I had a avian vet give me deworming medicin last year for my flock. Pyrantel is what it is called. The bottle says to give .1 cc per pound, ever 3 months, 2 weeks in a row. It is for some sort of worm in the soil. I have been using 5% seven dust in the run and in the chicken yard also, I dont know if this kills the worm. But it does get rid of the mites.