AAALAC International publishes “Guidance Statements” that are used as supplemental requirements or recommendations in dealing with certain issues.
On this page:
A. AAALAC International’s Assessment Process
B. Animals Included in the AAALAC International Accredited Unit
C. Institutional Responsibilities
D. Animal Environment, Housing, and Management
F. Occupational Health and Safety
AAALAC International promotes humane treatment of animals in science through voluntary accreditation and assessment programs. Its evaluations are based on widely accepted standards—principally, the Guide for the Care and Use of Laboratory Animals (Guide), alongside other recognized references such as the Guide for the Care and Use of Agricultural Animal in Research and Teaching (Ag Guide) and the European Convention ETS 123 (these three documents are the Primary Standards), AAALAC Position and Guidance Statements, as well as applicable legislation.
However, AAALAC International recognizes that rigid adherence to prescriptive guidelines may not always be the most effective or scientifically appropriate approach. Sometimes, thanks to the advent of new scientific information and new technology, there are situations where new methods or procedures not described in the Guide or other AAALAC standards may be available and result in equal or greater operational efficiency and welfare for the animals involved. In most cases, these exceptions involve a specific project or are limited in scope within an animal care and use program. Occasionally, exceptions are wider in scope and may involve the entire animal care and use program or even apply globally in the case of organizations with facilities in multiple countries; these are often referred to as program wide and global exceptions, respectively. As such, both types of exceptions to the Guide or other standards can be acceptable when justified and well-supported.
1. Performance-Based Approach
AAALAC endorses the performance-based approach to animal care and use. More information can be found in the Application of Performance Standards.
2. Flexibility Across Geographies and Models
AAALAC accredits animal care and use programs worldwide, spanning diverse regulatory, cultural, and scientific environments. As such:
3. Institutional Oversight and Documentation
Acceptable exceptions are not arbitrary. To be considered valid by AAALAC:
The concept of Performance Standards is explicitly highlighted in the Guide for the Care and Use of Laboratory Animals (Guide), Eighth Edition (National Research Council 2011). According to the Guide, the concept and application of Performance Standards is essential for the development of a comprehensive animal care and use program.
Regulations often include specific requirements on animal care and use program areas. When these requirements are rigid and measurable, they are called Engineering Standards. Typical examples of Engineering Standards are minimum animal primary enclosure sizes; ranges for environmental temperature, relative humidity, light intensity levels, and air exchange rates of animal rooms; lists of accepted or regulated procedures; minimum sanitation frequency of animal cages and accessories; and minimum temperature requirements for the rack washer rinse water. Engineering Standards do not provide for interpretation or any modification of the expected specific limits, parameters, or methods to achieve a particular outcome. Additionally, Engineering Standards may not exist for all species in the program.
Alternatively, Performance Standards define the outcome of activities or procedures in detail and provide criteria for assessing whether the outcome is achieved. These criteria may be based on simple measurable acceptable data (e.g., microbiological growth data after sanitation practices), or on more general interpretation of the outcome of a process (e.g., analysis of the questions raised on the oversight and ethical review processes).
AAALAC endorses the performance-based approach to animal care and use. This approach emphasizes outcomes—animal well-being, scientific validity, and regulatory compliance—over strict adherence to procedures. Institutions may deviate from Primary or other AAALAC standards or recommendations when:
This allows institutions to adopt innovative or tailored practices that suit their specific research, species, or facility conditions.
AAALAC International recognizes that the legal framework for the use of wild-caught animals in science and education can vary with local, state, national, or international regulations. In countries where regulations or guidelines may not exist regarding acquisition and use of wild-caught animals, AAALAC International recommends that institutions consider appropriate AAALAC International Reference Resources (https://www.aaalac.org/resources/reference-resources/ under "Species Specific") as baseline references. In all cases where the utilization of wild-caught animals is part of the accredited program, any applicable local and international regulations serve as the minimum standard, with guidance from the primary standards and Reference Resources utilized by AAALAC International supplementing these standards.
In situations where the need for non-purpose-bred animals is proposed and the justification for such use is not obvious from the study focus (e.g., research involving wild species), AAALAC International expects that the Institutional Animal Care and Use Committee or Oversight Board (IACUC/OB) will require a thorough and robust justification for the use of non-purpose-bred animals for any breeding or research purposes. Additionally, the IACUC/OB must ensure species-appropriate management of these animals.
The collective professional judgment of the IACUC/OB, principal investigator (PI), and Attending Veterinarian must ensure that all applicable legal and regulatory requirements are met for the capture, acquisition, and use of wild-caught animals. The institution should have a process to maintain and ensure appropriate management of any required regulatory documents and permits for the use of wild-caught animals. The Council on Accreditation may request documentation (e.g., applicable permits, acquisition records) to verify the legal acquisition of animals.
To ensure the integrity, independence, and credibility of the Institutional Animal Care and Use Committee or Oversight Body (IACUC/OB), institutions are expected to proactively identify, manage, and avoid conflicts of interest (COIs) in both membership composition and leadership roles. This is particularly important when individuals in positions of authority—such as the Institutional Official (IO) or Attending Veterinarian (AV)—serve as Chair or researcher. The IACUC/OB must function as an independent, objective body that provides impartial oversight of the animal care and use program. Undue influence, whether real or perceived, undermines ethical review, regulatory compliance, and public trust. Institutions are encouraged to give thoughtful consideration to the following factors to ensure avoidance of conflicts of interest in the leadership and composition of the IACUC/OB.
