Booker Calvin W, Abutarbush Sameeh M, Morley Paul S, Jim G Kee, Pittman Tom J, Schunicht Oliver C, Perrett Tye, Wildman Brian K, Fenton R Kent, Guichon P Timothy, Janzen Eugene D
Feedlot Health Management Services Ltd., PO Box 140, Okotoks, Alberta T1S 2A2.
Can Vet J. 2008 May;49(5):473-81.
The aim of this study was to describe the microbiologic agents and pathologic processes in fatal bovine respiratory disease (BRD) of feedlot cattle and to investigate associations between agents and pathologic processes. Ninety feedlot calves diagnosed at necropsy with BRD and 9 control calves without BRD were examined, using immunohistochemical (IHC) staining and histopathologic studies. Mannheimia haemolytica (MH) (peracute, acute, and subacute cases) and Mycoplasma bovis (MB) (subacute, bronchiolar, and chronic cases) were the most common agents identified in fatal BRD cases. Significant associations (P < 0.10) were detected between microbiologic agents and between agents and pathologic processes. When IHC staining was used, 25/26 (96%) of animals that were positive for bovine viral diarrhea virus (BVDV) were also positive for MH; 12/15 (80 %) of animals that were positive for Histophilus somni (HS) were also positive for MB; and all of the animals that were positive for HS were negative for MH and BVDV. This quantitative pathological study demonstrates that several etiologic agents and pathologic processes are involved in fatal BRD of feedlot cattle.
本研究的目的是描述育肥牛致命性牛呼吸道疾病（BRD）中的微生物病原体和病理过程，并调查病原体与病理过程之间的关联。对90头在尸检时被诊断为BRD的育肥牛犊和9头无BRD的对照牛犊进行了检查，采用免疫组织化学（IHC）染色和组织病理学研究。溶血曼氏杆菌（MH）（超急性、急性和亚急性病例）和牛支原体（MB）（亚急性、细支气管和慢性病例）是在致命性BRD病例中鉴定出的最常见病原体。在微生物病原体之间以及病原体与病理过程之间检测到显著关联（P < 0.10）。采用IHC染色时，牛病毒性腹泻病毒（BVDV）呈阳性的动物中有25/26（96%）也呈MH阳性；睡眠嗜血杆菌（HS）呈阳性的动物中有12/15（80%）也呈MB阳性；所有HS呈阳性的动物MH和BVDV均为阴性。这项定量病理学研究表明，几种病原体和病理过程与育肥牛的致命性BRD有关。
