Lung Pathology and Infectious Agents in Fatal Feedlot Pneumonias and Relationship with Animal and Treatment Information
DOI:
https://doi.org/10.21423/aabppro20084399Keywords:
Bovine respiratory diseases, BRD, feedlot, Mycoplasma spp, viruses, bacteria, fatal pneumonia, immunohistochemistryAbstract
Bovine respiratory diseases (BRD) occurring in the feedlot represent the major disease entity during the feeding period. Several bacteria, viruses, and Mycoplasma spp are reported as causative agents. Feedlot BRD may occur at various times, although the early disease appearing after arrival and processing often receives the most attention. The diagnostician and clinician are faced with several clinical presentations and agents/lesions in the fatal cases.
The purpose of this study was to chart the fatal pneumonia cases over a one-year period in one Oklahoma feedyard, recording agent identification, observed pathology and animal treatment information. These cattle died either in the sick pen or suddenly in regular feeding pens without treatment. A clinical diagnosis of BRD was assigned to all cases charted. Samples of lung collected at necropsy (fresh and formalin fixed) were submitted for agent identification and histopathology. In the later stages of the study, skin samples were tested for BVDV by immunohistochemistry (IHC).