2 doses first time, ideally 7 days apart, 10 days is the outside desired limit. Then 1 dose every 3 months for ivermectin. See also http://piggyville.com/index.php?id=9 , Ann Evan's website. Do you have any questions about the Panacur? I am not a vet or or vet tech. Just a piggy mom to Sammy now, the Penny Giggles at the bridge. Sandy