I am concerned for my rabbit as he usually eats a bowl full of pellets, hay and a handful of veg in the evening every day, but since saturday he is only eating small amounts of hay a small amount of water and veg, he has not touched his pellets and his behaviour as changed as he usually runs out as soon as I open the cage and runs around kitchen ect for a few hours but will not come out at all and is lying down a lot and looks uncomfortable?