Bovine coronaviruses, like other animal coronaviruses, have a predilection for intestinal and respiratory tracts. The viruses responsible for enteric and respiratory symptoms are closely related antigenically and genetically. Only 4 bovine coronavirus isolates have been completely sequenced and thus, the information about the genetics of the virus is still limited. This article reviews the clinical syndromes associated with bovine coronavirus, including pneumonia in calves and adult cattle, calf diarrhea, and winter dysentery; diagnostic methods; prevention using vaccination; and treatment, with adjunctive immunotherapy.

This article describes a new case of a rare syndrome including enamel agenesis of the primary and permanent dentition, delayed or absent eruption of the permanent dentition, coronal intraalveolar resorption and gingival enlargement. Renal symptoms include medullary nephrocalcinosis without any apparent cause, and evolution to a renal failure. The early diagnosis provided by the oral symptoms leads to a better renal prognosis. As a consequence, pediatric dentists should be aware of this pathology.

Abstract. 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.Key words: BEV; BEV-Oklahoma; Bovine; enterovirus; picornavirus; typhlocolitis.Bovine enterovirus (BEV) belongs to the family Picornaviridae (picornaviruses), which consists of small (18-30 nm), nonenveloped viruses with an icosahedral capsid that encloses a single copy of positive-sense RNA genome. BEV is in the genus Enterovirus, along with poliovirus, human enterovirus, coxsackieviruses, swine vesicular disease virus, echovirus 11, and others. Originally classified into several serotypes, only 2 serotypes, BEV-1 and BEV-2, are now recognized. 10,15,18,19 Because of the unavailability of type specific antisera or a commercially available diagnostic test, a genotypic classification, which supports previous recognized serological distinctions, has been proposed. 7 Despite the large volume of information available on other enteroviruses, very little documentation exists on the pathogenesis of BEV infections in cattle or on its prevalence in North America. Several case reports in the 1950s and 1970s document the isolation of BEV from feces and various tissues from apparently healthy animals or from animals with clinical signs that ranged from mild to moderate diarrhea to reproductive disease. 3,4,14,20 However, these older reports are difficult to interpret as they relied solely on serological assays or had identified more than one infectious agent. This report describes the isolation and partial characterization of BEV-1 from a fatal enteric disease case in a heifer. A 2-year-old, 455 kg, 7.5 months pregnant Aberdeen Angus heifer was presented to the Boren Veterinary Medical Teaching Hospital of Oklahoma State University with a 5-hour history of progressive abdominal pain of sudden onset. According to the owner, the heifer was showing signs of colic by kicking at her abdomen and repeatedly getting up and down; she had been acting and eating normally the day prior to presentation. The animal had been raised on the farm and considered healthy until the episode of colic. Her vaccination (CattleMasterH 4 + VL5: IBR-BVD-PI3-BRSV-Campylobacter fetus-Leptospira canicola...

Necropsy of 4 neonatal calves with a peracute syndrome of abdominal distention, diarrhea, dehydration, shock, and death revealed abomasal tympany, marked edema, hemorrhage, and emphysema of ruminal and abomasal walls and histopathologic lesions characteristic of forestomach acidosis. The presence of acid damage and the production of substantial quantities of gas strongly suggested that the pathogenesis of the syndrome involved exuberant fermentation of intragastric substrate. This supposition led to attempts to experimentally induce the syndrome by dosing neonatal calves with an alimentary tract flora, followed by milk replacer supplemented with excessive fermentable carbohydrate (D-glucose and cornstarch). Two of the 5 calves thus treated developed a syndrome very similar to that observed in naturally affected calves. Literature suggests involvement of several Clostridial species, Sarcina spp., and possibly other microbes or a combination thereof to be involved in very similar syndromes. Therefore it is suggested that this complex of lesions and clinical signs is not dependent on a single etiologic agent. Rather, it is proposed that the natural occurrence of disease requires a quantity of highly fermentable substrate (starch, glucose, lactose, etc.) and a bacterial flora that is capable of rapidly fermenting that particular substrate with a resultant production of gas and acid.

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