What would cause a juvenile bird to starve?

[Albanydog]

Mom found a juvenile Polish in the flock today just sitting and let her pick it right up, she brought it to me thinking it had a broken breast bone. After I warmed it up, and checked him out the lump turned out to be his very thin neck, not the breast bone. He appears to be starving? There was nothing in its crop until I forced some electrolyte water into him and now the crop is clearly squishy from the fluid.

 

[willowbranchfarm]

Does she have worms???

 

[Wayne&Kim1963]

I would give her dose of tylan 50 in mouth and see if that helps. 1/2cc for adult chicken and 1/4 cc for smaller juvinille bird and small small chicken few drops orall or I would try last ditch effort if nothing else helps to give them shot of penicillin 1cc and 1/2cc tylan 50 mixed together well in syringe for adult bird and lower both meds dosages the smaller the bird under the skin on breast or I have had some chickens get all skinny like that and I give them oxytetracycline powder I mix it on boiled eggs crushed with 1 minute oatmeal and feed it to them if they don't eat it I hand feed it to them so they make sure and get meds. I hate putting it in water so choose to do it this way and see if that helps. Never hurts to worm them too. I would powder it for mites too. Maybe mites sucking it down making it anemic. I also cut childrens chewable vitamins in chunks the chicken could swallow and give them pieces of those too. It really helps alot.
I do those things to try to keep the bird from dying. It makes me feel like I at least tried. Sometimes we just don't know why they are doing what they are doing.
I give mine ensure plus to drink down for energy when not eating. Works wonders for them too.