I hold this rooster every day and failed to notice this "thing" on his wing until it was so big it interfered with his primary flight feathers and I noticed they didn't look right. I wish I had been more observant! Anyway, his name is Baby and the problem seemed to stem from the metacarpus to the phalanges of his right wing. I had no idea if it was a tumor, cyst, or abcess, much less what to do about it. I couldn't find anything exactly like it on this forum and after reading up on the differences between tumors, cysts and abcesses in birds, I was still not sure exactly what I was dealing with. It was squishy but firm, no detectable odor, but hotter than it should have been. If it was a tumor, was it Mareks, or a malignant disease? It didn't look like the only picture of a fibrosarcoma that I could find: I noticed a matted clump of feathers on Baby's body where his wing rested. Fortunately, it was not another mass, just evidence that the thing on his wing had been seeping. I thought this must mean that it was either a cyst or abcess until I learned that tumors can seep too. It would have been so much easier if I had enough money to take Baby to an avian vet! I tried soaking his wing in epsom salt water to see if it would draw any infection out. It didn't help. I learned that avian exudate differs from human exudate. Our infections tend to result in a liquidy pus while avian infections result in a caseous substance. I concluded that if it was an abcess it would require more than epsom salt soaks to get the bacteria ridden cells out of the wound. After a couple glasses of courage (wine), I got out the scalpel and proceeded to investigate Baby's booboo more thoroughly. It would have been nice if I could have anesthetized him, but all I had was some ice to numb him a little and a soft blanket to cover his head so he wouldn't see what I was doing to him. He was very tough and brave, and fortunately, there wasn't much blood loss. Once I started to cut into it, I found a lot of residue from the infection (I think)! It was a solid, yellow substance that differed from the consistency of flesh or bone. Once exposed, It had an odor. I tried to get all of it out, cleaned the wound and put Baby to bed in my shower. Here is some of the stuff I dug out of it: And, here is poor Baby's wing after the surgery: Apparently, this was an abcess. Baby seems to be doing fine and hopefully this awful hole in his wing will heal quickly. He is a 2 and 1/2 yr. old Asil, and just the sweetest little guy! Here's a better picture of him: This was while I was just soaking his wing and not cutting on the poor little guy. Anyway, I've tried to document this the best I can because I know it might help somebody in the future.