Veterinary Guidelines for Anesthetics: Mice
Anticholinergics
- Atropine, 0.02-0.05 mg/kg SQ, IM, IV (1)
Tranquilizers
- Acepromazine 1-5 mg/kg SC, IP (1)
- Diazepam 5 mg/kg IP (1)
Dissociative Anesthetics
- Ketamine 50-100 mg/kg sedation only IP, IV (2)
- Ketamine 80-100 mg/kg IP + Xylazine 16-20 mg/kg IP (3, 4)
- Ketamine 100 mg/kg + Xylazine 20 mg/kg + Acepromazine 3 mg/kg IP (4)
Barbiturates
- Pentobarbital 30-40 mg/kg sedation only IP (2)
- Pentobarbital 50-90 mg/kg IP narrow safety margin (2, 4)
Local Anesthetic *
- Lidocaine 17.5 mg/kg SQ, local infusion or topical application (5)
- Bupivicaine 38 mg/kg SQ, local infusion or topical application (6)
- Convulsions induced by the administration of local anesthetic occur at the following concentrations: Bupivacaine >55 mg/kg, Lidocaine >110 mg/kg (7)
Inhalent Anesthetic
- Isoflurane 1-4% (2)
Other
- Tribromoethanol (Avertin) 125-250 mg/kg IP (2)
- Not a pharmaceutical-grade drug, and therefore must be aseptically prepared, and properly stored. Improperly prepared or improperly stored solutions or even frequent use may result in peritonitis, hepatotoxicity, or ileus. (8)
Analgesics
- Buprenorphine1 0.05-0.1 mg/kg SQ q 6-12 hrs (9)
- Butorphanol 2-5 mg/kg SQ q 4 hr
- Morphine, 5-10 mg/kg SQ q 4 hr
- Carprofen2 2.5-5 mg/kg SQ q 24 hr
- Ketoprofen 5 mg/kg SC q 12-24 hr
- Flunixin3 2.5 mg/kg SQ q 12-24 hr
1 Buprenorphine is a controlled substance (narcotic) with agonist/antagonist activity primarily at the µ opiate receptor. This drug may cause mild anorexia and slight hyperactivity in rodents. Due to delayed onset of action, buprenorphine should be administered at least 20 minutes prior to the completion of a surgical procedure. To prepare a dilution for smaller rodents, one 1 ml vial of Buprenex (0.3 mg/ml) is drawn into a sterile syringe and added to 19 ml of sterile 5% dextrose in water or 0.9% NaC1 and dispensed into a sterile vial (e.g. a sterile serum tube). Label the tube Buprenorphine HCl 0.015 mg/ml solution and the date prepared. Expiration date is either that from the original package, or 6 months from the date prepared. The solution must be protected from light. Administer 0.06-0.13 ml subcutaneously to an average 20 gram mouse.
2 Carprofen is a nonsteridal anti-inflammatory (NSAID) and analgesic drug with minimal risk for toxicity in animals. Oral administration may be by gavage or in Jello-O. Animals must be fed Jell-O for several days before procedure to acclimate them to the food. To prepare, mix Jell-O according to the package directions to make Jigglers. From the chart below, add an amount of carprofen to the corresponding volume of water, pour into ice cube trays for cooling with the corresponding volume per cube. Give ¼ cube to each animal.
| Species | Drug | Drug amount | Volume water | Cube volume |
| Mouse | Carprofen (Rimadyl) | 25 mg tablet | 100 ml | 1 ml |
| Rat | Carprofen (Rimadyl) | 25 mg tablet | 24 ml | 4 ml |
3 Flunixin meglumine (Banamine) is a nonsteroidal anti-inflammatory (NSAID), antipyretic, and potent analgesic drug, but has potential for GI ulceration, hepato- and nephrotoxicity in animals.
Example of potentially painful procedures
| Minimal to Mild Pain | Mild to Moderate Pain | Moderate to Severe Pain |
Catheter implantation |
Minor laparotomy incision |
Major laparotomy/organ incision |
Drug selection for alleviating pain in rodents
| Minimal to Mild Pain | Mild to Moderate Pain | Moderate to Severe Pain4 |
| Local anesthesia Lidocaine/Bupivacaine |
Lidocaine/Bupivacaine (adjunct to systemic analgesic) |
Lidocaine/Bupivacaine (adjunct to systemic analgesic) |
| Butorphanol 5 mg/kg SQ |
Buprenorphine 0.05-0.1 mg/kg SQ, q 6-12 hrs |
Buprenorphine 0.05-0.1 mg/kg SQ, q 6-12 hrs |
| Carporfen 2.5-5 mg/kg SQ |
Carprofen 5 mg/kg SQ, q 24 hr |
Carprofen 1-5 mg/kg SQ, q 24 hr |
| Buprenorphine 0.05-0.1 mg/kg SQ |
Morphine 10 mg/kg SQ, q 2-4 hr |
4 Severe pain may be better alleviated by the combination of NSAID and opioid drugs. This multimodal approach allows for action at different points on the pain pathways, and will allow for a lower dosage of both drugs to be given.
References
- Hawk CT, et. al. Formulary for Laboratory Animals 3rd Edition. Blackwell Publishing, Ames, Iowa. 2005
- Wixson SK and Smiler KL. Anesthesia and analgesia in rodents. In: Anesthesia and Analgesia in Laboratory Animals, Kohn DF et. al.Eds. Academic Press, New York. NY. pp. 165-200. 1997
- Green CJ, et al. Ketamine alone and combined with diazepam or xylazine in laboratory animals: a ten year experience. Laboratory Animals, 15:163-170, 1981.
- Arras M, et. al. Optimization of Intraperitoneal Injection Anesthesia in Mice: Drugs, Dosages, Adverse Effects, and Anesthesia Depth. Comp Med 51(5):443-456. 2001
- Grant GJ, et. al. Assessing Local Anesthetic Effect Using the Mouse Tail Flick Test. J. Pharmacol Toxicol Methods 29(4):223-226. 1993
- Grant GJ, et. al. Analgesic Duration and Kinetics of Liposomal Bupivacaine after Subcuteneous Injection in Mice. Clin Exp Pharmacol Physiol 30(12):966-968. 2003
- de Jong RH and Bonin JD. Deaths from Local Anesthetic-Induced Convulsions in Mice. Anesth Analg 59(6):401-405. 1980
- Meyer RE and Fish RE. A Review of Tribromoethanol Anesthesia for Production of Genetically Engineered Mice and Rats. Lab Anim 34(10):47-52. 2000
- Gades NM, Danneman PJ, Wixson SK, and Tolley EA.The Magnitude and Duration of the Analgesic Effect of Morphine, Butorphanol, and Buprenorphine in Rats and Mice. Contemp Topics 39(2):8-13. 2000
