“In this study we found that feeding mice house dust from homes that have dogs present protected them against a childhood airway infectious agent, respiratory syncytial virus (RSV). RSV infection is common in infants and can manifest as mild to severe respiratory symptoms. Severe infection in infancy is associated with a higher risk of developing childhood asthma,” says Kei Fujimura, a researcher on the study.
In the study Fujimura and her colleagues compared three groups of animals: Mice fed house dust from homes with dogs before being infected with RSV, mice infected with RSV without exposure to dust and a control group of mice not infected with RSV.
“Mice fed dust did not exhibit symptoms associated with RSV-mediated airway infection, such as inflammation and mucus production. They also possessed a distinct gastrointestinal bacterial composition compared to animals not fed dust,” says Fujimura.
Pet ownership, in particular dogs, has previously been associated with protection against childhood asthma development, says Fujimura. Recently she and her colleagues demonstrated that the collection of bacterial communities (the microbiome) in house dust from homes that possess a cat or dog is compositionally distinct from house dust from homes with no pets.
“This led us to speculate that microbes within dog-associated house dust may colonize the gastrointestinal tract, modulate immune responses and protect the host against the asthmagenic pathogen RSV,” says Fujimura. “This study represents the first step towards determining the identity of the microbial species which confer protection against this respiratory pathogen.”
We still don’t understand what causes allergies. There is compelling research that lack of exposure to common pathogens early in life causes the immune system to over-react later causing allergies (there are other factors too, of course). I have long believed that early exposure to common pathogens (like dog hair) may actually have a preventative effect.
So the message is – get a dog.