Our kids favorite chicken has had swollen feet for a couple weeks -- no sores,so not bumblefoot. Both legs/feet affected. We thought maybe mites so we treated for that -- poultry dust, dipped feet in mineral oil. We treat her with vaseline every couple of days. She has been putting herself to bed early these days, and today she is in the coop and laying around, not using her more affected foot at all. The toenail is now purple.... I've searched and searched the internet to no avail, I'm afraid it's too late. Help?