An Epizootic Form of Tyzzer's Disease in a Rat Colony

Abstract

An epizootic form of Tyzzer's disease was experienced in a rearing facility of laboratory rats with an infectivity and morbidity of 36 to 80% and 5 to 30%, respectively. With liver tissue from an affected rat, a spore-forming causative agent was successfully transmitted to other rats by oral inoculation in association with cortisone, producing 106 to 107 spores/g liver tissue.