Early dog exposure linked to lower asthma risk in children, study finds

Exposure to dog-related allergens in the first months of life may lower the risk of childhood asthma, a new study suggests. Researchers analyzed dust from the homes of 1,050 infants aged three to four months and followed them to age five. Over the follow-up period, 6.6% were diagnosed with asthma. Higher exposure to Can f1, an allergen shed by dogs, was associated with a 48% reduction in asthma risk compared with infants with lower exposure. The protective effect was strongest among children with a higher genetic risk for poorer lung function. By contrast, exposure to cat allergens or bacterial endotoxins showed no protective association. The findings were presented by Dr. Jacob McCoy of the Hospital for Sick Children in Toronto at the European Respiratory Society Congress in Amsterdam.

Researchers also reported that dog allergen exposure correlated with better lung function, measured by a standard spirometry test that records how much air a child can blow out in one second after a full breath. The team stressed that the mechanism is not yet understood, but they suggested early exposure to dog allergens could influence immune development or the nasal microbiome in a way that reduces sensitivity. They noted that dog allergen exposure was associated with better lung function and lower asthma risk, whereas cat allergens showed no protective effect. They cautioned that once a child becomes sensitized to dog allergens, symptoms can worsen, and more research is needed to understand the long-term implications of early exposure.

Dr. Erol Gaillard, who chairs the European Respiratory Society’s paediatric asthma and allergy expert group, said the results are intriguing but preliminary, and longer-term studies are needed to determine how living with pets might affect developing lungs. Sarah Sleet, chief executive of Asthma and Lung UK, noted that past guidance often recommended removing pets from families with wheezy children, but she called the new findings fascinating and underscored the need for more research and greater investment in lung health to understand how asthma develops and how it can be prevented or treated.

In a separate presentation at the same European Respiratory Society Congress in Amsterdam, researchers described a robot-assisted bronchoscope designed to improve early diagnosis of lung cancer. In a study of 78 patients with abnormal lung growths, 39 were treated with the robot-assisted kit in addition to CT guidance, while 39 received standard biopsy procedures. Using traditional techniques, doctors were able to reach and biopsy about 23% of the tumours. With the robot-assisted system, biopsy success rose to more than 84%. The robotic kit costs around one million euros and is intended to augment, not replace, existing imaging and biopsy approaches.

Experts caution that while the dog-allergen study offers potential insight into early-life factors that may reduce asthma risk, it does not establish a prescription for dog ownership as a preventive measure. The findings add to a growing but incomplete picture of how household environments influence allergy and lung development, and they highlight the need for additional research into immune development, microbiome interactions, and the long-term outcomes of early allergen exposure.