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Guidelines
Suggested parameters and sets of instructions outlining best practices and standards for accomplishing specific animal care and use research duties.

Guidelines on Anesthesia and Analgesia in Dogs

Unit for Laboratory Animal Medicine

| Approval Date:

August 23, 2024 12:00 am

This document has been designed by the ULAM veterinary staff as a guideline for sedation, anesthesia, and analgesia of laboratory canines. This is not intended to be an inclusive tutorial on all possible drug combinations that can be used in canines. The following guidelines are also general recommendations and consequently do not include reference to specific research associated concerns.

All surgical procedures, anesthetics, analgesics, antibiotics or other medications used on animals must be approved by the IACUC, described in the animal use protocol, performed by personnel listed on the protocol, and appropriately trained for the surgical procedure. Any techniques or drug protocols deviating from this document must be justified and approved in the IACUC protocol prior to application.

Responsibility

  1. Principal Investigator: Responsible to ensure appropriate anesthesia and/or analgesia is provided for all canines undergoing potentially painful procedures, including survival surgery, unless otherwise indicated in the relevant approved protocol.

Glossary Definitions

Anesthesia

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.
Related Terms: Analgesia, A/A, Local Anesthetic, Surgical/Anesthetic/Sedation Record

Analgesia

Provides pain relief without loss of consciousness.

Related Terms: A/A, Multimodal Analgesia, Pre-emptive Analgesia, Systemic Analgesic, Anesthesia

A/A

Anesthesia and analgesia.

Related Terms: Anesthesia, Analgesia

CRI

Continuous rate of infusion.

IM

Intramuscular.

IV

Intravenous.

Pre-emptive Analgesia

For the purpose of the Policy on Analgesia in Animals Undergoing Surgery, pre-emptive analgesia is analgesia administered before or immediately after an animal is anesthetized, but prior to initiation of a painful stimulus, such as skin incision.

Related Terms: Multimodal Analgesia, Analgesia, Anesthesia, Systemic Analgesic

SC

Subcutaneous.

Sedation

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. Handling and Restraint
    1. To avoid excessive anxiety in the pre- and post- anesthetic periods, provide an environment devoid of extraneous noise, including loud talking.
    2. The amount of restraint and its duration should be kept to the minimum required to accomplish the necessary procedure.
    3. To reduce the time of restraint, equipment and reagents should be ready to use prior to handling the animal.
    4. Pre-anesthetic doses of sedative/tranquilizer agents are often used to facilitate immobilization and to reduce anxiety.
  2. Pre-anesthetic Fasting
    1. Withhold food for at least 8 hours but no longer than 24 hours prior to sedation or anesthesia in order to reduce the risk of regurgitation and aspiration.
      1. Fasting periods for greater than 24 hours related to specialized procedures (ie. gastrointestinal procedures) should be described in the protocol.
    2. Do not withhold water prior to anesthesia or sedation.
    3. For neonatal or unhealthy animals, special care is required. Consult a ULAM Faculty Veterinarian prior to fasting these animals​.
  3. Apply sterile non-medicated ophthalmic ointment to the eyes to prevent corneal drying during anesthesia or sedation.

2. Routes of Administration

  1. More detailed information regarding injection techniques and maximum quantities safely administered to dogs can be found in Guidelines on Administration of Substances to Laboratory Animals.

3. Normal Monitoring Parameters

  1. More information on anesthetic/sedation monitoring requirements can found in Anesthesia and Sedation Monitoring Guidelines.
  2. The goal of monitoring should be to maintain normal cardiac function, respiratory function, and body temperature, and an appropriate depth of anesthesia. Understanding the basic physiologic effects of the anesthetics used is paramount to correctly interpreting monitoring parameters. More information on anesthetic and sedative effects on physiologic parameters can be found in Anesthesia and Analgesia Drug Descriptions.
    1. Without anesthesia
      1. Temperature = 100 – 102.5 oF; 38 – 39 oC
      2. Heart Rate (beats/min) = 70-180
      3. Respiratory Rate (breaths/min) = 20-40 resting
    2. With anesthesia
      1. Temperature = >98 oF; >37 oC
      2. Heart Rate (beats/min) = 60-80
      3. Respiratory Rate (breaths/min) = 10-12
    3. Pulse: Strong and regular (a lingual-tongue artery can be palpated if necessary)
    4. Blood pressure: Systolic blood pressure >90 mm Hg and mean >70 mm Hg
    5. Capillary refill time: <2s
    6. Mucous membranes: pink not pale, white, or blue

