Diagnosis and treatment of a novel papillomavirus in a North American porcupine (Erethizon dorsatum)

A nine-year-old sexually entire male North American porcupine (Erethizon dorsatum) was evaluated for multiple cutaneous masses that had progressively worsened over a seven-year period. Clinical examination revealed multiple exophytic pigmented papules, nodules and plaques on the muzzle, pinnae, limbs, palpebrae and periocular regions. Skin biopsies were consistent with papillomavirus-associated proliferative epithelial lesions. Using PCR primers specific for papillomaviruses, a partial fragment of the papillomavirus L1 gene was successfully amplified from the porcupine skin samples. Sequencing of the PCR product yielded a sequence with only 69% homology to the closest previously reported papillomavirus sequence, indicating this was a novel papillomavirus. Treatment was multimodal. A partial eyelid resection was performed, and a carbon dioxide laser and cryosurgery were used to treat focal lesions. Interferon-α 2A was also administered orally. These therapies resulted in a mild decrease in the size of the lesions followed by subsequent stabilisation over a period of 12 months.