I. Definitions

Study Area: Any investigator-managed building, room, area, enclosure, or other containment site in which USDA-regulated animal species [1] are housed for periods longer than 12 hours, or in which non-USDA-regulated animal species [2] are housed for periods longer than 24 hours.

AWARs: USDA Animal Welfare Act Regulations

DLAM: Division of Laboratory Animal Medicine

PHS Policy: Public Health Service Policy on Humane Care and Use of Laboratory Animals

The Guide: National Research Council Guide for the Care and Use of Laboratory Animals

II. Federal Regulations and Principles

The US Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training, Principle VII states that "the living conditions of animals should be appropriate for their species and contribute to their health and comfort. Normally, the housing, feeding, and care of all animals used for biomedical purposes must be directed by a veterinarian or other scientist trained and experienced in the proper care, handling, and use of the species being maintained or studied." In accordance with this principle, the USDA AWARs and the Guide set standards that are mandatory for the environment, housing, and management of laboratory animals; these documents form the basis for ARC evaluation of DLAM-managed animal facilities and investigator-maintained study areas.

III. ARC Requirements

The USDA AWARs require the ARC to conduct inspections of all animal facilities, including, but not limited to, areas where animals are maintained for periods longer than 12 hours, at least once every six months. PHS Policy stipulates that all areas where animals are held for periods longer than 24 hours must meet all requirements for housing areas described in the Guide.

Thus, this policy applies to:

  1. All areas where any USDA-regulated animal species is housed for more than 12 hours, and
  2. All areas where any non-USDA-regulated animal species is housed for more than 24 hours.

Animals may be housed in study areas provided:

  • Scientific justification for this arrangement is approved by the ARC. Please note that cost and convenience are not considered acceptable justifications for use of a study area. In some cases, certain species may be routinely housed outside of the DLAM-managed vivarium when DLAM facilities are inadequate for their appropriate housing. In other cases, animals may be housed within DLAM facilities, but in a room that is not managed by DLAM, or may be housed outside of DLAM facilities, but maintained by DLAM Husbandry staff. As with other study areas, the ARC must review and approve all PI-maintained housing requests. Please note that the ARC may rescind approval of any study area at such time as suitable vivarium housing becomes available. Approval may also be rescinded due to continued failure to maintain the room according to acceptable standards.
  • The study area is inspected and certified by the ARC at least once every six months.
  • ARC certification of a study area is valid for a 6-month period after the date of inspection with the condition that acceptable standards are maintained.
  • The DLAM Animal Health Technician (AHT) responsible for monitoring study areas [3] is notified when animals are brought to and removed from a study area in order to facilitate the identification of active areas which require oversight by the ARC and DLAM.
  • A Study Area Management (SAM) document is developed by the investigator and approved by the ARC.
  • Daily study area logs are maintained for periods when animals are present and retained for inspection by the ARC and/or DLAM staff for at least 6 months. (see Section IV.C.1).
  • Ventilation in the study area is adequate as measured by Facilities Management and approved by the ARC (see Sections IV.A.4 and IV.C.3).
  • The Campus Veterinarian or designee is given access (i.e., a key or combination) to the study area for evaluation of animal health and well-being (see Section V). Note: 24-hour access to the study area must be provided.

IV. Guidelines for Animal Environment, Housing, and Management

A. Animal Facility

  1. Sanitation
    The study area must have a regular sanitary maintenance schedule and must be kept clean, neat, and uncluttered. The Guide (p. 72) states that "all components of the animal facility...should be regularly cleaned and disinfected as appropriate to the circumstances and at a frequency based on the use of the area and the nature of likely contamination."
  2. Food/Bedding Storage
    Food and bedding materials must be stored in closed containers to avoid contamination and the potential spread of disease. Containers must seal so that vermin are excluded from the food and bedding being stored, and must be made of a material such that the container can be sanitized on a regular basis. It is important to note that contaminants in food can have effects on biochemical and physiologic processes, even if the contaminants are present in concentrations too low to cause clinical signs of toxicity.

    If food is not stored in its original bag, its milling date (found on the bag seam) must be indicated clearly on the food container.  If no milling date is listed on the food bag, label the bag with the date received.  With proper storage, food can generally be used up to 6 months after the milling, receipt, or purchase date.  However, the shelf-life of food can be shortened by several factors, including temperatures above 21°C (70°F), humidity extremes, unsanitary conditions, light, oxygen, and pests.

