Cure for what? The OP hasn't gotten the results from the necropsy yet to know what the pathogen was.I just had the same thing and found a very quick cure:
6 gloves of garlic
tsp oregano oil
1 cup vinegar
2 cups water
Blend all and add cornmeal.
The chickens go crazy for this stuff and in 2 days mine were all running around just like normal!!