I don't raise chickens but 4 wild chickens have lived in my yard/trees for years (in Florida). There are 3 roosters and one small white hen and they are all 10-12 years old . The hen has recently developed a very swollen neck on one side and seems to jut her breast out such that her head is cocked to the side. She is able to eat and drink and acts normal other than shaking her head some and looking somewhat lopsided. Could it be a tumor? Thanks!