Clinicopathological Correlation in an Acute Case of Infectious Bovine Rhinotracheitis: Postmortem Evidence and Comprehensive Diagnostic Analysis

Objective: To describe an acute case of Infectious Bovine Rhinotracheitis (IBR) in a Holstein cow through the clinicopathological correlation of clinical manifestations, postmortem macroscopic findings, and the pathogenic mechanisms associated with bovine herpesvirus type 1 (BoHV-1), thereby emphasizing the diagnostic value of necropsy under field conditions. Design/methodology/approach: A comprehensive clinical evaluation was conducted, followed by necropsy examination due to the unavailability of laboratory diagnostic testing. Clinical manifestations and macroscopic lesions affecting the respiratory, lymphatic, digestive, renal, hepatic, and cardiovascular systems were systematically documented. The findings were subsequently integrated through an extensive clinicopathological analysis. Results: Necropsy findings revealed a severe respiratory condition consistent with IBR, characterized by marked tracheal inflammation accompanied by coagulative necrosis and abundant seropurulent exudate. Bilateral pulmonary congestion, interstitial pneumonia, and fibrinous bronchopneumonia were also identified. Pronounced lymphadenopathy and enlargement of the retropharyngeal and tracheobronchial lymph nodes were observed, together with multisystemic involvement including congestive myocarditis, nephritis associated with tubular necrosis, hepatic congestion, and omasal and abomasal alterations suggestive of endotoxemia. Evidence of secondary bacterial coinfection was clearly documented. Overall, the lesions were highly consistent with infection caused by respiratory strains of BoHV-1. Limitations on study/implications: The absence of access to a nearby diagnostic laboratory precluded virological or serological confirmation; consequently, the diagnosis was established based on a robust clinicopathological correlation. Nevertheless, the necropsy examination enabled the implementation of immediate sanitary measures aimed at preventing additional economic and productive losses. Findings/conclusions: This case highlights the severe respiratory presentation of IBR, characterized by rapid clinical progression and a fatal outcome. The integration of clinical findings with postmortem observations enabled the identification of acute BoHV-1 infection exacerbated by secondary bacterial coinfections, thereby providing valuable information for sanitary surveillance, disease prevention, and herd health management in cattle production systems.