Does Having Pets Really Make Us Healthier?

New studies find little support for a "Pet Effect" on physical or mental health.

Posted Aug 31, 2018

Photo by damedeeso/123RF
Source: Photo by damedeeso/123RF

The $70 billion dollar pet products industry certainly promotes the idea that getting a pet will make you healthier and happier. For example, the giant veterinary pharmaceutical corporation Zoetis in partnership with the Human Animal Bond Research Institute (HABRI), an industry trade group, recently launched an advertising blitz they call The Pet Effect.  (See, for example, these clever ads extolling the healing powers of dogs and cats.) According to a Zoetis press release, “The Pet Effect campaign has assembled scientific evidence that demonstrates how pets improve heart health, alleviate depression, increase well-being, support child health and development, and contribute to healthy aging, as well as assist in treating a range of conditions from autism spectrum disorder to Alzheimer’s disease to post-traumatic stress disorder.” The idea that science has established that living with pets improves human health has certainly caught on with the public and even the medical profession. Indeed, a HABRI survey reported that 97% of family practice doctors now believe there are health benefits to owning a pet.

According to Mike McFarland, executive director of Zoetis Petcare Marketing, the goal of the new advertising barrage is to convince the public that there is “a growing body of scientific research that shows how important the human-animal bond is for human health.” The pet products industry, however, does not want you to know about the growing body of scientific research which has found that pet owners are not healthier or happier than people who don’t live with animals.

In his thought-provoking book The Animals Among Us: How Pets Make Us Human, the highly respected anthrozoologist and Psychology Today blogger John Bradshaw wrote, “Reliable studies have generally failed to find convincing proof that living with animals makes their owners healthier.”  A new study on the impact of pets on the physical and mental health of older adults supports his skepticism about the pet effect.

The Whitehall II Study

The research was conducted by Gill Mien and Robert Grant of Kingston University in London, and appeared in the journal BMC Geriatrics. (Read it here.) They analyzed data on pet ownership and health that was collected as part of an ongoing research project called the Whitehall II Study. This is a long-term investigation of the impact of occupational and social factors on the mental and physical health of British civil servants. Every two years since 1984, participants have been surveyed about their health and well-being.  Phase 9 of the study was collected between 2007 and 2009. In addition to questions about mental and physical health, the Phase 9 administration of the survey also included several items related to pet ownership. 

The study included 6,575 participants between the ages of 59 and 79. About 2,000 of these individuals lived with a pet. Thirty-seven percent of the subjects had dogs and 62% had cats. Most of the items in Phase 9 were standardized measures of physical and mental health. There were also questions related to the participants’ levels of exercise and aspects of the quality of their sleep. Finally, several questions concerned how the subjects felt about their neighborhoods, for example, friendliness, safety, and cleanliness.

The Results

As shown in this graph, there were no meaningful differences between physical and mental health pet owners and non-owners, though pet owners were slightly worse off on a few measures.

Graph by Hal Herzog
Source: Graph by Hal Herzog

Here are the results

  • General health and number of chronic illnesses – No differences
  • Quality of life – No differences
  • General mental health – No differences
  • Depression – Pet-owners were slightly worse off.
  • Depression & Anxiety Inventory – Pet-owners were slightly worse off
  • Cognitive status (Mini-Mental State Exam) – No differences
  • Mobility – No differences
  • Number of doctor visits – No differences
  • Taking hypertension drugs – No differences
  • Lung capacity – No differences
  • Body mass index – Pet-owners were slightly heavier.

In short, the researchers concluded, “There were little or no differences in health variables, other than slightly worse mental health and higher BMI in owners.”

The Good News?

The lack of impact of pets on the subjects’ health and well-being was striking. Believers in the pet effect, however, can take some small comfort in a few of the results.

Graph by Hal Herzog
Source: Graph by Hal Herzog

Exercise: As shown in this graph, dog owners engaged in considerably more mild and moderate exercise than non-pet owners. (There were no differences between the groups in their amounts of vigorous exercise.) But even this finding raises a troubling question about the pet effect. While the dog owners in the study were much more likely to get mild and moderate exercise, this increase in physical activity did not translate into any measurable impact on their health.

Similar results were obtained by a research team at Purdue University headed by Dr. Elizabeth Richards. These investigators conducted a year-long investigation of the impact of dog-walking on over-weight middle-aged women. In their final report to the funder (HABRI), they wrote, “A third purpose of this study was to examine the impact of increased dog walking on the differences across time in the health outcomes for the dog owners (weight, blood pressure, and blood lipids). There were no significant changes in weight, blood pressure, or blood lipids between groups or across time.” 

Sleep. Pet-owners in the Whitehall II study had less difficulty falling asleep than non-pet owners. But the pet-owners were also more likely to feel tired when they woke up. And although these differences were “statistically significant,” they were so small as to be practically meaningless.

Perceptions of Their Neighborhoods. Pet owners, and particularly dog owners, felt more positive about their neighborhoods than non-pet owners. But, as in the case of quality of sleep, the differences between the pet owners and non-owners, while statistically significant, were so small as to have few, if any, real-world implications.

Other New Studies Cast Doubt on the “Pet Effect

The Whitehall II study is just one of several recent large investigations which cast doubt on industry claims that getting pets makes people healthier and happier. For example, in a 2017 study researchers from the RAND Corporation found the health benefits attributed to pet-keeping are actually due to socioeconomic differences between pet owners and people not living with a companion animal. (See Large Study Finds Pet Owners Are Different). The RAND team also found that the cognitive and mental health advantages seen in children with pets is entirely due to factors such as race, ethnicity, and family wealth (See Why Kids with Pets Are Better Off).  And researchers from the Basset Institute reported that children with cats in their homes are more likely than kids with no cats to have been diagnosed with psychological problems. (See Do Children with Cats Have More Mental Health Problems?)

 The Inconvenient Truth about “The Pet Effect”

The truth is that three decades of research on the pet effect have produced a muddle of mixed results. (See here for a short review of these studies.) Some investigators have reported that pet owners are better off. Others, however, have found that pet owners have more psychological and health problems than non-owners. These include being more likely to suffer from migraines, insomnia, panic attacks, ulcers, high blood pressure, loneliness, and depression. And still other studies have reported that living with pets had no effect at all on human health and wellbeing. As you might expect, industry press releases extolling the benefits of pet ownership never mention this growing body of scientific research.

Don’t get me wrong. I am a life-long pet lover. I completely understand the joys and satisfactions that come from living with companion animals. Further, I know there are plenty of good reasons to bring pets into our lives. But getting a dog or cat because you think it will make you less lonely or live longer is not one of them.  The fact is that claims about the miraculous healing powers of pets are, for the most part, hype generated by the marketing departments of giant pet products corporations and their trade groups.

References

Herzog, H. (2011). The impact of pets on human health and psychological well-being: fact, fiction, or hypothesis Current Directions in Psychological Science, 20(4), 236-239.

Mein, G., & Grant, R. (2018). A cross-sectional exploratory analysis between pet ownership, sleep, exercise, health and neighbourhood perceptions: the Whitehall II cohort study. BMC Geriatrics, 18(1), 176.

Miles, J. N., Parast, L., Babey, S. H., Griffin, B. A., & Saunders, J. M. (2017). A propensity-score-weighted population-based study of the health benefits of dogs and cats for children. Anthrozoös, 30(3), 429-440.

Saunders, J., Parast, L., Babey, S. H., & Miles, J. V. (2017). Exploring the differences between pet and non-pet owners: Implications for human-animal interaction research and policy. PloS One, 12(6), e0179494.