1Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
2Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
3Department of Pathobiology, Veterinary Reference Laboratory, Veterinary Organization, Tehran, Iran
4Junior School of Veterinary Medicine, Bu Ali Sina University, Hamedan, 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.