• Anesthesia and Analgesia

• Medical Records

• Surgery

• Pre- and Post-operative Care

• Euthanasia

• Preventative Medicine

• Surveillance, Diagnosis, Treatment and Control of Disease

Anesthesia and Analgesia

All research procedures involving animals are reviewed by Duke's IACUC.  The review includes laboratory animal veterinarian assessment of selection of medication, does, and route of administration.  The DLAR veterinary staff is available upon request to provide assistance with or training in the proper administration and use of these agents.  To contact a Duke veterinarian fir assistance with animal medication choices, click here.

Monitoring of anesthetized animals is described in Guidelines For Anesthesia.

The Guide for the Care and Use of Laboratory Animals requires that any proposal to conduct painful procedures without anesthesia or analgesia must be scientifically justified by the investigator and approved by the IACUC.  These procedures, in particularly, will be evaluated through review of the proposed animal use protocol by the IACUC and observation by the DLAR veterinary staff and IACUC, and should be directly supervised by the responsible investigator.

Inhalation anesthetics are the safest agents available for the induction and maintenance of general anesthesia because of their rapid elimination from the lungs.  Detoxification by the kidneys and liver is minimized with these agents.  Their main disadvantage is that they require constant surveillance by the anesthetist.  The anesthetist must be familiar with the particular animal species' normal heart and respiratory rate because these are the most important parameters for monitoring depth of anesthesia.

The following table provides guideline for using the three most commonly used volatile inhalation anesthetics.  Please call DLAR Veterinary Services (684-2797) if you have specific questions pertaining to the use of gaseous anesthetics.

Suggested dosage for injectable pre-anesthetics, tranquilizers, anesthetics, and analgesics are provided by the respective link below delineated by species. The primary reference for the drugs and respective dosage was the Formulary for Laboratory Animals, 2^nd edition.  Note: Ketamine alone has no analgesic properties and must be use in combination with another drug with analgesic properties for painful procedures.  Additional guidelines on other drugs are available through the DLAR veterinary staff (684-2797). 

Local anesthetics may be used for minor procedures where a systemic anesthetic or analgesic is not warranted.  These agents (see table below) cause a loss of sensation without a loss of consciousness and are usually injected directly into an area that requires desensitization.  This technique is used chiefly for removal of superficial tumors, skin biopsies, and similar procedures. As a rule of thumb, 1 ml of a 2% local anesthetic solution is required for each centimeter of incision. 

Local Anesthetics

        * From Short:  Principles and Practices of Veterinary Anesthesia       

Medical Records

Written documentation of all surgical procedures, including the types, amounts, and time of administration of anesthetic, analgesic or tranquilizing drugs used and the physiologic parameters (i.e., heart rate, respiratory rate, body temperature, etc.) monitored during the procedure, is required. This documentation is subject to inspection by USDA inspectors, the DLAR veterinary staff, and the IACUC at any time.  In addition, all animal procedure, treatment, or clinical observation should be recorded in the individual animal's record or the investigator's experimental notebook.

Surgery

• Survival surgery: defined as any surgery from which the animal recovers consciousness.

• Major surgery: defined as any surgical intervention that penetrates a body cavity or has the potential for producing a permanent handicap in an animal that is expected to recover.

• Minor surgery: defined as any operative procedure in which only skin or mucous membrane is incised (e.g., vascular cutdown for catheter placement or implanting pumps in subcutaneous tissue). Because they are minimally invasive, gonadectomies on rodents and lower vertebrates are usually considered minor surgical procedures.

• Multiple major survival surgery: defined as two or more major survival surgical procedures performed at separate times on a single animal. It is permitted by the IACUC only under special circumstances, such as when the surgeries are essential and related components of a single scientific study. Cost alone is not an adequate reason for performing multiple major survival surgeries on an animal.

Major surgical procedures on mammals other than rodents must be conducted in DLAR and IACUC approved surgical facilities intended for that purpose, using aseptic techniques. These techniques include:

1. Wearing of sterile surgical gloves, gowns, caps and face masks;

2. Using sterile supplies and instruments; and

3. Preparing and maintaining an aseptically prepared surgical field.

Minor surgical procedures on mammals other than rodents may be performed in a suitably located and equipped laboratory area as approved by DLAR and IACUC.  Appropriate aseptic technique for these procedures includes:

1. A clean uncluttered work area;

2. Preparation of the surgical site including clipping of the hair, disinfection of the skin and draping of the surgical site with sterile drapes;

3. Use of sterile supplies and instruments; and

4. Use of sterile gloves and a surgical mask by the surgeon and any assistants working in the surgical field.

Surgical Procedures on rodent and non-mammalian species may also be conducted under the above conditions in laboratories or animal facility procedure rooms, subject to DLAR and IACUC approval.

Non-survival surgery: defined as any surgery in which the animal will not regain consciousness. Such procedures may be performed in a suitably located and equipped laboratory subject to DLAR and IACUC approval.

Pre- and Post-procedural Care

Pre-procedural Care: Animals (other than some rodents) should generally be fasted prior to anesthesia and surgery to prevent vomiting, aspiration, and problems associated with a distended intestinal tract. Small mammals with high metabolic rates should be fasted cautiously, as their need for feed intake is constant and fasting for periods longer than 2-4 hours could interfere with the rapidity of recovery and normal physiology.  Mice and rats are usually not fasted, due to anatomical features that prevent vomiting and the high metabolic need for nutrition.

