anesthetic 1
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December 21, 2010 Page 1
Common Anesthetic and Analgesic Agents1
We strongly recommend the use of pre-emptive analgesia for surgical and/or painful procedures unless
contraindicated. The information provided below is a starting point. Always seek veterinary advice when
developing anesthesia and analgesia for your studies or teaching protocols.
Check out the Virtual Anesthesia Machine at http://vam.anest.ufl.edu/.
Additional information is available from http://web.research.colostate.edu/LAR/anesthesia/appaa.aspx.
Amphibians
It is the recommendation that frogs be fasted for one day prior to anesthesia to prevent regurgitation.
Xenopus should be handled with soft nets for procedures performed without anesthesia. The use of
chemical restraint is required for prolonged or invasive procedures. A light plane of anesthesia is
characterized by a loss of righting reflexes, but withdrawal reflexes and gular (throat) respiratory efforts
remain. As the anesthetic level deepens, abdominal respiration is lost, followed by slowing of gular
(throat) movements, which stop as a surgical level is reached. The cardiac impulse (visible heartbeat)
should be retained, slowing or loss of cardiac impulse indicates an anesthetic overdose. Keep skin moist
during recovery; dechlorinated water with a pH of 6.5-8.5 is recommended.
AGENT DOSAGE COMMENTS
Tricaine methosulfonate
MS-222
Immersion bath dosages:
Tadpoles/newts: 200-500mg/L
Frogs/salamanders: 500mg/L to 2g/L
Toads: 1-3g/L
Injection dosage:
50-150 mg/kg IM, SC, IM
Anesthetic of choice, for Xenopus.
Concentrations over 500mg/L should be
buffered with NaHCO3; unbuffered
solutions have a prolonged induction
time and are irritating to the animal.
Induction: 5 min and recovery at 1-30
min.
Disadvantage of injecting MS-222 is
that solutions for injection require
filtration to ensure that it is sterile.
Benzocaine 50 mg/L; Larvae
200-300 mg/L; Frogs, salamanders
Dissolve with ethanol first
Ketamine
50-150 mg/kg SC, IM
Can be used for minor procedures e.g.
radiography.
Disadvantage: Animals anesthetized
with these drugs even at high doses
remain sensitive to pain. The surgical
use of these drugs is therefore limited to
preanesthetic use.
Tiletamine/zolazepam
(Telazol)
10-20 mg/kg SC, IM, IC Variable results, rapid recovery
1 Modified from a compilation by Dr. Sylvia Sigletary (2004).
Isoflurane 1-5%
Topical application: 0.03 to 0.06ml/g
applied to an absorbent pad with an
impermeable back.
Bubble into water to effect*.
Terrestrial animals - induction chamber
Pentobarbital 40-50 mg/kg; inject into dorsal lymph
sac, IC
Variable response may be best suited for
euthanasia
ANALGESIA
Buprenorphine 38 mg/kg SC Duration > 4h
Butorphanol 0.2-0.4 mg/kg IM Duration 12h **
Flunixin meglumine 25mg/kg intracelomic 4h **
Xylazine 10mg/kg intracelomic 12-24h**
* Smith. J. M. 2000. Isoflurane Anesthesia in the African Clawed frog (Xenopus laevis). Contemp. Topics 39 (6): 39-42.
**Terril-Robb, L. 1996.Evaluation of the Analgesic Effect of Butorphanol Tartrate, Xylazine Hydrochloride, and Flunixin Meglumine in Leopard Frogs (Rana pipiens). Contemp. Topics 35 (3): 54-56.
Cat Cats can vomit during induction and recovery. They need to be fasted for 6-8h before anesthesia and
observed carefully during recovery. They can have free access to water. Cats are prone to laryngospasm
during endotracheal intubation; a lidocaine spray is commonly used in practice to help prevent spasms. In
uncomplicated or short procedures gas anesthesia can be maintained with a correctly fitted nose cone.
“Masking down” is also used as an induction technique with animals that are properly sedated.
However, there is an increased risk, to the operator, from anesthetic gas exposure. Animals less than 7kg
should be placed on a nonrebreathing system when gas anesthesia is being administered.
