You can see the request for medical advice on the first aid page but I wondering what did this. I went out into the yard, There were @8 bantams and EE in a chicken wire pen, untouched. All the free ranging birds had scattered. One hen lost with just a few dozen feathers by the pool, My nasty banty cochin roo who was going to go out for adoption because he is a bully wobbled out of the forest with a limp, something tore all the feathers from the coxyis, it's bare and red, a good number of plumage is gone from his hackle feathers. He appears to be in shock. Who attacks during the day, leaves no blood, just some feathers. The cochin who survived (for now) lost a lot more feathers ( very cleanly and uniformly. looks like you took a belt sander to his butt) than the hen.