Management of an outbreak of rat theilovirus.

Rat theilovirus is a commonly reported infection in research rat colonies. The author's institution experienced an outbreak of rat theilovirus in a breeding colony of unique outbred rats. To manage this outbreak, the institution chose to use a 'test and cull' strategy because this approach is reported to be successful in mouse colonies infected with Theiler's murine encephalomyelitis virus, a related virus. Here the author describes the outbreak and subsequent management of rat theilovirus. The strategy successfully cleared the virus from the rat colony.