I have an 11 week old duck that has been acting fine until this morning when I went out to feed and water them she seems unable to stand or walk for very long. She seems very weak and doesn’t seem very interested in food. I have been feeding them mazuri waterfowl maintenance diet. It seems like it happened overnight so I’m not sure if it’s niacin deficiency or something else but I added extra niacin in their water. Does anyone know what else it could be? Should I separate her from the other ducks so they don’t walk over her or would that be too stressful for her?