Stroke / Paralyzed: What’s wrong with our girl - 2 yo hen?

Hey everyone — hoping to get some insight because we’re kind of stumped.

We have a 2-year-old hen who’s been declining slowly over the past week or so. It started subtle — we thought maybe she just needed her nails trimmed — then we wondered about wry neck, but now it’s looking more like something neurological.

Current symptoms:

Significant weakness on her left side

Kind of lopsided when standing/walking

Left eye is droopy

Tail is down

Very unsteady — using wings to balance

Not eating or drinking on her own

We’ve basically been in full support mode:

Giving vitamin E + selenium (in case it’s wry neck)

Started antibiotics (in case infection)

Added apple cider vinegar to water

Hand feeding (egg, etc.) — have to place food in the back of her throat

Syringing water to keep her hydrated

Other chickens in the flock are completely fine.

We’re considering trying ivermectin next in case of parasites, but honestly not sure we’re even on the right track at this point.

Has anyone seen something like this before? Does this sound like wry neck, Marek’s, inner ear infection, or something else?

Appreciate any thoughts — just trying to give her the best shot.