AGENT DOSAGE COMMENTS
Atropine 0.02-0.04 mg/kg IM, SC Anticholinergic. Duration of effect 30-60
min.
Glycopyrrolate 0.02 mg/kg IM, SC Anticholinergic. Duration of effect is 1-2
h. Some cats can have dry mouth after 2 h
on glycopyrrolate.
Acepromazine 0.05-0.1 mg/kg SC, IM Hypotension and prolonged recovery, but
very commonly used for calming
fractious animals for placement of IV
catheters and minor procedures.
Xylazine 0.4-0.9 mg/kg IM α2-adrenergic agonist. IV administration
can lead to hypotensive crisis. Reduces
cardiac output even when anticholinergics
are given. Reported to cause vomiting
Diazepam 0.2-0.4 mg/kg (max dose is 10
mg) IV
Duration of effect 30-180 min. More
rapid recovery the ace and xylazine, less
hypotension
Acepromazine + Oxymorphone 0.05mg/kg of each, IM A good sedative analgesia combination.
Anticholinergics are recommended to
prevent bradycardia.
December 21, 2010 Page 3
Ketamine + Xylazine 22 mg/kg + 1.1 mg/kg IM Duration of effect 20-30 min. Allows
enough muscle relaxation for intubation.
Poor recovery and hyperthermia.
Ketamine + Diazepam 10 mg/kg + 0.5mg/kg IV
Give ⅓ calculated dose as a
bolus with rest to effect.
Duration of effect is 20 min. Allows
enough muscle relaxation for intubation;
premedicate with anticholinergic.
K+Midazolam
Ketamine + Acepromazine 20 mg/kg + 0.11 mg/kg IM Duration of effect is 20-30 min.
Dexmedetomidine Reversible
Pentobarbital 20-30 mg/kg IV Duration of effect is 60-90 min. Repeated
doses of thiopental or pentobarbital will
greatly prolong the recovery from
anesthesia. Narrow margin of safety, poor
analgesic properties, long and sometimes
violent recovery periods. Recommended
for nonsurvival procedures.
Isoflurane 1-3% to effect Scavenge waste anesthetic gases.
Analgesics
Buprenorphine 0.01-0.02 mg/kg IM SC 6-8h, moderate pain relief, ceiling effect
Butorphanol 0.1-0.5 mg/kg Up to 4h, sedation last longer than
analgesia, moderate pain relief, ceiling
effect
Oxymorphone 0.02-0.05 mg/kg IV, IM, SC Duration 4h, minimal respiratory
depression and excellent analgesia
Morphine 0.25-0.5 mg/kg IM, SC Duration 4h, dosages over 0.5mg/kg can
cause excitement
Tramadol 1-5 mg/kg PO
Meloxicam 0.01 mg/kg Start at 0.01 mg/kg and decrease dose and
frequency over time
Carprofen 4 mg/kg IV, SC
Ketoprofen 1-2 mg/kg IM, IV, SC, PO q24h
Chicken and other Avian Species
The following issues should be considered when anesthetizing avian species. The use of supplemental
heat should always be used to protect against hypothermia. Other techniques which can protect against
hypothermia are minimizing feather plucking, circulating warm water blankets, warm water bottles, heat
lamps, heated lavage solutions, and heated IV fluids. Indwelling intravenous catheters are difficult to
maintain because avian vessels are very delicate; however, peri-anesthetically, these catheters are usually
suitable. For long term (up to 3 days) vascular access, intraosseous (IO) catheters, placed in the ulna or
tibiotarsus, are recommended. Supplemental oxygen via a facemask is recommended when injectable
anesthesia is used. Pre-anesthetic agents such as anticholinergic drugs, opioids, and benzodiazepines are
routinely used in avian patients as indicated by the procedures to be performed. Birds should be fasted 2-4
h to insure the crop is empty at the time of anesthesia. Prior to anesthesia the crop should be gently
palpated to sure it is empty. If the crop still contains food after a 4 hour fast, it is generally a sign of ill
health, and veterinary assistance should be sought. The crop can be manually emptied using a crop gavage
tube. Birds should be positioned with their head and neck slightly elevated during anesthesia. Isoflurane
or servoflurane are the anesthetic agents of choice in birds. Inhalation anesthetics can be administered
through a facemask placed over the head, air sac breathing tube, or by an oral endotracheal tube. When
using gas anesthesia, birds under 8 kg should be place on a nonrebreathing system.
