A team of researchers at the University of Gothenburg has found that when infants live with pets, they grow up to have fewer allergies and other diseases. In their paper published on the open access site PLOS ONE, the group describes their study of datasets that held information on children's health and whether they had lived with pets as infants, and what they found.

It is commonly believed that allowing infants and children to come into contact with germs helps their immune system to grow stronger, offering them more protection later in life. In this new effort, the team in Sweden sought to learn more about the possible benefits of germ exposure to infants living with pets in their home.

The study by the team consisted of analyzing data from databases built around two previous studies that involved tracking childrens' health and which also held information about pets in their homes. One of the datasets included information for 1,029 children that were either seven or eight years old. In that dataset, the researchers found that the incidence of allergies (which in this study included asthma, eczema, hay fever and allergic rhinoconjunctivitis) was 49 percent for children who had not been exposed to pets as infants. That number fell to 43 percent for children who had lived with a single pet as an infant and to 24 percent for children who had lived with three pets.

The second dataset held information on 249 children— it showed that the allergy rate for children growing up without a pet was 48 percent, 35 percent for children with one pet and just 21 percent for children who had grown up with multiple pets.

The researchers suggest that taken together, the two datasets show that the more exposure infants have to pets, they less likely they are to develop allergies later in life. They also note that having pets is just one way to reduce allergy risk, other factors such as being born vaginally, living on a farm and having more siblings have also been shown to reduce the risk—as has parents sucking on a baby's pacifier before handing it to them.

More information: Bill Hesselmar et al. Pet-keeping in early life reduces the risk of allergy in a dose-dependent fashion, PLOS ONE (2018). DOI: 10.1371/journal.pone.0208472

Journal reference: PLoS ONE