4. Physiologic Support

  1. Hypothermia
    1. An external heat source should be provided during the entire anesthetic and recovery period. For examples of approved external heat supplementation products, please refer to the Anesthesia and Sedation Monitoring Guidelines.
  2. Fluids
    1. Providing fluid support during anesthesia is important particularly if a procedure lasts one-half hour or more. More information on appropriate fluid rates can be found in Guidelines on the Performance of Surgery in Non-Rodent Mammals.
  3. Vascular Access
    1. The placement of an indwelling catheter is advised. Cephalic, lateral saphenous, and jugular veins are readily accessible in dogs for intravenous administration of drugs and fluids.
  4. Endotracheal Intubation
    1. Dogs are easily intubated with the use of a laryngoscope.
    2. Endotracheal tube sizes for 25-kg dogs are between 7.5 and 9 mm OD; for a 50-kg dog, sizes range from 10 to 15 mm OD. It is important to have several sizes available and ready with appropriate ties when attempting intubation.
    3. Application of sterile surgical lubricant to the tip of the endotracheal tube will help facilitate intubation. Inflate the cuff just enough to stop gas leakage (approximately 20 cm H2O). Over-inflation of the endotracheal tube cuff can damage the trachea.

5. Recovery

  1. More information on required monitoring parameters during post-operative recovery can be found in Guidelines on the Performance of Surgery in Non-Rodent Mammals.
  2. Recover animals in clean kennels or transport cages.
    1. Ideally, animals will be recovered in the surgery area so they can be appropriately monitored throughout the post-operative period.
  3. If a large number of surgeries are being conducted at one time, animals may be housed together following anesthesia and prior to full recovery if they are continually observed. This is to ensure that more alert animals do not injure non-responsive cage mates.
  4. Nutritional support should be withheld until the animal is fully recovered and ambulating normally.

6. Sedation Protocols

  1. Detailed information on all approved anesthetics and sedatives can be found in Anesthesia and Analgesia Drug Descriptions.
  2. All premedicants and sedatives should be administered 15-20 minutes prior to restraint or induction. Duration of action for sedative-analgesic combinations for use in minor procedures is generally 15-60 minutes depending upon combination used.
  3. The following drug combinations are for use with minor procedures or as premedicants prior to anesthetic induction.
    1. For dose ranges listed as IV, IM, and SC, use lower end of the range for IV administration.
      Sedation +/- Analgesia Drug or Combination Dosage Route
      Mild to moderate sedation Acepromazine 0.02 – 0.5 mg/kg
      0.3 – 0.125 mg/kg      		 IV
      IM / SC
      Dexmedetomidine 2 – 10 µg/kg SQ / IM / IV
      Midazolam 0.2 – 0.4 mg/kg IM / IV
      Mild to moderate sedation
      Mild analgesia      		 Acepromazine + Butorphanol 0.005 – 0.05 mg/kg
      + 0.1 – 0.4 mg/kg      		  IV / SQ / IM
      Midazolam + Butorphanol 0.10 – 0.20 mg/kg
      + 0.1 – 0.40 mg/kg      		 IM / IV
      Mild to moderate sedation
      Moderate analgesia      		 Acepromazine + Buprenorphinea 0.02 – 0.05 mg/kg
      + 0.01 – 0.02 mg/kg      		 SQ / IM / IV
      Midazolam + Buprenorphinea 0.10 – 0.20 mg/kg
      + 0.01 – 0.02 mg/kg      		 SQ / IM / IV
      Moderate sedation
      Moderate to strong analgesia      		 Acepromazine + Hydromorphone or Morphine or Oxymorphone or Fentanyl 0.010 – 0.060 mg/kg
      + 0.10 – 0.20 mg/kg or
      0.50 – 1.0 mg/kg or
      0.05 – 0.10 mg/kg or
      0.005 – 0.010 mg/kg      		 SQ / IM / IV
      Midazolam + Hydromorphone or
      Morphine or
      Oxymorphone or
      Fentanyl      		 0.10 – 0.20 mg/kg
      + 0.10 – 0.20 mg/kg or
      0.50 – 1.0 mg/kg or
      0.05 – 0.10 mg/kg or
      0.005 – 0.010 mg/kg      		 IM / IV
      Dexmedetomidine + Buprenorphinea 2 – 10 µg/kg
      + 0.01 – 0.02 mg/kg      		 SQ / IM
      Profound sedation
      Strong analgesia      		 Dexmedetomidine  + Hydromorphone or
      Morphine or
      Oxymorphone or
      Fentanyl      		 2 – 10 µg/kg
      + 0.10 – 0.20 mg/kg or
      0.50 – 1.0 mg/kg or
      0.05 – 0.10 mg/kg or
      0.005 – 0.010 mg/kg      		 IM / IV
      Tiletamine + Zolazepam (Telazol®) 6 – 13 mg/kg SQ / IM

