Antibody titres against canine papillomavirus 1 peak around clinical regression in naturally occurring oral papillomatosis.

Background: Most forms of canine papillomatosis are believed to be associated with papillomavirus infections. Canine papillomavirus type 1 (CPV1) is considered to be responsible for most oral cases and several forms of cutaneous papillomatosis.

Hypothesis/objectives: The aim of this study was to evaluate cases of naturally occurring oral papillomatosis with regard to the type of virus involved, antibody induction and remission time.

Methods: Forty dogs showing different degrees of classical oral papillomatosis were included as a single study group. Tissue and serum samples were acquired upon initial presentation; serum samples were collected again upon remission (n = 13) and after 3 months of convalescence (n = 4). None of the dogs underwent antiviral therapy. Tissue samples were tested by PCR to detect CPV DNA, while serum samples were tested using a specific enzyme-linked immunosorbent assay for antibodies against the L1 capsid protein of CPV1.

Results: All tissue samples were positive for CPV1 DNA, and 87.5% of all serum samples contained measurable levels of antibody against the virus (cut-off value 0.3). The average optical density measured in the enzyme-linked immunosorbent assay was 0.51 at initial presentation, 1.65 upon remission and 0.83 at 3 months postrecovery. Time to clinical regression varied between 1 month and 1 year.

Conclusions And Clinical Importance: These data support existing evidence for a high prevalence of CPV1 in canine oral papillomatosis. The healing process seems to correlate with a strong antibody response, and antibody titres peaked around the time of clinical recovery. In contrast to previous data from laboratory settings, the variation in remission time was very high.