General Expectations
Conflicts of Interest in Membership
Leadership Considerations (Chair Role)
Some Safeguards and Best Practices may include
The institution should have an adverse event assessment and reporting plan that defines what is considered an AE and addresses how adverse events are assessed by the IACUC or comparable Oversight Body (OB). This plan should also address risk assessment and include development of a mitigation plan to minimize or prevent future recurrences. When appropriate, the plan should also include the procedures for reporting to appropriate internal and external oversight bodies. Council will review the effectiveness of AE oversight, including the reporting plan, as part of the triennial on-site assessment and program review.
Each accredited unit should establish its own process for reviewing potential adverse events and determining what should be reported to AAALAC in accordance with the Rules of Accreditation.
AAALAC International requires accredited units to promptly report the following significant adverse events:
The unit is encouraged to contact/call the AAALAC Office if it is uncertain about the need to or the timing of reporting an adverse event.
Scientific rigor and experimental reproducibility directly impact the welfare and number of animals used in research, testing and teaching. It is AAALAC International’s view that programs should consider scientific rigor and experimental reproducibility when evaluating animal research activities. The evaluation may be based on an initial review by a grants review panel, and/or may be assigned to the Institutional Animal Care and Use Committee or Oversight Board (IACUC/OB) internal protocol review process. In either scenario, the IACUC/OB review should confirm that the protocol contains pertinent study design elements and ensure adherence to the principles of the 3Rs (replacement, reduction, and refinement). That review should include aspects such as the adequacy of the rationale for the use of animals, the purpose and design of the research-- including randomization, blinding, and controls-- the justification of species, and the proposed animal numbers (via statistical power analyses, if appropriate). Moreover, it should also include consideration of the availability of alternatives to the use of animals, less invasive procedures, and use of less sentient species, as well as the ethical use of animals under appropriate experimental conditions and housing environments. Use of an experimental planning checklist (e.g., the PREPARE Guidelines) into animal protocols for submission and approval may help assure consideration of these elements. To increase awareness of and competency when evaluating rigor and reproducibility, the IACUC/OB should confirm that the program provides education/training as well as direction/recommendations related to scientific rigor and experimental reproducibility to researchers and their staff as well as the IACUC/OB members. Appropriate reporting of experimental design methods in peer-reviewed journals is another important aspect of scientific rigor and experimental reproducibility (e.g., using the ARRIVE guidelines). Guidance on various aspects of scientific rigor and experimental reproducibility may be found at:
ACD Working Group on Enhancing Rigor, Transparency, and Translatability in Animal Research. https://acd.od.nih.gov/documents/presentations/06112021_RR-AR%20Report.pdf
ARRIVE 2.0 Guidelines – a checklist for reporting in vivo experiments in enough detail to add to the scientific knowledge base; endorsed by over 1,000 journals worldwide and available in multiple languages. https://arriveguidelines.org/
Experimental Design Assistant – a free online tool to help design robust animal experiments more likely to yield reliable and reproducible results; recommended by major funders worldwide. https://eda.nc3rs.org.uk/
PREPARE Guidelines – guidelines for planning research and experimental procedures on animals. https://norecopa.no/prepare
Additional Guidance Documents (not to be confused with AAALAC International Reference Resources):
Leung, V., Rousseau-Blass, F., Beauchamp, G., & Pang, D. S. J. (2018). Arrive has not arrived: Support for the arrive (animal research: Reporting of in vivo experiments) guidelines does not improve the reporting quality of papers in animal welfare, analgesia or anesthesia. PLoS ONE, 13(5). https://doi.org/10.1371/journal.pone.0197882
Liu, Y., Zhao, X., Mai, Y., Li, X., Wang, J., Chen, L., Mu, J., Jin, G., Gou, H., Sun, W., & Feng, Y. (2016). Adherence to ARRIVE guidelines in Chinese journal reports on neoplasms in animals. PLoS ONE, 11(5). https://doi.org/10.1371/journal.pone.0154657
Macleod, M. (2019). Did a change in Nature journals’ editorial policy for life sciences research improve reporting? BMJ Open Science, 3(1). https://doi.org/10.1136/bmjos-2017-000035
Nunamaker, E. A., & Reynolds, P. S. (2022). ‘Invisible actors’—How poor methodology reporting compromises mouse models of oncology: A cross-sectional survey. PLoS ONE, 17(10 October). https://doi.org/10.1371/journal.pone.0274738
Reynolds, P. S., & Garvan, C. W. (2021). Preclinical Research Reporting in Shock: Room for Improvement. In Shock (Vol. 55, Issue 5, pp. 573–580). Lippincott Williams and Wilkins. https://doi.org/10.1097/SHK.0000000000001544
Zhao, B., Jiang, Y., Zhang, T., Shang, Z., Zhang, W., Hu, K., Chen, F., Mei, F., Gao, Q., Zhao, L., Kwong, J. S. W., & Ma, B. (2020). Quality of interventional animal experiments in Chinese journals: compliance with ARRIVE guidelines. BMC Veterinary Research, 16(1). https://doi.org/10.1186/s12917-020-02664-1
AAALAC International expects the Institutional Animal Care and Use Committee or Oversight Body (IACUC/OB) to regularly review the animal care and use program and inspect animal facilities. This includes centralized and satellite (not centrally managed or maintained) housing, support areas, and labs where animal procedures are done. Regular reviews and inspections are important for overall monitoring and oversight. The Guide recommends these reviews and inspections happen at least once a year, but other regulations may require increased frequencies. AAALAC International encourages the IACUC/OB to carefully consider how often they should evaluate to ensure quality animal care and science. In some cases, more frequent self-assessments may be wise.
