Stress, trauma and the body

Home » Latest news » Stress, trauma and the body

With the new academic year upon us, I look forward to teaching MSc students about Human-Animal Interactions and the different subdisciplines of psychology, including biological psychology. This field examines how the brain, nervous system and body processes shape behaviour. Stress and trauma are central examples, because they show how quickly biological systems react and how long-lasting those changes can be. The stress response involves shifts in hormone levels, immune activity and neural circuits that influence how we think, feel and act.

For those who live or work with animals, the relevance is immediate. The same mechanisms that explain why people under strain develop migraines or gut problems also help us understand why dogs under chronic stress may show skin flare-ups, stomach issues or restlessness. It is this interplay between nervous system, hormones and behaviour that sits at the heart of biological psychology.

Whether human or canine, the body can hold on to what the mind cannot voice. This idea is central to understanding trauma and stress as embodied processes, and it reshapes how we respond to signs of distress across species.

How humans carry stress, and the body holds onto it

When emotions cannot be processed or spoken, they rarely disappear. Instead, the body takes on the task of carrying them. Backache, stomach pain, kidney problems, and even chronic fatigue can become the mute record of experiences that have not been faced. In this sense, the body becomes the historian of trauma, keeping account of what the mind cannot voice.

Neuroscience shows how this works. The body’s alarm system, the limbic network and the hypothalamic–pituitary–adrenal (HPA) axis, fire rapidly when danger is sensed. Cortisol and adrenaline flood the system, priming the body to fight or flee. This is where we may see the colour drain from someone’s face and eyes blink faster as they dry, as precious resources are redirected to the muscles and limbs, ready for action. There is also the freeze response, where the body reacts differently, often with sudden stillness or reduced responsiveness. When the physiological charge has no outlet, it can persist as muscle tension, headaches, gastrointestinal issues or disturbed sleep (Heim et al., 2000).

Somatisation is the clinical term for this process: when psychological distress is translated into physical symptoms. Someone unable to talk about their trauma may still feel it play out every day through migraines, gut problems, or muscle tension (Rief and Broadbent, 2007). Therapies that focus on body awareness, such as Somatic Experiencing or sensorimotor psychotherapy, aim to help individuals release this hidden load (Buckley, 2012). Clients are guided to notice cues such as shallow breathing, a knot in the stomach, or sudden muscle tightening, and learn to slowly regain control over their stress responses (Levine, 2010; Payne et al., 2015). While early results are encouraging, reviews emphasise that more substantial scientific evidence is still needed to confirm their effectiveness (Kuhfuß et al., 2021).

What dogs reveal about trauma

Dogs also show how stress and trauma are carried in the body. In rescue centre and kennel settings, prolonged stress is associated with elevated glucocorticoids and behaviours such as pacing, withdrawal, or repetitive licking (Hennessy et al., 2020). Dogs arriving in new environments often show disrupted sleep and higher cortisol until they settle (van der Laan et al., 2021).

In the home, the way we train and interact with dogs also has profound effects on the body and emotional responses. Those trained with aversive methods exhibit higher cortisol levels and a more pessimistic outlook compared to dogs taught using reward-based approaches (Vieira de Castro et al., 2020; Cooper et al., 2014). Stressed dogs may also sleep less soundly, mirroring the disturbed rest patterns seen in humans when stressed (Owczarczak-Garstecka et al., 2016).

Skin and gut health can tell the same story. Dogs with atopic dermatitis often display behaviours linked with anxiety, and in some studies show higher hair cortisol (Harvey et al., 2019; Park et al., 2025). Stress also disrupts digestion, changing how food moves through the gut and shifting microbial balance (Gué et al., 1989; Patel et al., 2024), which can lead to discomfort, and consequently influence the dog’s behaviour (Mills et al., 2020).

There is evidence too that humans and dogs carry stress together. Long-term cortisol patterns in dogs mirror those of their owners (Sundman et al., 2019). Yong and Ruffman (2014) even showed that a baby’s crying raised cortisol not only in parents but also in the family dog. The dog’s body, in effect, records what the human body carries.

