Respiratory infections caused by bacterial agents in cattle and sheep in the Province of Corrientes, Argentina

Abstract

Mannheimia haemolytica, Trueperella pyogenes and Pasteurella multocida are commensal bacteria of the upper respiratory tract of ruminants. However, in presence of predisposing factors, they can trigger the disease and even lead to death. The objective of this study was to determine the causes of morbidity and mortality in calves and lambs from 4 establishments located in the Province of Corrientes, Argentina. During of the period between June and August 2021, 4 cases of respiratory diseases were received at the INTA Mercedes, Corrientes, Animal Health Laboratory, both in cattle (3) and sheep (1). Incase of cattle, the morbidity in each the herd was 3.3% (5/150), 3.5% (7/200) and 12.4% (56/450). In the sheep flock, the morbidity was 8% (4/50). In sick animals, necropsies were performed and samples of lung and lung abscess were taken. In those samples, bacteriological culture and histological analysis were performed. Bacterial agents including T. pyogenes (1), M. haemolytica (2) and P. multocida (1) were detected, associated with the macroscopic findings and histological lesions. In our study, bacterial agents were detected as causing pneumonia represent in between 2 and 6% of mortality in the herds analyzed, so they should be considered as an important cause of death, in order to implement the necessary corrective and preventive measures.