Guidelines on Anesthesia and Analgesia in Ferrets

Unit for Laboratory Animal Medicine
Feb 15, 2015 12:00 am

This document was created by the ULAM veterinary staff as a guideline for anesthesia monitoring during surgery and sedation. This is not intended to be an inclusive tutorial on all possible methods and all equipment available for anesthesia monitoring.

Current veterinary anesthesia standards of care focus on reducing anesthetic morbidity. Adverse changes in normal animal physiology can be detected and corrected early through responsible use of anesthesia monitoring equipment and trained personnel dedicated to anesthesia monitoring. For more detailed information regarding monitoring capabilities and physiological systems, please reference Anesthesia and Sedation Monitoring Guidelines.

  • Responsibility

    1. Principal Investigator: Responsible to ensure appropriate anesthesia, monitoring and analgesia is provided for all animals undergoing surgical or sedation procedures.
  • Glossary Definitions


    This encompasses both of the following definitions:

    1. Local Anesthesia: Temporarily induces loss of sensation to a specific part of the body. May provide pain relief.
    2. Systemic Anesthesia: Temporarily induces loss of sensation with loss of consciousness. Only provides pain relief due to or during loss of consciousness.


    Central depression causing stupor where the animal is unaware of its surroundings but still responsive to painful procedures.

  • Procedures

    1. Prior to Anesthetic/Analgesic/Sedative Event

    1. Apply sterile non-medicated ophthalmic ointment to the eyes to prevent corneal drying during anesthesia or sedation.

    2. Vascular Access

    1. Ferret skin is very tough and contains a lot of subcutaneous fat which makes catheterization complicated. Ease of insertion of catheter can be created by making a small knick in the skin using the beveled edge of a 20g needle or small blade. The cephalic, lateral saphenous and jugular veins can be catheterized (22g, 24g, or 26g for smaller ferrets). Small blood samples (e.g. glucose measurements) can be taken from the lateral or caudal tail vein. If larger volumes are required, they can be collected from the jugular, cranial vena cava, cephalic or saphenous veins.

    3. Fasting and Endotracheal Intubation

    1. Ferrets readily vomit. Young ferrets (<3 years of age) should be fasted for approximately eight hours. However, ferrets over 3 years of age should not be fasted for longer than 3-4 hours because prolonged fasting can induce a profound hypoglycemic state (Matchett et al. 2012).
    2. A cuffed endotracheal tube with a 3-mm internal diameter should be used for ferrets >1kg. Small ferrets may require a cuffed or uncuffed 2.5-mm or less internal diameter endotracheal tube. Intubation is facilitated by applying 0.05ml of 2% lidocaine to the glottis to prevent laryngospasm (involuntary closure of the opening to the trachea).

    4. Monitoring and Recovery

    1. Standard mammalian monitoring techniques are applicable to ferrets – the goal of the monitoring should be to maintain normal cardiac function, respiratory function, ventilation, core body temperature, and depth of anesthesia. Understanding the basic physiologic effects of the anesthetics used is paramount to correctly interpreting monitoring parameters. Refer to anesthesia guidelines listed in the "Summary" section of this document for further details.


         Body Temperature   

         Heart Rate   

         Respiratory Rate   

         Normal Value   

         100 - 104 F (37.8 - 40 C)   

         180 - 300 bpm   

         30 - 40 bpm   

    2. Like other small mammals, ferrets are very prone to hypothermia. Moderate-to-severe hypothermia (<95 oF) requires active warming. The following actions are recommended to minimize heat loss:
      1. Warm the immediate environment with circulating water blankets or heat lamps
      2. Minimize clipping hair around the surgical site
      3. Use warmed surgical scrub solution to prepare the surgical site
      4. Substitute warmed sterile saline for alcohol during surgical scrubs
      5. Cover the ferret with appropriate surgical drapes
      6. Minimize anesthesia and surgical time.
    3. Recovery should occur in a warm, quiet location. Ferrets should be observed until fully recovered from anesthesia, and monitored to assure that they have re-established and are maintaining normal body temperature and hydration status.
    4. Post-surgical nutritional support can be beneficial to promoting recovery in ferrets. Contact veterinary staff ( for further information.

