Introduction
During the last decades, animal assistance in therapy, education, and care has greatly increased.
Today, the value of Animal-Assisted Interventions ( AAI ), including Animal-Assisted Therapy ( AAT ) is widely acknowledged.
Animal-assisted therapy is a type of therapy that involves animals as a form of treatment.
The goal of AAT is to improve a patient’s social, emotional, or cognitive functioning.
Animals used in therapy include domesticated pets (in particular dogs), farm animals and marine mammals.
Animals can be used in a variety of settings such as prisons, nursing homes, mental institutions and hospitals and in the home. Assistance dogs can assist people with many different disabilities; they are capable of assisting certain life activities and help the individuals navigate outside of the home.
Effects of Animal-Human Interaction
Andrea Beetz, Kerstin Uvnäs-Moberg, Henri Julius and Kurt Kotrschal analyze a lot of publications about the interaction between animals and man.
The table on the following link shows a summary of Original studies included in the review
Based on the presented evidence they conclude that contact with companion animals holds the potential to promote social interaction and functioning in children and adults with or without mental health problems.
The studies reviewed here clearly indicate the following positive effects of Human Animal Interaction ( HAI ) in several different domains and in humans of different age groups, with and without special medical, or mental health conditions:
- Improvement of social attention, behavior, interpersonal interaction, and mood
- Reduction of stress-related parameters such as cortisol, heart rate, and blood pressure
- Reduction of self-reported fear and anxiety
- Improvement of mental and physical health, especially cardiovascular health
(Dogs motivate obese children for physical activity: key elements of a motivational theory of animal-assisted interventions, 2013)
Limited evidence or very few publications exist for positive effects of HAI on:
- Reduction of stress-related parameters such as epinephrine and norepinephrine
- Improvement of immune system functioning
- Increased trustworthiness of and trust toward other persons
- Enhanced empathy and improved learning.
The authors propose that most of these effects of HAI may be mediated via the OT system and that the activation of this system represents the mechanism underlying these effects.
The Oxytocin System
Oxytocin is a mammalian neurohypophysial hormone, that acts primarily as a neuromodulator in the brain.
Oxytocin plays an important role in the neuroanatomy of intimacy, specifically in sexual reproduction, in particular during and after childbirth. It is released in large amounts after distension of the cervix and uterus during labor, facilitating birth, maternal bonding, and, after stimulation of the nipples, lactation.
Recent studies have begun to investigate oxytocin's role in various behaviors, including orgasm, social recognition, pair bonding, anxiety, and maternal behaviors.
For this reason, it is sometimes referred to as the " bonding hormone ".
Many physiological, psychological and behavioral functions are modulated via OT, as has been shown via experimental administration of OT in animals and humans.
- Effects on social interaction
Among the acute effects of OT is the stimulation of social interaction. It increases eye contact, empathy, face memory, trust, social skills, positive self-perception, and generosity and decreases depression. OT promotes maternal care behavior and bonding to the offspring.
(Oxytocin increases trust in humans, 2005)
It decreases glucocorticoid (i.e., stress hormone) levels in humans and non-human animals in particular in response to social stressors decreases blood pressure for several hours as well as heart rate and increases peripheral cutaneous circulation and skin temperature.
(Social support and oxytocin interact to suppress cortisol and subjective responses to psychosocial stress, 2003)
- Effects on anxiety, pain, and immune system
Oxytocin increases pain thresholds and has an anti-inflammatory effect in rats. It has also an anxiolytic effect in particular in relation to social threats.
(Oxytocin increases nociceptive thresholds in a long-term perspective in female and male rats, 1996)
- Effects on health and restoration
Furthermore, OT is associated with increases in the function of the parasympathetic nervous system controlling the endocrine system of the gastrointestinal tract, which is linked to an enhanced digestive function and growth and restoration.
As this short overview of OT-mediated effects shows, there is a major overlap of effects of HAI and OT and the following research shows that indeed HAI may activate the OT system in humans.
Effects of HAI on Oxytocin
Odendaal (2000); Odendaal and Meintjes (2003) documented a significant increase of plasma OT, as well as prolactin, phenylacetic acid, and dopamine, in both, humans and dogs after 5 to 24 min of stroking a dog. Interaction with one’s own dog resulted in a stronger effect than stroking an unfamiliar dog. This indicated that the increase in OT depends on the quality of the human-animal relationship: the closer the relationship, the more OT is released by the positive interaction including physical contact.
Miller et al. (2009) studied changes of plasma OT via interaction with the person’s own pet-dog, in men and women after coming home from work who had been separated from their dog during the day. Two conditions, interacting with the dog and reading quietly in the absence of the dog were compared. Interacting with the dog led to an increase in plasma OT in women, but not men, while this was not observed in the reading condition. In both conditions, men even showed a drop in OT levels. However, OT levels decreased more in the control condition, pointing toward a counteracting effect of interacting with the dogs on the OT system also in men.
In their study of female dog owners, who were instructed to stroke and talk to their own male dogs for 3 min in a laboratory setting, Handlin et al. (2011) found a significant increase in plasma OT in both women and dogs, but not in a control group without animal interaction.
Conclusion
Research on direct OT effects in HAI is still rare. But the existing evidence clearly points at the potential of interactions with animals, especially one’s own pet-dog, to increase OT levels in humans.
Andrea Beetz, Kerstin Uvnäs-Moberg, Henri Julius and Kurt Kotrschal propose that the release of OT via contact with animals may contribute to explain many of the effects of HAI documented by the studies included in our review.
There is also much indirect evidence on a potential link of HAI effects and the OT system. In fact, the effects of OT and of HAI largely correspond. Both, HAI and OT, were found to promote social interaction, to reduce stress and anxiety, and to enhance human health. OT is released via eye contact, but in particular, via pleasant tactile interactions which seem to play a major role for the OT-mediated decrease of stress levels. Oxytocin effects may be triggered in response to single meetings with animals, but stable relationships with animals such as pet ownership will be linked to more potent and long lasting effects due to repeated exposure to OT.
In addition, the bond between human and animal may contribute to OT release and oxytocin mediated effects. HAI effects are stronger with a familiar dog in comparison to an unfamiliar dog.
That the OT system plays a major role in social bonds has been documented by several studies and represent a core mechanism in explaining many of the positive effects of HAI.
Even in Italy the AAT is growing up, not only in private institutions, but also in public hospitals.
Pet therapy, via libera della Regione: cani e gatti in ospedale con i pazienti
Arezzo: bambina ricoverata in ospedale, il cane resta a farle compagnia
Roma, bimba lascia ospedale grazie al suo cane
References
- Psychosocial and Psychophysiological Effects of Human-Animal Interactions: The Possible Role of Oxytocin, 2012
- Animal-assisted therapy
- The Oxytocin
