I was just at the veterinarian with my Alaskan Malamute puppy of 12 weeks and took a fresh stool sample that showed round worm eggs. We weren't able to take a sample on the first visit and he was still treated for the worms. They told me that there was no way to get rid of them in your yard, except to burn the grass in the area. I thought that the snow and cold would kill them out, but they said it wouldn't. I do clean up the stools as soon as the dog does his business and then pour hot water with a little dishwash soap over the area.