Guide for the Care and Use of Laboratory Animals - Office of ...

2GUIdE FOR ThE CARE ANd USE OF LAbORATORy ANIMALSappropriate, chemical agents to destroy microorganisms. Cleaning withultrasound may be a useful method for small pieces of equipment.If automated watering systems are used, some mechanism to ensurethat microorganisms and debris do not build up in the watering devices isrecommended (Meier et al. 2008); the mechanism can be periodic flushingwith large volumes of water or appropriate chemical agents followed by athorough rinsing. Constant recirculation loops that use properly maintainedfilters, ultraviolet lights, or other devices to disinfect recirculated water arealso effective. Attention should be given to the routine sanitation of automaticwater delivery valves (i.e., lixits) during primary enclosure cleaning.Conventional methods of cleaning and disinfection are adequate formost animal care equipment. However, it may be necessary to also sterilizecaging and associated equipment to ensure that pathogenic or opportunisticmicroorganisms are not introduced into specific-pathogen-free or immunocompromisedanimals, or that experimental biologic hazards are destroyedbefore cleaning. Sterilizers should be regularly evaluated and monitored toensure their safety and effectiveness.For pens or runs, frequent flushing with water and periodic use of detergentsor disinfectants are usually appropriate to maintain sufficiently cleansurfaces. If animal waste is to be removed by flushing, this will need to bedone at least once a day. During flushing, animals should be kept dry. Thetiming of pen or run cleaning should take into account the normal behavioraland physiologic processes of the animals; for example, the gastrocolic reflexin meal-fed animals results in defecation shortly after food consumption.Cleaning and disinfection of the Macroenironment All components ofthe animal facility, including animal rooms and support spaces (e.g., storageareas, cage-washing facilities, corridors, and procedure rooms) should beregularly cleaned and disinfected as appropriate to the circumstances andat a frequency based on the use of the area and the nature of likely contamination.Vaporized hydrogen peroxide or chlorine dioxide are effectivecompounds for room decontamination, particularly following completion ofstudies with highly infectious agents (Krause et al. 2001) or contaminationwith adventitious microbial agents.Cleaning implements should be made of materials that resist corrosionand withstand regular sanitation. They should be assigned to specific areasand should not be transported between areas with different risks of contaminationwithout prior disinfection. Worn items should be replaced regularly.The implements should be stored in a neat, organized fashion that facilitatesdrying and minimizes contamination or harborage of vermin.Assessing the Effectieness of Sanitation Monitoring of sanitation practicesshould fit the process and materials being cleaned and may includevisual inspection and microbiologic and water temperature monitoring(Compton et al. 2004a,b; Ednie et al. 1998; Parker et al. 2003). The intensityof animal odors, particularly that of ammonia, should not be used as the