Morphopathological Changes of Natural Pneumonic Pasteurellosis in Calves

Document Type : Original Article


1 Department of Pathology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Tukh, Qalyobiya, Egypt 13736

2 Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Moshtohor, Tukh, Qalyobiya, Egypt 13736

3 Dept. of Veterinary Pathology, Faculty of Veterinary Medicine, Benha University, Tukh, Qalyobiya


Pasteurellosis is one of the infectious diseases of calves causing huge economical losses due to high morbidity, mortality, and treatment expenses of livestock. This study was conducted to describe the clinical presentation and pulmonary lesions of pasteurellosis infected calves. 167 lung specimens were collected from cadaver and slaughtered calves (15 days-2 years) and Pasteurella multocida (P. multocida) were identified in all the submitted samples using bacteriological examination and qRT-PCR. Our results showed upregulation of outer membrane protein (OMP) (virulent gene) of P. multocida in all submitted bacteriologically confirmed cases of pneumonic pasteurellosis. The clinical signs of infected calves were in form of fever, respiratory distress, frothy salivation, weakness, and inappetence. Grossly, lungs were consolidated with presence of multiple abscesses, hemorrhages, thickened pleura, and prominent interlobular septa. Microscopically, lungs revealed fibrinous, suppurative and fibrinopurulent bronchopneumonia with presence of bacterial colonies, heavy infiltrates of inflammatory cells, fibrin and RBCS inside the pulmonary alveoli and bronchioles. Multifocal necrotic areas in pulmonary parenchyma and intra-alveolar degenerated neutrophils (oat cells) were also seen in some pulmonary foci. We concluded that OMP87 overexpression reflects pasteurella infection even in formalin fixed lungs. Pasteurella is one of the prevalent causes of BRD and pneumonia of calves in Kalyobiya governorate. Fibrinopurulent bronchopneumonia and multifocal pulmonary necrosis were the predominant lung alterations in calves infected with p. multocida.


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