Eimeria acervulina is a species of Eimeria

Eimeria

Eimeria is a genus of Apicomplexan parasites that includes various species responsible for the poultry disease coccidiosis. The genus is named for the German zoologist Theodor Eimer...

that causes coccidiosis in older poultry

Poultry

Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...

. Lesions are limited to the anterior or first third of the small intestine. Diagnosis is made by on necropsy based on location and the pathognomic white to gray striations that appear on the mucosa or inner surface of the small intestine. Scrapings of the mucosa from diseased birds can reveal oocysts.