Guidelines for Surgeries on USDA-Covered and Agricultural Species used in Research or Teaching

A surgery is defined as a procedure in which an incision is made on a live, anesthetized animal. Survival surgeries are those in which the animal recovers from anesthesia, while animals are euthanized without recovery for non-survival surgeries. 

Major surgeries are determined by a high level of invasiveness, such as exposing a major body cavity, extended recovery periods, and an increased risk of complications. 

Minor surgeries are those that do not qualify for the definition of major surgeries. These surgeries are considered lower risk, do not expose a body cavity and cause little or no physical impairment. 

All procedures involving survival surgery in vertebrate animals must be performed using aseptic technique. They must have an appropriate selection of anesthetic agents and doses as well as the plan for perioperative analgesic use. Any person performing surgery should be appropriately trained prior to performing  work on live animals. This training must be documented within the approved IACUC animal use protocol. Principle Investigators are required to maintain detailed training records for each person approved for activities outlined in the IACUC approved animal use protocols. For training and additional resources and support contact the IACUC Office.

• For major and minor surgeries, the area should be physically separated from the location where the animal is clipped and prepped for surgery.
• USDA-covered vertebrates undergoing survival surgery require a dedicated surgical room.
• The surgical area should be clean and uncluttered. 
• All surfaces should be impervious and sanitizable. Verification of sanitization records should be available to the IACUC.
• Cardboard and paper products should not be stored in the surgery area. Plastic containers or other sanitizable containers, may be used for storage if needed. 
• Agricultural animals maintained for biomedical research should undergo surgery with techniques and in facilities compatible with the guidelines set forth in this section. 
• Some minor and emergency procedures commonly performed in clinical veterinary practice and in commercial agricultural settings may take place under field conditions. Even when conducted in an agricultural setting, however, these procedures require the use of appropriate aseptic technique, sedatives, analgesics, anesthetics, and conditions commensurate with the risk to the animal’s health and well-being.

• All instruments used in surgery should be cleaned and sterilized prior to each procedure. Acceptable as follows:
  • Autoclave
  • Ethylene oxide
  • Cold sterilants are not recommended but may be used if manufacturer’s instructions are followed and the instruments are properly rinsed prior to contacting the patient.
  • Other methods approved within the IACUC protocol on a case-by-case basis.
• Proper instrument and suture selection should be made in consideration for the procedure. Reach out to the UAV for resources on proper selection.

• All hair must be removed from the anticipated surgical site, leaving extra room to prevent accidental contact with the sterile surgical field. Hair may be removed by surgical clippers, hair removal creamers, or other methods approved on the protocol.
• Animals must be aseptically prepped prior to surgery – typically involving three alternating scrubs of chlorhexidine (or an appropriate disinfectant) and 70% alcohol (or an appropriate rinse).
• Minimum contact time of 2 minutes for chlorhexidine should be considered.
• Supplemental heat must be provided to prevent hypothermia for any surgeries lasting greater than 15 minutes. Direct contact with the heat source must be avoided.
  • Recommended heat sources include: forced air warming system, fluid warmers, hot water recirculating pads, heated surgery table tops.
  • Electric heating pads and blankets are not recommended due to potential dangers to patient safety. 
• Sterile eye lubrication must be provided to any patient anesthetized greater than 15 minutes to prevent corneal desiccation.
• In order to preserve a sterile field and avoid surgical site contamination, the prepared area should be draped or otherwise protected from potential contamination.

For major survival surgeries in non-rodent mammals, a dedicated surgeon preparatory sink should be available for aseptically preparing hands and arms. Minimum surgical attire should include sterile surgical gloves, cap, mask, and sterile surgical gown

• Intraoperative monitoring of the animal’s vitals, plane of anesthesia, timing, route, and dose of drugs/agents administered, and experimental procedures performed are essential components of perioperative monitoring and documentation.
• Anesthetic depth must be confirmed prior to incision. No response to stimuli indicates the animal is ready for surgery. 
• Animals should be monitored for respiration, color, anesthetic depth, temperature, and any additional criteria as described in the approved IACUC protocol. 
• Surgical records must be available for IACUC review. USDA covered species require individual surgical records. 
• Hydration level should be assessed in all animals. Any prolonged procedure should provide supplemental fluid therapy to the patient.
• For survival surgeries the body cavity must be closed with a protocol-approved method.
• Monitoring should assess circulation (e.g., heart rate and character (pulse pressure), ECG, blood pressure); oxygenation (e.g., mucous membrane color, pulse oximetry); ventilation (e.g., respiratory rate and character, capnography); and body temperature.
• Surgery/anesthesia records must include at least the following:
  • Date of procedure
  • Animal identification
  • Surgeon and PI names
  • Brief description of procedure
  • Time of induction and completion of anesthesia
  • All drugs administered, including dose, time, and route of administration
  • At a minimum (e.g., for minor and minimally invasive surgeries), temperature and heart and respiratory rates should be recorded immediately before and at the conclusion of the procedure.
  • For invasive procedures lasting more than 15 minutes, physiological parameters (minimally, heart rate, respiratory rate, body temperature and depth of anesthesia) should be continuously monitored with parameters recorded at least every 15 minutes.

• Immediately following surgery/anesthesia, animals should be placed in a clean, dry, and quiet environment where they can be observed closely by appropriately trained personnel while they recover from anesthesia.
• Animals should be monitored continuously until extubated, or until there is a strong swallowing reflex.
• Recumbent animals should be turned from side to side approximately every 15 minutes to prevent dependent pulmonary congestion, edema and muscle damage.
• All food and water bowls and any other physical hazards should be removed from the cage/pen where the animal is recovering from anesthesia.
• Ambient temperature should be adjusted accordingly (bair hugger, circulating water pad, heat lamp or warming board) to maintain normal body temperature. Heating pads are not recommended. Animals should not be left unattended with a warming device.
• The anesthesia or medical record during this period must document at least the following:
  • Extubation timing if applicable
  • At minimum, heart rate, temperature, respiration rate, and sedation level
  • Clinical abnormalities
  • Any treatments given (drug dosages and route of administration)
• The animal must be fully awake and ambulatory prior to returning to its home cage in the animal housing facility. 
• Monitoring of the animal must continue at appropriate intervals (as described in the IACUC-approved animal use protocol) throughout the postoperative period, which extends until the removal of sutures and the observation that incisions are healed. Monitoring may include:
  • Appetite and eliminations (urine and feces)
  • Abnormalities of surgical site (sutures, bandages, etc.)
  • All treatments given (drug dosages and route of administration)
• The post-operative and/or medical record during this period must document at least the following:
  • Periodic documentation of observation and normal recovery (as outlined in protocol)
  • Any clinical abnormalities
  • All treatments provided (including drug, dosage and route of administration)
• Any external closure that requires removal must be removed within the appropriate time frame.
• If the animal is normal and skin sutures are removed, specific post-surgical care and records are no longer required
• If progress in recovery from anesthesia or surgery is not as expected or if there are medical complications, veterinary staff should be contacted immediately.