain systems involved in cognition, memory and emotional regulation, including the hippocampus and prefrontal cortex (McEwen and Sapolsky, 1995; McEwen, 1998). Dogs experiencing long-term stress may show increased reactivity, reduced resilience, and impaired learning. In dogs kept under chronic restriction, sustained hormonal changes and altered immune responses have also been recorded (Beerda et al., 1999b), and in pet dogs, fear and anxiety have been linked to increased disease burden and shortened lifespan (Dreschel, 2010). From a welfare perspective, this means that unresolved stress is not simply a behavioural concern but a whole-body health issue.

Neuroscience also challenges the idea that dogs can "learn through pressure." Research across mammals shows that acute uncontrollable stress impairs prefrontal cortical function, the brain systems responsible for flexible learning and problem-solving, while strengthening more primitive threat responses (Arnsten, 2009). This means that techniques relying on fear, discomfort, or suppression may achieve outward compliance but do not support genuine learning or emotional safety. Instead, they reinforce threat associations and reduce trust. Studies comparing training methods in dogs consistently find that aversive-based approaches are associated with higher stress indicators, more pessimistic emotional states, and a poorer dog-owner relationship, without evidence that aversive methods provide a corresponding welfare or effectiveness advantage (Deldalle and Gaunet, 2014; Ziv, 2017; Vieira de Castro et al., 2020).

Importantly, safety is the foundation of neurological regulation. When the threat response subsides, the parasympathetic branch of the autonomic nervous system can predominate, supporting rest, digestion, social behaviour and the capacity to learn (Sapolsky, 2004). Behaviour work that prioritises predictability, choice, agency, and emotional security aligns with how the mammalian brain functions. Experimental research in animals has shown that the ability to predict and control a stressor dramatically reduces its physiological damage (Weiss, 1971), and predictability is now recognised as a core welfare factor for animals in human care (Bassett and Buchanan-Smith, 2007).

For guardians and professionals alike, the science offers a clear message in that stress behaviours are communication, not defiance. Supporting a dog's nervous system, through ethical handling, appropriate environments, and compassionate expectations, is not indulgent. It is biologically necessary.

Understanding stress at a neurological level moves us away from blame and towards responsibility. When we meet dogs where their nervous systems are, rather than where we wish them to be, we create the conditions for real, lasting behavioural change and genuine wellbeing.

References

Arnsten, A.F.T. (2009) 'Stress signalling pathways that impair prefrontal cortex structure and function', Nature Reviews Neuroscience, 10(6), pp. 410-422.

Bassett, L. and Buchanan-Smith, H.M. (2007) 'Effects of predictability on the welfare of captive animals', Applied Animal Behaviour Science, 102(3-4), pp. 223-245.

Beerda, B., Schilder, M.B.H., van Hooff, J.A.R.A.M., de Vries, H.W. and Mol, J.A. (1998) 'Behavioural, saliva cortisol and heart rate responses to different types of stimuli in dogs', Applied Animal Behaviour Science, 58(3-4), pp. 365-381.

Beerda, B., Schilder, M.B.H., van Hooff, J.A.R.A.M., de Vries, H.W. and Mol, J.A. (1999a) 'Chronic stress in dogs subjected to social and spatial restriction. I. Behavioral responses', Physiology and Behavior, 66(2), pp. 233-242.

Beerda, B., Schilder, M.B.H., Bernadina, W., van Hooff, J.A.R.A.M., de Vries, H.W. and Mol, J.A. (1999b) 'Chronic stress in dogs subjected to social and spatial restriction. II. Hormonal and immunological responses', Physiology and Behavior, 66(2), pp. 243-254.

Beerda, B., Schilder, M.B.H., van Hooff, J.A.R.A.M., de Vries, H.W. and Mol, J.A. (2000) 'Behavioural and hormonal indicators of enduring environmental stress in dogs', Animal Welfare, 9(1), pp. 49-62.

Deldalle, S. and Gaunet, F. (2014) 'Effects of 2 training methods on stress-related behaviors of the dog (Canis familiaris) and on the dog-owner relationship', Journal of Veterinary Behavior, 9(2), pp. 58-65.

Dreschel, N.A. (2010) 'The effects of fear and anxiety on health and lifespan in pet dogs', Applied Animal Behaviour Science, 125(3-4), pp. 157-162.

LeDoux, J. (1996) The emotional brain: the mysterious underpinnings of emotional life. New York: Simon and Schuster.

McEwen, B.S. (1998) 'Protective and damaging effects of stress mediators', New England Journal of Medicine, 338(3), pp. 171-179.

McEwen, B.S. and Sapolsky, R.M. (1995) 'Stress and cognitive function', Current Opinion in Neurobiology, 5(2), pp. 205-216.

Sapolsky, R.M. (2004) Why zebras don't get ulcers. 3rd edn. New York: Henry Holt.

Vieira de Castro, A.C., Fuchs, D., Morello, G.M., Pastur, S., de Sousa, L. and Olsson, I.A.S. (2020) 'Does training method matter? Evidence for the negative impact of aversive-based methods on companion dog welfare', PLoS ONE, 15(12), e0225023.

Weiss, J.M. (1971) 'Effects of coping behavior in different warning signal conditions on stress pathology in rats', Journal of Comparative and Physiological Psychology, 77(1), pp. 1-13.

Ziv, G. (2017) 'The effects of using aversive training methods in dogs: a review', Journal of Veterinary Behavior, 19, pp. 50-60.