Symptoms, Diagnosis, and Control Measures of Chicken Coccidiosis

Sick chickens are listless and depressed, with ruffled feathers and a retracted head, and reduced appetite; the crop is filled with fluid; the comb and visible mucous membranes are anemic and pale; the birds gradually become emaciated. Sick chickens often pass red, carrot-like droppings. If infected with Eimeria tenella, the droppings are coffee-colored at first and later become completely bloody. If measures are not taken promptly, the mortality rate can reach over 50%. If multiple coccidia species are involved in a mixed infection, the droppings contain blood and large amounts of sloughed intestinal mucosa.

Acute coccidiosis: listlessness and poor appetite, increased water intake; rough, disordered feathers; diarrhea, with droppings often containing blood; anemia, with visible mucous membranes,comb, and wattles pale; dehydration, with shriveled skin; reduced production performance; severe cases can cause death, with a mortality rate of up to 80%, typically 20-30%. Those that recover grow slowly.

Chronic coccidiosis: seen with infection by a small number of coccidia, and with infection by coccidia of low pathogenicity (such as Eimeria acervulina and Eimeria maxima). Diarrhea occurs, but the droppings are mostly not bloody. Production performance declines, and susceptibility to other diseases increases.