Ever since the domestication of dogs (Canis familiaris) circa 15,000 years ago, humans have continuously exerted selective pressures on dogs. Supported by the process of domestication, a unique interspecies affinity was established that continues to thrive in today’s modern society. Moreover, the dog-owner relationship has been proposed to have similarities to a child-parent attachment bond since both incorporate a sense of protection and comfort.

Various studies have indicated that physiological and hormonal interactions take place between dog-owner dyads. Both physiological and behavioral assessments can give valuable insights concerning an individual’s stress level. One of the most well-established physiological practices for gauging stress responses in humans and animals is to measure the activity of the hypothalamus-pituitary-adrenal (HPA) hormonal pathway and its production of the glucocorticoid hormone cortisol.

The most accurate representation of instantaneous HPA axis activity—and thus reflecting short-term cortisol—is represented within blood plasma samples. However, blood sampling is an invasive method that is known to increase cortisol levels. Salivary cortisol measures have been shown to correlate significantly with those from blood plasma, hereby designating less-invasively obtained saliva cortisol as an ideal alternative for determining acute stress levels. Hair serves as another promising non-invasive medium to measure HPA activity as it has been shown that chronic—or long-term—cortisol measures are reflected in the hair shaft.

Day-to-day life is full of potential stressors that can trigger acute and/or chronic stress responses. In western countries dogs are most commonly kept as companion animals and are thus regarded to be a vital part of the owner’s everyday life. This home setting is the perfect location to engage in shared activities with dogs which have been suggested to enhance the dog-human relationship. Up until now, only limited research has been conducted concerning possible effects of different lifestyles on dogs.

• Deeping our understanding of how the shared dog-owner lifestyle influences cortisol levels within dog-owner dyads.
• Investigate if acute and long-term owner cortisol levels are mirrored by their dogs and whether this is affected by leading a different shared lifestyle (e.g. pet or competing).