Fatal ulcerative and hemorrhagic typhlocolitis in a pregnant heifer associated with natural bovine enterovirus type-1 infection.

One 2-year-old, 7.5 months pregnant Aberdeen Angus out of a herd of 100 apparently healthy cows, died within 10 hours of hospitalization. At necropsy, multiple foci of mucosal hemorrhage and ulceration were observed in the spiral colon and cecum. Virus isolation from intestinal lesions yielded a cytopathic virus, which was revealed by electron microscopy to be an approximately 27 nm, nonenveloped virus. Further characterization by reverse transcription-polymerase chain reaction (RT-PCR), sequencing of the 5'UTR and partial VP1 coding region, and phylogenetic analysis classified the virus isolate as bovine enterovirus type 1 (BEV-1). No other significant pathogens were detected. This is the first report of BEV-1 isolated in the USA from an animal with fatal enteric disease in more than 20 years. Further investigation is required to determine the prevalence of BEV in North America and to establish the clinical relevance of this understudied virus.