Association between dog and cat ownership with cardiovascular disease: A systematic review and meta-analysis

Background: Numerous studies have described the correlation of pet ownership with cardiovascular diseases, with dog and cat ownership emerging as the predominant forms of pet companionship. Nevertheless, the studies that have examined how pet ownership affects cardiovascular diseases are lacking. Consequently, this systematic review and meta-analysis were carried out to investigate associations between owning a dog or cat and all-cause mortality and the risk of cardiovascular diseases and mortality.\nMethods: The PubMed, Embase, Web of Science, and Cochrane Library databases were comprehensively searched for identifying observational publications before August 14, 2023, that investigated the potential relationship between ownership of dogs or cats and cardiovascular mortality, all-cause mortality, and cardiovascular disease, encompassing myocardial infarction and stroke. The outcomes were explored with unadjusted, accessible relative risk values and adjusted hazard ratio values. Additionally, this work employed the random-effects model for analysis. Meanwhile, the Newcastle-Ottawa scale was employed to assess study quality.\nResults: We included 11 articles, comprising 3,940,200 subjects with an average 9.82-year follow-up. In unadjusted models, dog ownership decreased all-cause mortality by 30 percent (relative risk (RR) 0.70; 95%CI,0.60-0.82) and cardiovascular mortality by 24 percent (RR,0.76; 95%CI,0.69-0.84) in the general population compared with not owning a dog. Moreover, the correlation with all-cause mortality (hazard ratio (HR), 0.98; 95%CI, 0.86-1.12) and cardiovascular mortality (HR, 0.91; 95% CI, 0.78-1.07) was non-significant after adjusting for confounding factors. Nonetheless, dog ownership was slightly related to cardiovascular disease risk (HR, 0.98; 95% CI, 0.96-0.99). Cat ownership was not significantly correlated with all-cause mortality (RR, 0.95; 95%CI, 0.85-1.05; hazard ratio, 1.04; 95% CI, 0.98-1.12), cardiovascular mortality (RR, 0.82; 95% CI, 0.66-1.01; hazard ratio, 0.87; 95% CI, 0.69-1.11), and cardiovascular disease risk (HZ, 0.84; 95% CI, 0.57-1.22) among the general population. However, when considering only articles with over 10-year follow-up, cat ownership was associated with cardiovascular mortality (RR, 0.73; 95% CI, 0.60-0.88; HR, 0.79; 95% CI, 0.63-0.99). Additionally, owning cats and dogs led to reduced cardiovascular mortality in cardiovascular disease patients (HR, 0.81; 95%CI, 0.78-0.83).\nConclusion: In the general population, dog ownership is weakly related to decreased cardiovascular disease risk, but not markedly related to all-cause mortality and cardiovascular mortality, whereas cat ownership is not associated with all-cause mortality and the risk of cardiovascular diseases but is related to the reduced cardiovascular mortality risk. Long-term pet ownership appears to reduce mortality in people with established cardiovascular diseases, yet further studies are warranted for validation.