One of our ducklings, Skillet, is under the weather. I picked him up yesterday, and he threw up. I didn't worry too much, because I know if you startle a duckling, or accidentally put too much pressure on their crop, they can throw up. Well today, he is sneezing a bit, and shaking his head. He seems a little less active than normal, but not lethargic or anything. What should I do? Any help appreciated!