You probably won't see signs of worms in an adult fit dog. The old advice was worm every three months which was a compromise between the risk to humans from roundworm (Toxocara) and the wormer only lasting 24 hours so a few weeks later, the dog can be shedding eggs. But we know that the way the worm infections work, it is only the dogs/cats regularly eating prey (rodents and birds) that are significant hosts for Toxocara. So if they are eating venison, no problem, sheep ****, rabbits no problem, poultry can be, but I don't know about game birds.
It's a bit different if you have an entire bitch as the can shed eggs, especially if you are breeding.
So I suspect you don't need to worm. Certainly not for the heath of your dog. IF you have young children, then it's sensible to do it