In a study of 50 dog owners and 50 people who don't own dogs, test subjects interact with dogs they own, dogs belonging to others, and a robot dog manufactured by Sony. Researchers take blood pressure readings and blood samples from the people and the dogs. Preliminary findings show the best results from interaction between people and the dogs they own. Both the dogs and humans have experienced lower blood pressure, better levels of good hormones and decreased levels of hormones related to stress.
— Rebecca Johnson, Pet-a-Pet study, School of Nursing, University of Missouri at Columbia
Johannes Odendaal, of South Africa, found that after 20 minutes of quiet interaction, 18 people and 18 dogs had significant changes in beneficial hormones: oxytocin, a hormone associated with feelings of happiness; prolactin, associated with increased feelings of nurturing; endorphin, runner's high hormone; and phenylethylamine, which gives a feeling similar to the euphoria of chocolate. Cortisol, a stress hormone, decreased during the interaction.
— Research by Johannes Odendaal, Tshwane University of Technology in Pretoria, South Africa
People living with Alzheimer's disease ate more when sitting in front of fish tanks.
— Alan Beck, director of the Purdue University School of Veterinary Medicine
Animals eased feelings of loneliness among older people. This research at St. Louis University was the only study on this list to show a beneficial response to a mechanical dog. Others showed the mechanical dog had no benefits or poor benefits. The tests did not check blood hormone levels.
— William A. Banks, division of geriatric medicine, St. Louis University School of Medicine
Women who underwent surgery for breast cancer showed improved recovery and mental health if they owned a dog, cat, or other pet.
— University of Warwick, Coventry, United Kingdom
Dogs have a significant, beneficial health effect on people who live alone and have borderline hypertension.
— Millard Fillmore Hospital, Buffalo, NY
Owning a pet can buffer the response to mental stress better than ACE inhibitors—medications used to fight hypertension. Animals provided social support that reduced the response to stressful situations. "Those with high social support and pets had the lowest reactivity, and those with low social support and no pets had the highest reactivity."
— Hypertension Journal, 2001, study at University of Warwick, Coventry, United Kingdom
For older people, research suggests that pets can play a useful role in moderating the effect of aging on blood pressure.
— American Psychosomatic Society paper, 1997
A study of 6,000 households with people suffering cardiovascular disease showed dog and cat owners made fewer visits to doctors and had lower rates of medication for high blood pressure, cholesterol, sleeping difficulties, and heart problems. The researchers said the study supports "the notion that individuals with a close relationship to animals carry a lower burden of some risk factors."
— A paper at the International Conference on Human-Animal Interactions, Animals, Health and Quality of Life, 1995, Geneva