Once they get infested with worms, it becomes difficult to treat. Or if nothing else, takes a while to rid the birds of them. And some of these wormers, like Wazine, do not take care of the Roundworm eggs themselves. Only the adult worms. So another dose of Wazine or another type of wormer must be administered again in about 12 days...after the eggs hatch. But at least you are getting a handle on it. I hope they all make a complete recovery.