A six month old North American river otter, Lutra canadensis, was diagnosed positive for feline leukemia virus (FeLV) by the ELISA test after an acute onset of epistaxis and renal failure.

Feline Leukemia Virus (FeLV) is an oncornavirus belonging to the family Retroviridae. It was first reported in 1964 (Jarrett) and has been felt to be a viral disease restricted to felids. Members of the family Mustelidae (marten, wolverine, skunk, otter and badger) have not been considered to be susceptible to FeLV. The virus is wide spread in nature and has been shown to be involved in a myriad of diseases, both neoplastic and non-neoplastic, affecting a variety of body systems.