Coccidiosis is seldom seen in chicks under 3 weeks old, but usually seen in growing birds or young adult fowl.
Coccidiosis is transmitted by direct or indirect contact with droppings of infected birds. When a bird ingests coccidia, the organisms invade the lining of the intestine and produce tissue damage as they undergo reproduction. Within a week after infection, the coccidia shed immature descendants that are referred to as oocysts. The oocysts shed in the droppings are not capable of infecting another bird unless they pass through a maturation process (sporulation) in the litter. This sporulation occurs within a one to three day period if the litter is warm and damp but can take much longer if the conditions are cool and dry. After sporulation the coccidia are infective if consumed by a new host bird.
Since it is common for some healthy birds to possess some coccidia, flock history must be taken into consideration before an acurate diagnosis can be made. Coccidiosis cannot be prevented by sanitation alone and therefore certain measurements need to be taken with coccidiostats.
There are a number of coccidostats available, however these should be used precisely. These include Toltrazuril, Sulphonamides, Amprolium. Vitamins Vitamin A and Vitamin K in feed, or water as coccidosis cannot be treated by hygiene alone.