The researchers drew on data from all of the 1 million plus children born in Sweden from 2001 to 2010
They found that 5% of those in the pre-school age group were treated for asthma symptoms, while 4.2% developed asthma symptoms when they were aged 6.
Dogs and farm animals have similar preventive effects
They conclude that babies exposed to dogs during the first year of life had a 13% lower risk of asthma before school age. Exposure to farm animals was associated with a 31% lower risk of asthma during pre-school years and a 52% lower risk of asthma in school-aged children.
"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," the authors say. "This information might be helpful in decision making for families and physicians on the appropriateness and timing of early animal exposure."
Tove Fall also commented that the study result is in line up with the hygiene hypothesis that favours exposure to dust and dirt to improve our tolerance of common allergens. He says couples who are pregnant or are planning to have a baby shouldn't worry about getting a dog or a puppy if they want one.
However, she stresses that getting a dog will not cure a child's allergies and could make them worse.
'More studies needed' suggested Erika Kennington, Head of Research at Asthma UK.
News source: Web MD asthma Health Center