Bovine coronavirus associated syndromes

Abstract

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.

Fig. 1

BCoV antigen in macrophages was detected by immunohistochemistry (8F2) in formalin-fixed section of lungs from an adult cow showing clinical signs of lower respiratory tract infection.

Fig. 2

Immunohistochemistry on formalin-fixed section of the intestine submitted from a calf stained with 8F2 anti nucleoprotein antigen of BCoV. Brown staining in the crypts indicates positivity for BCoV.

Fig. 3

Nasal cells positive for BCoV by direct fluorescent antibody test using anti-BCoV fluorescein isothiocyanate conjugate. Swab was collected from a calf experimentally infected with a pneumoenteric BCoV (MN-1988).

Fig. 4

Interstitial pneumonia in a calf experimentally infected with MN-1988 pneumoenteric BCoV isolate.

Fig. 5

Pulmonary hemorrhages in a calf inoculated with a pneumoenteric isolate of BCoV.

Fig. 6

Crypt dilation after experimental infection of a calf with MN-1988 BCoV isolate.