I have been reading all about how ducks can get niacin deficient and I suspect that may be the case with my eight week old Muscovy ducklings. I have five that hatched the first week of May and I kept them on medicated chick starter for the first month. The last few weeks they have been free ranging and getting scratch feed. About a ten days ago one just suddenly couldn't walk, followed by two more a day later. The other two seem to be fine. They are eating, drinking and scooting around in the pen, but just can't stand. For the last week I have been giving them a liquid vitamin supplement and medicated turkey starter. The parents are three years old and I have never had a problem like this before. Hatched six healthy babies last year. So here's my question.....If it is a vitamin deficiency how long will it take for them to get better? I am quickly getting discouraged! They look so pitiful!