Entry and Exiting Animal Housing Areas

Unit for Laboratory Animal Medicine
Mar 11, 2022 12:00 am

Procedures for entry and exiting animal housing areas, including changing the Vivarium Dedicated Uniform and showering.


  • Responsibilities

    1. Husbandry Personnel
    2. Veterinary Personnel
    3. Investigative Personnel
  • Glossary Definitions

    Conventional Animals

    Animals with an undetermined microbiological status; animals are raised and maintained under standard conditions.

    Dedicated Work Uniform (DWU)

    Clothing that is designated as personal protective equipment (PPE), not worn outside of the work setting, and laundered using in-house facilities or by a professional laundry service.

    Examples include lab coats and scrubs used as PPE.

    Donning / Doffing

    The practice of personnel putting on and removing work-related protective gear, clothing and uniforms.

    Germ-Free Animals

    Animals that have no microorganisms living in or on them and are raised within germ-free isolators in order to control their exposure to viral, bacterial, or parasitic agents.

    Micro-isolation (MI) Technique

    Micro-isolation techniques for rodent cages involve creating controlled environments to house and maintain laboratory rodents, such as mice or rats, in conditions that minimize the risk of external contamination and ensure the animals' health and the validity of experimental results. These techniques include, but not limited to:

    • Working in a laminar flow hood when opening animal cages and handling animals.
    • Housing animals within specially designed isolator caging units.
    • Providing sterilized food, bedding, and environmental enrichment.

    Non-Rodent Mammal

    Rabbit, ferret, dog, cat, swine, sheep, cow, non-human primate, etc.

    Non USDA-Regulated Species

    A term that refers to animals whose care is NOT governed by the Animal Welfare Act. This includes rats of the genus Rattus and mice of the genus Mus bred for research, birds, fish, reptiles, and amphibians.

    Quarantine Animal

    Animals with disease or unknown health status.

    Specific Pathogen Free (SPF)

    Animals which are free of the specific pathogens tested for in the Unit for Laboratory Animal Medicine's Rodent Health Surveillance Program.

    Yellow or Potentially Contaminated Rooms

    Previously contaminated animal room and is now believed to be free from any contaminants. Prior to contamination status release, surveillance results must confirm "clean" status. Certain viral outbreaks may have insufficient information regarding the virus and require animal rooms to placed in "potentially contaminated" state at the discretion of the area veterinarian.

    USDA-Regulated Species

    A term that refers to animals whose care is governed by the Animal Welfare Act. USDA-regulated Species include all live or dead warm-blooded animals used in research except birds, rats of the genus Rattus, and mice of the genus Mus bred for research. This also excludes "cold-blooded" animals such as fish, reptiles, and amphibians.

  • Procedures

    1. Animal and Euthanasia Room Entry Procedures

    1. Ensure all entry room procedures are followed to maintain the health status of the animals.
      1. Hang personal items such as lab coats, jackets, bags and hats outside the room.
      2. Follow the designated personal protective equipment (PPE) instructions listed on the room entry procedures sign posted on the outside of the door and/or area entrance.
        1. Ensure proper attire is worn (long pants/skirt or equivalent leg covering and closed toed shoes).
        2. Euthanasia rooms require additional PPE over DWU.
        3. Don gown before gloves. Utilize head and thumb openings, if present.
        4. Pull gloves over the cuff of the gown.
        5. Discard gown if falls on the floor.
        6. Follow building specific procedures for location of donning and doffing PPE.
        7. PPE requirements may change during an outbreak.
      3. Change PPE between species.
        1. Area faculty veterinarians approve any deviations that may need to occur.
          1. Post approved deviations on a Special Treatment or Procedure form (SToP).
      4. Consult the area faculty veterinarian if there is a change in the health status of a room.
      5. Leave laboratory carts outside of the housing areas of:
        1. C. bovis free rooms
        2. Nude/SCID rooms
        3. Biocontainment rooms

