My chicken is 18 weeks old and can’t walk. She stumbles around and can’t seem to open the toes on one of her legs when she tries to take a step. When she stands this same leg also doesn’t hold her properly and the feathered top part of her leg stays touching the ground. She was quite malnourished but she is eating now I’ve brought food to her, the vet said it must be something she is born with or neurological. Can anyone offer insight?