Vic, we still use the Nemex2 to start off with good luck, then switch them to Panacur. We've been using the Nexmex for 20+ years and so far with good luck. Panacur i still believe is the best overall wormer for pups or big dogs. You can start them off with Panacur, but we've just always done it this way and we stick to it if it works for us.
Good Luck & call me some time to catch up!