AAALAC International expects these reviews and inspections should be frequent and thorough enough to identify and fix any issues in a timely manner. The IACUC/OB should show evidence of being actively involved in evaluating the program and facilities and ensuring corrective actions are timely. The findings from these reviews and inspections should be promptly communicated to the Institutional Official to support the institution's research, testing, and teaching goals.
The frequency of reviews should match the complexity of the program to ensure effective oversight. AAALAC’s site visitors may discuss the frequency based on performance-based outcomes. For example, if many issues are found across several program areas, this may indicate poor oversight by the IACUC/OB. This performance-based approach can also be used to adjust the frequency of reviews for specific areas or facilities based on past concerns.
AAALAC International recognizes that the legal framework for the use of wild-caught animals in science and education can vary with local, state, national, or international regulations. In countries where regulations or guidelines may not exist regarding acquisition and use of wild-caught animals, AAALAC International recommends that institutions consider appropriate AAALAC International Reference Resources (https://www.aaalac.org/resources/reference-resources/ under "species-specific") as baseline references. In all cases where the utilization of wild-caught animals is part of the accredited program, any applicable local and international regulations serve as the minimum standard, with guidance from the primary standards and Reference Resources utilized by AAALAC International supplementing these standards.
In situations where the need for non-purpose-bred animals is proposed and the justification for such use is not obvious from the study focus (e.g., research involving wild species), AAALAC International expects that the Institutional Animal Care and Use Committee or Oversight Board (IACUC/OB) will require a thorough and robust justification for the use of non-purpose-bred animals for any breeding or research purposes. Additionally, the IACUC/OB must ensure species-appropriate management of these animals.
The collective professional judgment of the IACUC/OB, principal investigator (PI), and Attending Veterinarian must ensure that all applicable legal and regulatory requirements are met for the capture, acquisition, and use of wild-caught animals. The institution should have a process to maintain and ensure appropriate management of any required regulatory documents and permits for the use of wild-caught animals. The Council on Accreditation may request documentation (e.g., applicable permits, acquisition records) to verify the legal acquisition of animals.
The Guide for the Care and Use of Laboratory Animals (Guide), NRC 2011, does offer some guidance on the issue of what should be some of the traits of the nonaffiliated (public) member. The Guide states this person should represent the general community interests in the proper care and use of animals, should not be laboratory-animal users, and not be affiliated with the institution or be members of the immediate family of a person who is affiliated with the institution. The OLAW/ARENA Institutional Animal Care and Use Committee Guidebook (which is an AAALAC International reference resource) expands on this by stating that the nonaffiliated member can bring significant value to the committee by bringing a non-institutional perspective to the research endeavor. For programs with an NIH Assurance, OLAW provides some additional guidance in their frequently asked questions section of their website (http://grants.nih.gov/grants/olaw/faqs.htm#IACUC_1) by stating that "the unaffiliated member should have no discernable ties or ongoing affiliation with the institution, and may not be a member of the immediate family of a person who is affiliated with the institution. Immediate family includes parent, spouse, child and sibling. Appointment of an individual who is unambiguously nonaffiliated is the best way to fulfill the letter and spirit of this provision." Using a former employee as the nonaffiliated member is certainly a gray area that might come into question during a site visit based on the above guidance, especially in context of the comments about the value of that member bringing a non-institutional perspective to the research endeavor and not having any discernable ties or ongoing affiliation with the institution. While not specifically prohibited, the Institutional Official should give special consideration to the use of a former employee as a nonaffiliated member to ensure that both the intent and the spirit of the Guide are being met
Our IACUC receives protocols that require use of drugs or other chemicals not formulated for clinical use, which we understand to be characterized as non-pharmaceutical-grade compounds. We would appreciate AAALAC's guidance on the distinction between pharmaceutical- and non-pharmaceutical- grade compounds and how to evaluate this aspect of these protocols.
A pharmaceutical-grade compound is defined as any active or inactive drug, biologic or reagent, for which a chemical purity standard has been established by a recognized national or regional pharmacopeia (e.g., the U.S. Pharmacopeia (USP), British Pharmacopeia (BP), National Formulary (NF), European Pharmacopoeia (EP), Japanese Pharmacopeia (JP), etc.). These standards are used by manufacturers to help ensure the products are of the appropriate chemical purity and quality, in the appropriate solution or compound, to ensure stability, safety, and efficacy.
AAALAC International acknowledges that in an animal care and use program non-pharmaceutical-grade compounds often are necessary for scientific research. Where the use of non-pharmaceutical-grade substances may be essential for the conduct of science, the goal of the IACUC (or comparable oversight body (OB)) should be to consider the health and well-being of the animals while aiding the researcher in minimizing potentially confounding experimental variables and maximizing reproducibility of the research. The Council on Accreditation will apply a performance approach to its assessment of the use of non-pharmaceutical-grade compounds, and will expect that the IACUC/OB has established acceptable criteria for use of such compounds within the institution and for review and approval of their use.
AAALAC distinguishes between two scenarios when considering the use of non-pharmaceutical-grade compounds:
Clinical Use - compounds used for the clinical treatment of animals and to prevent or reduce/eliminate animal pain or distress. Whenever possible, pharmaceutical-grade compounds must be used.
Research Use - compounds used to accomplish the scientific aims of the study. If available, and suitable, pharmaceutical-grade compounds are preferred.
In all cases when non-pharmaceutical-grade preparations are used, AAALAC International expects investigators and the IACUC/OB to consider the following factors:
One of the tasks that AAALAC International expects to be performed by the IACUC (or comparable oversight body - OB) is the oversight of approved research protocols involving animal care and use at the institution, once they have started. This post-approval monitoring (PAM) procedure is considered important to help ensure that animal study procedures are conducted in accordance with the approved protocol, to identify and review potential unexpected outcomes or adverse events and their management, and ensure the principles of the 3R’s are applied. AAALAC acknowledges that in some countries and institutions there may be other institutional bodies or named individuals (e.g., animal welfare officers, compliance staff, quality assurance units) participating in this process. In all cases, AAALAC applies a performance-based approach based on the efficacy of the system in place, while acknowledging that the final authority over the process relies on the IACUC/OB.
