Equus caballus papillomavirus 8 (EcPV8) associated with multiple viral plaques, viral papillomas, and squamous cell carcinoma in a horse.

BACKGROUND

Equus caballus papillomavirus 8, a recently discovered virus, has been reported to cause generalised papillomavirus in horses.

OBJECTIVES

To describe a case in which multiple viral plaques, viral papillomas, squamous cell carcinoma (SCC) in situ and invasive squamous cell carcinoma (ISCC) were associated with EcPV8 in a horse.

STUDY DESIGN

Case report.

METHODS

A 16-year-old mixed breed horse presented with dozens of raised crusted papular to nodular lesions over a course of 4 years. Masses had been surgically excised four times and cisplatin beads and emulsion were implanted on three different occasions; however new masses continue to develop in sites of previous masses as well as new sites.

RESULTS

Multiple viral plaques, viral papillomas, SCC in situ and ISCC, localised to the inguinal region, were diagnosed via histopathology. EcPV8 DNA was detected via PCR.

MAIN LIMITATIONS

Since only a few cases have been reported, we do not know the incidence of EcPV8 nor how often it may be associated with SCC in situ or ISCC without further study.

CONCLUSIONS

This is the fourth reported case of viral papillomatosis in the context of an EcPV8 infection in a horse. This is the first case in which SCC has been associated with EcPV8.