June 2022

Animal: Bovine, 1-year-old

Organ: Lung

History:  Formalin-fixed lung was submitted. There was a case history of acute respiratory distress with a rapid fatal outcome. A PCR-kit for 7 respiratory pathogens was performed. The results were positive for Mycoplasma bovis and Bovine Respiratory Syncytial Virus

Macroscopical findings: Cranioventral lung lobe consolidation with multifocal to coalescing formation of abscesses within chronically dilated bronchi and bronchioles

Histopathological findings: Multifocal to coalescing necrosis of the bronchial and bronchiolar epithelial lining with dilation (bronchiectasia). These larger airways are filled with hypereosinophilic material and karyorrhectic cellular debris (lytic necrosis), surrounded by a dens rim of degenerate and necrotic neutrophils and a mild fibroblast proliferation. Multifocally, there is type II pneumocyte hyperplasia and hypertrophy. Alveolar lumina are filled with inspissated eosinophilic material (fibrin). HE stain

Diagnosis: Lung: Necropurulent bronchopneumonia, with bronchiectasia, chronic, multifocal to coalescing, marked

Contributor: Nermin Caliskan,  Animal health lab Flanders (DGZ Vlaanderen), BELGIUM