AGENT DOSAGE COMMENTS
Ketamine + Diazepam 75mg/kg IM + 1mg/kg IV
5-30 mg/kg IM + 0.5-2 mg/kg IM,
IV
Chicken, give diazepam 10 min
after ketamine, pain reflexes
intact, lasts 90-100 min.
Most species
Ketamine + Midazolam 10-40 mg/kg + 0.2-2 mg/kg SC,
IM
Most species
Atropine 0.02-0.04 mg/kg IM, SC Most species
Midazolam ).2-0.5 mg/kg IM, Sc Most species
Isoflurane 3-5% induction, 1.5-2.5%
maintenance
Most species
Analgesics
Butorphanol 1-4 mg/kg IM, SC
not to exceed q4hr
κ-opioid receptor agonism has
been shown to be more
important for establishment of
antinociception.
Carprofen 1 mg/Kg SC
5-10 mg/kg IM, IV, PO
This dose was shown to increase
the walking ability of lame
chickens#
Joint working group, 2001§
Meloxicam 0.5 mg/kg SC, PO q12h Based on PK data in Indian
Ring-necked parakeets, and has
been extrapolated clinically to
multiple other species
Tramadol 5 mg/kg PO q12h Based on PK data in Bald Eagles
#The Veterinary Clinics of North America, Heard Darrly, Volume 4, Number 1, January 2001 W.B. Saunders § Joint Working Group on Refinements. Laboratory birds: refinement in husbandry and procedures. Lab. Anim. 35(Suppl. 1), 2001.
December 21, 2010 Page 5
Dog
In survival surgical patients, baseline data can identify any preexisting physical or physiological
abnormalities. The review of pre-surgical blood work and performing a physical examination are
common methods used to evaluate surgical patients. It is recommended that complete blood count,
parasite examination and chemical evaluation of both kidney and liver function be included in the pre-
surgical work-up.
Intramuscular injections are commonly delivered to the caudal thigh muscles. However, IM injection in
this location can cause deposition of the agent in the fascial plane. This can result in both decreased
absorption and possible damage to the sciatic nerve. Drugs administered in either the cranial thigh or
lumbar muscles are better absorbed and preferred locations for IM injections. However, if the caudal
thigh muscle is used, direct the needle backwards.
AGENT DOSAGE COMMENTS
Atropine 0.02-0.04 mg/kg IM, SC Anticholinergic. Duration of effect 30-
60 min
Glycopyrrolate 0.02 mg/kg IM, SC Anticholinergic. Duration of effect is
60-120 min
Acepromazine 0.01-0.05 mg/kg, IV,
0.05-0.1 mg/kg IM, SC
Hypotension and prolonged recovery,
but very commonly used for placement
of IV and minor procedures in fractious
animals.
Xylazine 0.5-2.0 mg/kg IM Duration 30-60 min α2-adrenergic
agonist with short lived analgesic
properties. IV administration can lead to
hypotensive crisis. Reduces cardiac
output even when anticholinergics are
given has been reported to cause
vomiting
Sedative Combination:
Acepromazine
Oxymorphone
0.05mg/kg of each, IM A good sedative analgesia combination.
Anticholinergics are recommended to
prevent bradycardia.
Propofol 0.3-0.5 mg/kg/min
Recommended combination for
animals with compromised
cardiovascular function:
Propofol 1-2 mg/kg IV +
Slow bolus fentanyl 7-10μg/kg
and atropine 0.005-0.01mg/kg
IV
Propofol is a sedative/hypnotic. It can be
used in induction or maintenance of
general anesthesia. An opioid or α2-
agonists must be added for surgery,
because of its poor analgesic properties.
There are rapid induction and recovery
times Some of the adverse effects are
apnea, bradycardia and hypotension.
Ketamine + Diazepam 10 mg/kg + 0.2-0.4 mg/kg IV.
Give ⅓ as bolus then titrate to
effect
Duration 20 min used for short periods
of restraint or minor procedures or for
intubation
Telazol 1-3 mg/kg IM, IV For tracheal intubation. For large dogs
use lower end of the recommended dose.
