We got a brochure from McDonald's listing the ingredients of all of their
foods.  I would recommend you try to get the same, but from looking it
over, the following items do not list dairy:

Regular and Quarter Pounder Buns
Big Mac Buns
Beef Patty
Crispy Chicken Breast Filet
Fish Filet Patty (natural flavoring)
French Fries (natural flavor)
Garden Salad
   note: Grilled Chicken Breast Filet has whey, so those salads are out
Fat Free Herb Vinaigrette (natural flavor)
Eggs, Pasteurized Eggs
English Muffins
Cooking Spray Oil
All Bacons
Hash Browns (natural flavor)
Jams
Baked Apple Pie
McDonaldland Cookies
Burger Condiments

The Deluxe Roll contains milk, so you have to specify different buns if
you order Deluxe items.  Also, the margarine (and butter, of course) is
unsafe, and I don't know if that is added by employees in preparing
breakfast foods.  If cheese goes on the grill, there is also the chance of
cross-contamination.  As always, double check this stuff:

McDonald's Nutrition Information Center
McDonald's Corporation
Oak Brook, IL 60521
630-623-FOOD
(on brochure)

Hope this helps...

Gail