I have a year old golden comet hen that is limping badly. She still gets around, but slowly. The limp has progressively gotten worse over the last week.She has had a drooped tail for over a month, but the limp only showed up a week ago. The flock has undergone treatment for worms and lice lately, but the other 5 seem just fine. The lame hen has a good appetite and still roams with the others. Her feet look fine and I haven't been able to find a tender spot. Any suggestions?