Duckling with runny eye

One of our new ducklings has got some kind of problem with her eye. It is runny and has a little yellow pus in it. The eye lid keeps getting stuck shut but opens after a warm water rinse. Only one eye is affected and none of the other (14) ducklings are showing any similar symptoms. I first noticed the problem about 24hr ago. The birds are about two weeks old.

I have the duckling separated from the others but am wondering about a diagnosis and a home treatment. Any ideas? Thanks

Paul
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