A prospective cohort study in Finland studied the incidence of respiratory infections in 397 children from birth to 1 year. A multivariate analysis found that children with no dogs at home had more respiratory tract infections than children with dogs at home (adjusted odds ratio (aOR) 1.31; 95% confidence interval (CI) 1.13–1.52). Those with dogs at home also had almost half as many episodes of otitis media (aOR 0.56; 95% CI 0.38–0.81) and were prescribed fewer courses of antibiotics (aOR 0.71; 95% CI 0.52-0.96). Univariate analysis suggested that the duration of contact with both dogs and cats was associated with decreased morbidity from respiratory infectious diseases. This was not a large study; the effect size was fairly small and the study design means that the results are susceptible to confounding factors. However, at least cats and dogs did not appear to cause infections.
Reviewer: David Isaacs, email@example.com