UPDATE: So we had a black star female, not even 6 months old yet, that had a bulge in its neck. A feather was trying to poke out so we took an exacto knife, cut the skin and pulled out a slimy feather about 1 1/2 inches long but the bulge was still there. So we took the hen to Total Care Mobile Veterinary Practice LLC in Colorado Springs, CO a week later and Dr. Rivera Gosciniak (who is really nice) and her assistant went to work on her. Put the hen to sleep, made an incision and found not puss or a acorn looking cyst but 2 HUGE BALLS OF INGROWN FEATHERS!!!! Absolutely shocking.
This ingrown feather issue happens rarely, usually to young chickens growing small feathers or rapid growth (probably comes from too much of a certain hormone or could be related to diet in how the chicken handles some nutrients). Removal can sometimes lead to part of the cyst or growth connected to blood vessels and the chicken can bleed to death but thats more rare. More often its the hardened acorn looking cyst or pocket of puss. Then theres this....
Not one, but 2 huge balls of feathers!!
They removed all the follicles and cleaned it out and they stitched it up loosely (they leave it slightly open) for irrigating the wound and allowing it to heal up from the inside out. Chickens have great ability to fight off infection in their skin even when its dirty.
Best part is this surgery only cost us $100 bucks! Total Care Mobile Vet does house calls too but we chose to take out chicken in. They see all animals except horses.