Pneumonia in Algerian Ouled Djellal sheep: Bacteriological study and macroscopic aspect of lung lesions

Respiratory diseases in sheep are a multifactorial etiology syndrome, causing great economic losses. This study was carried out with the aim of establishing a bacteriological diagnosis of respiratory diseases in sheep, on the basis of lungs with macroscopic lesions taken from sheep slaughtered at the Blida abattoir. A total of 150 samples (swabs and lung parenchyma) from 75 Ouled Djellal sheep, aged six to twelve months old, with pulmonary lesions, were collected to determine possible correlations between the etiological agents and the type of lesion. Hepatization (or consolidation) was the main lesion observed (70%), preferentially localized on the right apical lobe (88% of the cases). This is a special form of pneumonia called atypical pneumonia. A varied microbial flora was isolated, alone or in association, namely bacteria with respiratory tropism as well as others of secondary infection. The bacteria most frequently isolated were γ-hemolytic streptococci (18%), Escherichia coli (17.5%), Micrococcus species (14.5%), and coagulase-negative staphylococci (10.5%); the large family of Enterobacteriaceae represented nearly 43% of the isolates. The pneumotropic bacteria (Mannheimia haemolytica and Pasteurella multocida) which count for 5.6% of the isolates, turned out to be correlated with the hepatization lesions.