The inbred Wistar Kyoto rat was received at Taconic from M&B A/S in 1998 at F61. M&B (formerly Mollegaard) received the strain from the NIH Animal Genetic Resource in 1975 at F13. The NIH-stock was obtained in 1971 as non-inbred Wistar stock from the Kyoto School of Medicine. Cesarean derived in 1999, Taconics Foundation Colony of inbred WKYs is maintained in a plastic-film gnotbiotic isolator. Breeders from the FC are regularly transferred to Taconics WKY Production Colony which is maintained in an MPF Barrier Unit.