Cocci is one of those things that all chickens carry, kinda like dogs, they all carry mange but some dogs immune systems allow it to express. Cocci however once shed is one of those things that then become contagious to others as they step in stool and they eat off something that has it on it. At 2-3 weeks is when they are most susceptible to it expressing though older birds have been known to show it from time to time under the right (but wrong) situations. Hang in there lady!!
