Anesthesia for Laboratory Animals

Purpose: To fulfill the suggestion from the Guide for the Care and Use of Laboratory Animals: "Guidelines for the selection and proper use of analgesic and anesthetic drugs should be developed and periodically reviewed and updated as standards and techniques are refined." This policy provides the recommended dosages for anesthesia and analgesia for the commonly used species at University of Oregon. In general, an analgesic agent should always be administered after any type of surgical procedure unless there is a scientific justification for not doing so. That justification must have been approved in the animal care and use protocol by the IACUC after considering all classes of analgesic drugs. Additionally from the Guide: Agents that provide anesthesia and analgesia must be used before their expiration dates and should be acquired, stored, their use recorded, and disposed of legally and safely.

Scope: All AWS, TeACS and research personnel who work with laboratory animals.

Procedure: 

MOUSE

Anesthesia:

1. Isoflurane at 3-5% for induction, 1-2% maintenance

2. Ketamine / Xylazine / Acepromazine Cocktail:

  • In general, for mice the range for ketamine in combination with other drugs is 50-100 mg/kg, for xylazine 4-10 mg/kg and for acepromazine 1-5mg/kg. To use ketamine alone, 85-200 mg/kg, xylazine alone 4-12mg/kg and acepromazine alone 2-5mg/kg. Alone these agents may provide sedation but minimal analgesia.
drug Concentration dose volume in mix
Ketamine 100 mg/ml 65 mg/kg BW 1.0 ml              
Xylazine 20 mg/ml 13 mg/kg BW 1.0 ml              
Acepromazine 10 mg/ml 2.0 mg/kg BW 0.3 ml              
Sterile Water     7.7 ml              

Administer IP at a dose of:

Mouse body weight Volume cocktail

20 g                           0.13 ml

25 g                           0.16 ml

30 g                           0.20 ml

35 g                           0.23 ml

3. Ketamine / Xylazine Cocktail:

Drug concentration dose volume in mix
Ketamine 100 mg/ml 65 mg/kg BW 0.2 ml              
Xylazine 20 mg/ml 13 mg/kg BW 0.2 ml              
Sterile Water     0.6 ml              

Administer .1 ml/30 gm mouse IP

4. Ketamine / Medetomidine +/- Acepromazine

Administer Ketamine at a dose of 50-75mg/kg and Medetomidine at 0.5-1.0mg/kg, mixed in 1 syringe, given IP. May not produce surgical-plane anesthesia for major procedures. If redosing, use ketamine alone. May be partially reversed with Atipamezole. If combining with Acepromazine, dose Ace at 1-5 mg/kg.

5. Acepromazine / Fentanyl

Administer at a dose of 2-5 mg/kg Ace and 0.05-0.4 mg/kg fentanyl, mixed in 1 syringe given IP. May redose at ½ the induction dose if needed.

6. Ketamine / Midazolam

Administer Ketamine at a dose of 25-75 mg/kg and Midazolam at 1-10 mg/kg mixed in 1 syringe given IM, IV or IP. Reverse midazolam with equal volume (of midazolam alone) of flumazenil SC or IM at end of procedure.

Analgesia:

  1. Buprenorphine 0.05-0.2 mg/kg SC q 12 hr
  2. Buprenorphine SR 0.5-1.0mg/kg SC q 72 hours
  3. Meloxicam 0.2-0.5 mg/kg PO or SC SID perioperatively
  4. Meloxicam SR 4.0 mg/kg q 72 hours
  5. Carprofen 2-5 mg/kg PO or SC SID perioperatively.* 
  6. Ketoprofen 2-5mg/kg PO or SC SID perioperatively

* Higher doses of up to 10mg/kg SID of carprofen may be needed to control pain in mice. Use for no more than 3 days and be aware of increased risk of gastric ulceration.

