Jul 15, 2026 More Than Companionship: How Dogs May Improve Human Well-Being
It is now widely accepted that sharing one’s home with a companion animal, especially a dog, confers both organic and mental health benefits on the humans in the pet-owning household. This recognition of the health benefits of companion animals has been shaped by marketing campaigns from pet food companies, whose product sales, currently around $65 billion per annum in the U.S., are directly related to the number of people who share their homes with companion animals. However, as Dr. Harold Herzog continues to document, the available scientific studies on the health benefits of pets have yielded a very mixed bag of positive, negative and inconclusive results.
One of the strongest relationships between companion animals and human health concerns cardiovascular health. An early study on animal therapy, published in 1980, found that pet owners who had experienced a heart attack were much less likely to die from a subsequent cardiovascular event compared to non-pet owners. This finding led to numerous follow-up studies investigating the impact of companion animals on various cardiovascular parameters.
In 1992, Warwick Anderson and his colleagues at Monash University in Australia published an intriguing report as part of a larger cardiovascular trial. This trial examined factors associated with cardiovascular disease among 5,741 participants attending a free screening clinic at the Baker Medical Research Institute in Melbourne. Anderson reported to me that he had added a question on pet ownership in part because he was tired of hearing that pets conferred a health benefit for their human companions, and he wished to disprove those claims. However, the study then found that the 784 pet owners in the sample had significantly lower systolic blood pressure and plasma triglyceride levels than the 4,957 non-owners! The socioeconomic profiles of pet owners and non-owners appeared comparable.
In 2013, the American Heart Association published a Scientific Statement on the topic, which included two key recommendations.
- Pet ownership, particularly dog ownership, may be reasonable for reduction in CVD risk (Class IIb; Level of Evidence B);
- Pet adoption, rescue, or purchase should not be done for the primary purpose of reducing CVD risk (Class III; Level of Evidence C).
[Class IIb represents weak evidence where the recommendation is optional, while Class III represents a situation where the evidence suggests the recommendation is not useful or may even be harmful.]
In a recent (May 15, 2026) Editorial in the American Heart Association subsidiary journal, Circulation: Cardiovascular Quality and Outcomes, Dr. Dhruv S. Kazi revisits the health impact of companion dogs and refers to two recent papers by Kramer et al., Dog Ownership and Survival: A Systematic Review and Meta-Analysis, and Mubanga et al., Dog Ownership and Survival After a Major Cardiovascular Event: A Register-Based Prospective Study. While both papers reported a positive effect of dog ownership on human health, Dr. Kazi identified three specific questions that must be answered:
- Is the observed association real?
- Is the observed association likely to be causal?
- If the association is real and causal, what are the implications?
Dr. Kazi concluded that the answer to the first question is relatively straightforward. Since the association between dog ownership and improved survival has been replicated across multiple countries and in different populations (both the general population and individuals with preexisting cardiovascular disease), the association is unlikely to be a chance finding.
However, addressing the second question regarding causality is complex. First, it is essential to explore whether unobserved confounders could explain the observed association. Generally, pet owners tend to be younger, wealthier, better educated and more likely to be married, all factors that can lead to better cardiovascular outcomes. Additionally. dog owners often have higher incomes, which are linked to lower rates of tobacco use, diabetes mellitus, and obesity. So, the improved cardiovascular outcomes might be partly due to these socio-economic factors and comorbidities.
Finally, it is also possible that causality runs in the reverse direction, with healthier individuals more likely to own a dog. However, in the Swedish studies by Mubanga et al., the association between dog ownership and lower mortality remains significant even after controlling for sociodemographic variables.
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