Abstract

We studied the pathology, epidemiology and clinical significance of genital herpesvirus infection in a zoo collection of bottlenose dolphins. Samples from the genital mucosa were tested by PCR, targeting the DNA polymerase of herpesvirus. Herpesvirus was significantly associated with the occurrence of mucosal plaques on the genital mucosa. Biopsies form a penile plaque showed epithelial hyperplasia by histology, contained herpesvirus-like particles by EM and tested positive for herpesvirus by PCR.

Herpesvirus was successfully cultivated and a direct ELISA was developed for anti-herpesvirus antibodies. 95% of adults were seropositive and seroconversion occurred around the age when first sexual intercourse behavior was observed.

In other species, herpesvirus is associated with abortion, perinatal mortality and urogenital neoplasia. Six cases of abortion and perinatal mortality were investigated by PCR, no evidence of a herpesvirus infection was found. Retrospective analysis of all necropsy reports of animals deceased in this collection since 1990 revealed no occurrence of urogenital tumors.

It is concluded that the newly cultivated herpesvirus probably causes benign genital plaques, is endemic in this group of dolphins and is likely transmitted by sexual contact.

Acknowledgements

The training staffs of Dolfinarium Harderwijk and Parc Asterix, the laboratory technician Vivian Emmer, are acknowledged for their assistance with obtaining and processing of the samples.