One component of a PAM program is the periodic program review and facility inspection by the IACUC/OB. The collaboration of research personnel in the self-evaluation or and in proactively reporting protocol changes, and involvement of animal care and veterinary staff are very important for the success of the PAM process. As indicated in the Guide, PAM methods may include continuing protocol review; laboratory inspections, conducted either during regular facilities inspections (link to Guidance Statement) or separately; veterinary or IACUC/OB observation of selected procedures and evaluation of personnel competency; and observation of animals by animal care, veterinary, and IACUC/OB staff and members.
Factors that may be considered when deciding on the frequency of PAM and on the attention to be paid to specific protocols include history of (non)compliance; potential risks to animals or staff; severity of experimental procedures; and legal requirements (e.g., triennial review required by PHS in the US). Although AAALAC agrees that ensuring compliance with approved protocols is critical, AAALAC International interprets the Guide recommendation for a PAM program in the broadest sense for the international community, namely that there will be a system for ensuring animal procedures conform with the approved protocol or study plan (including amendments), and that unexpected outcomes or adverse events are appropriately managed.
Behavioral Management is a comprehensive approach aimed at enhancing the welfare and health of animals used in science and education and consequently, research reproducibility. By focusing on species-specific behavior as a key indicator, a Behavioral Management program improves various aspects of animals’ lives, including but not limited to housing, husbandry, and handling techniques.
A comprehensive approach to Behavioral Management should be an essential element of the animal care and use program. Considerations for cage, pen or enclosure space and how it is furnished, choice of substrate/bedding, social housing, animal handling and restraint, opportunities for choice and control of aspects of their home enclosure, appropriate preparation of animals for science and education through habituation and training, opportunities for exercise, and provision of food and other resources to provide stimulation and alleviate boredom should be included.
Environmental enrichment and social housing are critical components of the Behavioral Management Program.
Environmental enrichment refers to the process of enhancing the living conditions of research animals to promote their natural behaviors and improve their overall welfare. It is crucial because it helps reduce distress, prevent abnormal behaviors, and improve the reproducibility of research by ensuring animals are in a healthy environment. Abundant literature has been produced on the benefits and means of implementation of enrichment strategies. Environmental enrichment has been adopted globally as standard practice in animal care and use programs and is already required in the legislation of some countries.
In general, provision of environmental enrichment will include appropriate housing and enclosure space including any elements that facilitate natural behavior depending on the different species needs (e.g., exploring, digging, hiding, chewing, exercising, nest building, manipulating, foraging, climbing).
Environmental enrichment should be provided in a consistent manner across the animal program, with due attention to animal welfare, and personnel and animal safety.
Implementation of environmental enrichment should also take into account the scientific goals of the study for which the animals are used; enrichment should be considered an independent variable and, thus, suitably controlled. Therefore, “consistency” in the implementation of the enrichment program does not necessarily mean that all animals must be provided with the same enrichment, but that the enrichment decided to be appropriate for each species, study or housing conditions, is applied consistently.
To ensure implementation of effective enrichment strategies, training on the enrichment program should be one aspect of the overall training program for all personnel taking care of animals at all levels and designing and performing animal experiments. AAALAC International expects that the IACUC/OB, with the collaboration of the veterinarians, animal care staff and researchers will coordinate and review periodically the implementation of the enrichment program and continuously monitor and adapt it to meet evolving standards and scientific understanding.
Social housing will be considered by AAALAC International as the default method of housing unless otherwise justified based on social incompatibility resulting from inappropriate behavior, veterinary concerns regarding animal well-being, or scientific necessity approved by the IACUC or equivalent oversight body (IACUC/OB).
AAALAC recognizes that sometimes research objectives, the health condition of the individual animal, and/or the challenges associated with the social behavior of some species, strains and/or sex of the animals may preclude social housing. Not all members of a social species are necessarily socially compatible. Social housing of incompatible animals can induce chronic stress, injury, and even death. In some species, social incompatibility may be sex biased. The research and welfare benefits and consequences of both affiliative and aggressive species-typical natural social behavior should be considered.
When necessary, single housing of social animals should be limited to the minimum period necessary and, where possible, visual, auditory, olfactory and, depending on the species, protected tactile contact with compatible conspecifics should be provided. If such contact with compatible conspecifics is not possible, additional enrichment should be offered, such as safe and positive interaction with the animal care staff, as appropriate to the species of concern; periodic release into larger enclosures; supplemental enrichment items; and/or the addition of a companion animal in the room or housing area
The institution's policy and exceptions for single housing should be reviewed on a regular basis and approved by the IACUC/OB, with the collaboration of the veterinarians, researchers and animal care staff.
There may be a spectrum of social experience that can be made available to an animal based on the species, health, and use of the animal. These experiences are important because, when properly managed, they can significantly enhance the welfare of the animal. Full time social housing is the optimum manner to provide social experience. However, when full time housing with conspecifics is not possible, whether due to social incompatibility, veterinary concerns or scientific necessity, other social experiences should be considered such as part time access (e.g., overnight, when the animals are between studies, defined periods of time during the day, etc.) to full contact with conspecifics or protected contact that allows interaction In this manner, the social experience of the animal occurs as a normal aspect of the animal's housing environment or as a separate activity that occurs outside of the primary enclosure, such as in a play yard, exercise cage, animal holding room aisle or facility corridor, etc. The staff responsible for the day-to-day management and oversight of the social experience of the research animals should be well versed in recognizing aggressive and affiliative behaviors of the various species in their care to provide for rapid identification and any necessary intervention.
