Neurological Chicken (Trigger Warning)

4 year old chicken. Found mid morning yesterday lying on her side in the run. She wasn’t able to get up on her own. Some things I noted:

-overly red comb. There’s some damage, probably from her sisters pecking her when she was down. She is one of my top hens so not bullied prior to this.

-overheated even when inside the house. When holding her upright, I felt how warm she was and she was panting. Outside was a very mild day and she was in the shade.

-toes are curled and she doesn’t want to bend them back. I kept her laid on her side all night because she couldn’t stay upright with her toes.

-keeps moving her head oddly as well as her beak. As I was syringe feeding vitamins and egg, she kept crossing her beak and making a chomping noise.

Today we found her upright sitting on her ankles with feet curled back. She’s moving her head more normally now. I even got her to eat some pellets mixed with water and vitamins.

I don’t believe it’s Marek’s between her age and lack of other symptoms. She’s not egg bound as I’ve done an internal and external exam. I’m leaning towards botulism toxicity or vitamin deficiency. Anyone have any ideas? I’m going to keep treating her as I have been since there’s improvement. Just want to know what else I should add.