I hope I'm posting this on the correct index, and I'm sorry if I misuse any chicken terms, as we are new to chickens and still learning. This is not an emergency but we're not sure if this is normal or not. Have almost 11 week old birds (2 ISA browns, 1 Amerecauna hen, 1 cockerel and one barred rock, the other died). I just noticed today on the female Amerecauna that she has a very defined baseball-size squishy mass, feels subcutaneous (like a water ballon just under the skin) centered on the breast just below the neck. She's not acting funny but coincidentally (or maybe not) she has vomited twice (that we know of), once yesterday, once today, but both times were while my son (4 yrs old) was holding her on her back. Other than that we have not noticed anything different. I checked the others and did notice a similar finding on one of the Isa Browns but much smaller, maybe the size of a ping pong ball. Does anyone know what this is, is it bad? I work in the medical field and happen to have sterile syringes/needles and was tempted to aspirate it to find out what was inside, but thought it would be best to post here first!!!