More Pets, Less Asthma?

Asthma risk may be lowered with childhood exposure to dogs, farm animals


If you're an animal lover, your children may be in luck. New evidence suggests that Fido may play a role in childhood asthma risk.

A new study from Sweden found that exposure to dogs or farm animals during a child's first year of life may reduce the risk of developing asthma by age 6.

"For what we believe to be the first time in a nationwide setting, we provide evidence of a reduced risk of childhood asthma in 6-year-old children exposed to dogs and farm animals," wrote study co-author Tove Fall, PhD, an associate professor of epidemiology at Uppsala University in Sweden, and colleagues. "This information might be helpful in decision making for families and physicians on the appropriateness and timing of early animal exposure."

Asthma is a condition in which the airways can narrow, swell and produce excess mucus, making it difficult to breathe.

For this study, Dr. Fall and team looked at the potential link between asthma risk and early animal exposure in Swedish children born between 2001 and 2010. Of the more than 1 million children born during that time, 376,638 preschool-age and 276,298 school-age children were included in this analysis.

These researchers used data from the Swedish registry on dog and farm animal registration, asthma medication and diagnosis, and potential confounding factors like parental asthma or whether a child was first-born.

Dr. Fall and team found that 14 percent of preschool-age children and 8.2 percent of school-age children were exposed to dogs, while 0.5 percent of preschool-age children and 0.3 percent of school-age children were exposed to farm animals.

About 5 percent of preschool-age children exposed to animals experienced an asthmatic event before age 7. For school-age children, that figure was about 4.2 percent.

In school-age children, dog exposure before age 1 was tied to a 13 percent lower risk of asthma. Farm animal exposure was tied to a 52 percent lower risk.

In preschool-age children, farm animal exposure before age 1 was similarly tied to a 31 percent lower risk of asthma. However, dog exposure was only tied to a reduced risk of asthma in children age 3 or older.

This study was published online Nov. 2 in the journal JAMA Pediatrics.

The Swedish Research Council, the Stockholm County Council, the Strategic Research Program in Epidemiology at Karolinska Institutet and the Swedish Heart Lung Foundation funded this research.

Several study authors disclosed potential conflicts of interest.