I'm new to chicken illness, but I know Mareks can take different forms... Mine didn't have Mareks, but for clarification, the symptoms I saw were: chicken #1, petite, young, silky pullet - quick onset paralysis (was trying to move legs, but they were barely moving and she was unable to get up or move them well) died within 24 hours (she appeared ok the previous night... We found her late morning, and she was gone early evening); chicken #2, VERY vigorous easter egger - twisted neck(crazy twisted), unable to fly (but initially could move) progressing over several days to more serious paralysis. Sadly, died within hours of receiving the report. Didn't notice curled feet or eye symptoms...
Just posting in case this info could help someone... And I am not against culling if something serious is suspected... In my case, I was leaning towards Marek's (as was the veterinarian when I explained symptoms), and all the chickens would have alrwady been exposed... The vet said not to do anything rash, so we chose to wait and see (but took precautions to avoid possibly transmitting to other locations, feed store, friends with chickens etc.)