I dont flea and worm at the same time, in fact i only worm my dogs about every 9mnths, cos i know what they eat.!! And i use Frontline Plus, from a place called Discount Vet supplies, (online) and this kills the fleas, eggs and Larvae, unlike the frontline you get here that only kills the fleas, it also kills ticks, it is imported from Australia, and used in hot countries. i paid under £30 for 6 pippettes last May, and still have 2 left, and this is for large dogs.Good value or what!!