So my duck hatched a month ago. May13. He seems to have grown just fine with out any problems. While growing I noticed they would lay down a lot. Never thought anything of it. But I noticed the knots at the of his legs which made me worried and look into it and have come to the conclusion that it could be a niacin deficiency. He still seems to walk just fine. I don’t see much difficulty for them. But now that he’s an older duckling can this problem be fixed? Will it grow worse and if so what will be the outcome. Please help my little fella.