Physiological Effects of Human-Animal Positive Interaction in Dogs - Review of the Literature

Abstract

Positive human-animal interactions (HAI) are known to increase the quality of life in both humans and dogs. Although there are several reviews on the benefits of HAI in humans, there are no reviews on the effects of positive HAI in dogs. Therefore, the aim of this paper is to provide a review of the articles indicating the physiological changes in dogs that correlate with welfare, during and after positive interactions with humans. The reviewed scientific papers were published between 2000-2014. HAI took place either in the laboratory context or in natural settings, such as Animal Assisted Therapy (AAT) locations or dog shelters. The dogs interacted either with their owners, with a familiar person or with an unfamiliar person. The measured physiological variables were the level of blood pressure, heart rate and the levels of several hormones. The studies indicated that positive HAI was usually associated with a significant decrease in blood pressure and in the levels of cortisol, as well as with a significant increase in the levels of b-endorphin, oxytocin, prolactin, phenylacetic acid and dopamine. Some studies had contradictory results, where the levels of cortisol were higher after interaction, suggesting there are other factors which may mediate/moderate the effects. The studies which also measured the physiological changes in humans reported positive correlations between the changes in dogs and the ones in humans.