Impact of dog and/or cat ownership on functional constipation at 3 years of age: the Japan Environment and Children’s study

PURPOSE: This investigation assessed the impact of dog and/or cat ownership during infancy on the presence of functional constipation (FC) at 3 years of age. METHODS: The fixed data of 73,936 singleton births from a large national birth cohort study commencing in 2011 were used to identify FC as estimated by Rome III at 3 years of age. Multiple logistic regression analysis was employed to search for correlations between FC development and dog and/or cat ownership in early childhood. RESULTS: A total of 8,459 toddlers (11.6%) met the Rome III criteria for FC at 3 years of age. Overall, 57,264 (77.5%) participants had never owned a dog or cat. We identified 7,715 (10.4%) infant-period owners, 1,295 (1.8%) current owners, and 7,762 (10.5%) long-term owners. Multivariate analysis showed that infant-period ownership remained significantly associated with the risk of developing FC at 3 years of age after adjusting for covariates (adjusted OR [95% CI] 1.09 [1.01–1.19] based on non-ownership). CONCLUSIONS: This Japanese large nationwide survey uncovered a possible adverse effect of infant-period dog and/or cat ownership prior to 6 months of age on FC status at 3 years of age. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12887-023-04412-4.