Tachycardia and hypertension are
common. Premedicate with
acepromazine, opioid or xylazine
provides a smoother recovery.
Pentobarbital 20-30 mg/kg IV
Isoflurane 1-3% to effect Scavenge waste anesthetic gases.
Analgesics
Buprenorphine 0.01-0.02 mg/kg IM, SC q6-8h Flecknell (1985)
Butorphanol 0.1-0.5 IM, IV q2-4h
Carprofen 2.2-4.0 mg/kg PO, IV, SC for a
max of 3 d or 1 mg/Kg for 5 d
Meloxicam 0.2 mg/kg PO
Ketoprofen 5 mg/kg IM Potent COX inhibitor, preoperative
administration inhibited platelet
aggregation (Lemke, 2002). Use caution
when given pre-operatively, supportive
fluid therapy is recommended.
Fentanyl 50µg/h transdermal patch
Fentanyl has a very short duration of
action (30-45 min.). Therefore, it is most
effectively used as a continuous drip
either intraoperatively and/or post-
operatively
Tramadol 2-3 mg/kg PO q6-12h
Flecknell (1985). The management of post-operative pain and distress in experimental animals. Anim. Tech. 36(2): 97-103. Mathew N (ed) (1999) The Veterinary Clinics of North America Small Animal Practice, Volume 29, number 3. W.B. Saunders.
Lemke, KA, Runyon CL, Horney BS (2002) Effect of perioperative administration of ketoprofen on whole blood platelet aggregation, buccal
mucosal bleeding time, and hematologic indices in dogs undergoing elective ovarhysterectomy. J Am Vet Med Assoc 220(12): 1818-1822
Ferret
Small mammals can develop hypoglycemia if fasted. However, the possibility of vomiting and aspiration
does exist whenever ferrets are anesthetized. Thus, fasting for a minimum of 4h not to exceed 8h is
recommended. In animals over 3 years of age fasting should not exceed four hours. In addition, water
should be withheld for 2h prior to anesthetic procedures. Ferrets respond well to gas anesthesia, but a
decrease by up to 40% of the packed cell volume should be expected when ferrets are exposed to
Isoflurane, halothane, or servoflurane. As with the cat a properly fitted nose cone can be used to
administer gas anesthesia. Furthermore, an induction chamber can be used but some animals may
become excitable during this procedure. The ferret is easily intubated; recommended endotracheal tube
size ranges from 2.5-3.5mm. The topical application of 0.05 ml of a 2% lidocaine solution will prevent
larygospasm. A nonrebreathing anesthesia circuit is recommended for ferrets. Body temperature is
rapidly lost in small mammals, which results in prolonged recovery and bradycardia. Thus, the use of
recirculation hot water blankets, rectal core temperature monitoring and heated recovery areas is
recommended.
AGENT DOSAGE COMMENTS
December 21, 2010 Page 7
Atropine
Glycopyrrolate
0.04-0.05 mg/kg IM, SC
0.01mg/kg IM, SC
Anticholinergic. Recommended to
control salivation associated with
ketamine, tiletamine-zolazepam,
administration or gas induction.
Acepromazine 0.1-0.25 mg/kg IM,SC Light to moderate sedation, no
analgesia, not recommended for
debilitated animals.
Xylazine
*REVERSAL AGENT:
Yohimbine (0.2 mg/kg IV; 0.5
mg/kg IM)
1.0 mg/kg IM,SC Profound sedation, good muscle
relaxation, analgesia, bradycardia,
arrhythmias and hypotension. Not
recommended for debilitated animals.
Diazepam 1.0-2.0 mg/kg, IM
0.5 mg/kg PO, IM, IV q6-8h
Light tranquilization no analgesia
Smooth muscle relaxation
Midazolam 0.3-1.0 mg/kg, IM, SC Light tranquilization no analgesia
Butorphanol 0.1-0.5 mg/kg IM, IV Provides analgesia, improves recovery
in tiletamine-zolazepam/xylazine
combinations
Ketamine 20-30 mg/kg IM When used alone muscle relaxation is
poor analgesia brief and salivation is
excessive. Recovering animals may
paddle Recommended for restraint
only.
