My baby chick has had pasty butt for 4 weeks (pretty much her whole life), hasn't grown except her feathers, and now has a weird crust forming on the corners of her beak. From what I've seen in the brooder she's not picked on. She has great energy, never acts sick. We've separated her for a few days, no difference other then her being sad. We've given her nurtradrench, probotics, everything! Does anyone know what could be going on with her? :-(