Multiple Survival Surgeries


The Guide for the Care and Use of Laboratory Animals (the Guide, NRC 2011) states:

  • "Surgical procedures in the laboratory setting may be categorized as major or minor." (p. 30)
  • Regardless of classification, multiple surgical procedures on a single animal should be evaluated to determine their impact on the animal's well-being. Multiple major surgical procedures on a single animal are acceptable only if they are included in and essential components of a single research project or protocol and are scientifically justified by the investigator, or if necessary for clinical reasons. (p. 30)
  •  "Some procedures characterized as minor may induce substantial post-procedure pain or impairment and should similarly be scientifically justified if performed more than once in a single animal." (p. 30)


Major survival surgery: any surgical procedure that penetrates and exposes a body cavity or produces substantial impairment of physical or physiological functions (9 CFR, Parts 1 and 2), or involves extensive tissue dissection or transection (Guide). Examples include but are not limited to: laparotomy, thoracotomy, ovariectomy, nephrectomy.

Minor survival surgery: a surgical procedure that does not expose a body cavity and causes little or no physical impairment. Examples include: wound suturing, percutaneous biopsy, lymph node biopsy, and subcutaneous osmotic mini-pump implantation.

IACUC Policy

Protocols that propose multiple survival surgical procedures on a single animal, whether minor or major must provide justification in the protocol application. Proposal of multiple major survival surgeries must satisfy the criteria above taken from the Guide. Cost savings is not an adequate justification for multiple survival surgeries.

A specific timeline detailing when surgical procedures will be performed must be included in the protocol. Adequate time between procedures should be provided so that the animal can return to pre-surgical homeostasis (return to pre-surgical weight and hydration status, and none to a minimal level of pain).

Supportive care and adequate analgesia must be provided to the animals between procedures.

The IACUC may require periodic reporting from the Principal Investigator to track the outcomes of the multiple survival procedures.

Approved: December 2012

Revision Approved: 10/2017, 9/2019