Review of respiratory pathology for field clinicians

For all various production methods, bovine respiratory disease has been described as the most common, causing the greatest production loss. With the current increasing scrutiny on the prudent use of antimicrobials, a definitive diagnosis has increased in importance. In commercial cattle operations, buiatricians are rarely called to attend to individual animals with respiratory disease. More often, we are tasked with a problem in a herd or a cohort of that herd. Almost spontaneously part of that task becomes making necropsy diagnoses. Examination of the respiratory tract at necropsy includes dissection of the upper respiratory tract, thorax, and abdomen. Explanations for clinical disease are usually evident with an extensive gross dissection of the aforementioned areas. In many cases the use of diagnostic support like histopathology, microbiology and molecular diagnostics, like immunohistochemistry, may be critical to outline changes to the management of the problem.