I DO NOT deworm unless worms are present. I take a stool sample to the vet for an exam, if worms are present, then I deworm.....I haven't ever had worms in any litters, nor would I EVER deworm a puppy at the age of 2 weeks! No need to inject chemicals & poisons into their system if not needed! BYW, mine play in the grass, leaves and landscaping, I don't have any dirt but if I did they would play in that too!