Its very difficult when our beloved ducks get sick and die. I lost a pekin drake last year -- he stopped walking and despite all kinds of treatment and therapy [I did take him to a vet] he died suddenly 5 months later. It was thought that he had a pelvic tumor but I didn't want an autopsy. He...
Sorry for your loss
I doubt that black/greenish poop was abnormal. He had probably been eating weeds.
It's hard to know what happened. Tell us more about his death. Did he just collapse and die suddenly, or were there any other symptoms that morning or before he died?
Many pekins live only...