I have eight GORGEOUS (I will try to post a pic--they have laced feathers and come in slate grey and a brown grey). mutt ducks that were hatched out of a runner boy and a white layer (we think. I found a nest of 21 eggs, 8 incubated and hatched). They are about 3 months old. This morning they seem happy enough but are moving their head/neck like they want to gag, mouth open. They are not acting sick except for that. It will be hard to treat their water since they drink out of a large pond that they also swim in, that we have outfitted with a drain a couple feet away so we can drain and refill it without putting our hands in the water. I guess we can just put the whole pack of antibiotics in there? It would get on tgeir skin too though. Any suggestions? If I use an antibiotic, which one is better?