In the center of the house, the tools which could grind wheat into flour were covered with thick dust and the trace of mice, a rude donkey saddle and some stained sacks lying nearby it.

A new study published Monday found that exposing mice to dust from households where dogs were allowed outdoors significantly changed the composition of gut microbes in the mice.

Mice who ate the dog dust were protected against RSV infection symptoms, like inflamed, mucus-coated airways, suggesting exposure helped them stave off the virus.