UCSF home page UCSF home page About UCSF Search UCSF UCSF Medical Center
UCSF navigation bar
Alternatives to the Use of Animals in Research
Species-Specific Information & Drug Formulary
Standard Procedures & Guidelines
Policies & Regulations
Animal Care & Use Program
How to Apply to the IACUC
Frequently Asked Questions
Report an Animal Welfare Concern
Animal Research & Care
Laboratory Animal Resource Center(LARC)
Training Program
Working Safely with Animals


These guidelines apply to all surgical procedures performed on mammals other than rodents.


Survival surgery: Any surgery conducted on animals that are expected to recover from anesthesia.

Major surgery (or major operative procedure): Any surgical intervention that penetrates and exposes a body cavity or any procedure that produces substantial or permanent impairment of physical or physiological functions. Multiple major survival surgeries require scientific justification in the approved IACUC protocol. Major operative procedures on non-rodents will be conducted only in facilities intended for that purpose which shall be operated and maintained under aseptic conditions.

Minor or non-major surgery: Minor surgery does not expose a major body cavity and causes temporary or no physical impairment. The IACUC may require some minor surgical procedures to be performed with procedures and facilities suitable for major surgery. Non-major survival surgery (e.g., intravascular cannula insertion, wound suturing, CSF collection, intracerebral inoculations and joint fluid collection) must be performed using aseptic procedures, but does not require a dedicated surgical facility. The room should be clean and well organized and conform to accepted standards of veterinary care.

Non-survival (terminal) surgery: Any surgery or procedure conducted on animals that are not allowed to regain consciousness is considered non-survival surgery. Non-survival surgeries require neither aseptic technique nor dedicated facilities, if the subjects are not anesthetized long enough to show evidence of infection. In the approved protocol, the principal investigator must describe the length of the procedure and steps taken to minimize the possibility of infection. If performed in a dedicated sterile surgery site, non-survival surgeries should be performed so as not to compromise the site’s suitability for survival surgery. No expired drugs or fluids are allowed, but expired medical materials may be used with justification and approval by the IACUC. Non-survival surgeries not performed aseptically or in a dedicated facility must at least be performed in a clean area, free of clutter and personnel present in the area must observe reasonable cleanliness practices for both themselves and the animals.


  • Survival surgery on non-rodent mammals must be performed using sterile instruments and aseptic procedures such as: Preparation of the patient, such as hair removal and disinfection of the operating sites with an appropriate disinfectant such as chlorhexidine or povidone iodine.
  • Preparation of the surgeon such as the provision of decontaminated surgical attire, surgical scrub procedures, and use of masks, hair covering, and sterile gowns and surgical gloves.
  • Sterilization of instruments, supplies, and implanted materials; and
  • The use of operative techniques to reduce the likelihood of infection

Wherever feasible, furniture and equipment not intended to be used during survival surgery shall be removed from the immediate surgical area or covered. Items on countertops or open shelves in the immediate surgical area that are not intended to be used during the surgical-experimental procedure shall be placed into non-porous lidded containers. The floor and all exposed work surfaces shall be disinfected prior to major survival surgery. Walls, ceilings, light covers and equipment shall be maintained clean and disinfected as necessary to prevent contamination of the surgical field. During surgery, the space close enough to the surgical field to reasonably generate contamination of the field should contain only surgical/experimental equipment, sterilized surgical instruments, and sterile items necessary to the surgical and experimental procedures.

Expired materials may not be used for survival surgery. 
All drugs, medical supplies, and sterilized items used during surgery must be current.


  • Activities that involve surgery must include appropriate provision for pre-operative and post-operative care of the animals in accordance with established veterinary medical and nursing practices.
  • The surgical team for major survival surgery in non-rodent mammals should include at least one dedicated person whose primary duties are to monitor the animal and document anesthesia.


  • Remove hair and perform initial surgical scrub on the surgical site. Use a separate area from where the surgery is to be conducted.
  • Prepare the surgical site(s) with an appropriate skin disinfectant after the animal has been positioned for surgery.
  • Surgeons must don surgical masks and hair covers, then wash and dry their hands before aseptically donning sterile surgical gowns and gloves.
  • A separate sterilized instrument pack must be used for each animal.

