Hmmm...possibly Ivermectin??? And when worming with Wazine most observe an egg withdrawal. It really comes down to whether someone might react to the active ingredients in the med/treatment. You're not supposed to eat the meat/eggs when giving antibiotics. But I've used amoxicillin and my husband/son ate the eggs just fine. I'm allergic to amoxicillin, so I did not eat the eggs for two weeks. But most folks don't know whether they'd have an issue with some wormers or meds, so would not risk it. I've used Frontline on my cats/dogs (and even my alpacas) many times, and gotten it on my hands and such. So I don't think anything of eating an egg from a hen that's been treated topically... But my way is not necessarily the best way!!