I have a sick Cayuga Drake who is only 7 months old. I went out to feed the ducks 10 altogether and he wouldn't eat or drink and couldn't walk. I brought him inside and gave him electrolytes, water, fresh corn, and feed. He didn't eat feed for 2 days and only ate some of the corn. He hasn't been drinking much water and is somewhat aggressive. He has no visible wounds on his feet or body although he is skinny. He is now (2 days later) able to stand but won't quack or do anything else. Is he recovering and how can I help him get better and gain weight?