last night we found one of our chickens limping whenever we went to round them up. our chickens free-roam throughout the day and we let them roost in the barn at night. her hip is swollen and she barely/doesn’t use her left leg. i examined the area but there’s no visible wounds. if it helps explain it at all we’ve had problems with raccoon/possum attacks and have lost a few chickens. we’ve killed as many of the predators as we can but it’s a work in progress and we’re starting to lock our chickens up. in the picture i attached you can see the swelling and how she’s favoring her right leg. any idea what it could be or what we should do to fix this?