Clarification on what is and is not barrier housing:


Rodent barrier housing is NOT the normal housing condition in DLAR. Barrier housing refers to 1) immunocompromised or other animals where maintaining environmental sterility is critical and 2) animals infected with biohazardous agent (ABSL2 & 3) where agent inactivation is critical. In the former case the goal is protection and the feed, water, caging, and bedding is sterile either through being purchased as sterile (irradiated) or autoclaving. In the case of biohazardous agents, the caging and contents are subjected to autoclaving after animal housing to destroy the biohazardous agents.  In both cases, the caging is subjected to sterilization procedures which require additional labor, equipment, and shortens caging life expectancy. 

The routine housing of mice and rats in individually ventilated caging (IVC’s) or microisolators is NOT barrier housing. These caging systems are used to minimize disease transmission between caging and to reduce allergen exposures. 


Harold F. Stills, Jr., DVM, DACLAM