A recent study shows that living with dogs reduces a child’s risk of asthma by 15%.
According to experts, living in extremely clean conditions early in life can increase a person’s susceptibility to allergies. In fact, the researchers found that contact with farm animals significantly reduces a child’s chances of developing allergies.
Experts say the findings can be explained by the hygiene hypothesis which suggests that living in too-clean conditions decreases the body’s resistance to allergy conditions like asthma.
The researchers analyzed data of 1 million children born between 2001 and 2010 in Sweden.
Exposure to dogs during the first year of life was associated with a 15% lower likelihood of childhood asthma, while living close to farm animals reduced the risk by 52%.
According to the hygiene hypothesis, the lack of early exposure to microbes and parasites may prevent a young child’s immune system from developing properly. As a result, a lack of natural checks on unwanted immune responses lead to allergies.
“Earlier studies have shown that growing up on a farm reduces a child’s risk of asthma to about half,” Lead researcher Dr. Tove Fall, of Uppsala University in Sweden, said in a statement. “We wanted to see if this relationship also was true also for children growing up with dogs in their homes.
“Our results confirmed the farming effect, and we also saw that children who grew up with dogs had about 15% less asthma than children without dogs.”
“Because we had access to such a large and detailed data set, we could account for confounding factors such as asthma in parents, area of residence and socio-economic status.”
In Sweden, dog and farm animal ownership are required to be registered by law, visits to a specialist physician and their prescription is always recorded. This organized system of national databases is accessible by scientists.
“These kind of epidemiological studies look for associations in large populations but do not provide answers on whether and how animals could protect children from developing asthma,” co-author Prof Catarina Almqvist Malmros, of Sweden’s Karolinska Institute, said. “We know that children with established allergy to cats or dogs should avoid them, but our results also indicate that children who grow up with dogs have reduced risks of asthma later in life.
“Thanks to the population-based design, our results are generalizable to the Swedish population, and probably also to other European populations with similar culture regarding pet ownership and farming.”
The study was published in the journal JAMA Pediatrics.