Many of the HW meds are Ivomec based which does not kill hooks - only Safeguard does and it's a 3 day treatment. So said my vet last month. There's a granule safeguard, a liquid or he said larger dogs can use the horse paste at double the dose on the weight syringe. He said that's the only thing that gets hookworms and whipworms. Ivomec does not.