A national study of more than 30,000 children found that living with a cat was not associated with better asthma control, worse lung function, or asthma recurrence, calling into question long-standing concerns about cat ownership in families managing childhood asthma.
Study: Cat exposure and asthma outcomes in a cohort of children with asthma and allergies. Image credit: Anna Nass/Shutterstock.com
In recent research, Allergy frontier evaluated the association between exposure to cats and asthma outcomes in children with established asthma and allergies.
Cat ownership remains controversial in asthma settings
Asthma is a chronic respiratory disease characterized by airway inflammation and hyperresponsiveness that frequently affects children around the world. Environmental exposures, particularly contact with companion animals, are increasingly recognized as important factors influencing asthma management. Although furry animals are often evaluated collectively in risk assessments, different allergen profiles and patterns of human-animal interactions across species can differentially impact asthma prevalence.
Despite high cat ownership in Europe, clinical recommendations for managing cat exposure in children with asthma are inconclusive. The majority of existing research has focused on the effects of childhood exposure to cats on the risk of developing asthma and allergic rhinitis, with relatively little attention paid to the effects of continued exposure in children who have already been diagnosed with asthma.
Current evidence regarding the relationship between cat exposure and asthma morbidity in this population is inconsistent. Some studies report no independent association, while others suggest sensitization and viral infection as more important determinants.
Notable research gaps include limited sample size, selective recruitment, and primary reliance on self-reported clinical outcomes. Additionally, the influence of specific cat characteristics on domestic allergen abundance and subsequent asthma morbidity has not been well investigated. As a result, it remains uncertain whether these factors meaningfully influence asthma outcomes, highlighting the need for comprehensive population-based studies that address these methodological limitations.
Does exposure to cats affect asthma outcomes in children?
The current cross-sectional cohort study included all children aged 4 to 17 years with asthma and airway allergies born in Sweden between 2006 and 2020. Asthma and allergic rhinitis diagnoses were confirmed using a validated algorithm based on diagnosis and drug codes. Children were excluded if they had migrated, died, or if parents’ sociodemographic data were missing.
Cat exposure was defined as parent cat ownership recorded during 2023. Asthma outcomes were tracked in 2023 and 2024, focusing on asthma exacerbations, asthma severity, Asthma Control Test (ACT) scores, and forced expiratory volume in 1 second (FEV1).
Asthma exacerbation was defined as either an emergency or unplanned hospital visit, a specialist asthma outpatient visit, or four or more administrations of short-acting beta2-agonist (SABA) within 1 year. Moderate to severe asthma was classified using dispensed asthma medications and adapted Global Initiative on Asthma (GINA) treatment steps.
Children were considered to have moderate-to-severe asthma if they were receiving multiple controlling medications, such as an inhaled corticosteroid (ICS) in combination with a leukotriene receptor antagonist (LTRA) or a long-acting beta2 agonist (LABA), or if they were prescribed theophylline or a biologic.
Exposure to cats is not associated with more severe asthma in children
From an initial cohort of 32,010 children with persistent asthma and allergies, 1,733 were excluded due to migration, death, or missing parental data. The resulting study population consisted of 30,277 children with a median age of 9.5 years. 38.6% were female and 9.4% had contact with cats.
Compared to the unexposed group, the cat-exposed group had a higher proportion of females, similar initial asthma severity, and similar parental asthma and allergy history. The frequency of severe allergic rhinitis was 11.5% in the cat-exposed group versus 14.2% in the unexposed group.
Asthma exacerbations occurred in 3.3% of the cat-exposed group versus 3.5% of the unexposed group. Moderate to severe asthma affected 9.6% of the cat-exposed group and 10.1% of the unexposed group. Cat exposure was not significantly associated with asthma-related endpoints, and effects did not vary by age or gender.
In a subset of 1,428 children with both ACT and FEV1 data, including 97 exposed to cats, this group was older and had more severe baseline asthma and allergic rhinitis than the overall cohort. Uncontrolled asthma was reported in 22.3% of the unexposed group and 16.5% of the cat-exposed group, but this difference was not statistically significant. ACT and FEV1 z-score distributions, mean FEV1 z-scores, and FEV1/FVC ratios were comparable between groups, indicating that cat exposure did not affect lung function or airway restriction.
Within the cat-exposed group, asthma outcomes were not affected by cat number, sex, or age. Similar null results were obtained when excluding children exposed to dogs. Bias analysis for possible exposure misclassification was inconclusive as adjusted odds ratios ranged above or below 1 across all scenarios.
The researchers noted that because the Swedish National Cat Registry was only recently established, cat exposures may be under-recorded, and some cat-owning households may be classified as not exposed.
Cat ownership was not associated with worse outcomes in childhood asthma
Children with asthma and allergies showed no association between cat exposure and asthma exacerbations, severity, lung function, or asthma control. These findings suggest that exposure to cats may not adversely affect asthma outcomes in this population. This information can help families and clinicians make informed decisions about pet ownership for children with asthma or allergies.
However, some limitations should be considered. This study lacked data on allergen-specific IgE sensitization, patterns of monosensitization and polysensitization, previous cat ownership, duration of cat ownership, and whether cats were primarily kept indoors or outdoors. These factors may influence asthma severity but could not be assessed in the current analysis.
The authors also cautioned that these findings apply particularly to children with established asthma and airway allergies and should not be generalized to non-allergic asthma. Differences in pet ownership, climate, and environmental exposure may also limit the applicability of the findings to other countries and populations.
Importantly, previous studies have reported different associations between exposure and asthma outcomes in dogs, so the researchers noted that the lack of an association in cats should not be assumed to apply to all furry animals.
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Reference magazines:
- Putri, R. R., Lundholm, C., Hedman, A., Mubanga, M., Karim, H., Konradsen, J. R., and Almqvist, C. (2026). Cat exposure and asthma outcomes in a cohort of children with asthma and allergies. Frontiers in Allergy, 7, 1840756. Doi: https://doi.org/10.3389/falgy.2026.1840756. https://www.frontiersin.org/journals/allergy/articles/10.3389/falgy.2026.1840756/full
