So, let me start by saying my chickens are like my kids....they even tend to wander into the house from time to time. However, I have had several in the last 2 days become listless and not walk, arch their head over. I have separated them and taken them to what we call our hospital (hay barn). Our chickens are mainly free range and are giving layer crumbles. Their pen is in between 2 sets of pig pens. The pig pens had ticks which we have treated. Not sure what else to do. Thanks in advance for your help. Oh, we have had a lot of rain in the last month, but all is dried up.
When you say arch their head over, do you mean it's twisted back? The only things I can think of are wry neck, which is the better alternative and fairly easy to treat, or Marek's disease, which unfortunately isn't so good.
Could definitely be botulism. Fowl Cholera also has paralysis and twisted neck as symptoms. Both these would be more sudden and tend to effect a large number of birds at once than Mareks.