Morphologic changes and immunohistochemical detection of viral antigen in ovaries from cattle persistently infected with bovine viral diarrhea virus

Abstract

Objective - To identify morphologic differences in ovaries from cows persistently infected with bovine viral diarrhea virus (BVDV) and determine ovarian cell types infected in these cows. Design - A comparative study of ovaries in cattle persistently infected with BVDV and cattle not persistently infected with BVDV, using morphologic and immunohistochemical analysis. Animals - 6 postpubertal cows persistently infected with BVDV and 6 postpubertal cows not persistently infected with BVDV. Procedure-Ovaries were compared morphologically by counting the number of normal structures present on 3 histologie sections taken from each ovary. Immunohistochemistry was accomplished, using an indirect, monoclonal antibody-linked, avidin-biotin-peroxidase complex procedure. Results - Significant (P < 0.01) decrease in the number of tertiary follicles, graafian follicles, atretic follicles, and corpus hemorrhagicum/luteum/albicans was observed in cows persistently infected with BVDV. No difference in numbers of primordial or secondary follicles was observed. Immunostaining of BVDV antigen in luteal cells and macrophage-like cells was evident in ovaries from cows persistently infected with BVDV. Conclusions - Cows persistently infected with BVDV appear to have significant morphologic changes in their ovaries that suggest reduction in normal ovarian activities. Furthermore, BVDV antigen can be identified in specific ovarian cell types in cattle persistently infected with BVDV. Clinical Relevance - The changes observed may reduce reproductive performance in cows persistently infected with BVDV, and may be of importance when trying to salvage valuable genetic material from persistently infected cows through embryo transfer. It is yet to be determined whether similar findings are true in cows acutely infected with BVDV.