Orogenital neoplasia in Atlantic bottlenose dolphins (Tursiops truncatus)

This study describes lingual papillomas and squamous cell carcinomas (n = 11) and genital papillomas (n = 4) in Atlantic bottlenose dolphins (Tursiops truncatus) evaluated from January 2000 to January 2005. Tumors were found primarily in adult dolphins of both sexes living in free-ranging and captive conditions. Three dolphins had multiple lingual tumors of mixed histological type, consisting of papillomas and squamous cell carcinomas, suggesting malignant transformation of the benign papillomatous lesions. To our knowledge, this is the first report of oral papillomas in bottlenose dolphins and concurrent oral neoplasia that included both sessile papilloma and squamous cell carcinoma in the same dolphin. Additionally, it is the first known report of genital papillomas in free-ranging bottlenose dolphins from Atlantic coastal waters. The unusually high occurrence of related benign and malignant orogenital epithelial neoplastic lesions in a short period suggests that the lesions may represent one or more emerging diseases. Preliminary evidence suggests that these tumors may be of infectious etiology, possibly having an orogenital route of transmission.