buff orphington w/ swollen neck and poor appetite

[willtheycallmeblessed]

i noticed yesterday that our buff seemed to be pulling her head down into her neck (does that make sense??)...like she wasn't stretching out her neck. well, today when i threw some scraps out to the birds, she seemed reluctant to hop out of the coop and was bypassed by one or two of the other chickens. she appears to have a swollen neck (throat?). she seemed to want to eat, but only picked up a piece or two of food and dropped it back on the ground. any ideas? also, her eggs have been misshapen and the shells have been a bit on the thin side lately. i really appreciate any advice. thanks a lot!