title: Pathology and molecular characterization of recentLeucocytozoon caulleryicases in layer flocks.
abstract: Leucocytozoonosis was found in three layer farms in chickens with suspected fatty liver or fatty liver hemorrhagic syndrome in Korea between 2009 and 2011. These layer chicken flocks showed both mortality and decreased egg production for one or two weeks when they were between 59 and 82 weeks old. At the necropsy, the most prominent gross lesions were found in the liver, which was enlarged, had a fragile texture, exhibited yellowish discolorations, and had various hemorrhagic lesions. Tissue reactions associated with megaloschizonts specific forLeucocytozoon caulleryiwere prominent upon microscopic examination of the liver without significant lipidosis. In addition, the ovaries and uterus were the most affected organs for Leucocytozoon caulleryi multiplication, which led to decreased egg productions. Molecular studies with formalin-fixed, paraffin-embedded tissues were performed in search of a partial region of the cytochromebgene for hemosporidian parasites. Based on these results, the causal agent was determined to be closely related toLeucocytozoon caulleryireported in Japan and Malaysia. In this study, we describe recently re-occurring leucocytozoonosis in layer chickens, which required histopathology for disease diagnosis. To prevent outbreaks and maintain chicken health and egg production, layer chickens need to be monitored for symptoms of leucocytozoonosis.
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea|Division of Basic Research, Bureau of Ecological Research, National Institute of Ecology, Seocheon 33657, Korea
authors.forename: Hae Rim
authors.initials: HR
authors.lastname: Lee
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
authors.forename: Bon-Sang
authors.initials: BS
authors.lastname: Koo
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
authors.forename: Eun-Ok
authors.initials: EO
authors.lastname: Jeon
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
authors.forename: Moo-Sung
authors.initials: MS
authors.lastname: Han
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
authors.forename: Kyung-Cheol
authors.initials: KCh
authors.lastname: Min
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
authors.forename: Seung Baek
authors.initials: SB
authors.lastname: Lee
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
authors.forename: Yeonji
authors.initials: Y
authors.lastname: Bae
authors.affiliation: Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea|Avian Disease Laboratory, College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea; moip@cbu.ac.kr
authors.forename: In-Pil
authors.initials: IP
authors.lastname: Mo
keywords: chicken leucocytozoonosis; Leucocytozoon caulleryi; layer chicken flocks; histopathology