Korea had experienced second epidemic highly pathogenic avian influenza (HPAI), and there were the seven affected farms, including two breeder duck farms, from 22nd November 2006 to 6th March 2007. Here, we reported the clinico-pathological characteristics of domestic breeder ducks farms naturally infected with HPAI virus (H5N1). Clinically, the most ducks showed various signs from depression, decreased egg production and feed consumption to even, death. The most commonly gross changes were hepatomegaly, splenomegaly, petechial and ecchymotic hemorrhage on the liver surface, a white stripe on the cardiac muscle, and severely hemorrhagic and deformed eggs. The most significant histopathological changes were necrosis of various cells such as neuron, lymphocytes, cardiac myocytes, hepatocytes, blood vessels and pancreatic acinar epithelium. The viral antigen was mainly detected in the endothelium of blood vessels of various organs and tissues, peripheral nerves and neuronal cells. Based on the above results, we identified that HPAI H5N1 induced systemic infection in the adult breeder ducks.

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• 김민정(국립수의과학검역원) | Min-Jeong Kim (National Veterinary Research and Quarantine Service)
• 조성준(국립수의과학검역원) | Seong-Joon Joh (National Veterinary Research and Quarantine Service)
• 김민철(국립수의과학검역원) | Min-Chul Kim (National Veterinary Research and Quarantine Service)
• 이윤정(국립수의과학검역원) | Youn-Jeong Lee (National Veterinary Research and Quarantine Service)
• 정옥미(국립수의과학검역원) | Ok-Mi Jeong (National Veterinary Research and Quarantine Service)
• 우계형(국립수의과학검역원) | Gye-Hyeong Woo (National Veterinary Research and Quarantine Service)
• 권준헌(국립수의과학검역원) | Jun-Hun Kwon (National Veterinary Research and Quarantine Service)
• 모인필(충북대학교 수의과대학) | In-Pil Mo (College of Veterinary Medicine, Chungbuk National University) Correspondence