Splenic T-cell lymphoma in a North American River Otter (Lontra canadensis)

BACKGROUND: Splenic lymphoma is commonly reported in domestic ferrets (Mustela putorious furo), but very rarely reported in wild Mustelidae species, including otters. One report described B-cell splenic lymphoma in an Asian small-clawed otter (Aonyx cinerea) that metastasized and was the primary reasoning for humane euthanasia (Stedman and Mills, 2014). CASE DESCRIPTION: The current report describes a case of splenic T-cell lymphoma in a captive North American river otter (Lontra canadensis). The otter died several weeks after splenectomy and no evidence of metastasis was found on gross necropsy or histopathological evaluation. CONCLUSION: The splenectomy performed on this individual was presumptively curative for its splenic lymphoma. Extensive myocardial fibrosis was found, and suspected to have caused severe cardiac arrhythmia leading to acute death.