That's fine. Buy it, or maybe splurge and get their health pack, which is probably less expensive at Jeffers, but you should also find a vet to do routine fecals for you.i told them what you said. this is what they said- Zyfend A is unique in that it doesn't kill parasites; rather, it helps to break down their defenses so that the chicken's own, natural defenses can effectively kill the parasites. Once compromised by Zyfend A, the chicken's immune system, stomach acids, and "good" gut bacteria will all work in concert to clear out intestinal parasites. i want to get something that is going to be healthy for them. not a chemical based formula. it has essential oils in it, which we a bunch of them at home