I recently found a chicken tonight and she could not walk and had slightly labored breathing. Her feet and legs were blue. She is drinking water, but I am worried that it is marek's disease. I have seperated her from the rest of the flock. Is there any way that I can save her? Or at least make it better for her? Should I get some vaccinations for the rest of my flock? What was so bad was that this was all of a sudden. Within three hours this happened.