Retrospective Analysis of 50 Postnatal BVDV Outbreaks in Cattle from Central Argentina: Clinical, Pathological, and Epidemiological Insights.

Bovine viral diarrhea virus (BVDV) is an important pathogen in cattle and causes considerable economic losses worldwide. In Argentina, where there is no national control program, BVDV remains endemic. In this retrospective study, the epidemiological, clinical and pathological features of postnatal BVDV-associated diseases in 50 outbreaks in central Argentina (1995-2024) were analyzed. Data were obtained from field reports, necropsies, and virological results (virus isolation, RT-nPCR, immunochromatography). No seasonal pattern was found. Acute infections (AIs) and mucosal disease (MD) occurred with similar frequency. Clinical signs included salivation, weakness, emaciation and diarrhea. The lesions were widespread and involved the gastrointestinal tract, skin, lymphoid tissues and spleen. Although MD cases has more extensive tissue involvement, no significant differences in morbidity, mortality or distribution of lesions were observed between AIs and MD. BVDV-1b was the most frequently detected subtype. These results highlight the challenges of BVDV control in extensive production systems. Strengthening diagnostic surveillance, implementing targeted vaccination and eliminating persistently infected animals are essential to reduce BVDV impact in endemic regions such as Argentina.