Other studies have found this same association - that living with a dog or farm animal has health benefits such as lower risk of allergies and asthma. In a Swedish nationwide study looking at over a million children, the association between early exposure to dogs and farm animals and the risk of asthma was evaluated. All children born in Sweden from January 1, 2001, to December 31, 2010 were included. The researchers found that exposure to dogs and farm animals during the first year of life reduces the risk of asthma in children at age 6 years. From Science Daily:
A team of Swedish scientists have used national register information in more than one million Swedish children to study the association of early life contact with dogs and subsequent development of asthma. This question has been studied extensively previously, but conclusive findings have been lacking. The new study showed that children who grew up with dogs had about 15 percent less asthma than children without dogs.
A total of more than one million children were included in the researchers' study linking together nine different national data sources, including two dog ownership registers not previously used for medical research...."Earlier studies have shown that growing up on a farm reduces a child's risk of asthma to about half. 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 percent less asthma than children without dogs.
"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. 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" says Catarina Almqvist Malmros, senior author on the study, Paediatrician at Astrid Lindgren Children's Hospital and Professor in Clinical epidemiology at Dept of Medical Epidemiology and Biostatistics at Karolinska Institutet, Stockholm.