Ketamine + Xylazine 10-25 mg/kg + 1-2mg/kg IM, SC Light anesthesia for noninvasive
procedures, good analgesia, cardiac
arrhythmias, bradycardia,
hypertension. Animals become quite
hypoxic
Ketamine + Diazepam 10-20 mg/kg + 1-2 mg/kg IM,
SC
Recommended for sedation only, poor
analgesia, cardiac arrhythmias,
paddling and sneezing on recovery,
not suitable for surgical procedures,
animal must be supported during the
recovery period.
Tiletamine-zolazepam 12-22mg/kg IM At lower dosage good for sedation
only, but respiration is abnormally
shallow and rapid. At higher dosage
sedation, muscle relaxation, variable
analgesia, long recovery time,
paddling, and apnuestic breathing.
Isoflurane 1-5% Scavenge waste anesthetic gases.
Analgesics
Buprenorphine 0.01-0.05 mg/kg SC, IM, IV,
TM (transmucosal) q8-12h
Butorphanol 0.05-0.5 mg/kg SC, IM q2-4h May cause significant sedation
Oxymorphone 0.05-0.2 mg/kg q4h SC, IM, IV
q2-4h
Some sedation and respiratory
depression
Hydromorphone 0.05-0.2 mg/kg SC, IM, IV q8h Minimal respiratory suppression
Morphine 0.5-1 mg/kg SC, IM Sedation and respiratory suppression
Flunixin meglumine 0.5-2.0 mg/kg SC, IV q12-24h
0.3 mg/kg PO, SC q24h
Can be given PO, but must mask the
bitter taste with syrup
Ketoprofen 1 mg/kg SC PO, SC, IM q24h Use with caution until long term safety
studies are available
Meloxicam 0.2 mg/kg SC, IM q24h Use with caution until long term safety
studies are available
Caprofen 1.0 mg/kg PO q12-24h Use with caution until long term safety
studies are available
Tramadol 5 mg/kg PO q12h Empirical usage, data lacking other
than clinical efficacy
* reversal agents also reverse the analgesia of the α2 agonists.
Fish
Immersion is the preferred method of anesthesia. It is recommended that two separate tanks of water be
used one for induction and the other for recovery. In addition, animals should be fasted for 24h prior to
anesthesia, maintained in a clam state until induced. Fish should be handed with wet gloved hands. The
loss of the equilibrium indicates attainment of the first stages of anesthesia. Surgical anesthesia is attained
when there is no response to stimuli and respirator rate is very slow. Gill movements should be
maintained through anesthesia. Fish that stop spontaneous gill movement should be placed in a recovery
bath pushed though the water to oxygenate the gills.
AGENT DOSAGE COMMENTS
Tricaine methane sulfonate (MS
222)
15-50 mg/L water
50-100mg/L bath (induction);
50-60 mg/L maintenance
Sedation
Surgical anesthesia
This agent is acidic and must be
buffered
Benzocaine 15-40 mg/L bath
50-100 mg/L
Transport sedation
Anesthesia
Less water soluble than tricaine
Isoflurane 0.4-0.75 ml/L induction
0.25-0.4 ml/L maintenance
Isoflurane is distributed by spraying it
under surface of the water with a 25
gauge needle. Disadvantage: difficult
to scavenge waste gases
Butorphanol 0.05-0.1 mg/kg IM
0.4 mg/kg IM in koi
Heard D (ed) The Veterinary Clinics of North America Exotic Animal Practice. Volume 4, number 1. W.B. Saunders
Gerbil
AGENT DOSAGE COMMENTS
Atropine 0.1-0.4 mg/kg SC, IM
Diazepam 3-5mg/kg IM Sedation
Ketamine 40-60 mg/kg IM Light sedation, heavy sedation at higher
doses. Marked individual variation
December 21, 2010 Page 9
Ketamine + Diazepam 50 mg/kg IM + 5 mg/kg IP
Ketamine + Medetomidine 75 mg/kg + 0.5 mg/kg IP
Ketamine + Xylazine 50 mg/kg + 2 mg/kg IP
Tiletamine/Zolazepam (Telazol)
+ Ketamine
20 mg/kg + 10 mg/kg IP
Medetomidine 0.1-0.2 mg/kg SC Light to moderate sedation
Atipamazole Medetomidine reversal
Yohimbine 0.5-1 mg/kg IV Xylazine reversal
Pentobarbital 50-90 mg/kg IP Respiratory depression and mortality
Isoflurane 2-5% induction, 0.25-4%
maintenance
Anesthetic of choice. Scavenge waste
anesthetic gases.
