I have a peiking duck who about 10 weeks old, and he’s laying on his belly with his legs out behind him. He’s eating and drinking as normal, and pruning. I can manually bend his legs but when I try to stand him up his feet curl under and won’t spread out unless I help him, when I get him on his flat feet he stands vertically and won’t bend, he cantbear his weight. We have him isolated as to not get trampled, I don’t know what to do. Help, please.