June 21, 2012
Dogs: Saving Your Family From The Dangers Of Asthma
A new study released this week is sure to cause cat owners everywhere to bristle with envy. As it turns out, Man´s Best Friend may be able to do more than fetch and protect your family from intruders. Having a dog in the house could also protect your family against respiratory infection linked to asthma, as well as lessen your chances of catching the common cold.
It´s not so much the dogs themselves which protect against these microbial attacks, simply their presence in the house. New research from the University of California, San Francisco (UCSF) suggests house dust from homes with dogs can work to protect against these infections. The research was presented at the 2012 General Meeting of the American Society for Microbiology.
“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.
Dr. Susan Lynch, a co-investigator of the study and professor at UCSF told ABC´s Good Morning America, “Mice aren't identical to humans. There are obvious differences, but we can do things in the animals that we could not possibly do in humans, and we can get samples to examine disease that would be very difficult to assess in humans."
To conduct the study, Fujimura and team compared three different groups of mice. One group was fed house dust from homes with dogs before being infected with RSV, a second group was infected with RSV but had no exposure to the house dust, while a third group acted as the control. According to a statement announcing the study, Fujimura said, “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.”
The team chose to test the mice with RSV due to its wide exposure. Nearly everyone has been exposed to the virus within their first few years of life. Though it´s seen almost everywhere, it can sometimes be severe and even fatal in premature and chronically ill infants. RSV is also the leading cause of respiratory diseases, such as bronchitis and pneumonia. It has even been associated with an increased risk of developing asthma.
Fujimura says their study isn´t the first time dog ownership has been associated with protecting children against asthma. In fact, her team has also recently demonstrated the composition of house dust with cats or dogs in the home is much different from house dust without animals on a bacterial level.
“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.”