Every spring and autumn we use flubenvet medicated food to worm our girls but this is the first year we have used the powder first dose sunday and guess what? This mornings poop showed huge mature worms! This is a first (our girls are 1 and 4 years old). Now what? Apart from cleaning washing the coop again and we use net text ground sanitiser in the run,how can we prevent them picking them up again when they free range in the garden? Do we need to retreat in 3weeks?