Ducks dying one by one

[Senna95]

How is the weight on the surviving ducks?

 

[dotknott]

I think pig poop is a common vector for a number of pathogens including parasites. This includes a number of diseases that can be spread between animal species.

 

[DGandC]

I do not have a long history of Ducks (yet), but I have found that nutrition can be sly and critical. They may be missing some critical nutrient, so try going back to Non-medicated Chick Starter, the kind that says on the bag that it is for DUCKS, etc. And watch those table scraps. Some like potato peels can be harmful to ducks. My little Buff Orpington started falling flat on her back and looking dead. Soon as I moved her back to the feed for Ducklings, she improved. I only give the ducks Romaine lettuce from my table. The rest of the greens they get on their own. Make sure they have more water than you'd think. They need to rinse their whole head in the water. All 16 ducks and my 4 geese are doing fine.

You said they sleep with the piglet, but do they eat with him too? Perhaps the pig is keeping them from eating as much as you think?