The IACUC/OB, with the collaboration of the veterinarians, researchers and animal care staff should identify appropriate performance criteria, as well as a process for assessment, and ensure that the adequacy, safety, comfort and configuration of the animal environment is regularly reviewed to meet animal welfare and research quality needs. Animals should be adequately acclimated to their environment, as well as habituated to handling before experimentation begins to reduce stress as well as experimental variability. Non-aversive animal handling and positive reinforcement training methods should be used whenever possible to minimize stress and it should be performed by adequately trained personnel. When developing a performance-based approach to Behavioral Management, careful consideration should be given to addressing the specific needs of each species, taking into account factors such as, age, sex, animal size, group sizes and social structure, duration of study and behavioral needs according to current scientific understanding.
Behavioral Management should be applied to all animals including commonly used species such as mice, other rodents, and fish. The following species exhibit unique Behavioral Management and housing needs in addition to what is already described in other AAALAC standards.
Dogs are generally social, athletic animals with a strong affinity for people. In managing the behavior of laboratory dogs, it is essential to address their social and physical needs to enhance welfare:
Nonhuman primates are non-domesticated species with significant cognitive capacity and require thoughtful housing and Behavioral Management programs to reduce the likelihood of injuries, boredom and frustration from developing in captive research settings. Key Behavioral Management needs for primates in research include appropriate housing environments, opportunities for social housing with familiar animals, habituation and desensitization to facility personnel, as well as research equipment and procedures, stimulating resources that are rotated on regular intervals to reduce boredom, and training to increase predictability and reduce stress during various procedures.
Although inherently social creatures, rabbits are a highly territorial species and social incompatibility issues often arise when they are not provided with sufficient space in their home enclosure. Intact adult males may not aways be suitable for social housing because of behavioral aggression, but juvenile rabbits, castrated male rabbits, and intact adult females may often be socially housed (generally in same sex groups in research settings). Does with litters should not be group housed with other adult rabbits, but kits can be mixed between litters at weaning. It is essential to provide hiding places or visual barriers and escape routes when introducing adult females to minimize agonistic encounters. As relationships between animals can evolve due to changes in physiological status, age, and experimental manipulation, ongoing observation of rabbit interactions is needed to detect and promptly address significant signs of social incompatibility.
Other factors that may improve the Behavioral Management of rabbits include:
Rats are highly intelligent and social animals that respond well to positive human interactions. Consideration for housing and optimal Behavioral Management for rats in research settings has not generally kept pace with other species. As for other species, rats benefit from opportunities to perform a full range of postural adjustments and movements, including climbing, stretching vertically, hopping, and running and facilitation of such behaviors should be considered. Except for stud males kept long term for breeding, it is rare for rats of either sex to require separation due to intolerable agonistic encounters. As for other species, rats require sufficient space and enclosure furnishings (e.g., tunnels or huts) to be able to move out of sight and avoid agonistic encounters. Other factors that may improve Behavioral Management of rats include:
Most AAALAC-accredited facilities will already have many aspects of a Behavior Management program in place. These should be incorporated into a coherent program, expanded where needed, and tailored to each species housed within the facility. A key means of improving current programs is to employ an ‘outcomes-focused’ approach, that is, one that asks what behaviors are normal for a given species and should be promoted. Addressing some needs may require structural modifications of housing enclosures; however, other needs can be met with simple materials or procedural changes. This will remain an evolving area within the field and one that accredited units should continue to monitor to ensure they are promoting good animal welfare and quality science.
Maintenance of monogamous pair breeding mice (one adult male and one adult female) is simple and allows tracking of their litters and minimizes overcrowding. In general, outbred mice that produce larger litters are best propagated by a pair breeding strategy. However, continuous mouse breeding groups (such as trio breeding, one adult male and two adult female mice, or harem breeding, one male and three or four adult female mice) is commonly proposed to increase breeding efficiency, especially for some strains that are difficult to propagate.
Individuals responsible for the maintenance of these colonies who propose the group breeding scheme must accept full responsibility of the health and welfare of the animals and establish additional animal husbandry criteria to ensure adequacy of cage space for mothers and pups. The increased husbandry practices should include but not limit to ensuring adequate animal observation and frequency, applying established criteria for separation of pregnant females and multiple litters, the suitable cage change frequency, the prompt weaning of mature pups as well as the prompt separation of animals if the number of animals becomes greater than the established criteria.
When considering cage space/animal density policies, it´s expected that the Institutional Animal Care and Use Committee or comparable Oversight Body (IACUC/OB) always considers national or regional regulations, policies and guidelines animal behavioral needs, and critically evaluates objective measures of outcome-based performance standards. The proposed cage type should allow all animals to make normal movements and postural adjustments and rest away from soiled areas, provide free access to food and water, and provide sufficient space for mothers with litters to allow the pups to develop to weaning age without detrimental effects to the mothers or the litters. This evaluation should include consideration of strains that have potential large litter sizes, number of adults, the age of female mice, the need for cross-fostering, the growth rate of pups and the average litter size or whether one or more litters are present or possible number of different litters of pups at potential age ranges, the calculation of anticipated number of animals to be produced and to be used or the plan needed for surplus animals, as well as the successful outcomes that support animal well-being.
