Hello my names Brian. I have 5 ducks about 5-6 weeks old. The have been outside for almost 2 weeks now. I believe out little runt has niacin deficiency. He almost acts ill and lethargic. He's not too active and he is quite. But he has trouble walking and can barely stand. He can't preen in the pool either. The rest are fine. I have read alot on here about leg problems and niacin issues. My question is should I isolate this little guy to make sure he is getting all the meds or just treat them all with niacin in the water and brewers yeast? I grabbed that stuff yesterday and have it to all last night. He appears worse today. I read about some liquid vitamin drops to get. I could give those to only him. I bought antibiotics at TSC thinking he was sick. Should I still give antibiotic just in case? Any swift help is greatly appreciated. I'm new to this and worried about the little guy.