Pneumonia caused by Mannheimia haemolytica in goats at a slaughterhouse in Rasht, Iran

Bronchopneumonia caused by Mannheimia haemolytica and Pasteurella multocida, in sheep and goats often occurs in livestock that are under stresses such as transportation, milk catching, changing diets, or being with other animals from other farms. In this study, from June to November 2018, 230 goats at a slaughterhouse in Rasht were examined for pulmonary lesions. Of the total 230 samples, 82 cases (35.6%) had one or more macroscopic lesions. Mannheimia haemolytica, Pasteurella multocida and Bibersteinia trehalosi were detected in 0.9%, 0.45% and 0.45% of positive samples, respectively. In two cases (0.9%), bronchiectasis was observed in the lower anterior region. In the microscopic view of the tissue sections, with the exception of one case that had typical symptoms of acute interstitial pneumonia and oxidative phase observed, 81 other cases (35.2%) showed typical symptoms of enzootic pneumonia and, in one case, focal necroses were observed. The inflammation of the pleura was not seen in goats less 6 months of age, but was observed in 44% of samples 6-12 months and 95% of samples more than 12 months. Based on this study that was conducted for the first time in the north of Iran, enzootic pneumonia and inflammation of the pleura are the most important problems of goats over one year and Mannheimia haemolytica can be one of the potential causes of pneumonia.