Purpose
The purpose of this policy is to define the requirements for housing and procedure locations, describe daily and periodic care requirements for vertebrate animals and cephalopod species, and define monitoring needs for temperature, humidity, and lighting in housing areas at the University of Washington.
Background
Per the Animal Welfare Act (AWA) regulations, “indoor housing facilities shall have ample lighting, by natural or artificial means, or both, of good quality, distribution, and duration as appropriate for the species involved. Such lighting shall be uniformly distributed and of sufficient intensity to permit routine inspection and cleaning. Lighting of primary enclosures shall be designed to protect the animals from excessive illumination.” The Guide states similarly that “lighting should be diffused throughout an animal holding area and provide sufficient illumination for the animals’ well-being while permitting good housekeeping practices, adequate animal inspection including for the bottom-most cages in racks, and safe working conditions for personnel.” The Guide further states that “albino rodents are the most sensitive to phototoxic retinopathy” and states that “for animals that have been shown to be susceptible to phototoxic retinopathy, light at the cage level should be between 130 and 325 lux.” The Guide further allows for the use of management practices, such as shelters, rotation of caging, or variable light controls to reduce light exposure in rooms where light levels may exceed 325 lux.
Light levels have not been definitively established for other species in the literature.
The AWA regulations mandate that indoor housing facilities be “sufficiently heated and cooled when necessary to protect animals from temperature and humidity extremes and to provide for their health and well-being.” Further, the AWA regulations have determined species-specific absolute minimum and maximum temperatures for USDA-covered species, and specifies that more than 4 continuous hours outside of these ranges is a reportable non-compliance. The Guide notes: “Maintenance of body temperature within normal circadian variation is necessary for animal well-being. Animals should be housed within temperature and humidity ranges appropriate for the species, to which they can adapt with minimal stress and physiologic alteration.
Policy
It is the goal of the IACUC to support the efforts of the University of Washington to conduct vertebrate animal activities in facilities managed by the Department of Comparative Medicine (DCM) or the Washington National Primate Research Center (WaNPRC). Some aquatic animal housing and procedure spaces may be outside of DCM or WaNPRC management at this time but will be supported by veterinary services. The IACUC must approve all housing or procedure spaces prior to use.
It is expected that housing of vertebrate animals, except aquatic animals, will occur within DCM-managed or WaNPRC animal facilities. Whenever possible, procedures for vertebrate animals will also occur within DCM or WaNPRC animal facilities (see exceptions below).
Regulations require that all vertebrate animals at the University of Washington are observed at least daily for general health, food, water, cleanliness, and environmental parameters (temperature & humidity). In addition, cage changes, room cleaning, and other animal care activities are required on a periodic basis determined by species, caging type, and other parameters. It is the policy of the IACUC that these daily and periodic activities should be performed by trained DCM or WaNPRC personnel, on schedules determined by DCM or WaNPRC. Health checks, provision of care, and environmental monitoring should be documented using established practices. In addition to DCM/WaNPRC daily monitoring, lab staff should monitor animals assigned to their protocols regularly, no less than weekly, or as specified in the IACUC-approved protocol.
The IACUC understands there may be special circumstances that require precise timing of animal care duties by DCM or WaNPRC staff to minimize disruption to an on-going experiment. In these instances, the Principal Investigator (PI) must coordinate the observation and care of animals with the animal care staff in the vivarium where the animals are housed.
In extreme circumstances where there is clear scientific justification (and IACUC approval) for vivarium personnel to not enter a room, the PI must work with DCM or WaNPRC to develop a method for video monitoring (or equivalent) of the animals on days when vivarium personnel cannot enter the room. Please refer to the “Exceptions to Policy” section at the end of this policy for additional information.
For all animals, no matter who is providing daily care, clinical procedures must only be performed with veterinary directives under direct or indirect supervision of a veterinarian.
In rodent housing rooms, light intensity should be monitored minimally once every 3 years. Additionally, rooms should be assessed whenever changes to light fixtures are made or upon request when staff perceive a change in lighting. In rooms with >325 lux measured 3 meters from the floor, light intensity should additionally be measured in a manner that represents actual animal exposure at the level of the animal cage. When light levels within the cage are confirmed to be >325 lux, cages should be immediately moved to a location <325 lux and lighting for the room should be adjusted as needed.
For non-rodent housing rooms, light levels must be adequate to allow for observation of the animals and must not be so bright so as to cause discomfort in the staff or animals. Light levels should be measured as needed based on human and animal perceived comfort.
Standard species-specific light cycles are used to ensure a uniform and diurnal light cycle for research animals. Standard light cycles are critical for the psychological and physiological well-being of research animals and to eliminate variability in research data. Activities which disrupt the diurnal cycle (e.g., turning on overhead room lights or hood lights in animal rooms during the dark cycle) should be avoided. For some studies, it is appropriate to house animals in rooms with a reversed light cycle, e.g., rodents (which are nocturnal and thus most active at night) enrolled in certain behavioral studies. When appropriate for the species involved, red lights should be used if it is imperative that animals are examined during the dark cycle.
