Housing mice in a caging system with automatic flushing

Male Har:(ICR)BR mice were housed 8 wk in wire bottom cages over paper, in wire bottom cages over an automatic cascade flushing system, or in solid-bottom plastic cages with bedding material. There were no substantial differences in general health or weight gain. Pentobarbital LD50 values were lower for the mice housed in wire bottom cages than for the mice in solid bottom cages with bedding. This difference was probably related to gastrointestinal content. It appears that the automatic cascade flushing system is suitable for housing mice for periods up to 8 wk.