I have a 3 year old barred rock hen that has this big, golf ball-sized tumor on her neck. It's bright red, (about the color of her comb) and held on with a tiny thread of skin. It flops around when she walks and kinda grosses me out. She's had it at least 6 months and it's getting progressively larger. She is still healthy and laying, so I haven't gotten to excited about it, but does anyone have any idea what it is?