Eimeria infections among commercial laying chickens in Nigeria: the prevalence and clinico-histopathological changes.

Coccidiosis is known to affect a wide range of animals including chickens. This study was designed to determine the nation-wide prevalence and clinico-histopathological changes associated with Eimeria infections in commercial laying birds in Nigeria. One Thousand eight hundred and forty-three (1843) commercial laying chickens from 28 states and the Federal Capital Territory (FCT) of Nigeria, between 2007 and 2016 were examined for the presence of Eimeria parasites and for clinicopathological lesions. Simple flotation and the McMaster techniques were used to confirm the presence of Eimeria oocysts and estimate the oocyst load. Positive samples were sporulated for the purpose of species differentiation. Gross and histopathology were carried out accordingly. Two hundred and seven (207) faecal samples/carcasses were positive for Eimeria infections (11.23%; 95% CI = 9.87-12.75). Eimeria tenella and E. necatrix were the most prevalent species. The highest mean oocyst per gram (OPG) was recorded in E. acervulina (5260.87 (± 1838.35)). The prevalence of Eimeria infections in commercial laying birds within the states ranged between 4.4% (Kaduna State), and 33% (Ebonyi and Lagos States), and 21.1% in FCT. There was a higher prevalence of Eimeria infections in commercial laying birds that are less than 1 year compared to those above a year. Eimeria infections was 2.19 times more likely to occur during the wet season compared to the dry season (95% CI = 1.59-3.06; χ2 = 23.29; P = < 0.01). One hundred and eighty-five (185) carcasses showed moderate petechiae to ecchymotic intestinal/caecal mucosa, while 22 carcasses showed severe petechiae to ecchymotic intestinal/caecal mucosa with bloody intestinal lumen. This study appears to be the first nation-wide study on the prevalence and clinico-histopathological changes associated with Eimeria infections in commercial laying chickens in Nigeria. © Indian Society for Parasitology 2022.