    2. Animal Room Entry Order

    1. Rodent Room Entry Order:
      1. Enter rooms, within the same workday, as follows:
        1. Germ-Free
        2. C. bovis free
        3. Nude or SCID
        4. SPF clean room (Green)
        5. SPF potentially contaminated (Yellow)
        6. The following rooms are of equal health status and can be entered in any order between SPF potentially contaminated (Yellow) and conventional rooms:
          1. SPF biocontainment
          2. SPF contaminated (Red)
          3. Quarantine
        7. Conventional
      2. Exceptions to the room entry order:
        1. Enter prairie vole rooms AFTER all other rodent and rabbit rooms.
          1. Wash hands up to elbows and change DWU if there is a need to return to another rodent or rabbit room after entering a prairie vole room.
      3. PPE in Rodent Rooms – Non-USDA Regulated Species
        1. With a LFH and microisolator caging:
          1. DWUs and gloves, or
          2. Designated personal protective equipment (PPE) as listed on the room entry procedures sign
        2. Without a LFH and/or microisolator caging AND when cages are being opened:
          1. Designated personal protective equipment (PPE) as listed on the room entry procedures sign
          2. DWUs and gloves are acceptable when cages are not being opened.
      4. PPE in Rodent Rooms – USDA Regulated Species
        1. Designated personal protective equipment (PPE) as listed on the room entry procedures sign
    2. Non-rodent Mammal Room Entry Order:
      1. PPE in Rabbit Rooms
        1. Wear disposable CLOTH gowns.
          1. Change gowns when torn and/or soiled.
      2. Enter rabbit rooms AFTER guinea pig rooms.
        1. All personnel change DWU if there is a need to return to a guinea pig room after entering a rabbit room.
      3. Enter non-rodent mammal rooms (per species) in quarantine LAST within a workday.
      4. Ensure PPE is changed between all non-rodent mammal rooms.
    3. Alternate PPE is provided by the individual’s department if personnel are unable to wear the PPE as required and if deemed to be at least as effective as the required equipment. Personnel are not able to conduct the work tasks in which PPE is deemed necessary if unable to wear required PPE or alternate PPE is not acceptable.  Consult EHS, the faculty veterinarian, and the employee.
    4. Animal Room Exiting Procedures:
      1. Remove and dispose of all PPE immediately prior to exiting the room, pod, hall, or other designated area.

    3. Animal Room Contamination

    1. Rodent Contamination:
      1. Place appropriate contamination signage on the door of the animal room if contaminants are present.
        1. Include don/doff procedures on door signage.
      2. Don a disposable gown and gloves PRIOR to entering a room with confirmed contaminations.
        1. Doff PPE based on room signage.
    2. Non-rodent Mammal Contaminations:
      1. Place appropriate contamination signage on the door of the animal room if contaminants are present.
        1. Include don/doff procedures on door signage.
      2. Don required PPE PRIOR to entering a room with confirmed contaminations.
        1. Additional PPE must be worn over DWU.

    4. Personal Hygiene and Clothing Procedures for ULAM Personnel

    1. Showering:
      1. Shower, including washing hair, and don clean DWU prior to entering a Nude/SCID rodent room after working in an SPF contaminated (Red) rodent room or conventional animal room.
    2. Clothing
      1. General DWU Procedures
        1. Discard DWU in dirty laundry bin at the end of the workday, or at any other required time that DWUs must be changed, to be laundered per building procedures.
        2. Wash and dry DWU in research areas only. DWU must not be removed from the University of Michigan campus.
        3. Change DWU when traveling backward in room entry order, e.g. travelling from SPF clean room (Green) to Nude/SCID room (See Procedures section 2.a.i.1 thru 7).
        4. Disinfect shoes/boots with an appropriate disinfectant when entering an SPF large animal room after a quarantine or biocontainment large animal housing room.
        5. Change DWU PRIOR to breaks and lunches if traveling from:
          1. Contaminated rooms
          2. Conventional rooms
          3. Dirty side cage wash
        6. Change DWU PRIOR to leaving the vivarium to enter a public space unless:
          1. Traveling from one animal area to another.
          2. Additional PPE is worn over DWU while  working within the animal facility.
        7. Change soiled or wet DWU after completing current task or as soon as possible.
        8. Change DWU AFTER break, lunch, or meeting if duties involve working in clean side cage wash.
        9. Change DWU when working in between different dirty side cage wash areas.
  • Appendix A: Animal Room Status Color Indicator Descriptions

    Red: Contaminated

    • Room pressure: refer to the CODA worksheet FINAL in the ULAM Cafe
    • The room is contaminated, or the contamination has been removed, but the room has not yet been disinfected. Depending upon the contamination, suspect animals are tested before being moved out of a RED room or shipped.
    • Animals testing negative can be moved to a Yellow or Green room. Animals testing positive should be culled, rederived, or treated.
    • New Arrivals may be redirected to a Green room for the duration of the contamination.

    Yellow: Potentially Contaminated

    • Room pressure: refer to the CODA worksheet FINAL in the ULAM Cafe
    • Rooms with the contamination removed that have been disinfected but do not have new surveillance results back. Rooms that received arrivals from contaminated rooms before we learned about the contamination.
    • Room remains at Yellow status until the next round of surveillance comes back negative. Animals can be moved to other Yellow rooms, or to Red rooms.
    • Animals testing negative can be moved to Green rooms.

    Green: Clean

    • Standard housing rooms without contamination.
    • Rooms with the contamination removed that have been disinfected and have negative post-cleanup surveillance results.
    • Animals can be moved from any Green room to Green, Yellow, or Red rooms. If they are moved to a Yellow or Red room, they cannot move back to a Green room.
  • Appendix B: Animal Room Contamination Sign

  • Appendix C: Animal Room Potential Contamination Sign

  • Appendix D: PPE Risk Prioritization