Involvement of canine oral papillomavirus in generalized oral and cutaneous verrucosis in a Chinese Shar Pei dog.

Severe papillomatosis developed in the oral cavity and spread throughout the haired skin of the trunk and limbs of an 8-month-old female Chinese Shar Pei dog. The dog had received corticosteroids prior to referral, which was associated with the onset of demodecosis and papillomatosis. Papillomavirus structural antigens were detected in biopsies by immunohistochemistry using a panel of monoclonal and polyclonal antibodies. An 8.2-kilobase papillomavirus-specific DNA molecule was detected in the cutaneous lesions by high stringency Southern blot hybridization using a cloned canine oral papillomavirus DNA probe. Restriction enzyme analysis revealed that the virus in the cutaneous lesions was identical to the canine oral papillomavirus. Discontinuation of the steroids combined with the use of a mitocide, antibiotics, and an autogenous vaccine resolved the demodecosis and papillomatosis. This case report suggests that corticosteroid-induced immunosuppression can expand the tissue tropism of papillomaviruses.