Although the Eurasian Otter Lutra lutra is afforded special protection under the Widllife and Countryside Act (1981), and is defined as globally threatened in the Government's Biodiversity Action Plan, we know remarkably little about the diseases and causes of mortality affecting this species. With the support of the Environment Agency, the first author has been carrying out detailed post-mortem examinations of Otters found dead in south-west England since December 1988.