Parapoxviral vulvovaginitis in Holstein cows.

A group of Holstein first-calved heifers developed small pustules and ulcers on the vulva and in the vagina during the first 1-4 wk postpartum. The lesions varied from small red pinpoint foci to pustules and ulcers, 3-5 mm diameter. Some ulcers coalesced to form large ulcerated areas up to 15 mm diameter. In some animals, these ulcers progressed to become deep ulceration of the vaginal and vulvar mucosa with >50% of the mucosa involved. Vaginal biopsies from 4 heifers and vaginal individual swabs from 8 heifers for a combined sampling of 9 heifers were taken for clinical assessment. Six of the 9 heifers had parapoxvirus based on histopathology and/or PCR. Histologic examination of the biopsies of the pustules identified ballooning degeneration of the epithelium with degenerate epithelium containing eosinophilic intracytoplasmic inclusions consistent with a parapoxvirus in 3 of 4 biopsies. Testing for bovine herpesvirus 1, 2, and 4, bovine viral diarrhea virus, bovine papular stomatitis virus, and orf virus remained negative.