Amplification of three different papillomaviral DNA sequences from a cat with viral plaques.

A 3-year-old cat from New Zealand developed three small raised non-ulcerated plaques on the face. Serology detected antibodies against feline immunodeficiency virus (FIV). Histology of the plaque revealed epidermal hyperplasia with keratinocytes either distended with large blue-grey cytoplasmic bodies or with shrunken nuclei surrounded by a clear halo. Papillomavirus (PV) antigen was detected immunohistochemically and feline viral plaque was diagnosed. Swabs were taken of both lesional and non-lesional skin, and polymerase chain reactions were used to detect PV DNA. Three different PV DNA sequences were amplified, one from a Felis domesticus PV type 1 (FdPV-1) previously amplified from a feline viral plaque, a second (FdPV-JM) previously amplified from feline cutaneous squamous cell carcinomas, and a third FdPV-MY that was not reported previously. All three sequences were amplified from swabs of both lesional and non-lesional skin. These results extend the geographical range of FdPV-1 outside North America and also demonstrate the ability of FdPV-1 to asymptomatically infect feline skin. However, the detection of multiple PV sequences within both lesional and non-lesional samples makes it difficult to determine whether or not any of the PVs caused feline viral plaque development in this cat. This is the first time PV DNA has been detected in a feline skin swab sample. Additionally, it is the first report of multiple PVs being detected in a single sample from a cat. This may suggest that FIV infection predisposes cats to cutaneous PV infection.