I have been avoiding answering this one for AGES...but finally could avoid it no longer while ds was eating shepherds pie this evening. "It's made of animals, darling"
Ds (looking stricken, lip wobbling) "No mummy, it can't be made of animals. (little laugh) Not animals! How could a animal be meat?"
Me: "When animals die, they sometimes turn into meat for us to eat"
Ds (crying quite hard now, not eating) "But they don't die! I don't want them to. They aren't meat! You are telling me things that make me sad!"
Me: 'I'm sorry darling. We won't talk about it any more if you don't want to"
Oh dear.