Preputial papillomatous epidermal hyperplasia in a guinea pig (Cavia porcellus)

Primary preputial lesions in male guinea pigs (Cavia porcellus) are rare. A 3.5-year-old intact male guinea pig was presented with severe pain and preputial hyperemia caused by urine scalding of its enlarged hyperemic papillomatous preputium. The papillomatous preputium was surgically resected by a circumferential incision at the proximal edge of the skin changes on both the proximal and distal preputial skin. The affected tissue was removed by blunt dissection, followed by intracutaneous continuous sutures. The recovery was uneventful and the guinea pig was discharged the same day on oral medications. Six months later, minor threadlike papillomas redeveloped on the perianal skin and on the medio-plantar surface of the right hindleg. Removal was successful, and further papillomas did not develop. Histopathology from the initial surgery confirmed epidermal orthokeratotic hyperkeratosis, with keratohyaline granules. Histopathology and macroscopic morphology raised the suspicion of papillomavirus induced skin changes. No further diagnostics were performed. Hyperkeratosis may have been exacerbated by the chronic skin irritation of urine getting trapped in between papillomatous nodules, as seen in humans with severe cases of diaper dermatitis. Papillomavirus should be considered in guinea pigs with preputial papillomas. Prognosis is good with surgical removal of affected tissue.