RESUMEN
Reports of severe enteric disease of unknown etiology affecting lactating mice have appeared in the literature. Clostridial disease similar to that seen in cattle and sheep on high-carbohydrate rations and caused by Clostridium perfringens has been suspected in these mouse outbreaks but has not been isolated from affected mice. The present report describes a severe, necrotizing enterocolitis associated with overgrowth of C. perfringens type A in lactating Swiss-derived (ND4) mice. Mice nursing large litters of pups in the second week of life were the most severely affected. The organism isolated from dead or moribund mice was positive by polymerase chain reaction assay for the gene for the C. perfringens a toxin, but actual toxin production was not determined. The disease in this mouse colony was ameliorated by increasing the fat and calorie content of the diet of lactating dams, which each received 1 g peanut butter every 48 h.