Research, husbandry, and clinical procedures must be scheduled to not interrupt the dark cycle (e.g., lights should not be turned on during dark phases) for animals unless there is scientific justification for such deviation approved as part of the IACUC protocol or for the provision of clinical care when approved by the AV (or authorized designee).
All animal housing areas should have lights on automatic timers, unless otherwise approved in the IACUC protocol as a husbandry exception. It is highly recommended that rooms also have light monitor alarms to verify that light cycles are functioning properly. If lights are not alarmed, confirmation of proper dark cycles should be visually assessed by staff at least twice per year.
Animals must be housed in areas with ambient temperatures consistent with the Animal Welfare Act regulations and The Guide for the Care and Use of Laboratory Animals and with facility SOPs.
All animal housing areas must have continuous temperature monitoring with automatically-generated alarms based on pre-determined temperature settings appropriate for the species. Mechanisms must be in place to respond to alarms in a timely manner and restore temperatures to normal ranges.
At UW, desired temperature ranges are generally a more narrow range than specified by federal regulations. Temperatures outside of the species-appropriate ranges (as defined by facility SOPs) warrant immediate response and correction. All facilities should have a contingency plan for supplemental heat or cooling as appropriate for the species housed there. If temperatures cannot be restored to desired ranges promptly, animals may need to be relocated to an appropriate environment.
Any temperatures outside of regulatory ranges as well as any temperature abnormalities (outside of facility SOP ranges) significant enough to warrant corrective measures or animal relocation must be promptly communicated to the Attending Veterinarian. Temperature deviations outside of regulatory ranges for more than 4 continuous hours and any detrimental animal effects secondary to the temperature abnormalities will be reported to the IACUC.
The IACUC acknowledges that humidity can be difficult to control without compromising the desired air change frequency and/or temperature, and further acknowledges that animals are adaptable to a broader range of humidity levels as compared to other environmental parameters. Humidity must be monitored in all terrestrial animal housing areas. Whenever possible, these animal housing areas should be maintained with 30-70% relative humidity. Ideally, animal housing areas should be equipped with humidity controlling devices, but the IACUC recognizes that not all vivaria currently have this functionality. Humidity levels <30% and >70% will be reported to the AV with the exception of the Arizona Breeding Colony.
Nonhuman primates housed at the Arizona Breeding Colony are well-adapted to ambient humidity levels outside of this target range. Humidity is monitored in the indoor areas of the housing facility but is especially difficult to control given the environment. At this facility, values outside of the range are anticipated and do not necessarily require notification of the AV unless there are animal impacts.
Any detrimental animal effects secondary to humidity abnormalities will be reported to IACUC.
Vertebrate aquatic animals and cephalopod species may be housed outside of DCM-managed spaces but will be supported by DCM veterinary services and must be housed and cared for in a manner consistent with DCM-approved procedures. Staff providing care must receive appropriate training in the care and use of the species under their care as well as training in sick animal recognition, reporting to Veterinary Services, IACUC protocol approved euthanasia, and proper documentation of husbandry and care procedures.
Room and/or system temperatures should be monitored as described above with monitoring and alarm systems associated with response plans as described. Water temperature will also be monitored. Additionally, water quality/chemistry must be assessed as appropriate for the type of animal and housing system used. Water quality/chemistry monitoring parameters should minimally include temperature, pH, ammonia, and conductivity for most species as well as nitrite, nitrate, alkalinity, hardness, and dissolved oxygen, for most animals housed in recirculating aquaculture systems (RAS). Static and flow-through aquatic systems may have altered monitoring parameters as per veterinary recommendations. Aquatic housing systems should be equipped with continuous temperature and/or other water quality/chemistry monitoring with automatically-generated alarms based on pre-determined settings appropriate for the species and system in use.
Exceptions to this policy may be made if it can be shown that housing or procedure locations cannot be accommodated within a DCM or WaNPRC animal facility, or that care of animals cannot be provided by DCM or WaNPRC staff. Requests for exceptions must be included as a Husbandry Exception in the protocol and must include a clear justification for the request. New requests for exceptions must be submitted as protocol amendments.
Existing or newly-approved animal housing and procedure spaces outside of DCM facilities (“lab-managed spaces”) will be reviewed at least every three years during protocol review. In approved lab-managed spaces, all daily and periodic care activities must be performed by specially trained individuals whose training includes the appropriate Lab-Managed Animal Care courses offered through the UW Center for Laboratory Animal Training Resources.
Approval of daily and periodic care exceptions is valid only for experiments with a Husbandry Exception described in the protocol. If conditions of approval are not met (for example, animals are not checked when they are supposed to be, or cage change is not done in an appropriate time), the IACUC has the option to re-review and revoke approval of the husbandry exception.
References
- AWA, Title 9, Ch.1, Part 3, Subparts A-F
- Guide for the Care and Use of Laboratory Animals. Eighth Edition. Washington, D.C. The National Academies Press. 2011.
- Anderson, Kevin. “Are the Lights on or Off” ALN Magazine, November 4, 2013. https://www.laboratoryequipment.com/article/2013/11/are-lights-or
Approval/Review Dates
Originally Approved: 07/21/2016
Last Reviewed/Revised by the IACUC: 06/15/2023