Living with cats is not likely to aggravate asthma in those with the condition, a new study of over 30,000 children suggests.
Asthma is one of the most common causes of hospitalisation among children, with nearly 1 in 10 children and adolescents living with the condition.
The prevalence varies across countries, regions, and environments, with as many as 1 in 5 children living with asthma in the British Isles and parts of the Middle East and Oceania.
Air pollution, smoking, childhood viral infections, obesity, and pre-existing allergies like eczema or hay fever are known to be risk factors, with some patients also self-reporting that exposure to animal dander sometimes triggers asthma attacks.
However, clinical data proving that animal hair triggers asthma has been minimal, coming mostly from small studies.
Now, scientists have shown that sharing a home with cats is not likely to worsen the outcomes of children with asthma and allergies.
“Here we show in a nationwide cohort of children in Sweden with asthma and allergies, that children living with a cat had similar asthma severity, exacerbation, asthma control, and lung function to children living without cats in the short term,” said Resthie R Putri, an author of the new study published in the journal Frontiers in Allergy.
“We also did not see any differences in asthma outcomes related to the number of cats, the cat’s sex, or the cat’s age,” said Dr Putri, a post-doctoral researcher from Karolinska Institutet in Stockholm.
The study analysed health data from 30,277 children between four and 17 years old diagnosed with asthma or an airway allergy.
Participants were observed for over 24 months until 2024 to track asthma outcomes, drawing records on their diagnoses, emergency hospital visits, prescribed medications, asthma control test and spirometry tests.
About 1 in 10 children involved in the study lived in a household that had at least one cat as of 2023.
This data was obtained from Sweden’s National Cat Register, where registering one’s pet cat is mandatory for all such felines born after 2008.
The analysis revealed that there was no significant association between exposure to pet cats and asthma outcomes.
Scientists found that moderate-to-severe asthma, based on prescribed asthma medications, occurred in 1 in 10 of the cat-exposed children compared to the same 10 per cent of the non-exposed children.
Asthma flare-ups occurred in just over 3 per cent of the cat-exposed children, and nearly the same fractions of the non-exposed children.
“One possible explanation is that cat allergen exposure is very common, even outside the home,” explains Dr Putri.
“Children who do not have cats at home may still be exposed in shared environments such as schools or public transportation, which could explain why we didn’t see a difference,” she says.
