Bearded dragon still and twitch

Question
Yestarday my g-friends dragon stopped moving he looks limp his eyes and tail respond to touch  and movement but he wont turn his head very far he wont eat and he hasnt touched water for a while, his legs (all 4) twitch/shake, what wrong with him? sick? dieing?

Answer
Malcom,                                                      I thought he might have been going into brumation , which is like a hibernation, but the leg shake is not good. He may be showing signs of MBD metabolic bone disease. I would take him to a vet immediately. Sometimes when they are not producing enough calcium whether it be lighting or not enough of a substitute it can cause this. He may need an injection of vitamins.I don't know in what way you are keeping him...lighting etc.... but these are not good signs. Take him to a good reptile vet and keep me posted... good luck, tina