I saw a roundworm in one of my chickens droppings this evening. I have wazine and plan to treat with that tomorrow. When is the best time to repeat it after the initial dose or do I have to use something else(I know it only gets rid of adults)? I have read the egg withdrawal period is 14 days. Safeguard(is the egg withdrawal for this one 14 days also?) is the only other one I think I have good access to other than wazine. Does it create resistance if you use more than one kind for "one total treatment?" I have seen some say if used wazine then use that again and others say use something else for second dose. Thank you!