Local Anesthesia:

       1. Lidocaine 2% - Dilute 1:4 for final concentration of .5 %. Do not exceed 7mg/kg total dose SQ or intraincisional 

       2. Bupivacaine 0.5% - Dilute 1:1 for final concentration of .25%. Do not exceed 4mg/kg total dose SQ or intraincisional

*WARNING:  Response of different strains, stocks, ages, or sex of mice to anesthetics can vary widely.  A dosage that will only lightly anesthetize one strain may kill another.  Dosages must be adjusted accordingly at the beginning of a project.  Consult with the Veterinary staff during this process.

 

RAT

Anesthesia*:

  1. Induce with Isoflurane at 2-4%, and maintain at 0.5-1.5% depending on procedure.
  2. Ketamine / Xylazine / Acepromazine cocktail:

In general, for rats the range for ketamine in combination with other drugs is 40-100 mg/kg,for xylazine 2-10 mg/kg and for acepromazine 0.4-2.5 mg/kg. To use ketamine alone, 50-100 mg/kg, xylazine alone 1-5 mg/kg, acepromazine alone 1.5-5 mg/kg. Alone these agents may provide sedation but minimal analgesia.

drug Concentration dose volume in mix
Ketamine 100 mg/ml 40.5 mg/kg BW 2.5 ml              
Xylazine 20 mg/ml 8.0 mg/kg BW 2.5 ml              
Acepromazine 10 mg/ml 0.4 mg/kg BW 0.25 ml              
Sterile Water     4.0 ml              

Administer 0.15 ml/100 g  IP

     3. Pregnant Rat - Ketamine / Xylazine Cocktail:

drug Concentration dose volume in mix
Ketamine 100 mg/ml 90 mg/kg 2.0 ml              
Xylazine 20 mg/ml 9 mg/kg 1.0 ml              

Administer 1.3 ml / kg BW IM

     4. Ketamine / Xylazine Cocktail:

drug Concentration dose volume in mix
Ketamine 100 mg/ml 75 mg/kg BW 0.75 ml              
Xylazine 20 mg/ml 5 mg/kg BW 0.25 ml              

Administer 1 ml/kg IM, IP

5. Ketamine / Medetomidine

Administer at a dose of 60-90 mg/kg of Ketamine and 0.5-1.0 mg/kg of Medetomidine, mixed in one syringe and given IP. May not produce surgical-plane anesthesia for major procedures. May be partially reversed with Atipamezole

            Analgesia:

  1. Buprenorphine 0.01-0.05 mg/kg SC q 8-12 hr
  2. Buprenorphine SR 1.0-1.2 mg/kg SC q 72 hours
  3. Meloxicam 0.2-2 mg/kg PO or SC SID perioperatively
  4. Meloxicam SR 4.0 mg/kg SC q 72 hours
  5. Carprofen 2-5mg/kg PO or SC SID perioperatively

*WARNING:  Response of different strains, stocks, ages, or sex of rat to anesthetics can vary widely.  A dosage, which will only lightly anesthetize one strain, may kill another.  Dosages must be adjusted accordingly at the beginning of a project.  Consult with the Veterinary staff during this process.

RABBIT

Anesthesia:

1. Ketamine / Xylazine

Administer Ketamine at a dose of 35-50 mg/kg and xylazine at 5-7 mg/kg, mixed in 1 syringe, given IM. Will not produce analgesia or a surgical-plane anesthesia for major procedures. If redosing, use ketamine alone. May be partially reversed with Atipamezole. 

2. Ketamine / Midazolam

Administer Ketamine at a dose of 15-25 mg/kg and midazolam at 2-3 mg/kg, mixed in one syringe IM. Reverse midazolam with equal volume (of midazolam alone) of flumazenil SC or IM at end of procedure.

3. Acepromazine 

Adminster 0.75-2.0 mg/kg IM 

These 3 protocols can be followed with administration of isoflurane if a deeper plane of anesthesia is required.

