Forget for a minute about mad cow disease and think about other terrible stuff transmitted through ground meat such as e-coli (remember the Jack in the Box deaths 10 years ago?). My older boy is going to be five in February. He has never had a hamburger (or ground meat of any kind). I don’t plan to start either of my boys on hamburgers (despite the fact that my younger son would eat anything that doesn’t move and some things that do). Maybe I’m being alarmist, but why take the risk?