      aPre-emptive analgesia, particularly opioids 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.

  4. Anticholinergics are/may be used to treat and/or prevent anesthetic and preanesthetic bradycardia, decrease airway and salivary secretions, dilate the pupil, block vagally mediated reflexes, and block the effects of
    parasympathomimetic drugs.

    1. Atropine 0.02-0.04 mg/kg SC, IM, or IV
    2. Glycopyrrolate 0.01 – 0.02 mg/kg SC or IM

7. Anesthetic Protocols

  1. For dose ranges listed as IV, IM, and SC, use lower end of the range for IV administration.
  2. Anticholinergics
    1. Atropine 0.02-0.04 mg/kg SC, IM, or IV
    2. Glycopyrrolate 0.01 – 0.02 mg/kg SC or IM
  3. Injectable Anesthetic Induction Agents Used in Dogs
    Drug Dose and Route Notes
    Ketamine + Midazolam 5 mg/kg (K)
    + 0.28 mg/kg (M) IV or IM
    • May be mixed in same syringe.
    • Ketamine may sting with IM application.
    • For IV administration, administer midazolam first, then titrate ketamine to effect.
    • Average duration 10 – 20 minutes.
    Ketamine + Diazepam 5 mg/kg (K) IV or IM
    + 0.25 mg/kg (D) IV
    • Diazepam can only be given IV.
    • Ketamine can be given IM or IV (stinging may occur IM).
    • For IV administration, administer diazepam first, then titrate ketamine to effect.
    • Average duration 10 – 20 minutes.
    Ketamine
    + Dexmedetomidine
    + Opioid
    “Doggie Magic”    		 1 – 3 mg/kg (K)
    + 2 – 10 µg/kg (D)
    + an opioid such as
    butorphanol 0.1 – 0.2 mg/kg or
    buprenorphine 0.005 – 0.01 mg/kg or
    hydromorphone 0.05 – 0.2 mg/kg
    IV or IM
    • Provides anesthesia AND analgesia.
    • May be combined into same syringe.
    • Dexmedetomidine cannot be used in dogs < 2 kg.
    • Peak sedation 20 – 30 minutes after administration.
    Tiletamine + Zolazepam (Telazol®) 2 mg/kg IV or
    5 mg/kg IM
    • Good for fractious dogs, but rough recovery.
    • Average duration 10 – 30 minutes.
    Propofol 4 – 6 mg/kg IV in unmedicated animals

