In utero exposure to pets is associated with asthma and wheezing in Mexican American children

The relationship of domestic pet ownership with the risk of childhood asthma: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The relationship between pet ownership and childhood asthma remains controversial. In recent years, there have been increasing studies with large sample size. Therefore, we conducted this systematic review and meta-analysis to evaluate the relationship between pet ownership and childhood asthma.

METHOD

Relevant research was retrieved from PubMed, Cochrane, EMBASE, and Web of science. The retrieval was as of October 1, 2021. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the included studies. Stata 15.0 was used to conduct the meta-analysis.

RESULTS

A total of 60 studies with large sample size published between 1995 and 2021 were included in this systematic review and meta-analysis, which included 18 cohort studies and 42 case-control studies covering 27 countries and 1,871,295 children. As shown by meta-analysis results, cat ownership (OR = 1.18, 95%CI: 1.05∼1.33) and dog ownership (OR = 1.12, 95%CI: 1.0 0∼1.24) have a significant bearing on the occurrence of childhood asthma. Pet ownership was also positively correlated with the occurrence of severe childhood asthma (OR = 1.15, 95%CI: 1.11∼1.20).

CONCLUSION

Pet ownership, especially cats and dogs, is associated with the occurrence of asthma in children.

Dog keeping at home before and during pregnancy decreased the risk of food allergy in 1-year-old children

Introduction

The relationship between allergen exposure to animals in pregnancy and the development of allergic symptoms is not clear.

Aim

To evaluate the association between prenatal and postnatal exposure to pet ownership and development of atopic dermatitis, food allergy and wheezing in children at the age of 1 and 2.

Material and methods

The mother-child pairs included in this study were part of the Polish Mother and Child Cohort. Mothers in each trimester of pregnancy and 1 year after childbirth have completed a questionnaire on animal exposure. Children's health status was assessed at around one year and two years of age.

Results

Keeping a dog at home before and during pregnancy (every trimester) decreased the risk of food allergy in the first year of life. On the other hand, keeping any animal other than a dog (cat, hamster, guinea pig, rabbit) before pregnancy and during each trimester separately increased the risk of food allergy in the first year of life of children. Keeping a guinea pig in the first trimester of pregnancy increased the risk of wheezing in the first year of life. The analysis did not show any significant associations between keeping animals at home before and during pregnancy and the occurrence of atopic dermatitis in the second year of life.

Conclusions

Keeping a dog at home before and during pregnancy decreased the risk of food allergy in 1-year-old children. This effect was eliminated in case of having a cat, hamster, guinea pig, or rabbit.

Pre-natal and post-natal exposure to pet ownership and lung function in children: The Seven Northeastern Cities Study

To evaluate the association between pre-natal and post-natal exposure to pet ownership and lung function in children, a cross-sectional study named Seven Northeastern Cities (SNEC) study was conducted. In this study, children's lung function including the forced expiratory volume in 1 second (FEV₁ ), forced vital capacity (FVC), maximal mid-expiratory flow (MMEF), and peak expiratory flow (PEF) were measured by spirometers, and pet ownership situations were collected by questionnaire. Analyzed by multiple logistic regression and generalized linear modeling, we found that for all subjects, pet exposure in the first 2 years of life was significantly associated with lung function impairment of FVC<85% predicted (adjusted odds ratio [aOR]=1.28; 95% confidence interval [CI]: 1.01, 1.63). For current pet exposure, the increased odds of lung function impairment ranged from 35% (aOR=1.35; 95%CI: 1.12, 1.62) for FVC<85% predicted to 57% (aOR=1.57; 95%CI: 1.29, 1.93) for FEV₁ <85% predicted. The in utero exposure was not related to lung function impairment. Compared with other pets, higher odds were observed among children with dogs. When stratified by gender, girls with current pet exposure were more likely to have lung function impairment than boys. It implies self-reported exposures to pets were negatively associated with lung function among the children under study.