With my last demise, a Faverolle named Blizzard, I will never be really sure if it was dehydration/heat stress or Marek's or both. I hate the second guessing myself. She didn't eat or drink for 5 days, then drank a tiny bit for 2 days. She did stand a bit, but didn't walk, or walked with wings. And it's like if I gave her an antibiotic, which one? What would I be treating? Would it have mattered? It's just so hard , isn't it?