Environmental Enrichment for Animals SOP

Unit for Laboratory Animal Medicine
May 15, 2018 12:00 am

This document outlines the use and approval of environmental enrichment for all vertebrate animals.

  • Responsibility

    1. Enrichment Committee Designee: Includes veterinarian, husbandry manager, husbandry supervisor or other enrichment committee members responsibly for approving new enrichment items. Approval procedures can be found under Procedures section 3 below.
    2. Trainer or Area Husbandry Supervisor: Train husbandry technicians in proper technique and application of any enrichment items.
    3. Husbandry Technicians: Provide enrichment to the animals, record application and changing of the enrichment on the appropriate paperwork.
    4. Area Husbandry Supervisor: For all USDA-covered species obtain PI approval before implementing any enrichment items.
  • Glossary Definitions

    Animal Enrichment Database (AED)

    The central database used to track the approval status and details of all enrichment methods and items used.

    Principal Investigator (PI)

    The researcher who has received protocol approval to conduct the study.

    Social Species

    Species regarded as highly interactive with members of their same species and whose psychological well-being is associated with social interactions. Examples of social species include, but are not limited to, canines, primates, rodents, rabbits, sheep, and swine.

    Special Treatment or Procedure (SToP) Form

    A form that indicates special procedure differing from standard operating procedure (SOP). These are typically placed on the inside of the animal room door. See Request for Special Treatment or Procedure (SToP) Form for more information.

  • Procedures

    1. Animals That Receive Enrichment

    1. All vertebrate animals must receive enrichment regardless of their social housing status unless a SToP Form is in place and it is justified in the AUP or for animal health reasons.
    2. Singly housed animals must be provided more than one enrichment item. Additional enrichment item(s) should be different from the first enrichment item. The additional enrichment item(s) should be added at the first cage change when the animal is noted to be singly housed. Suggestions for various species include:
      1. Mice, gerbils, hamsters, voles: these animals should have at least one form of nesting material. The additional enrichment item can be a different form of nesting material, for example if mice currently have a nestlet, envirodry or an enviropak could be added. Other secondary enrichment options are available on the AED.
      2. Rats and guinea pigs: these animals should have at least one hiding opportunity in the form of a shelter or shelf. The additional enrichment item can be a different form of hiding opportunity, for example if the rats have a shelf, a tube or shelter could be added. Other secondary enrichment options are available on the AED. Nesting material can be provided as a secondary enrichment item to rats, however nesting material is generally not considered as valuable for rats as it is for mice. Where possible, the additional enrichment item(s) should be rotated for novelty on subsequent cage changes.
      3. Large animal species such as rabbits, pigs, sheep, cows, cats and ferrets: at least two different items from the species' approved enrichment database should be provided to singly housed large animals. Where possible, different categories of enrichment should be provided. For example, rather than providing two different kind of balls, provide a ball and a mirror or chew toy. Where possible, enrichment items should be rotated for novelty on subsequent cage changes.
        1. Enrichment strategies differ for animal’s either single housed alone in room or with conspecifics in room. See Appendix A for a hanging quick guide for these cases.
      4. Dogs and NHP: for suggestions for these species, please see the species-specific SOPs in the Related Documents section.
    3. To encourage novelty of environmental enrichment items and to alleviate resources, limit the number of items given appropriately (i.e. offer only 2 items to a singly housed animal; for a pair of larger animals, offer 1-2 items per animal).

    2. Providing Enrichment

    1. Provide enrichment to animals unless a SToP Form is in place stating otherwise.
    2. Review enrichment options as described in the AED and select an appropriate enrichment item based on species and individual animal size.
    3. Where applicable:
      1. Ensure smaller items do not go down drains.
      2. If item can be pushed out through the cage bars, do not use as sole enrichment item.
      3. Remove any item that is broken or excessively worn; recover all broken pieces.
      4. If hanging items are no longer hanging, locate and remove clip.
      5. Watch for animals ingesting pieces of items.
      6. Any items on chains must be no longer than three chain links (plus fasteners) or must be appropriately covered.
    4. Change enrichment items at regular intervals or when required per AED and when possible, rotate items to maintain novelty of the items.
      1. Record the date and the type of enrichment item on the Enrichment Rotation Log (Appendix B).
        1. Rodent and rabbit enrichment is replaced or sanitized at cage change. Type of enrichment does not need to be recorded on Room Sheet (e.g. Animal Room Log Sheet) or on an Enrichment Rotation Log (Appendix B).
        2. NHP enrichment is recorded on the Nonhuman Primate Enrichment and Husbandry Log.

    3. Approval of New Enrichment Items

    1. Use of any enrichment item not found on the AED must be approved prior to implementation.
      1. Contact the Enrichment Committee with new enrichment ideas or examples via this survey link Request for Approval of New Enrichment Item. Provide the following information relevant to the enrichment item:
        1. Costs for each item (purchase price or labor to construct)
        2. How labor intensive the enrichment is projected to be
        3. Novelty of enrichment item
        4. Proposed schedule of applying and rotating enrichment
        5. Item disinfection requirements
      2. Enrichment Committee designee evaluates each item and determines if the item should be approved. Once an item is approved, the Enrichment Committee designee ensures the details are entered into the AED. Information to be included in the AED include:
        1. Item name
        2. Item description
        3. Approved species use
        4. Application schedule
        5. Approved disinfection procedures (if applicable)
      3. Certain items may be used on a trial basis before approval. This will be determined by the Enrichment Committee designee and must be done only after prior approval is obtained from the PI.
      4. If an item is not approved, the information will be entered into the AED along with the reason why the item was not approved.

    4. Training

    1. Husbandry technicians applying enrichment items must be trained in proper application and use of items before employing use of any items. Trainers or area supervisors ensure training of all relevant items in their area.
    2. Training can be done by:
      1. Providing detailed descriptions of application of items via the AED.
      2. Demonstrations of application must be provided for any items that;
        1. involve safety concerns for the humans or animals (i.e. NHP enrichment)
        2. are not routinely used
        3. involve direct handling of the animals (i.e. hand walking canines)

    5. Cleaning / Sanitizing Enrichment Items

    1. Clean, disinfect, sanitize or discard items in accordance with the information in the AED.
    2. Certified wood enrichment items must not be sanitized or disinfected. Once placed in a cage, wood enrichment items must be transferred with animals to clean caging until the wood becomes soiled, splintered or brittle.
      1. Soiled, splintered or brittle wood enrichment items must be discarded and replaced as needed.
  • Appendix A: Swine & Sheep Minimum Enrichment Room Poster

  • Appendix B: Enrichment Rotation Log

Topic: Enrichment

If you have questions or comments about this document, contact ULAM Veterinary Staff (email or call 734-936-1696).