I have 13 ducklings 3 are around 4.5 weeks old and 10 are around 4 weeks. All but one are fine. The one pekin 4 weeks old is bow legged and extremely pigion toed. I have tried adding niacin to its diet but the flock feed I use has enough niacin in it. The bigger it gets the worse it gets. It gets around ok but it definitely falls and struggles more than the rest. I don't believe it is a niacin problem, mYbe an injury or birth defect. Any suggestions? It's the one on the right obviously lol.