Continual early exposure to dogs may alleviate asthma

According to a presentation given during the American Academy of Allergy, Asthma and Immunology (AAAAI) meeting February 23-27 at the San Diego Convention Center, exposure to dogs in infancy and early childhood is associated with reduced symptoms of asthma.

“Dog Exposure at Birth Through Age 3 Reduces the Risk of Asthma at Age 6” was authored by a dozen researchers at the University of Wisconsin’s School of Medicine and Public Health and was presented by Nicholas Hallett at the AAAAI convention. “We are interested in determining what dog exposure at birth would have on further immune development,” Hallett said.

The work was part of the Childhood Origins of ASThma (COAST) project and evaluated the relationship of pet ownership on asthma diagnosis and wheezing on 253 children. The children enrolled in the program have at least one parent with a history of allergies or asthma.

The children were divided into four groups: those whose families had dogs both at the child’s birth and age three, those with dogs at birth but not at age three, those with dogs at age three but not at birth, and those without dogs at either age. “Dog exposure significantly reduced the number of children who had positive RASTs [Radialallergosorbent tests] for any allergen,” Hallett said.

Of the four groups studied, 18 percent of the children who had dogs at both birth and age three were diagnosed with symptoms of asthma by age six while 34 percent of children who didn’t have dogs at either age were diagnosed. Those with dogs at age three but not at birth had a 31 percent asthma rate while those with dogs at birth only had a 25 percent rate.

“Effects on immune development are less pronounced by age three,” Hallett said. “We conclude that there may be a developmental window.”

The COAST project also explored cat ownership and ownership of both cats and dogs but did not find such a correlation between cat ownership and reduced asthma rates. “Dogs only was the only one that seemed to be significant,” Hallett said.