Is Caesar dressing vegetarian?
No...it normally contains anchovies. (sometimes you can find it without) Or, you can easily make your own without anchovies.
And don't forget that some vegetarians do not eat eggs- so in addition to anchovies, eggs are an essential ingredient- it's a mayonnaise after all.
You can create a vegetarian alternative to Caesar dressing, but the anchovies are what gives it its unique flavor.
If you want a nice vegetarian Caesar Salad dressing without eggs or anchovies, try the recipe in the The Silver Palate New Basics Cookbook:
1 teaspoon lemon zest
3 tablespoons fresh lemon juice
2 cloves garlic, minced
1 teaspoon white wine vinegar
2/3 cup extra virgin olive oil
1 teaspoon coarsely ground pepper
1/2 teaspoon salt
Combine the lemon zest, juice, garlic and vinegar in a small bowl, and whisk well. Slowly add the olive oil, whisking constantly until smooth. Add the pepper and salt and set aside. Makes one cup.
I have seen a suggestion to use capers to give the dressing a salty hit, as a stand-in for the anchovies. Haven't tried it yet, but why not?