While the Guide for the Care and Use of Laboratory Animals (Guide), NRC 2011 recommends solid bottom cages be sanitized at least once a week, it goes on to say that some types of cages might require less-frequent sanitation, which include individually ventilated cage (IVC) units. The Guide stresses the use of performance standards when making these determinations. As an example, scientific studies have looked at environmental conditions (1) and cage changing frequency (2) for IVC systems and determined that under normal circumstances, changing cages in these types of units once every two weeks provided for an acceptable environment for the mice. However, there are other factors to take into consideration. While this frequency of cage changing may be acceptable for many mice, it may not be acceptable for others (e.g., diabetic mice that exhibit increased urine output). The Institutional Animal Care and Use Committee or comparable oversight body (IACUC/OB) should review current cage changing practices for IVC units based on current literature and other factors (phenotype of the mice, type of bedding, housing density, etc.). For an IVC cage change interval longer than 2 weeks, verification of microenvironmental conditions may include measurement of pollutants such as ammonia and CO2, microbiologic load, observation of the animals' behavior and appearance, and the condition of bedding and cage surfaces. Also, as with any performance standard, there should be a system in place to monitor the outcome and report back to the IACUC/OB.
Recognizing the critical impact the transportation of research animals has on the quality of research and that the welfare of the animals being transported is governed by a number of regulatory agencies, what are AAALAC International's expectations to ensure humane transport of research animals?
AAALAC recognizes that the continuation of humane transportation of animals is vital to the research enterprise. However, this can be a stressful experience for the animals. The total experience of the animal during transport is influenced by many factors. It is expected that the parties involved are aware of and comply with all applicable regulatory requirements for the transportation of animals and the critical importance of ensuring that the animals are treated humanely at all times during the journey. Please refer to AAALAC International's Reference Resources (http://www.aaalac.org/resources/reference-resources/) for additional guidance.
The following points should be considered:
Security: The consignor of the transportation containers and arrangements should ensure that the possibility of damage, misdirection and breach of biosecurity is reduced to a minimum by the use of suitably recognized reputable transport operators and sub-operators. Procedures should be in place to prevent theft or adulteration of transportation containers.
Species specific transportation: Containers and transport vehicles should provide appropriate environmental conditions for the species being transported and personnel should have appropriate knowledge relative to animal biosecurity to maintain the animals' health status.
Transportation Logistics: Special attention should be given to the mode of transport and the journey times should be minimized as much as possible. Journey plans should be in place with alternate plans available in case of disruption of the original plan. The receiving institution should be informed about the itinerary and any changes in the timetable or any deviations from the plan which occur during transport. The receiving institution should have arrangements in place to receive the animals and trained personnel are available at the receiving institution to ensure the animals are removed from the shipping containers and inspected in a timely manner.
Commercial carriers: When commercial carriers are used, they should be appropriately licensed, and they should use well-designed animal transport vehicles which are capable of maintaining appropriate environmental conditions for the species being transported, which are documented through appropriate record keeping. The drivers must be trained in the transport of animals and the regulations thereof. When non-commercial carriers are used they and their vehicles should be approved by the IACUC /OB.
Planning for unexpected events: In case of an unexpected event, everyone in the transport chain should have a common understanding of contingency plans and knowledge of emergency contact persons who are available to respond during each segment of the journey. A clear emergency plan should be available and all the relevant information about contact persons, containment of the animals, and other relevant information should follow the animals on the crate or containers.
Intra-institutional transport: When animals are being transported within an institution, the IACUC/OB should approve the vehicle(s) and the personnel who perform this function, taking into account the relevant points described in this FAQ. Responsibility of the IACUC/OB: The IACUC/OB (or comparable oversight body) and veterinarian should evaluate transportation of animals to ensure compliance with regulatory expectations as well as attention to the animals' well-being.
Pain prevention and alleviation are fundamental responsibilities in veterinary medical care, particularly in the context of procedural and surgical interventions. In research settings, the ethical and scientific imperative to manage pain requires the judicious use of anesthetics and analgesics. A veterinary care program must include assessment of animal well-being, comprehensive management of pain, appropriate surgical and perioperative care, and an effective anesthesia and analgesia plan including consideration of preemptive analgesia. A multi-modal approach, utilizing agents from different pharmacologic classes with synergistic or additive effects to target multiple pain pathways, should be considered. Such strategies optimize analgesic efficacy while minimizing adverse effects associated with any single drug. Elements of perioperative care, including sedation, analgesia, and anesthesia, must be integrated into protocol development and reviewed by the Institutional Animal Care and Use Committee (IACUC) or equivalent Oversight Body (OB). These considerations apply not only to surgical models but also to non-surgical procedures that may result in pain. Ensuring these components are addressed and documented reflects a commitment to both animal welfare and research integrity. Non-pharmacological interventions (e.g., supportive care, modifying husbandry conditions, etc.) may also be considered as part of a multi-modal pain management strategy to enhance comfort, support recovery, and further mitigate pain.
Close and regular monitoring of animals, with documentation and objective assessment of well-being, is a critical component of effective pain management. This may include recording clinical signs, applying species-appropriate pain scoring systems, and verifying that analgesics and anesthetics are administered as prescribed or outlined in the approved protocol. Equally important is the evaluation of the effectiveness of these agents in alleviating pain, which must be assessed and adjusted as needed to ensure optimal animal welfare. Protocols must clearly define species-specific and experimentally anticipated indicators of pain, along with humane endpoints, to guide timely and appropriate intervention.
Oversight by the Attending Veterinarian is essential in ensuring that monitoring practices, drug administration, and protocol adherence meet the highest standards of veterinary care and regulatory compliance. Veterinary anesthesia and analgesia are constantly evolving fields, with new insights and advancements frequently emerging in the scientific literature. As such, it is incumbent upon responsible veterinarians to stay informed of the latest research and developments in veterinary practice.
