Have been looking online for ages now but cannot find how often you should treat for worms in a DC!! All I can find is that as a matter of course one should worm your children in the Spring. I have just wormed the whole family after a "suspected" case of worms in my DD but we have LOADS of animals, whom I have also wormed at the same time, so worried it could be picked up again. How long does the worming meds protect for?