Chick with chronic pasty butt

[hollyclark04]

I have a chick about five or six days old raised by a momma hen. I noticed bad pasty butt on day five-ish so brought her in, took some time but was able to remove external hardened poop and she relieved herself massively. But I noticed below her vent is really hard and yellow skin. I put her back outside over night with momma and sibling chicks but she is having a hard time keeping up this morning and is bound up again. I removed external again and put her inside with heat lampfood and water. I am concerned about the hard area. Does anyone know what it is or what I can do to help her?

 

[hollyclark04]

Baby girl did not make it. I wonder if it’s possible that she was originally a twin yolk egg, only she was fertilized and absorbed the unfertilized yolk into her body (hence the yellow bulge under her vent that I was referring to yesterday)

 

[mixedUPturk]

Sorry i followed to see if anyone had any insight but idk what was going on there

 

[Cyprus]

Infected yolk sac.