AAALAC International acknowledges that there can be very diverse anesthetic and analgesic regimes for different procedures and situations. This diversity is essential to accommodate the varying needs of different species and the specific requirements of distinct research protocols. The evaluation of these regimes is conducted according to performance standards and current veterinary practice, ensuring that the chosen methods are both effective and humane.
By adhering to these standards, AAALAC International ensures that animal welfare is prioritized while maintaining the integrity and reliability of scientific research.
Because anesthesia is a critical component of the veterinary care program, and the use of anesthetic gases may pose a risk to personnel, anesthetic machines and vaporizers should be evaluated for safe and effective operation. This should follow an established schedule, consistent with the intensity of use and manufacturers’ recommendations. Properly functioning gas anesthesia machines and vaporizers are key to the delivery of accurate doses of anesthetic agent to the animal, and to the safety of personnel, avoiding the exposure to waste anesthetic gases.
The precision vaporizer should be maintained according to the recommendations of the manufacturer and may include on-site calibration and/or having the precision vaporizer returned to the manufacturer for more extensive work. Factors that may affect the schedule for service include the type of anesthetic agent used, the frequency of use of the machine, as well as the type of vaporizer used.
The anesthesia machine (what the vaporizer is attached to) can vary in complexity. There are many factors to consider (e.g., frequency of use, age of machine, environmental conditions, etc.) when developing a program for anesthesia machine maintenance and upkeep, and all components need to work properly as an integrated unit.
Several aspects may be considered for the calibration and maintenance program:
More detailed guidance on checking anesthetic equipment can be found at: https://anaesthetists.org/Home/Resources-publications/Guidelines/Checking-Anaesthetic-Equipment
AAALAC International considers allergy prevention to be an important topic and a key component of the occupational health and safety program. The use of engineering controls (appropriate facility design, operation, and use of safety equipment) is preferred as the primary means to minimize personnel allergen exposure. Administrative controls (appropriate processes and procedures) are the secondary means to reduce allergen exposure. Personal Protective Equipment (PPE) should be used as an adjunct to engineering and administrative controls, rather than the initial or single means of protection. The activities most associated with allergen exposure are handling animals, cage changing, dumping soiled bedding, and other routes of exposure to animal excretions (such as laundry). Appropriate engineering controls may include: proper animal facility design and function with separation of functional spaces; a well-designed heating, ventilation and air conditioning (HVAC) system with appropriate airflow patterns and air pressure differentials; consideration of cage systems and designs which minimize personnel exposure; and the use of containment equipment such as cage changing stations, bedding dump stations, and other exhausted or downdraft work benches. AAALAC International site visitors evaluate occupational health and safety programs and the methods used to prevent or minimize research animal allergen exposure through review of the procedure of risk assessment by qualified occupational health and safety personnel, periodic personnel health evaluations, engineering controls, administrative controls, the appropriate selection and use of PPE, and ongoing personnel education and training.
As part of the occupational health and safety program, consideration should be given to personnel exposure to harmful airborne particulate materials or vapors including dusts, fogs, fumes, mists, gases, smokes, sprays, and animal allergens. The primary protection should focus on preventing or minimizing atmospheric contamination with engineering control and administrative control measures. If, following appropriate risk assessment, it is decided that personal respiratory protective equipment is needed in addition to available engineering/administrative control measures, the ancillary guidance, as described below, should be considered to assure personal protection when respirators are used.
When personal protective equipment are necessary to protect individuals from contaminant exposure, an institutional program (Respiratory Protection Program or Personal Protective Equipment Program) is required. The Program is a cohesive collection of written worksite-specific procedures and policies that, taken together, address all relevant respiratory protection elements, including guidance for personal protective equipment selection (including appropriate protection factors); evaluation by an occupational health professional of the suitability of the individual to be medically able to wear the respirator and health hazards associated with the use of respiratory protection devices; qualitative and/or quantitative fit testing*; and respirator use training to include inspection, maintenance and care, quality, quantity and flow of breathing air, and routine and emergency use procedures.
When selecting personal protective equipment, it is important to consider that respiratory protection devices are specific to (or appropriate for) the contaminant type. For example, an N95 or FFP1-3 filtering face piece is often used for protection for respirable dust, smoke, and aqueous fog (aerosols), whereas chemical or gas exposures are better mitigated with a Chemical Cartridge/Gas Mask, Powered Air-Purifying Respirator (PAPR), or Self-Contained Breathing Apparatus (SCBA). Note that for air-purifying respirators, knowing the hazard and the amount of hazard in the air is important for selecting the proper filters/cartridges. Additionally, most dust masks or medical (surgical) facemasks do not seal tightly to the face, thus allowing airborne hazards, including animal allergens, to enter the breathing zone; and are not approved as respirators.
How often should vermin* traps (live trap or lethal) be checked by staff?
The Guide for the Care and Use of Laboratory Animals (Guide), NRC 2011 indicates that pest control managed by the animal care and use program personnel should be designed to prevent, control, or eliminate the presence of or infestation by pests in the animal environment. The Guide states (pg. 74) that "If traps are used, methods should be humane; traps that catch pests alive require frequent observation and humane euthanasia after capture" and also notes (pg. 112) that "all animals should be observed for signs of illness, injury or abnormal behavior by a person trained to recognize such signs. As a rule, such observation should occur at least daily." The Guide (pg. 105) further indicates that an adequate veterinary care program consists of assessment of animal well-being and effective management of pain and distress. The Guidelines of the American Society of Mammalogists for the Use of Wild Mammals in Research, an AAALAC International Reference Resource, indicate that lethal traps should result in a clean, effective kill and should be checked at least once a day, and in the event that an animal is still alive, it should be immediately dispatched in accordance with guidelines of the American Veterinary Medical Association.
