if you do moxidectin only 1 dose a month is needed as it has a very long half life of 20 plus days. ivermectin is not needed when taking moxidectin , I was told by farm vets that a 5 day fenbendazole double dose can be taken 2 weeks later and i did this with no ill effects. that was for this month of june and I will only take moxidectin once a month for july ,august and September with no other meds.