  3. Temperature and Humidity
    Temperature and humidity must be monitored and recorded on a daily basis. In Study Areas housing non-aquatic species, monitoring and recording of temperature is accomplished using the SensoScientific Environment Monitoring Device; installation of this device is a requirement for such Study Areas and an annual service fee is associated with use of the Device. Installation of this Device is not required in study areas housing aquatic species or in Study Areas otherwise exempted by the ARC (e.g., where other devices are used to monitor these variables within animal enclosures).

    Relative humidity in the room should be maintained within 30 to 70% for mammalian species. The acceptable relative humidity range is wider for aquatics. There is no lower limit but care should be taken to check water levels in tanks more frequently when humidity is low. Relative humidity for aquatics should not reach a level sufficient to cause condensation on tanks, which impedes observation of the animals.

    Unless special environmental conditions are approved by the ARC, and documented in the area SOP, the area temperature must be appropriate to the species (see table below). According to the Guide (p. 43), "Exposure to wide temperature and humidity fluctuations or extremes may result in behavioral, physiologic, and morphologic changes, which might negatively affect animal well-being and research performance as well as outcomes of research protocols." Temperature extremes can affect research results, alter an animal's performance, or lead to clinical effects and death.

  4. Recommended Dry-Bulb Temperatures for Common Laboratory Animals
    Mouse, rat, hamster, gerbil, guinea pig
    Cat, dog, nonhuman primate
    Farm animals and poultry
  5. Ventilation
    Ventilation "provides an adequate oxygen supply; removes thermal loads caused by the animal, personnel, lights, and equipment; dilutes gaseous and particulate contaminants including allergens and airborne pathogens; adjusts the moisture content and temperature of room air; and, where appropriate, creates air pressure differentials (differential air flow) between adjoining spaces" (the Guide, p. 45). Although factors such as species, animal size, number of animals, type of bedding, and frequency of cage-changing can affect the minimum ventilation rate required, an acceptable general standard for a vivarium room containing the maximum animal density permitted by other constraints is 10-15 fresh-air changes per hour. Investigator's laboratories are frequently set up in space not designed to permit 10-15 fresh-air changes per hour. An acceptable general standard in such cases is that the maximum number of animals in a study area be reduced proportionately. Although lower or higher ventilation rates may be required in certain instances, provisions must be made to ensure that "heat loads, particulates, odors, and waste gases" do not accumulate in an animal's primary enclosure (the Guide, p. 46). The air pressure differential should be checked and recorded on a weekly basis and the fresh-air changes per hour will be evaluated every 3 years and reported to the ARC. If the rate of fresh-air changes per hour drops below 10, the ARC will re-evaluate approval of the study area based on the above considerations.
  6. Illumination
    The Guide (p. 48) states that, "in general, 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 the bottom-most cages in racks, and safe working conditions for personnel. Light in animal holding rooms should provide for both adequate vision and neuroendocrine regulation of diurnal and circadian cycles...A time-controlled lighting system should be used to ensure a regular diurnal cycle, and system performance should be checked periodically to ensure proper cycling." Several factors should be considered when determining adequate illumination, such as light intensity and wavelength, duration and time of light exposure during the circadian cycle, animal pigmentation and light history, body temperature, hormonal status, age, species, sex, and animal stock/strain.
  7. Noise
    Unnecessary noise in the study area should be minimized. The Guide (p. 50) recommends that, "to the greatest extent possible, activities that generate noise should be conducted in rooms or areas separate from those used for animal housing" and that "radios, alarms, and other sound generators should not be used in animal rooms unless they are parts of an approved protocol or an enrichment program."
  8. Hazardous Agents
    Hazardous biological, chemical, or physical agents must not be stored or used where animals are housed.
  9. Other
    Access to study areas is restricted to individuals listed on an approved animal protocol; as such, the room must be secured at all times (e.g., via card key, hard key, signage, etc). Doors must fit tightly within the frame to prevent escape of or injury to animals.

B. Animal Care and Husbandry

  1. Daily Observation of Animals
    In order to comply with federal requirements (USDA AWARs §2.33(b)(3) and the Guide, pp. 87 & 112), animals must be observed daily, including weekends and holidays, by qualified personnel to assess their health and well-being. Daily observation of animals must be recorded in the study area log (see Section IV.C.a). Additionally, USDA AWARs §2.33(b)(3) requires that a mechanism of direct and frequent communication with the attending veterinarian exist so that timely and accurate information on problems of animal health, behavior, and well-being is conveyed. Contact a Division of Laboratory Animal Medicine (DLAM) veterinarian at x42571 for animal health concerns. Animals that are found sick or dead should also be reported to the DLAM veterinarian. The DLAM Emergency Phone Tree extension (x52200) should be kept readily available in case of an after-hours veterinary emergency.
  2. Food/Water
    Adequate provisions for feeding and watering of animals must be made at all times. According to the Guide (p. 65), "animals should be fed palatable, uncontaminated diets that meet their nutritional and behavioral needs at least daily, or according to their particular requirements, unless the protocol in which they are being used requires otherwise." To avoid contamination, food must be stored properly and provided in feeders that are so placed to prevent contact of food with feces and urine.