In considering the information provided by the above references, the Council on Accreditation has determined that live mouse traps should be checked at least daily to prevent potential animal distress related to food or water deprivation. If the live trap provides food and water, then the IACUC should determine the appropriate frequency of checking traps. Alternatives to "sticky/adhesive" live board traps should be used for mice to avoid unnecessary animal distress as required by the Guide as part of a program of adequate veterinary care. Lethal traps (e.g., snap traps) should be checked daily so that in the event that a animal is still alive, it can be promptly euthanized. Council also considers that this guidance applies to all mice, be they laboratory or vermin mice.
*Excluding arthropods
The AAALAC International Program Description has a table (Appendix 11, Heating, Ventilation and Air Conditioning (HVAC) System Summary) where comprehensive HVAC data are requested. Can you clarify AAALAC’s expectations for HVAC performance data for buildings used in agricultural programs?
Proper air quality for animal facilities is important for the health and welfare of the animals as well as for the personnel working in the facilities. The Guide for the Care and Use of Agricultural Animals in Research and Teaching (Ag Guide), American Dairy Science Association®, the American Society of Animal Science, and the Poultry Science Association 2020, provides a description of Ventilation and Air Quality (p. 18) as well as guidance on methods and strategies to optimize the environment. In agricultural settings, the design and use of the buildings will determine the extent of HVAC information that is needed. In agricultural situations, the assessment of relative pressurization and air exchange rates may be unnecessary. However, pressurization is important for containment facilities at ABSL-3-Ag. The provision of emergency power to exhaust fans is critical for animal housing where mechanical ventilation is required to maintain air quality and environmental temperatures. AAALAC site visitors will consider the buildings’ design and function and utilize the recommendations of the Ag Guide when assessing the HVAC data and air quality for agricultural programs.
Although the Guide indicates that rooms with MR scanners or in which cryogen gases are stored must be equipped with oxygen sensors and a method for increasing room ventilation to exhaust inert gases during cryogen filling, AAALAC International recognizes that institutions may apply a variety of alternative methods to maintain personnel safety in areas where cryogen gases are used. AAALAC International expects that all institutions, through their occupational health and safety program, should conduct a critical risk assessment of hazards associated with the management of MR scanners and cryogen gases and implement appropriate safety measures to protect personnel. This should include periodic reassessment of safety equipment and procedures. Personnel working in these areas should be trained to recognize the hazards associated with MR scanners and cryogen gas storage, and in the relevant safety features and procedures.
The importance of temperature and relative humidity (RH) relates to thermoregulation, important for animals or species with limited capacity to regulate body temperature (e.g., neonates, amphibians); respiratory health, because extremes in temperature or RH may exacerbate respiratory conditions or support growth of pathogens or allergens; or other specific pathological problems (e.g., ring tail due to prolonged low RH).
However, the control of temperature and RH is particularly difficult in certain areas due to extreme climate and limitations of heating, ventilation and air conditioning systems. Additionally, animal husbandry activities may provoke temporary fluctuations (e.g., residual water in large species enclosures).
Rather than prescribing rigid numerical limits, AAALAC International embraces a performance-based approach that allows institutions to justify and demonstrate how their environmental parameters meet the needs of the species housed and support the goals of the animal care and use program. In this context, AAALAC encourages institutions to:
If no issues are identified by the institution or the AAALAC site visit team that may compromise the health and well-being of the animals or jeopardize the integrity of animal studies, then it is not likely that the Council on Accreditation considers this variation a problem. If, however, animal welfare or study issues are reported that can be linked to variation in temperature or relative humidity, then AAALAC expects the institution to address the lack of control of temperature or RH to ensure animal welfare and reliable data.
Overview
Determining the use of recirculated air and the appropriate proportion of fresh and recirculated air requires careful evaluation. Where HEPA filtered recirculated air is used without gaseous filter, a greater proportion of fresh air (50%) is recommended. However, where both HEPA and gaseous filtering are performed, a greater percentage of recirculated air may be appropriate. Because ventilation needs vary by species, space, and risk level, decisions should be based on measurable environmental parameters and the performance of the filtration system in use.
Risk assessment along with filtration, recirculated air ratio, environmental quality, proper maintenance and husbandry practices help ensure that air quality supports animal health, personnel safety, and operational efficiency. By integrating routine assessment with appropriate engineering controls, facilities can achieve an evidence-based balance between air cleanliness, energy consumption, and cost while meeting accepted standards for high-quality animal care.
Key Considerations
1. Risk Assessment
Because airborne pathogens and contaminants can travel in exhaust air, recirculating air—especially among multiple animal rooms—can present cross-contamination risks.
Situations where recycling exhaust air may be inappropriate include:
Air from non-animal areas (e.g., offices, certain storage areas) may pose less risk and typically requires less-intensive filtration.
2. Filtration Requirements Particulate Filtration
If recirculated air is used:
3. Environmental Quality Requirements
Even when air is recirculated, the system must maintain:
Good husbandry practices—such as frequent bedding changes, optimal stocking density, and appropriate sanitation—help maintaining safe air quality, especially when recirculation is used.
4. System Maintenance and Monitoring
Proper operation of HVAC systems requires periodic measurement of recirculation rates, regular preventive maintenance and documented evaluation. The following should be considered as part of regular review:
Failure to maintain filtration or monitoring systems can render them ineffective, increasing risks to animals and people.