I have a call duck which seems to be under the weather. He is one of a few that are at the moment locked away due to the threat of avian flu. None of them seem too happy, but yesterday, one looked more fed up than the others.I knew something was wrong when i went into the pen and he didn't move. He seems to be loosing his balance and walking funny, also does not seem too keen on sitting down. Iv'e separated him from the others so that he doesn't get bullied or injured more, plus hes warm and dry. There are no cuts or damage to his feet or wings, however one side of his breast is more prominent than the other side. He keeps twitching/shaking his tail which made me think of ticks and mites, but nothing to be seen. the pen is rinsed down every day and their pool (kids pool) is changed and rinsed every day too. They are being fed layers pellets, corn plus extra veg for boredom (broccoli, corn on the cob, spouts, lettuce and fruit to chase). I've checked the feed to ensure its not damp or contains any mold, plus we have just had an inspection with samples taken with no problems found. As I say, I've put him away from the others, warm and dry with plenty to eat and drink, but I'm still unsure, and the vet isn't too keen on seeing him at the moment as he doesn't really want poultry in his surgery with the threat of avian flu. He will come out but we have to wait for a visit time to become available. I have it in my head that it is something or nothing, either Niacin deficiencies (so vitamin supplements) or Botulism,which is fatal if i have read right, but as i say they haven't been around any stagnant/stale water. Any help and advice will be much appreciated!