We all love to pet our dogs but health experts say its crucial that we wash our hands to avoid putting our health at risk. A 2009 study even found that dogs were more likely to swap germs with their owners through petting than by sleeping next to them in bed. Medical experts told 'Best Life Online' that if you don't wash your hands after petting your pooch, you could pick up parasites, a bacterial infection or a fungal skin infection. You may even transfer an illness to your other pets.