Marek's disease or injury?

[Chicken202]

Recently one of our hens was attacked by what we assumed was an animal, and it ripped up her back (it could have been the rooster too, but I doubt it.) She was able to get up to the nesting box at first, but now she's unable to move one of her legs. She had a lot of poop caked into her feathers, and it smelled terrible (not the normal chicken poop terrible, it literally smelled like death). It was very watery and caked into her feathers. She's still drinking but I've only seen her eat once or twice. Normally I'd panic about Marek's disease, but I'm not sure if it's a nerve problem as a result of a spinal injury. Does anybody know what it could be?

 

[nuthatched]

Look for an open wound, soak off the poop.

 

[Chicken202]

I did that. The feathers were ripped out of her back but there's no wound on her leg. It's basically just limp and if I try to straighten it away from her body she extends her wing but doesn't seem in pain.