I have 3 Egyptian geese. They are about 12 weeks old. 2 of them are fine.. feathered and full grown, but one has problems. It's about half the size of the others and only has wing feathers and some on head and butt. Its lower back to its wings is only fluff and its neck is really thought feeling with some fluff and really little feathers that you can only see if pick her up and get really close. She's stopped growing and her feathers did awhile ago. What's wrong with her? Anything I can do for her? Is she going to die?