it is a chicken that is not mine and joined my own flock of 1 rooster, 3 adult hens (2 yr old and one 8 months) and 2 young chickens (4 mos). my rooster cornered it and pecked it causing injuries (a hole in the crop, hole in the neck where the crop came out). sewn the tear in and outside. put antibacterial antibiotic (for human use) healed completely but today (3 days after swelling under skin of that side where the injury was. i think it broke a wing because it is limp. not limp before the fight. appetite is good. no discharge anywhere. scratching his head now and then - mites?