BVDV induced gastro-neuropathy outbreak in a feedlot calves around Tehran (Iran)

An outbreak of a lethal disease was reported in 4–6-month-old Holstein calves in a feedlot around Tehran. The signs of central nervous system and gastrointestinal system (GI) involvement were observed in the diseased animals. Necropsy samples of GI, liver, kidney, spleen and lung from 3 died animals were prepared for histopathological examination. Blood and formalin-fixed ear notch samples of 6 calves were submitted for RT-PCR, antigen-capture ELISA (ACE) and immunohistochemistry (IHC) for the detection of BVDV. The results of ACE on buffy coats were negative but RT-PCR of all 6 cases and IHC of 4 cases were positive for BVDV infection. Based on the clinical signs and pathological findings in the GI system and brain, we strongly suggest that the BVDV may represent a gastro-neuropathogen strain. To the best of our knowledge, this is the first outbreak of gastro-neuropathogenic BVDV infection in Iran, which may be acquired postnatally.