Pathological Changes Associated with Natural Outbreak of Swine Pasteurellosis

Swine pasteurellosis is an acute infectious disease and is considered to be one of the most economically important diseases in Asia particularly in South and South East Asia leading to huge economic loss in livestock industry. A study was conducted to analyze the histopathological alterations caused by cytotoxins released by Pasteurella multocida serotype B, which caused Swine pasteurellosis in descript as well as nondescript pigs of Chhattisgarh, India. Affected animals exhibited pyrexia, dullness, staggering gait, anorexia, serous nasal discharge and dyspnoea. Typical lesions of oedematous swellings noted in the pharyngeal region. Case fatality rate was 95% in adult animals and 100% in piglets. The causative organism, Pasteurella multocida was isolated and characterized by biochemical tests and the detection of the KMT1, CapB, toxA, and ompH genes was performed using Polymerase Chain Reaction (PCR). Gross lesions included severe pneumonia and haemorrhages in lungs, petechial haemorrhages on serous membranes and other visceral organs. Lymph nodes were enlarged, oedematous and haemorrhagic. The histopathological lesions developed in lungs were typical fibrinous bronchopneumonia, multifocal suppuration and severe thickening of pleura. Heart showed presence of thrombi, haemorrhages and necrosis of myocardium. Hepatic architecture showed server haemorrhages and necrosis while kidneys and spleen showed degenerative and necrotic changes.