Meta-analysis of ten studies links dog ownership to 24% lower all-cause mortality risk

A systematic review and meta-analysis in Circulation Cardiovascular Quality and Outcomes pooled ten observational studies on dog ownership and survival. Studies published between 1950 and May 24, 2019 were identified by searching Embase and PubMed. Together they yielded data from 3 837 005 participants and 530 515 events, with a mean follow-up of 10.1 years doi.orgCirculation Cardiovascular Quality and Outcomesdoi.orgOpen source ↗.

Earlier reports had linked dog companionship to lower blood pressure, an improved lipid profile and diminished sympathetic responses to stress. Previous studies of survival, however, gave inconsistent results. The authors therefore evaluated the association of dog ownership with all-cause mortality, with and without prior cardiovascular disease, and with cardiovascular mortality.

All-cause and cardiovascular mortality

Dog ownership was associated with a 24% lower risk of all-cause death compared with nonownership (relative risk 0.76; 95% CI, 0.67–0.86). Six of the ten studies showed a significant reduction in the risk of death. Two independent reviewers extracted the data, and the pooled results were assessed with a random-effects model.

When the analysis was restricted to studies evaluating cardiovascular mortality, dog ownership was associated with a 31% lower risk of cardiovascular death (relative risk 0.69; 95% CI, 0.67–0.71; I2, 5.1%) doi.orgCirculation Cardiovascular Quality and Outcomesdoi.orgOpen source ↗.

Prior coronary events and limitations

Among individuals with prior coronary events, living in a home with a dog was associated with an even larger reduction in all-cause mortality (relative risk 0.35; 95% CI, 0.17–0.69; I2, 0%). The wide confidence interval in this subgroup reflects a smaller body of data than in the overall analysis.

The authors name a possible limitation: the analyses were not adjusted for confounders. All included studies were observational, so the results show an association and do not establish that owning a dog changes survival.

The authors conclude that dog ownership is associated with a lower risk of death over the long term, possibly driven by a reduction in cardiovascular mortality doi.orgCirculation Cardiovascular Quality and Outcomesdoi.orgOpen source ↗.