I bought five muscovy ducklings, last weekend, Inoticed within a day or two that one of them was breathing a little heavier, kind of gasping.I did a little reading and suggestions were to add Duramycin to their water. they are in a brooder box with a heat lamp that they can get out from underneath if they get too warm which I have not seen too often, they are not huddling like the cold either so I think the temperature is good. They have a bowl of water to dip their heads and the go in the bath tub at least once daily for a good swim. Today I noticed another duckling seems to be starting with the same symptoms but more mild. Any other suggestions or advice?I'm planning on moving them to a shed where they can have a larger brooder to increase the surface area for it to stay dryer.