Hello all. I have a 5 week old Pekin duckling that has thrashed 3 times, in about 19 hours. We will hear her in the brooder, and when we get there she is laying, thrashing her wings, her neck in a strange position. Is it a lack in her nutrition? She is on starter/ grower, with added yeast flakes sprinkled on top every day or other day. Any suggestions would be so much appreciated!! She also shakes every now and then. Not sure what is going on. Please help.