Religion and cafeteria food

Some of our families do not participate in the breakfast or lunch program for fear that their children will unwittingly eat meat or pork products. Avoiding meat is fairly easy by simply referring to the menu that goes home. The issue becomes how to avoid all meat products. For example, if the hot dogs are all beef, what is the casing made of? Is there gelatin made of pork by products in the soups and salad dressings? Is anyone interested in developing an elementary cafeteria school guide for followers of Islam, Judaism and Hinduism? Any comments about how you have dealt with this?