Water therapy also does wonders for their strength. If she can swim (possibly alone?) it could be a big help for her also.
My mind went more to breed than actually trying to help with her possible sickness, I’m so sorry. The vitamins are a good idea also. It’s odd for her to be experiencing...
I’m honestly not sure what she is, but I don’t think she is pekin. At least not full pekin. She would be more solid white by now, and would have a deep yellow bill. Coming from tractor supply, I guess it depends on the hatchery they use in your area, but they don’t normally deal in hybrids, so...
That’s definitely not a pekin duckling, could be a Saxony? Did the store have a possible list of breeds in the bin?
If it’s a runner or a Saxony or something else, that could easily explain why it’s smaller. Pekins get huge very fast.
If the others aren’t picking on her, I’d definitely put...