I have used poultry dust in the pen and a dose of ivermec inj in water can do at same time i have also used frontline a tiny bit on head and a tiny bit around vent (Make sure you do not spray on vent) but i wait about 2-3 weeks after the iver. The frontline is long lasting and strong so be careful. I would repeat with the ivermec again aprox 2-3 wks after frontline give a dose of vita electro and probiotic after each treatment. After these repeated doses you can add oregano to their diet to help as a preventative. hope that helps