The Wistar rat is selected at the Wistar Institute, Philadelphia, USA, prior to 1910. In 1932, from Wistar Institute to Glaxo Laboratory, UK. In 1933, from Glaxo to the Dutch Institution for Nutrition, Amsterdam. In 1941, the Unilever Company, Vlaardingen, the Netherlands, obtained a breeding stock from Dutch Institution for Nutrition. Thereafter, the Unilever stock was referred as the Wistar Unilever or WU rat.
In 1958, transferred from Unilever to TNO Central Institute for the Breeding of Laboratory Animals. To Harlan Laboratories through acquisition in 1986. Harlan became Envigo in 2015.