I never rely on a fecal exam to tell me if my dogs have worms. My vet told me many years ago that worms are like chickens: they don't lay eggs every day and if you happen to do a fecal exam on a day they aren't laying eggs, you will get a negative result. So... I always keep my dogs on a worming schedule, and worm them whether they need it or not. I don't bother doing fecals. Some people might not agree with this but it works for me!
