How did you treat it?
A strong dose of corid (1.5 tsp powder/gal water) for 7 days. And we treated all the chickens. If I remember correctly, we treated for worms at the same time with safeguard for goats at a dose of 5 cc/gal for 5 days.
Our rooster was still not well after this and he got 10 days bactrim in addition. But he made a full recovery! Good luck!