German researchers have found that having a dog in the house reduces the risk that young children will develop allergies. The result stems from a six-year study of 9,000 children, in which parents answered detailed questionnaires about possible allergic symptoms in their kids. Blood samples were also taken from some children to test for antibodies to common allergies.

The reason behind the results is unclear, but scientists believe early exposure to germs carried in the pet’s fur can help children’s immune systems develop. The same effect was not seen in kids who frequently interacted with dogs but didn’t have one in the home.

The study was performed at the National Research Centre for Environmental Health in Munich, Germany, and the results were published in the European Respiratory Journal.