Exercising caution and research opportunities

While these parallels are striking, they need careful handling. Human trauma research often relies on self-report, whereas with dogs we interpret physiology and behaviour without direct access to their inner states. So, a restless dog may be stressed, but they may also be bored, hungry or in need of a toilet break. The aim is to avoid over-simplified anthropomorphism while also recognising data that shows dogs experience a wide emotional range, display differing personality types and individual differences, and share important physiological similarities with us. Biological psychology reminds us that behaviour is always shaped by interacting systems, nervous, hormonal and environmental, and no single sign is enough on its own.

Furthermore, many canine stress studies are also based in rescue centres, kennels or laboratories, which differ from the family home. Drawing direct lines between human and dog trauma risks oversimplifying what is complex biology. So, future work can help close these gaps. Controlled studies could test whether body-based interventions such as structured touch, proprioceptive games, or controlled movement reduce stress in dogs. And, more research is needed to understand how scent-based games and activities promote optimistism in dogs, improving welfare. Exploring how an owner’s own stress patterns affect their animals could shed light on co-regulation, while giving people practical strategies without fuelling guilt. Comparative neuroscience may also clarify where trauma circuits overlap and where they diverge between species.

Practical advice and support for owners, guardians and professionals

Encouragingly, work is already moving in this direction. A recent paper by Corridan et al. (2024) has argued for adopting trauma-informed care in veterinary behavioural practice, recognising that dogs with anxiety disorders may benefit from approaches that acknowledge how past stress shapes present behaviour. Such research highlights how biological psychology and trauma science can be translated into practical frameworks that improve welfare on the ground.

Some of my peers leading the way in trauma-informed practice in recent years, providing valuable educational resources to support anyone living or working with dogs, include:

• Clinical Animal Behaviourist & Trainer Danielle Beck
• The team at Barking Brains – a neuroscience outreach platform, and
• Animal behaviourist Daniel Shaw

As responsible dog owners and guardians, it is clear that when it comes to training our animals, choosing positive-reinforcement-based methods supports learning and also promotes a more positive mood and better health. Crucially, it reduces the risk of stress being written into the body through disrupted sleep, digestive upset, or other physical signs of strain.

Key takeaway

The body holds the record of stress. A spasm, a sleepless night, or a dog’s repeated pacing are reminders to pay attention and respond with insight and compassion, rather than fall back on one-size-fits-all answers or labels such as ‘naughty’ or ‘stubborn’.

If you notice changes in your pet’s behaviour, or find their actions confusing or concerning, consult your veterinarian first. Then seek support from a registered Clinical Animal Behaviourist, who can work with you to identify the underlying causes and create an appropriate plan. You can find your nearest practitioner via the Animal Behaviour & Training Council’s directory.

