My gander, Ryan Gosling, has been getting progressively worse. He was previously the boss in a flock of 11 girls and 3 other boys. About 6 weeks ago, my husband first noticed that he fell over continuously when he tried to herd him out of part of the garden. Since then,I have switched to a higher quality feed, wormed everyone, and started vitamin supplements. However, Ryan has got progressively worse. He has become thin, spends a lot of time sitting, and looks pale around his eyes. I noticed yesterday that he had quite a heavy lice infestation so I dusted him with pestene. All lice appear to be dead today.... but he isn't walking at all. His voice is faint compared to normal. Still eating seed mix, still drinking, faeces looks normal...perhaps with a little more of the white part compared to his flock. He's not being picked on. The rest of my birds look healthy enough, though one goose has had dropped wrists since she went broody in December. I'm not sure why this has happened either. My flock consists of 15 geese, 12 muscovies and 9 chickens. They are locked in a 100m2 pen overnight but free range during the day. There is shelter but the geese elect to stay out, no matter the weather. So to summarise:What can I do? can anyone suggest what he may be suffering from? He's been treated for parasites, should I administer an antibiotic? What one? How much?