Growing up with a dog in the house may lower a child’s risk of developing asthma, according to a new Swedish study. The research, published Nov. 2 in the journal JAMA Pediatrics, found that exposure to dogs at a young age is associated with a reduced risk of asthma at age 6.
“Earlier studies have shown that growing up on a farm reduces a child’s risk of asthma to about half,” lead study author Tove Fall, assistant professor in epidemiology at Sweden’s Uppsala University, said in a news release. “We wanted to see if this relationship also was true for children growing up with dogs in their homes.”
For the study, Fall and her colleagues analyzed over a million records from all Swedish children born from Jan. 1, 2001 to Dec. 31, 2010. The records were cross-referenced with information about their families’ medical history and, because dog ownership registration has been mandatory in Sweden since 2001, with pet and farm ownership.
The researchers looked at the rates of asthma among preschool children ages 1 to 5 and at 6-year-old schoolchildren. “Because we had access to such a large and detailed data set, we could account for confounding factors such as asthma in parents, areas of residence and socioeconomic status,” Fall said in the news release.
Findings showed that children who grew up with dogs in the home were nearly 15 percent less likely to develop asthma than those who were not exposed to dogs. The study also confirmed previous research that showed children who grow up around farm animals have lower rates of asthma.
While the study did not address why the presence of a dog in the home during a child’s early years may buffer him or her from asthma, the authors offered several possible explanations. “It might be due to a single factor or more likely, a combination of several factors related to a dog-ownership lifestyle or dog-owner’s attitudes, such as kids’ exposure to household dirt and pet dust, time spent outdoors or being physically active,” Fall told CBS News.
“One of the main hypotheses at the moment is that kids in animal environments breathe air that contains more bacteria and bacterial fragments, which could actually lower their risk of asthma,” Fall added. “As a parent in a dog-and-baby household, it is nearly impossible to keep everything clean, and maybe this is a good thing for your baby’s future health.”
However, Fall cautioned against bringing a furry friend into the house if your child is already allergic to dogs. She also emphasized that the study shows a correlation, but does not prove that having a dog will prevent asthma.
“We are quite sure that our findings are robust concerning the lower risk of asthma in Swedish dog households, but with this type of study we can never be sure that the dog in itself protects the baby from asthma,” Fall said.