Rat Anesthesia/Analgesia

Rat Anesthetics and Analgesicspdf format, Adobe Acrobat Required

Note that all of these doses are approximations and must be titrated to the animal’s strain, age, sex and individual responses. Significant departures from these doses should be discussed with a veterinarian. Doses will also vary depending on what other drugs are being administered concurrently.

All doses are listed as milligrams per kilogram (mg/kg) unless otherwise noted. Dilution of injected drugs allows more precise dosing, but may shorten the shelf-life of the compound (diluted drugs should be labeled, then discarded after 1 month) source UCSF

Inhalation Anesthetics

Drug Name Dose (mg/kg) & Route Frequency Notes

Recommended:
Isoflurane

1-3% inhalant to effect (up to 5% for induction).

Whenever general anesthesia is required

Survival surgery should have concurrent preemptive analgesia.
Use precision vaporizer


Ketamine Combinations

Drug Name

 Dose (mg/kg) & Route Frequency Notes

Ketamine-Medetomidine

75-100 + ~0.5-1 IP (in same syringe)

As needed

May not produce surgical-plane anesthesia for major procedures. If redosing, use ketamine alone. May be partially reversed with Atipamezole


Ketamine-Xylazine

75-100 Ket + 5-10 IP (in same syringe)

As needed

May not produce surgical-plane anesthesia for major procedures, though more reliable than in mice. If redosing, use ketamine alone. May be partially reversed with Atipamezole or Yohimbine

Ketamine-Xylazine-Acepromazine

75 - 100 + 2 - 6 + 1 – 2IP (in same syringe)

As needed

May not produce surgical-plane anesthesia for major procedures. If redosing, use ketamine alone. May be partially reversed with Atipamezole or Yohimbine

Ketamine-Midazolam

75-100 + 4-5 IP (in same syringe)

As needed

May not produce surgical-plane anesthesia for major procedures, but may be useful for restraint.


Reversal Agents
Drug Name Dose (mg/kg) & Route Frequency Notes

Atipamezole

0.1 - 1.0 subcutaneous or IP

Any time medetomidine or xylazine has been used

More specific for medetomidine than for xylazine (as a general rule, Atipamezole is dosed at the same volume as Medetomidine, though they are manufactured at different concentrations)

Yohimbine

1.0 – 2.0 SC or IP

For reversal of xylazine effects

 


Other Injectable Anesthetics
Drug Name Dose (mg/kg) & Route Frequency Notes

Sodium pentobarbital (Nembutal)

40 – 50 IP

Recommended for terminal/acute procedures only, with booster doses as needed. May occasionally be appropriate for survival procedures

Consider supplemental analgesia (opioid or NSAID) for invasive procedures, especially when used on a survival basis.


Opioid analgesia
Drug Name Dose (mg/kg) & Route Frequency Notes

Recommended:
Buprenorphine

0.01 - 0.05 SC or IP

Used pre-operatively for preemptive analgesia and post-operatively every 6-12 hour

For major procedures, require more frequent dosing than 12 hour intervals. Consider multi-modal analgesia with a NSAID. High doses of buprenorphine may lead to pica behavior in rats.


Non-steroidal anti-inflammatory analgesia (NSAID)

Note that prolonged use my cause renal, gastrointestinal, or other problems

Drug Name Dose (mg/kg) & Route Frequency Notes

Recommended:
Carprofen

4-5 SC

Used pre-operatively for preemptive analgesia and post-operatively every 12-24 hour

Depending on the procedure, may be used as sole analgesic, or as multi-modal analgesia with buprenorphine.

Recommended:
Meloxicam

~ 0.2 PO , IM or SC

Used pre-operatively for preemptive analgesia and post-operatively every 12-24 hour

Depending on the procedure, may be used as sole analgesic, or as multi-modal analgesia with buprenorphine.

Recommended:
Ketoprofen

2 – 5 SC

Used pre-operatively for preemptive analgesia and post-operatively every 12-24 hour

Depending on the procedure, may be used as sole analgesic, or as multi-modal analgesia with buprenorphine.

Flunixin meglumine

~ 2 SC

Used pre-operatively for preemptive analgesia and post-operatively every 12-24 hour

Depending on the procedure, may be used as sole analgesic, or as multi-modal analgesia with buprenorphine.


Local Anesthetic/Analgesics

(Lidocaine and Bupivicaine may be combined in one syringe for rapid onset and long duration analgesia)

Drug Name Dose (mg/kg) & Route Frequency Notes

Lidocaine hydrochloride

Dilute to 0.5%, do not exceed 7 mg/kg total dose, SC or intra-incisional

Use locally before making surgical incision

Faster onset than bupivicaine but short (<1 hour) duration of action

Bupivicaine

Dilute to 0.25%, do not exceed 8 mg/kg total dose, SC or intra-incisional

Use locally before making surgical incision

Slower onset than lidocaine but longer (~ 4-8 hour) duration of action

Updated April 1, 2008 by SAK