Operative procedures:

  • All procedures must be performed as per the approved protocol in an IACUC approved area. The animal must be maintained at an appropriate plane of anesthesia throughout the procedure. Refer to Anesthesia Guidelines.
  • Monitoring and documentation during the operative procedure must be as in the approved protocol.
  • Surgical wounds must be closed using appropriate techniques and non-expired sterile materials.


  • All postoperative care, monitoring, and documentation must be according to the approved protocol.
  • Animals must be continuously monitored during recovery until righting reflexes have returned. Refer to Anesthesia Guidelines
  • Generally, remove non-absorbable external skin closures 10 to 14 days post-operatively.
  • Records for surgery, anesthesia and post-operative care should be maintained.

After surgery, all instruments must be cleaned either manually or ultrasonically to remove debris, blood, oil, etc; and then sterilize prior to next surgery.

Cleaning Instruments

  • Manual cleaning
  1. Rinse instruments with water as soon as surgery is over.
  2. Scrub each instrument with a soft brush in warm water with an instrument detergent with a pH near 7.0-8.5. Wear gloves and be mindful of sharp edges on instruments.
  3. Inspect each instrument for proper function and cleanliness; particularly box locks, grooved ends, and other hidden areas.
  4. Rinse the instruments with water (distilled if available) to ensure removal of detergent. Distilled water is used to prevent mineral deposits on the instrument surfaces. If distilled water is not available and tap water is used, hand-dry the instruments to remove mineral deposits from the water.
  5. Instrument "milk" can be used to lubricate instruments.
  • Ultrasonic cleaning

Ultrasonic cleaning is a more effective cleaning method than manual cleaning. It can penetrate areas that a hand brush cannot reach. Cleaning is accomplished by the use of high frequency sound waves converted in the solution into mechanical vibrations, which pull soil out of instruments. The ultrasonic method typically removes about 90% of soil. However, it is important to recognize that it does not sterilize, or eliminate the need for initial removal of obvious blood and soil. Ultrasonic cleaning is most effective when it follows a preliminary manual cleaning to remove accessible debris from the instruments. When using an ultrasonic cleaner, always follow manufacturer's instructions carefully.

Sterilizing Instruments

All instruments used in survival surgeries must be sterile. Specific sterilization methods should be selected on the basis of physical characteristics of materials to be sterilized. Delicate materials may be sterilized using gas-sterilization (e.g. Ethylene Oxide). Sterilization indicators should be used to identify materials that have undergone proper sterilization.
The use of liquid chemical sterilizing agents (e.g. Glutaraldehyde and Ortho-phthalaldehyde (OPA)) must be conducted in approved facilities with adequate ventilation systems and should be used with adequate contact times. Chemically-sterilized instruments should be rinsed with sterile water or saline before use. Alcohol is not a sterilizing agent.

  1. All articles to be sterilized must be clean.
  2. All articles to be sterilized should be packaged in materials (such as paper, muslin, cloth, peel packs, etc.) that protect them from contamination. The material must be porous enough to allow the penetration of the sterilizing agent (e.g. steam).
  3. Date (must include the sterilization date) and label the sterilized items. If multiple sterilizers are used by a laboratory group, the specific sterilizer should also be indicated on the package. The efficacy of the sterilizing process should be measured at regular intervals with a biological indicator (refer to UCSF Biological Safety Manual for procedures).
  4. Store sterilized items in a clean, dust-proof and low-humidity area. Closed storage cabinets prevent contamination more effectively. Storage under sinks or in places likely to result in wetting must be avoided.
  5. Any sterilized package that is dropped or torn or has come in contact with moisture is considered contaminated and must be cleaned, repackaged and re-sterilized. All packages containing sterile items should be inspected before use to verify package integrity and dryness.
  6. If the package has remained intact and dry, items may be considered sterile until the time of use.