Diagnosis and treatment of a novel papillomavirus in a North American porcupine ( <i>Erethizon dorsatum</i> )

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.