All animals should be evaluated by performing a brief physical examination and recording baseline physiologic measurements of such parameters as body temperature, heart rate, and respiratory rate prior to the administration of an anesthetic agent. Animals should be weighed and dosages of agents administered calculated individually according to body weight measurements.  Larger animals should also have a pre-surgical CBC and baseline serology to confirm the presence of physiologically normal organs and body function.  

Post-procedural Care: Post-surgical care includes clinical observation of the animal to ensure uneventful recovery from anesthesia and surgery.  Animals must be monitored until the animal achieves sternal control.  Intervals between observations (and documentation of those observations) should not exceed 10 minutes.  Further information on post-procedural care can be found in Guidelines For Anesthesia.

An intensive care unit is maintained by the DLAR for the purpose of recovering critical patients, and DLAR postoperative care for all animals is available for a nominal fee. Once the animal has been returned to its normal housing area, subsequent care may be necessary. This may include administration of supportive fluids, analgesics, or other drugs.  Monitoring of the animals should include daily body temperatures, clinical observations for signs of pain, abnormal behavior, appetite and excretory functions, and providing adequate care of surgical incisions.

The investigator is responsible for supportive care unless arrangements have been made to contract DLAR veterinary staff for these services. Written post-procedural records including date, time, person making the observations, condition of animals, and any treatments/procedures performed should be maintained for inspection by USDA, DLAR, and IACUC. Examples of surgical record and other forms may be obtained from the DLAR veterinary staff (684-2797).

Euthanasia:  Euthanasia is generally performed at the end of a project or during a procedure in which animals experience severe or chronic pain or distress that cannot be relieved by therapeutic intervention. Since there may be a need to euthanize animals for unanticipated reasons even on protocols that do not include euthanasia as part of the planned project, at least one method must be documented for each species used in a protocol. The euthanasia method chosen must be appropriate for the species and research use described by the protocol, and must be consistent with the recommendations from the 2000 Report of the American Veterinary Medical Association Panel on Euthanasia.  If the method deviates from AVMA recommendations, the deviation must be justified scientifically and approved by the IACUC. Euthanasia should be performed quickly and efficiently in a nonpublic area, and generally not in rooms in which animals are housed.  If CO2 gas is being used to euthanize rodents, a second method of euthanasia MUST also be performed to assure death. 

The links below provide commonly approved agents and methods of animal euthanasia delineated by species and a general discussion by method. DLAR staff is available to demonstrate and discuss these methods of euthanasia or other potential techniques subject to approval by the IACUC.

• Agents and Methods of Euthanasia by Agent

• Comments Concerning Methods of Euthanasia 

Preventive Medicine

Animal procurement: Newly acquired animals can introduce disease into established colonies. In addition, production colonies maintained by suppliers occasionally experience outbreaks of disease. The DLAR veterinary staff monitors animal health quality from different suppliers and maintains quality control data provided by vendors. This information can be provided to investigators to assist in choosing appropriate sources of animals.

Quarantine and Acclimation: With some species of laboratory animals, quarantine is necessary to minimize the introduction of disease into established colonies. The extent of the quarantine period is determined by the species and by knowledge of the animal's source and previous history as well as by regulatory requirements. For example, nonhuman primates must undergo a state mandated quarantine period of no less than 30 days. Arriving animals, regardless of source, should be allowed an acclimatization  period before use. Such a period allows the animal to recover from shipping stress, adapt to its new surroundings and become physiologically stable. A minimum acclimation period of 48 hours is suggested for all species.   Exceptions to an acclimatization period must be scientifically justified in the IACUC approved protocol.

Separation of species: Physical separation of animals by species is generally recommended to reduce the possibility of transmission of latent diseases and to prevent possible inter-species aggression or distress. This separation is usually accomplished by housing different species in separate rooms. Even when animals of the same species are obtained from multiple sources, their microbiological status may differ, in which case separate housing as provided by barrier caging or separate rooms may be advisable.

Surveillance, Diagnosis, Treatment and Control of Disease

A comprehensive veterinary medical program is in effect for all animals maintained at Duke University. Study or DLAR personnel check animals daily in their rooms daily, including weekends and holidays, for signs of illness, injury, or abnormal behavior. In cases where such observation will interfere with experimental objectives, prior arrangements must be made with the DLAR to ensure adequate monitoring of animals and environmental systems.

To ensure the health status of animals maintained on campus, general medical surveillance procedures have been developed for each species. For example, in-house health monitoring is done for rodents as part of a sentinel monitoring program and is in effect in all DLAR-managed facilities. Serology, bacteriology, and parasitology samples are periodically taken from each sentinel cage and submitted to either in-house or contract diagnostic laboratory for rodent comprehensive testing. If evidence of adventitious viruses, parasites, or bacterial pathogens are discovered and confirmed in the sentinel animals, investigators are notified.  Health surveillance information, including information provided to us by our vendors, is maintained on file and available to investigators upon request. Contact the DLAR veterinary staff (684-2797) for more information on the surveillance, diagnosis, treatment, and control of animal diseases, including the possible affects of disease on experimental animal models.

Veterinary Medical Care:  Veterinary care is provided as required, 24 hours a day, 7 days a week. Any health problem or concern with animal care noted by any animal user at any time, including evenings, weekends and holidays, should be reported immediately to the DLAR veterinary or husbandry staff.  After normal working hours, the veterinary staff may be reached via pager ( number).   See the EMERGENCY page for more information.