We've taken our 8yr old Rhode Island Red hen (Big Girl) to the vet and had her beak looked at. The Veterinarian believes it's a tumor growing off her beak. She is still eating fairly normal but we do have to switch things up for her from time to time as its grown to make it easier for her to eat. She has had it for about 6 months and it suddenly got bigger. As its grown outward we've noticed its spreading to the inside of her beak as well but there is no mass look to it inside it just looks like the inside of her beak changed colors. It is only on her bottom beak and has taken over the entire right side. We did two weeks worth of Clavamox 250mg twice a day and nothing seemed to change. We also clean it daily with warm water since she still digs in the dirt and she gets food stuck to it. At night we apply SSD (Silver Sulfadiazine) cream to it after cleaning. When she scratches at it, it will occasionally bleed (main reason we did antibiotics). It also occasionally seems to "flak" or "shed".