---

References

• Buckley, T. (2012) Trauma and the body  An introduction to Sensorimotor Psychotherapy. Lutterworth,  Leicestershire: Sensorimotor Psychotherapy® Institute.
• Cooper, J.J., Cracknell, N., Hardiman, J., Wright, H., and Mills, D. (2014) The welfare consequences and efficacy of training pet dogs with remote electronic training collars in comparison to reward-based training. PLOS ONE, 9(9), e102722. https://doi.org/10.1371/journal.pone.0102722
• Corridan, C.L., Dawson, S.E., and Mullan, S. (2024) Potential benefits of a ‘trauma-informed care’ approach to improve the assessment and management of dogs presented with anxiety disorders. Animals, 14(3), p.459. https://doi.org/10.3390/ani14030459
• Gué, M., Del Rio-Lacheze, C., Eutamène, H., Théodorou, V., Fioramonti, J., and  Bueno, L., (1989) Stress-induced changes in gastric emptying, postprandial motility and intestinal transit in dogs. Gastroenterology, 96(3), pp.711-716. https://doi.org/10.1016/0016-5085(89)91678-8
• Harvey, N.D., Shaw, S.C., Craigon, P.J., Blott, S.C., and England, G.C.W. (2019) Behavioural differences in dogs with atopic dermatitis suggest stress could be a significant problem associated with chronic pruritus. Animals, 9(10), 813. https://doi.org/10.3390/ani9100813
• Heim, C., Ehlert, U., and Hellhammer, D.H. (2000) The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders. Psychoneuroendocrinology, 25(1), pp.1-35. https://doi.org/10.1016/S0306-4530(99)00035-9
• Hennessy, M.B., Willen, R.M., and Schiml, P.A. (2020) Psychological stress, its reduction, and long-term consequences: what studies with laboratory animals might teach us about life in the dog shelter. Animals, 10(11), p.2061. https://doi.org/10.3390/ani10112061
• Kuhfuß, M., Maldei, T., Hetmanek, A., and Baumann, N. (2021) Somatic experiencing – effectiveness and key factors of a body-oriented trauma therapy: a scoping literature review. European Journal of Psychotraumatology, 12(1). https://doi.org/10.1080/20008198.2021.1929024
• Levine, P.A., 2010. In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness. Berkeley: North Atlantic Books.
• Mills, D.S., Demontigny-Bédard, I., Gruen, M., Klinck, M.P., McPeake, K.J., Barcelos, A.M., Hewison, L., Van Haevermaet, H., Denenberg, S., Hauser, H., Koch, C., Ballantyne, K., Wilson, C., Mathkari, C.V., Pounder, J., Garcia, E., Darder, P., Fatjó, J., Levine, E. (2020) Pain and Problem Behavior in Cats and Dogs. Animals.10(2):318. doi: 10.3390/ani10020318.
• Owczarczak-Garstecka, S.C., Burman, O.H.P., Craigon, P.J., and  Murray, J.K. (2016). Can sleep and resting behaviours be used as indicators of welfare in shelter dogs? PLOS ONE, 11(10), e0163620. https://doi.org/10.1371/journal.pone.0163620
• Park, G.W., Ataallahi, M., Park, K.H. (2025) Stress level in companion dogs with and without atopic dermatitis. Journal of Animal Science and Technology. 67(2), pp.468-476. doi:10.5187/jast.2024.e28.
• Patel, K.V., Hunt, A.B.G., Castillo-Fernandez, J, Abrams, C., King, T., Watson, P., Gregory, C.A., and Amos, A. (2024) Impact of acute stress on the canine gut microbiota. Scientific Reports. 14, 18897. https://doi.org/10.1038/s41598-024-66652-3
• Payne, P., Levine, P.A., and Crane-Godreau, M.A. (2015) Somatic experiencing: using interoception and proprioception as core elements of trauma therapy. Frontiers in Psychology, 6, p.93. https://doi.org/10.3389/fpsyg.2015.00093
• Rief, W., and Broadbent, E. (2007) Explaining medically unexplained symptoms—models and mechanisms. Clinical Psychology Review, 27(7), pp.821-841. https://doi.org/10.1016/j.cpr.2007.07.005
• Sundman, A.-S., Van Poucke, E., Holm, A.-C.S., Faresjö, Å., Theodorsson, E., Jensen, P., and Roth, L.S.V. (2019) Long-term stress levels are synchronized in dogs and their owners. Scientific Reports, 9(1), p.7391. https://doi.org/10.1038/s41598-019-43851-x
• van der Laan, J.E., et al., 2021. Restless nights? Nocturnal activity as a useful indicator of welfare in shelter dogs. Journal of Veterinary Behavior, 43, pp.7-14. https://doi.org/10.1016/j.jveb.2021.04.006
• Vieira de Castro, A.C., Barrett, J., 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. https://doi.org/10.1371/journal.pone.0225023
• Yong, M.H., and Ruffman, T. (2014) Emotional contagion: dogs and humans show rapid physiological responses to human infant crying. Behavioural Processes, 108, pp.155-165. doi: 10.1016/j.beproc.2014.10.006.