Coccidiosis in poultry

Eimeria spp.

Coccidians are microscopic parasites commonly found in poultry (chickens, ducks, geese and their relatives). 

The infective stages (oocysts) are swallowed by the bird. These release small forms (sporozoites) that enter the cells of the intestinal wall and multiply to produce many more parasites (merozoites) that, in turn, invade other intestinal surface cells. 

Initially there are no signs of disease, but as the infection progresses birds may appear dull and depressed, show decreased appetite, and have loose or bloody droppings.

After several cycles of build-up of the disease the infective stages develop and pass out with the faeces thereby exposing other birds to infection.

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