I been a vet tech for 40 years parvo is a DNA it lives up to 2 years in the ground some times more bleach and heat kills parvo in your yard parvo can get stuck to a person and they can spread parvo if you had a pet die from parvo please dont get a other one right away even with 1st shots a pet can still get parvo if the next door neighbor pet had parvo it could travel to your house so i hope this helps out alot of people my heart goes out to all who lost a loved