    5. Monitoring Pain

    1. Signs of pain in ferrets may include, but are not limited to, the following:
      1. Abnormal posture
      2. Reluctance to curl into normal position
      3. Reluctance to move
      4. Dull
      5. Lethargic
      6. Elevated respiratory rate
      7. Deep respirations
      8. Hunched
      9. Arched back
      10. Teeth grinding
      11. Stilted gait

    6. In the Event of an Emergency

    1. Contact veterinary staff at 734-936-1696 during business hours (Monday to Friday 8am to 5pm) or Department of Public Safety after hours, weekends and holidays at 734-763-1131.

    7. Common Ferret Anesthetics and Other Agents


       Dose and Route   



       1 mg/kg SC, IV, IP or   
       equal volume to administered           dexmedetomidine   
    • Reversal for dexmedetomidine   
       Carpenter, 2013   
       0.04 - 0.05 mg/kg IM, IV, SC   
    • Anticholinergic (bradycardia, hypersalivation)   
       Ko and Marini, 2008   
       0.01 mg/kg IM or SC   
    • Anticholinergic   
       Mason, 1997   
       Induction: 5%   
       Maintenance: 1.5 - 3%   
    • Inhalant anesthetic of choice   
       Wixson, 1997   
       Induction: 8%   
       Maintenance: 2.5 - 4.5%   
    • Inhalant anesthetic   
       Ko and Marini, 2008   
       + Xylazine   
       10 - 30 mg/kg ketamine IM   
       + 1 - 2 mg/kg xylazine IM   
    • Minor procedures   
    • May add an anticholinergic as premedication   
       Mason, 1997;   
       Wixson, 1997   
       + Dexmedetomidine   
       5 mg/kg xylazine IM   
       + 40 ug/kg dexmedetomidine IM   
    • Minor procedures including induction   
    • 45 min duration   
    • May add anticholinergic as premedication   
       Carpenter 2013   
       + Xylazine   
       + Butorphanol   
       15 mg ketamine IM   
       + 2 mg/kg xylazine IM   
       + 0.2 mg/kg butorphanol IM   
    • Effective for short term procedures   
    • Duration 90 min   
    • Analgesic properties   
    • Watch for respiratory depression   
       Ko and Marini, 2008   
       Butorphanol &   
       2 mg/kg xylazine IM   
       0.2 mg/kg butorphanol IM   
       15 mg/kg ketamine IM   
    • Effective for short term procedures   
       Ko and Marini, 2008   
       + Zolazepam   
       22 mg/kg IM   
    • Excellent for most minor procedures, but long recovery time   
       Mason, 1997;   
       Wixson, 1997   

    8. Ferret Analgesics and Local Anesthetics


       Dose and Route   



       0.1 - 0.5 mg/kg IM or SC every 4 hrs   
    • Opiate agonist-antagonist   
    • Coverage for mild to moderate pain   
       Mason, 1997   
       Buprenorphine a   
       0.01 - 0.03 mg/kg IM, IV or SC every 8 - 12 hrs   
    • Opiate agonist   
    • Mild to moderate pain   
       Mason, 1997   
       1 - 2 mg/kg diluted with saline   
       Infiltrate surgical site   
       Ko and Marini, 2008   
       2 - 4 mg/kg SC, IM, IV, PO every 24 hrs   
       Ko and Marini, 2008   
       Flunixin meglumine   
       0.5 - 2.0 mg/kg IV or SC every 12 - 24 hrs   
    • NSAID   


       1 - 3 mg/kg SQ, IM, IV, PO every 24 hrs   
    • NSAID   
       Ko and Marini, 2008   
       2 mg/kg diluted with saline   
       Infiltrate surgical site   
    • Local Anesthetic with 60 min duration   
    • Can be used pre- and post-surgery   
       Ko and Marini, 2008   
       0.2 mg/kg SC, IM, IV, PO every 24 hrs   
    • NSAID   
       Ko and Marini, 2008   
       0.5 - 5.0 mg/kg IM or SC every 2 - 6 hrs   
    • Opiate agonist   
    • Mild to severe pain   
       Mason, 1997   
       0.04 mg/kg IV or IM once   
    • Narcotic reversal agent   
       Mason, 1997   
       0.05 - 0.2 mg/kg IM or SC every 6 - 12 hrs   
    • Opiate antagonist   
       Mason, 1997;   
       Wixson, 1997   
       5 mg/kg PO every 24 hours   
    • NSAID   
       Carpenter, 2013   

     a Preemptive analgesia, particularly opiates like buprenorphine, can reduce the dose of anesthetics required for surgical anesthesia and increase the respiratory depression associated with anesthetics. When preemptive analgesia is used, consider reducing the dose of anesthetic (whether inhalant or injectable) to the low end of the recommended range. Anesthetic depth must be carefully monitored and drug doses may need to be titrated to maintain appropriate levels. With new projects, sexes, strains or anesthetic analgesic combinations, assess a subset of animals before expanding to use in a larger cohort.

