Can a child with asthma live with a cat: what the research shows
Parents of children with asthma often face a painful question: is it okay to keep a cat at home or will it increase the risk of attacks? A major new study from Sweden shows that the mere fact of living with a cat was not associated with a more severe course of asthma in children with already diagnosed asthma and allergies.
Researchers from the Karolinska Institute and Clinical Centres in Sweden analysed data from 30,277 children aged 4 to 17 years. They compared asthma in children who lived in a household with a cat with those who did not have a cat at home.
An important caveat: this does not mean that cats are "safe for everyone" or that a child with allergies can have a pet without consulting a doctor. The study was observational: it shows no discernible association in this group of children, but does not prove a universal causal pattern.
Details
The study included children born in Sweden between 2006 and 2020. All had confirmed diagnoses of asthma and respiratory allergies. The scientists used data from national registers: medical diagnoses, requests for specialised care, prescriptions for medication, and information about cats from the Swedish National Cat Register.
Exposure to cats was determined simply: whether the child's parents had at least one cat registered in 2023. There were 2,862 such children, or 9.4 per cent of the total sample. The children were followed for 24 months, from 2023 to 2024.
The main indicators were asthma exacerbations and moderate-to-severe or severe asthma. An exacerbation was defined as an emergency or unplanned access to specialised care because of asthma or frequent dispensing of rapid-acting medication. Disease severity was assessed by prescribed medication.
The results were very similar in both groups. Asthma exacerbations occurred in 3.3% of children who lived with cats and in 3.5% of children without cats at home. Moderate or severe asthma occurred in 9.6% of children in the group with cats and 10.1% of children in the group without cats. After adjusting for age, sex, baseline asthma severity, parental allergy, socioeconomic factors and other parameters, no significant association was found between cats and worsening asthma.
In a fraction of the children - 1,428 - additional data were available: an asthma control test and spirometry, that is, lung function measurements. Here, too, the scientists saw no differences between children with and without cats. Nor did it matter how many cats were in the house, what sex and age they were.
One possible explanation is that cat allergens are not only found in homes where cats live. They can be brought in on clothing and are found in schools, transport and other public places. So a child without a cat at home can still come into contact with cat allergens on a regular basis.
But the work has limitations. The scientists did not know which allergens the children were sensitive to, did not have complete information on the duration of cat ownership, and could not perfectly account for all cases where a cat was in the family but did not make it into the new national registry. In addition, the results were obtained in Sweden and may not be fully transferable to other countries with different climates, housing conditions and pet ownership habits.
Why it is important
For families where a child already has asthma and allergies, the question of pets often becomes a source of anxiety. Cats are often perceived as an obvious risk factor, but scientific evidence on the topic has long remained conflicting.
The new work is important because it does not rely on a small group of patients and not only on parental surveys, but on large national registries. It shows: in this Swedish cohort, a cat in the house alone was not associated with more frequent seizures, heavier treatment or worse lung function.
The practical conclusion should be cautious. The study does not override individual cat allergy or replace the advice of an allergist or paediatrician. In a particular child, contact with a cat may still cause symptoms, especially if sensitisation to cat allergens is confirmed.
Background
Asthma is one of the most frequent chronic diseases in children. Its course depends on many factors: heredity, infections, air pollution, tobacco smoke, obesity, allergic rhinitis, eczema and other allergic conditions.
Pets have long been a controversial topic in allergology. On the one hand, animal hair, dander, saliva, and skin particles can carry allergens and provoke symptoms in sensitive people. On the other hand, studies do not always show a simple link between having a pet at home and worsening asthma.
The authors of the new paper emphasise: previous studies were often small, selective or relied on self-reports. A large sample from national registers therefore helps to clarify the picture, although it does not remove all questions. It is particularly important to further study children with a confirmed sensitivity specifically to cat allergens.
Source
Study: Resthie R. Putri, Cecilia Lundholm, Anna Hedman, Mwenya Mubanga, Hanna Karim, Jon R. Konradsen, Catarina Almqvist. Cat exposure and asthma outcomes in a cohort of children with asthma and allergy. Frontiers in Allergy, 2026.