Duckling edema??

[zeberman]

I have a couple 2 week old muscovy ducklings. 1 seems to be growing normally, but the other is very small and also has edema on her back, neck and chest. At least it seems like edema, she is very puffy and swollen. I believe it may be due to metal toxicity as she was kept in a metal tub for several days where I didn't realize she was pecking and chipping off flakes of the walls (galvanized steel wash tub). I have done the molasses toxicity flush for 8 hours from the sticky thread on this site, but am still unsure what the exact problem is. She appears healthy aside from the puffiness and is very active and eating very well. Any ideas or anyone ever experienced anything like this?? Any help would be great.

-freaked out mama