Great news! I haven't heard of that one. I also didn't think worms could be prevented - only treated so it might be worth researching what effect it might have?
That's why you treat every month. To kill off any worms that may have infected the dog before it causes any major problems
Edited: It is also worth noting that not all intestinal parasites are easy to find on diagnostic tests. When we tested for heartworm a blood sample was required and even that was not 100% said my vet. So I think it's really important to take the advise of local vets because they know what threats are found locally and how to minimise risk of infection.