Analgesia:

1. Buprenorphine 0.01-0.05 mg/kg SC, IV q 6-12 hrs.

2. Carprofen 5mg/kg SC or PO q 24 hrs.

3. Meloxicam 0.3-0.6 mg/kg SC or PO q 24 hrs.

OWL

Anesthesia:

     1. Induce with Isoflurane at 4%, maintain at 1-1.5% at .8-1 L/min O2

     2. Ktamine / Diazepam Cocktail:

drug Concentration dose
Ketamine 100 mg/ml 10-30 mg/kg BW              
Diazepam 5 mg/ml 1-1.5mg/kb BW              

Administer IM in same syringe. Once anesthetized, intubate and maintain with Isoflurane at .5-1.5%.

Analgesia:

  1. Meloxicam 5mg/ml, 0.3mg/kg SC SID
  2. Ketoprofen 100mg/ml, 2mg/kg SC or IM SID or BID

 

NONSURVIVAL RODENT ANESTHESIA

  1. Avertin 250mg/kg IP
  2. Urethane 75-1000mg/kg IP
  3. Chlorprothixene 5mg/kg IP with Isoflurane

 

FISH - ZEBRA DANIOS, GAR, STICKLEBACK

Anesthesia:

1. MS-222 (TMS)

Prepare TMS Stock Solution (4.0g/L) (0.4%)

  •  Add 400 mg to 97.9 ml DD water in stock solution liquid container.
  •  Adjust pH to 7 by adding 2.1 ml 1 M Tris, pH 9.0.
  •  Test solution pH using calibrated meter.
  •  If solution is higher than 7.0 pH use HCl to adjust it.
  • If solution is lower than 7.0 pH use Tris, pH 9.0, to adjust it.

Prepare TMS Anesthetizing Bath (168 mg/L) (0.0168%)

  •  Add 4.2 ml TMS Stock Solution to 100 ml fish-safe water in fish-safe container.
  •  Increase volumes as needed for procedures but keep same solution concentration, e.g., 84.0 ml to 2000 ml.

Sedation:

  •  Add 1.25 ml TMS Stock Solution to 100 ml fish-safe water in fish-safe container.
  •  Increase volumes as needed for procedures but keep same solution concentration, e.g., 25.0 ml to 2000 ml.

For detailed instructions for performing fish anesthesia, see Anesthesia of Fish with MS-222 (TMS) SOP

2. Clove OIl (Eugenol)

The recommended dose to elicit stage 5 anesthesia in zebrafish is 60–100 ppm eugenol for 6–12 min. Levels of 2–5 ppm may be used safely to sedate zebrafish for extended periods (less than 8 h) to facilitate procedures such as transport. See Anesthesia of Fish with Clove Oil (Eugenol) SOP for details.

3. Hypothermia

Fish are immobilized for minor procedures by gradually lowering the water temperature to l2'C by adding ice chips. See Anesthesia of Fish with Hypothermia SOP

For all species, there may be additional anesthetic protocols that are appropriate for a particular species or experimental design. Other published protocols may be included or added to to an AUP after undergoing VCC. See references listed below.

Approvals: 

 

Approved by date
IACUC Committee June 2016, October 21, 2020              

Appendices: 

REFERENCES

  • Altman, B. (1997). Avian medicine and surgery. Philadelphia: W.B. Saunders.
  • Flecknell, P. (2015). Laboratory animal anesthesia, 4th Edition. San Diego: Academic Press Limited.
  • Fox, J. (2015). Laboratory animal medicine, 3rd Edition. San Diego: Academic Press limited.
  • Grush J, Noakes D, Moccia R. 2004. The Efficacy of Clove OIl as an Anesthetic for the Zebrafish, Danio rerio. Zebrafish. 1(1):46-53.
  • Johnson-Delaney, C. (1996). Exotic companion medicine handbook for veterinarians. Zoological Education Network.
  • McKelvey, D., & Hollingshead, K. (2003) Veterinary anesthesia and analgesia. St. Louis: Mosby.
  • Westerfield, M. (1993). The Zebrafish Book. Eugene: University of Oregon Press.

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