  • References

    1. Baumans V, Coke C, Green J, Moreau E, Peterson-Kane E, Reinhardt A, Reinhardt V, Van Loo P eds. Making Lives Easier for Animals in Research Labs, Animal Welfare Institute, Washington, DC, 2007.
    2. Carpenter JW, Marion CJ. Exotic Formularly, 4th ed. Elsevier Saunders, St. Louis, Missouri, 2013.
    3. Flecknell P, Waterman-Pearson eds. Pain Management in Animals, WB Saunders. London England, 2000.
    4. Fox JG, Anderson LC, Loew FM, Quimby FW eds. Laboratory Animal Medicine 2nd Ed. Academic Press, London England, 2002.
    5. Fox, James G. (1988). Anesthesia and surgery. In "Biology and Diseases of the Ferret" (James G. Fox, ed.) pp. 289-302. Lea & Febiger, Philadelphia, Pennsylvania.
    6. Gaynor J, Muir W, Handbook of Veterinary Pain Management, Mosby, St. Louis Missouri, 2002.
    7. Hrapkiewicz K, Medina L, Holmes D. Clinical Laboratory Animal Medicine, 2nd ed. Iowa State University Press, Ames, Iowa, 1998.
    8. Ko J and Marini RP. (2008). Anesthesia and Analgesia in Ferrets in "Anesthesia and Analgesia in Laboratory Animals". Academic Press, San Diego, CA. 443-455.
    9. Ko JCH., Smith TC, Kuo W-C & Nicklin, CF. (1998). Comparison of anesthetic and cardiorespiratory effects of diazepam-butorphanol-ketamine, acepromazine-butorphanol-ketamine, and xylazine-butorphanol-ketamine in ferrets. J Amer Anim Hosp Assoc. 34:407.
    10. Matchet CA, Marr R, Berard FM, Cawthon AG, Swing SP. (2012). The Laboratory Ferret. CRC Press, Boca Raton, FL.
    11. Mason DE. (1997). Anesthesia, analgesia, and sedation for small mammals. In "Ferrets, Rabbits, andRodents" (EV Hillyer and KE Quesenberry, eds) pp. 378-382. WB Saunders Company, Philadelphia, Pennsylvania.
    12. Plumb DC. (1995). "Veterinary Drug Handbook." Iowa State University Press, Ames, Iowa.
      Recognition and Alleviation of Pain and Distress in Laboratory Animals, National Academy Press, Washington, DC, 1992.
    13. Schaeffer DO. (1994). Miscellaneous Species: Anesthesia and Analgesia. In "Research Animal Anesthesia, Analgesia and Surgery." (AC Smith and MM Swindle, eds.) pp. 107-111. Scientists Center for Animal Welfare, Greenbelt, Maryland.
    14. Thurmon JC, Tranquilli WJ, Benson GJ. (1996). Swine. In "Lumb and Jones' Veterinary Anesthesia" (TC Thurmon, WJ Tranquilli, and GJ Benson, eds.) 3rd ed. pp. 627-644. Williams and Wilkins, Baltimore, Maryland.
    15. Wixson SK (1997). Anesthesia and Analgesia in Ferrets. In "Anesthesia and Analgesia in Laboratory Animals" (DF Kohn, ## SK Wixson, WJ White, and GJ Benson, eds.), pp. 274-279. Academic Press, San Diego, California.
Species: Ferrets

If you have questions or comments about this document, contact ULAM Veterinary Staff ( or 734-936-1696).

The ULAM Training Core ( or 734-763-8039) can be contacted to provide training in techniques at no charge.

For any concerns regarding animal health after work hours or on holidays/weekends, contact DPS (3-1131) who will contact the on-call veterinarian.