    Additionally, animals must have access to "potable, uncontaminated drinking water according to their particular requirements" (the Guide, p. 67). To avoid microbial cross-contamination, the Guide recommends either replacing water bottles or refilling them provided they are returned to the same cage from which they were removed. Watering devices should be checked daily to ensure proper operation and must be washed and sanitized at least weekly. Water that is not obtained through DLAM should be tested to assure water quality.

  3. Cages/Bedding
    The Guide (p. 70) states that "soiled bedding should be removed and replaced with fresh materials as often as necessary to keep the animals clean and dry and to keep pollutants, such as ammonia, at a concentration below levels irritating to mucous membranes."  Bedding changes for static rodent cages can vary from daily to weekly depending on factors such as number and size of animals, cage size, urinary and fecal output, and experimental conditions. Cages on individually ventilated cage racks may be changed less frequently (e.g., every other week).

    All cages must be cleaned and sanitized on a regular basis. The frequency of cage sanitation may vary depending on specific husbandry practices, such as bedding type, cage type and size, animal density, and frequency of bedding changes.  Cages should be sanitized at least once a week, unless an alternative schedule is documented in the Study Area Management document and approved by the ARC.

C. Record-keeping

  1. Study Area Log
    Records of animal care, room maintenance, and environmental conditions are required to be posted in the study area and kept updated by responsible personnel. Attached is a sample study area log which can be modified as appropriate to the protocol and animal species. The format of the modified log should be kept on file and should accurately reflect the tasks performed and the frequency of each task as described in the Study Area Management document (see Section IV.C.2).

    Study area logs are to be available for inspection upon request of the ARC and/or DLAM staff for 6 months.

  2. Management Document for Animal Husbandry and Study Area Maintenance
    A description of procedures for animal husbandry and study area maintenance must be submitted to the ARC administrative office (please see attached SAM document) and approved by the ARC. The Study Area Management (SAM) document must be kept on file and available for inspection by representatives of the ARC, the Campus Veterinarian, and regulatory agencies during normal business hours.
  3. Room Ventilation
    A copy of Facilities Management's report regarding room ventilation (exhaust and air exchange rate) must be submitted to the ARC administrative office. This document must be kept on file and available for inspection by representatives of the ARC, the Campus Veterinarian, and regulatory agencies during normal business hours.

V. Veterinary Access

The Campus Veterinarian must be given access (i.e., a key or combination) to the study area in order to ensure the provision of adequate veterinary care in accordance with federal requirements. Specifically, the USDA AWARs §2.33(a)(2) mandates that "each research facility shall assure that the attending veterinarian has appropriate authority to ensure the provision of adequate veterinary care and to oversee the adequacy of other aspects of animal care and use." Furthermore, the Guide (p. 14) states that "the attending veterinarian (AV) is responsible for the health and well-being of all laboratory animals used at the institution," and that "the institution must provide the AV with sufficient authority, including access to animals, and resources to manage the program of veterinary care." Similarly, the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC) International requires that "the attending veterinarian must have access to the institution's animals used in teaching and research." As described in the ARC Policy Authority of the Attending Veterinarian, “The attending veterinarian must have unrestricted access to all areas where animals are used or housed (including the vivarium, research laboratories, and research study areas).” Such access must be available 24-hours/day, 7 days/week.

[1] [A]ny live or dead dog, cat, nonhuman primate, guinea pig, hamster, rabbit, or any other warmblooded animal which is being used, or is intended for use in research, teaching, testing, experimentation, or exhibition purposes, or as a pet. This term excludes birds, rats of the genus Rattus, and mice of the genus Mus, bred for use in research.
[2] Rats of the genus Rattus, mice of the genus Mus, and all non-mammalian vertebrate species.
[3] Contact information for the DLAM AHT that monitors these locations is provided directly to PIs and lab managers.

Approved 11/22/99; Revised 12/99, 10/01, 7/28/03, 10/23/06, 2/9/09, 1/18/11, 6/13/11, 11/14/16, 4/24/17; Updated 7/25/11, 1/23/17, 2/24/20