Early-life cat and dog ownership may potentially exacerbate the risks associated with cat- and dog-specific allergic sensitization, according to a study published in The Journal of Allergy and Clinical Immunology. However, the findings do not support early-life cat and dog ownership increasing the risk of school-age asthma. Angela Pinot de Moira, PhD, and colleagues studied associations of early-life cat and dog ownership with school-age asthma, including the role of type (cat vs dog), timing (never, prenatal, or early childhood) and degree (number) of ownership, and the role of allergic sensitization. They harmonized data from 77,434 mother-child dyads (aged 5-11) from nine birth cohorts. Associations were examined using adjusted logistic regression models, fitted separately for each cohort, and combined using random-effects meta-analysis. Cat and dog ownership were not associated with catand dog-specific allergic sensitization. However, cat- and dog-specific allergic sensitizations were strongly associated with school-age asthma.