DLAR Message: Social Housing of Animals

To: Research personnel conducting animal studies
From: David Schabdach, D.V.M.
Attending Veterinarian and Sr. Executive Director, DLAR
Date: October 11, 2013

The current edition of the Guide for the Care and Use of Laboratory Animals released in 2011 and adopted by both AAALAC and NIH's Office of Laboratory Animal Welfare (OLAW) emphasizes and encourages the social housing of animals in compatible pairs or groups. The Guide considers the "default" housing of social species to involve pair or group housing. Single housing should be the exception and be based on either experimental requirements or animal health or welfare concerns. The IACUC implemented a policy on 2/27/13 entitled Social Housing of Laboratory Animals to provide guidance on social housing standards and practices at the University of Pittsburgh. The policy can be reviewed on the policies page of the IACUC website.

Pair or group housing is expected for animals unless otherwise explained and justified in the IACUC approved animal protocol. Single housing of animals may be infrequently required for veterinary medical or animal welfare concerns as determined by a DLAR veterinarian. A veterinary exemption for single housing cannot be granted to replace the need for an IACUC approved exception.

There are some common animal colony and program management practices where single housing is acceptable. These program wide exceptions to social housing do not require an
IACUC approved protocol exception or a veterinary exemption. Acceptable program wide situations for single housing include:

  • Some aspects of rodent in house breeding colony management such as
    • Single housing pregnant females prior to delivery
    • Single housing animals of either sex at weaning when the litter contains a single male and/or single female
    • Single housing male rabbits. Female rabbits must be socially housed unless found to be incompatible with other female rabbits.
  • Certain situations associated with perioperative management and care such as
    • Single housing to accomplish pre-surgical fasting
    • Single housing up to 7 days for post-operative recovery and observation
  • Single housing due to experimental group attrition (e.g., one animal remaining in an experimental group)
  • Documented aggressiveness or social incompatibility
  • The unavailability of another socially compatible animal


A number of animals across DLAR facilities have been found single housed without an IACUC approved (protocol) exception, a veterinary exemption, or meeting one of the program wide criteria described above. Effective Monday, November 4th, animals found inappropriately single housed will be reported as noncompliance to the Research Conduct and Compliance Office. I recommend that research personnel review the current housing status of their animals as well as their IACUC approved protocols to ensure that any protocol related need for single housing is appropriately documented and managed.

Thank you in advance for supporting the animal care program's social housing practices. Please contact me directly if you have any questions regarding this communication.