Sick 5 year old Wyandotte. Please help.

My sweet Wynonna Wyandotte is not doing so well. Background: I have two backyard chickens Rolf and Wynonna, both female, around the same age, exact same food and living conditions. We are in north Florida, so it is very hot, but they have shade and water always available. These two girls are my troopers. They have survived possums, ospreys, dogs, and the constant hugs from my kids. Both are vaccinated and neither have had any serious health issues ever.

Wynonna started acting a little drunk about a week ago. Sluggish, just not herself. This then turned into her walking a few steps and then laying down, then repeating. Now she can't walk or stand. She was eating and drinking when I put her food and water in front of her, but she has stopped doing this for herself. I have been needleless syringe feeding her for two days. I started her on antibiotics, acv in her water, and a yogurt/feed puree. While inspecting her i did find a half dollar sized scab on her side above her leg. I have cleaned and cared for this and its healing nicely. Rolf is perfectly fine.

She is vaccinated. She's been in Florida her entire life with no heat issues. She stopped laying eggs about three days before she presented her drunk behavior.

I'm leaning towards botulism, just because i have a neighbor that has thrown moldy food over my fence for my girls in the past.

Any suggestions?