    1 – 4 mg/kg IV in premedicated/sedated animals
    • Deliver titrated volume over a couple of minutes as rapid administration will lead to apnea and hypotension.
    • Very rapid onset and recovery.
    • CRI may be used for anesthetic maintenance (see below).
    Alfaxalone 1 – 4 mg/kg IV
    • Deliver titrated volume over a couple of minutes as rapid administration will lead to apnea and cardiovascular depression.
    • Rapid onset and recovery.
  1. Anesthetic Maintenance Protocols
    1. Inhalation Agents
      Drug Dose Notes
      Isoflurane 4 – 5% induction
      1 – 2% maintenance
      • Requires use of calibrated vaporizer specific to isoflurane
      Sevoflurane 7 – 9% induction
      3 – 5% maintenance
      • Requires use of calibrated vaporizer specific to sevoflurane
  1. Total Intravenous Anesthesia (TIVA) Maintenance
    Drug Dose Notes
    Propofol CRI 0.5 – 0.4 mg/kg/min
    • Begin CRI after initial induction dose.
    Morphine
    + Lidocaine
    + Ketamine CRI    		 0.10 (M) mL/kg/h
    + 0.10 (L) mL/kg/h
    + 0.10 (K) mL/kg/h
    • Dilute 60 mg Morphine + 500 mg Lidocaine + 60 mg Ketamine in a 500 mL bag LRS.
    • Deliver @ 1 mL/kg/hr
    • Mixture is light sensitive.
    • Protect from light for prolonged use.
    • Initial loading doses as follows:
      • (M) 0.5 mg/kg IM or very slow IV
      • (L) 0.5 – 1.0 mg/kg IV
      • (K) 0.25 – 0.50 mg/kg IV

8. Neuromuscular Blocking Agents (NMBA)

  1. Extreme care must be taken to ensure that a proper level of anesthesia and analgesia is achieved prior to administering a neuromuscular blocking agent.
  2. Neuromuscular blocking agents require special monitoring procedures which are detailed in Anesthesia and Sedation Monitoring Guidelines.
    1. Concurrent positive pressure ventilation is required.
      Drug Dose and Route Duration of Effect Notes
      Atracurium besylate 0.10 – 0.40 mg/kg IV or
      0.2 – 0.5 mg/kg IV loading dose followed 5 min later by CRI of 3.0 – 9.0 µg/kg/min.      		 20 – 40 minutes
      • Do not dose more than every 20-30 minutes unless peripheral nerve stimulator is applied or signs of neuromuscular blocker recovery are observed.
      • Dilute in D5W or 0.9% NaCl.
      • Do NOT mix with other drugs.
      Vecuronium bromide 0.10 mg/kg IV or
      0.10 – 0.20 mg/kg/hr      		 25 minutes
      • Subsequent doses of 0.04 mg/kg IV may be administered.
      Pancuronium bromide 0.05 – 0.1 mg/kg IV 45 – 60 minutes
      • Duration is dose dependent.
      • Higher dose administered initially with lower doses repeated if needed.

9. Local Anesthetics

  1. Appropriate for minimally invasive procedures such as skin biopsy, or as a supplement to sedation, anesthesia, and analgesia.
    1. Local anesthetics are excellent analgesics for use in minor procedures or as “splash blocks” for post-operative incision pain.
      Drug Dose and Route Duration of Effect Notes
      Lidocaine 1 – 2% 2.0 – 4.0 mg/kg SQ infiltration or
      local nerve block      		 5 – 10 minutes to onset
      1 – 2 hours duration
      • Addition of 1ml of 8.4% sodium bicarbonate / 10ml lidocaine reduces discomfort of injection.
      • Potential for CNS toxicity manifesting as seizures.
      Bupivacaine 0.25 – 0.5% 1.0 – 2.0 mg/kg SQ infiltration or
      local nerve block      		 20 – 30 minutes to onset
      3 – 5 hours duration
      • Never give IV (Cardiotoxic if given IV)
      • DO NOT exceed maximum dose and ALWAYS aspirate prior to injection to guard against inadvertent IV administration.
      • Can be diluted with saline to increase volume
      Liposomal Bupivacaine 5.3 mg/kg
      Tissue infiltration      		 72 hours
      • Should not be allowed to come into contact with topical antiseptics.
      • May be administered diluted with up to an equal volume (1:1 by volume) of normal (0.9%) sterile saline or Lactated Ringer’s solution.
      • Do not mix with other local anesthetics or other drugs prior to administration.
      • Administer with a 25 gauge or larger bore needle.
      Combination Lidocaine 2% &

      Bupivacaine​ 0.5%

      		 1 mg each Quick onset of lidocaine with prolonged duration of bupivacaine​
      Addition of 1:200,000 epinephrine delays absorption and prolongs local anesthesia

