Anal fibropapillomas containing bovine papillomavirus type 2 DNA in two groups of heifers

AbstractCASE HISTORYAnal warts were observed in heifers in two unrelated groups of animals. Heifers in one group developed visible warts 4 months after manual rectal examination and heifers in the other group developed warts 5 months after examination using a hand-held rectal ultrasound probe.CLINICAL FINDINGSLarge exophytic proliferative anal masses were observed in 5/15 (33%) heifers in one group and 13/149 (9%) heifers in the second group. Heifers in the second group were also noted to have similar masses on the underside of the tail at sites previously used for venepuncture and some of the heifers had skin warts. Despite the large size of the anal masses, none of the heifers showed clinical signs of systemic illness.HISTOPATHOLOGICAL FINDINGSAn anal mass was removed from one heifer in each of the two groups. Sections from both masses showed hyperplastic epithelium covering a proliferation of well-differentiated fibroblasts consistent with fibropapillomas. Small numbers of cells within the epidermis ha...