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Policy#: 529-323

Title: ANIMAL USE PROCEDURE: Animal Surgery

Effective: 10/20/2021


Related Policies and Guidance


  • Survival / nonsurvival surgery: Nonsurvival surgery involves procedures where the animal is euthanized without recovery from anesthesia. All other surgeries are considered survival surgery.
  • Major surgery: Major survival surgery penetrates and exposes a body cavity or produces substantial impairment of physical or physiologic functions (such as laparotomy, thoracotomy, craniotomy, joint replacement, and limb amputation).
  • Minor surgery: Minor survival surgery does not expose a body cavity and causes little or no physical impairment (such as wound suturing; peripheral-vessel cannulation; vascular catheter implantation; subcutaneous pump implantation; subcutaneous implantation of tumor cells,  and most procedures routinely done on an "outpatient" basis in veterinary clinical practice).

Nonsurvival surgery

At a minimum in nonsurvival surgery, the surgical site should be clipped, the surgeon should wear gloves, and the instruments and surrounding area should be clean.

Minor surgery

Minor procedures are often performed under less-stringent conditions than major procedures but still require aseptic technique, instruments, appropriate anesthesia and analgesia (if indicated).

Multiple major survival surgery

Multiple major survival surgical procedures on a single animal are discouraged but may be permitted if scientifically justified in an approved AUP. For example, multiple major survival surgical procedures can be justified if they are related components of a research project, if they will conserve scarce animal resources, or if they are needed for clinical reasons. If multiple major survival surgery is approved, particular attention must be made to animal well-being through continuing evaluation of outcomes. Cost savings alone is not an adequate reason for performing multiple major survival surgical procedures.

Animal Use Protocols

It must be clearly stated within the Animal Use Protocol whether the surgical procedures should be classified as non-survival or survival, minor or major, and if there will be multiple major survival surgeries. Protocols must include a description of the procedure that addresses the use of aseptic technique, anesthetics, recovery, and analgesia (see “Guidance 529-260, Aseptic Rodent Surgery” for more information). If applicable, a rigorous justification for the use of multiple survival surgeries must be included. All protocols involving survival surgery will be discussed at a convened meeting of the IACUC.

Surgical Facilities

  • Rodent surgery: survival surgery on rodents does not require special facilities and may be done in a laboratory under appropriate conditions if approved by the IACUC. The area must be easily sanitized, clean and uncluttered and not used for any other purpose during the time of surgery. Further details regarding rodent surgery can be found in Guidance 529-260, Aseptic Rodent Surgery.
  • Non-mammalian surgery: requirements for survival surgery on non-mammalian species will be reviewed in a case-by-case manner. At a minimum, surgery on non-mammalian vertebrate species should adhere to the facility requirements placed on rodent surgery.
  • Other mammalian species: major survival surgery on non-rodent mammals requires a dedicated suite of 3 rooms and aseptic technique. Consultation with the Campus Veterinarian is recommended during the planning stages of such a facility, as well as during preparation of the AUP covering such procedures. Minor surgical procedures can be performed under less stringent conditions if they are performed in accordance with standard veterinary practices.

Record keeping

Surgical records must include the timing and dose of anesthetic administration, notations indicating monitoring of anesthetic prior to and during surgical procedures, and the timing and results of monitoring during anesthetic recovery. If the associated experimental data does not inherently include a record of the surgical procedure, then the surgical record should include a short description of the procedure.

Aseptic technique

Aseptic technique includes preparation of the animal, such as hair removal and disinfection of the operative site (typically three alternating scrubs of Betadine and alcohol); preparation of the surgeon, such as decontaminated surgical attire, surgical scrub, and sterile surgical gloves; sterilization of instruments, supplies, and implanted materials; and the use of operative techniques to reduce the likelihood of infection. See “Guidance 529-260: Aseptic Rodent Surgery” for more information.


The dose (mg/kg), vehicle and volume of anesthetic must be listed on the AUP, including potential supplemental dosing information and the criteria for administering it. A system for monitoring the anesthetic depth, physiologic function and assessment of clinic signs and conditions must be outlined in the AUP and employed during surgical procedures. See “Guidance 529-349: Guidelines for Rodent Anesthesia and Analgesia” for more information.

Animal Maintenance

For many species, as soon as the animal is anesthetized, ophthalmic ointment should be applied to the eyes to protect the corneas.

Because of the cardiovascular and respiratory disturbances caused by anesthetic agents, equipment needed to maintain normal body temperature should be obtained and its use delineated in the AUP. See “Guidance 529-260: Aseptic Rodent Surgery” for more information.


It is important that individuals involved in a surgery have had appropriate training to ensure that good surgical technique is practiced. Training should include maintenance of asepsis, gentle tissue handling, techniques for minimal dissection of tissue, appropriate use of instruments, effective hemostasis, and correct use of suture materials and patterns. See “Guidance 529-260: Aseptic Rodent Surgery” for more information.


During the anesthetic-recovery period, attention should be given to thermoregulation, cardiovascular and respiratory function, and postoperative pain or discomfort. A system must be clearly outlined in the AUP that defines the parameters to be monitored, including the criteria for intervention and a description of that intervention. Typically, this includes response to stimuli, depth and quality of breathing, and monitoring of temperature. For after anesthetic-recovery, monitoring is often less intense but must include attention to basic biologic functions of intake and elimination and behavioral signs of postoperative pain, monitoring for postsurgical infections, monitoring of the surgical incision, bandaging as appropriate, and timely removal of skin sutures, clips or staples.

Vivaria Surgical Records

Rodent Surgical Cards must be annotated with the procedure and date. Anesthetic, analgesic, antibiotic administration and animal's condition must also be annotated on the surgical cage card.


Pain is a stressor and, if not relieved, can lead to unacceptable levels of stress and distress in animals. The proper use of anesthetics and analgesics in research animals is an ethical and scientific imperative. Preoperative or intraoperative administration of analgesics should be considered as they may enhance postsurgical analgesia. See “529-349: “Guidelines for Rodent Anesthesia and Analgesia” for additional information. Subsequent monitoring of animals must include the administration of analgesia in response to behavioral manifestations of pain or distress, unless a scientific justification is provided in the AUP and approved by the IACUC. Indicators of pain and distress are species specific, but can include vocalization, abnormal appearance or posture, and immobility. Unless the contrary is established, it should be assumed that procedures that cause pain in humans also cause pain in animals.

Updated: 12/9/04, 4/6/09, 8/13/12, 9/20/21