http://www.hoof-smart.com/2010/02/16/horse-health/targeting-small-strongyles-with-fenbendazole-purge-deworming/ ALBENDAZOLE AND IVERMECTIN do not claim to treat the encysted larvae that keep re-infecting once they come out of hibernation which can be years later. moxidectin was used in a trial for humans. http://www.ncbi.nlm.nih.gov/pubmed/14517193 I am at the point where the encysted ones are my only problem at this point. I did ICUS protocol almost to the letter for 7 months and have kept control to a minimum. the advice I got was from a farm vet on treating the encysted EL3 AND L3 larvae. the 1st link was from farm vet and the 2nd I saved from another post from someone on curezone about moxidectin in human studies.