There's a number of pastuerized egg sources.
Firstly, eggs pasteurized in the shell. Cook's Illustrated tested these and found them indistinguishable in all applications except fried. Pasteurization is a heat process so it mimics some of the characteristics of an old egg. A spready thinner white and a weaker yolk sac.
Second, a pasteurized and processed egg along the lines of Egg Beaters. Not Egg Beater's precisely as they have no yolk which is what you really need in a Caesar dressing. But there are other products like that that would work.
And powdered eggs. Don't scoff, powdered eggs have improved greatly in the recent past. No longer are they the green tinged rubbery things without taste. Theyr'e not perfect but for a dressing, they'd be an excellent choice if food safety is your top concern.
I'm not worried about eggs needing pasteurization so much if they come from a reputable source and there isn't a known problem with the eggs in your area. However, If I were serving a less than fully cooked egg to an at-risk person (pregnant, old, very young, immuno-compromised) I'd try for a pasteurized product.
