Gosling help!!

We have a brooder with 2 goslings and 4 ducklings, all from the same place, all 2 weeks old. We just fed them, same bag of feed as before and now the goslings seem to be having siezures the ducklings are fine Help!

Any ideas how to save our girls?

One just died. She was FINE 5 minutes ago?! The other one seems slightly better. Mustardy poo came out of the other and water came out of her beak DH is trying resusitation

We totally cleaned out the brooder. Ducks are still fine.

I checked the feed, no mold, clumps, off colors or smells. And all my babies are eating the from the same bag of unmedicated starter, I've got 4 brooders.

I'm wondering if it could have been something in the bedding? I use straw. Straw very rarely has mold spots the way hay does, but I'm wondering if I missed something. It wouldn't take much - but why both goslings and none of the ducks? They had to both get into something at the same time. They were fine, everyone was eating and drinking and then 2 minutes later I look in the brooder and both goslings have their heads thrown back and their eyes were twitching. Then they started to fling their heads about and thrust with their feet and a minute later one was gone, then the next minute the other was gone.

It was so amazingly fast.

Then I thought perhaps they got waterlogged, as their water dish was empty when I went to feed them (I don't think for long, they are in the LR and checked several times a day, also, the ducks are quick to set up a racket if the water gets low), but again, why both goslings and none of the ducks? The water dish is big enough for all of them to get a drink at once and the goslings had never bullied the ducklings away from food or water before.

We're all so upset and I'm checking and re-checking everything, trying to figure out what the trigger was. It is just devastating to lose them both in an instant like that and no idea why.