Overview

• Researchers from The Hospital for Sick Children analyzed dust from the homes of 1,050 infants at 3–4 months in the Canadian CHILD cohort and followed them to age five, with results presented in Amsterdam.
• Higher levels of the dog allergen Can f1 in early-life household dust were associated with about a 48% lower likelihood of a doctor-diagnosed asthma by age five.
• Children with greater early exposure to dog allergen also showed better lung function at five years, measured by forced expiratory volume in one second (FEV1).
• The association appeared stronger among children with higher genetic risk for poorer lung function.
• No protective link was found for the cat allergen Fel d1 or for bacterial endotoxin, and both the study team and independent experts emphasized the need for replication and peer-reviewed validation.