A link between dental abnormalities and loss of genetic variation has
been reported for unconfined populations of American bison Bison bison
(Linnaeus, 1758) but not for captive populations. From a zoo herd wit
h a small founder population and likely history of inbreeding, we repo
rt the first recorded occurrence of dental abnormalities in captive bi
son and the first case of supernumerary second premolars in bison.