I've been raising 4 ducklings, two pekins, a khaki campbell, and a ???. They've been on unmedicated chick food with vitamin supplements in their water, which included niacin, with a fresh water option also available. Their cage is cleaned daily and they have a heat lamp that keeps things toasty. Their pen has two sections an indoor warm spot with the heat lamp and pine shavings and a little run outside (fully enclosed though) so they can move freely between the two. We've been changing their water three or four times a day so they've never run out. They've been additionally supplemented with home grown greens. But they keep dying. It will look like they lose control of their legs, they aren't deformed it's like they stop being able to us their muscles. One od our pekins died first. He started moving sluggishly, then was unable to walk or hold his head up. Shortly thereafter we were down to three. We were so afraid of a virus we immediately moved the survivors to a clean pen and watched them closely. To be safe I added more niacin directly to their feed. For about 2 weeks they were completely symptom free and seemed to be happy healthy little ducklings. Then the other pekin started moving slowly and losing control of her legs, so we isolated her and watched her. She would have bouts of it and then be perfectly fine minutes later. Her legs were healthy, not bowed or swollen, and she had full control of them except during her episodes.For her the whole sad process took about a week and then we lost her. We would think she'd recovered and then we'd see a relapse. The third duckling died quickly like the first, though he did have some time where he seemed fine after his initial incident. One morning he was zooming around the brooder making a merry little mess and the next he wasn't. So now we're down to one and desperate to keep her healthy. Any ideas? I'm so at a loss.