About a day ago I noticed my hen on the ground. She could not walk or even stand up, I've also noticed a lump between her legs. Today I took her to an avian vet. He's unsure what the lump might be, but its definitely not an egg. He also ran a blood test and found no infection's. He believes it might be one of three things. Lack of calcium, a virus, or some type of perisite. I'm truly sadden and believe that it might be marek's disease. I've separated the sick hen from the rest of the flock. They are in completely different rooms, is there anything I can do to protect the flock?