10. Analgesics

  1. Canine signs of pain include but are not limited to the following:
    1. Reluctance to move
    2. Quiet
    3. Unalert
    4. Hunched appearance
    5. Abnormal posturing
    6. Increased respiration
    7. Unprovoked growling
    8. Decreased appetite
    9. Social isolation
    10. Abnormal aggression
    11. Guarding of painful area
    12. Lick / scratch painful area
    13. Restlessness
  2. Preferred opioid analgesics are buprenorphine, hydromorphone, or morphine.
    1. Buprenorphine and other narcotic agonists can be completely reversed with naloxone.
  3. The preferred non-steroidal anti-inflammatory (NSAID) is carprofen because it is generally well tolerated by the gastrointestinal tract, has good duration of effect, and does not appear to adversely affect platelet function.
  4. Opioids and NSAIDs can be combined for their additive or synergistic analgesic effects.
    Drug Dose and Route Duration of Effect Notes
    Opioids
    Buprenorphine (Buprenex®) 0.005 – 0.02 mg/kg
    IV, IM, SQ    		 6 – 8 hours
    • Good analgesic.
    Hydromorphone 0.05 – 0.2 mg/kg
    IV, IM, SQ    		 4 hours
    • Occasional vomiting and panting.
    • Good analgesic.
    Morphine 0.25 – 2.0 mg/kg
    IM, SQ    		 4 hours
    • Frequent vomiting and panting.
    • Doses exceeding 1 mg/kg may result in constipation.
    • Good analgesic.
    Oxymorphone 0.05 – 0.10 mg/kg
    IV, IM, SQ    		 3 – 4 hours
    • Less vomiting than with hydromorphone and morphine.
    Fentanyl Infusion 10 – 30 µg/kg/hr IV intra-op
    1 – 5 µg/kg/hr IV post-op
    2 – 3 µg/kg loading dose    		 CRI Bolus: 10 – 30 minutes
    • Decreased heart rate and respiratory depression during surgery.
    Fentanyl patch (Duragesic®) 50 µg/hour patch (10 – 20 kg) transdermally
    75 µg/hr patch (20 – 30 kg)    		 1 – 3 days
    • Requires up to 24 hours to take effect, avoid concurrent opioids.
    Tramadol
    • Not recommended due to poor bioavailability.
    NSAIDs
    Carprofen (Rimadyl®) 2.2 mg/kg PO (1.0 mg/lbs)
    4.4 mg/kg PO or SQ    		 12 hours
    24 hours
    • NSAID
    • Recommended for use with musculoskeletal pain.
    Ketoprofen 2 mg/kg SQ, IM, IV for the first day followed by 1mg/kg once daily 24 hours
    • Recommended not to exceed 3 days duration due to possible GI side effects.
    Meloxicam 0.2 mg/kg PO, IV or SC for the first day,
    followed by 0.1 mg/kg PO once daily    		 24 hours
    • Recommended not to exceed 7 days duration due to possible GI side effects.
    Deracoxib (Deramaxx®) 1 – 2 mg/kg PO for osteoarthritis pain
    3 – 4 mg/kg PO for post-operative pain    		 24 hours

References

  1. Flecknell, P. (2009) Laboratory Animal Anesthesia, Third Edition, Academic Press, Ltd., London.
  2. Plumb, DC. (2011) Veterinary Drug Handbook. PharmaVet Inc, Stockholm, Wisconsin.
  3. Thurmon, JC, Tranquilli, WJ, & Benson, GJ eds. (1996). In Lumb and Jones’ Veterinary Anesthesia, 3rd ed. Williams and Wilkins, Baltimore, Maryland.
  4. The Veterinary Anesthesia & Analgesia Support Group (www.vasg.org)
  5. Hawk et al. (2005) Formulary for Laboratory Animals. Blackwell Publishing, Ames, Iowa.
  6. Giuliano EA. Regional Anesthesia as an Adjunct to Lid Surgery (PT50). Western Veterinary Conference 2006.

SPECIES: Dogs

TOPICS: Anesthesia and Analgesia

Questions?

If you have questions or comments about this document, contact ULAM Veterinary Staff ([email protected]).

The ULAM Training Core ([email protected] 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 DPSS (3-1131) who will contact the on-call veterinarian.