Analgesics
Flunixin 2.5 mg/kg IM SC q12-24 h
Buprenorphine 0.01-0.05 mg/kg SC, IV q8-12h
0.1-0.2 mg/kg SC q8h
Oxymorphone 0.2-0.5 mg/kg IM q6-12h
Carprofen 5 mg/kg SC q24h
Goat/Sheep
Fasting for 32-48h can reduce rumen volume, however, most anesthetized ruminants will require a
stomach tube to be placed to prevent bloating and to protect the airway from regurgitated rumen contents.
Atropine is usually not given to ruminants because it does not reduce the volume of saliva produced.
Ventilation is easily impaired due to both bloating and the mass of the abdominal viscera. The use of
intermittent positive pressure ventilation should be considered. During inhalation anesthesia the palpebral
reflex is depressed but not lost. The eyeball is rotated medioventrally when the patient is in a light plane
of anesthesia and center during anesthesia. A dilated pupil is a sign of anesthetic overdose.
AGENT DOSAGE COMMENTS
Acepromazine 0.02-0.05 mg/kg IV
0.05-0.2 mg/kg IM, SC
Long duration of action will
prolong anesthesia recovery, not
an analgesic, minimal depression
of fetal oxygenation in the
unstressed state.
Xylazine 0.02-0.15 mg/kg IV
0.05-0.2 mg/kg IM, SC
Dose-dependent sedation and
analgesia, higher dosage
associated with regurgitation
Detomidine 0.01-0.04 mg/kg IM, IV
Medetomidine 5-25 µg/kg IM, IV
Pentobarbital 20-30 mg/kg IV Very short duration 10-20 min,
profuse salivation, decreased
respiration rates, hemoglobinuria
Propofol 4-6 mg/kg induction. 20-25
mg/min constant infusion
Supplement with local anesthesia
or systemic analgesic if surgery is
performed.
Ketamine
Xylazine
2.2-7.5 mg/kg IV; 5-15 mg/kg IM
0.1 mg/kg IV; 0.1-0.2 mg/kg IM
Good muscle relaxation,
regurgitation is not common.
Supplemental oxygen
recommended in pregnant and
debilitated animals
Ketamine + Diazepam 2.2-7.5 mg/kg + 0.2 mg/kg IV Rapid onset, duration of effect 15-
20 min allows intubation, minimal
regurgitation, little
cardiopulmonary dysfunction
Ketamine + Medetomidine 1 mg/kg + 25 µg/kg IM
0.5 mg/kg + 20 µg/kg IV
Not for major surgical procedures
Isoflurane 1-3% Scavenge waste anesthetic gases.
Analgesics
Carprofen 0.7-4.0 mg/kg IV Long plasma half-life 48-72h
Meloxicam
Buprenorphine 0.005-0.01 mg/kg IM q4-6h
(Flecknell 1986)
Concurrent use of NSAIDS is
recommended with opioids
Flunixin meglumine (Banamine) 1.1-2.2 mg/kg q24h IV, IM
Phenlybutazone 1 mg/kg, 1 g/sheep q24h PO, IM
Xylazine 5 mg loading dose then
continuous infusion at 2 mg/kg IV
(grant 2001)
Ruminants have a high density of
α2-adrenergic receptors compared
to opioid receptors. Monitor
animals closely for potential
hypoxia when using these drugs.
Bupivicaine 2 mg/kg IV, IM, local infiltration
Guinea Pig
Guinea pigs are difficult to anesthetize. Avoid fasting pregnant guinea pigs especially close to term. A
number of different injectable combinations have been evaluated. However, there is a lack of
reproducible results, between animals and investigators. In addition, ketamine can cause self mutilation at
the injection site after IM injection. Gas anesthesia produces consistent and reliable results. However,
breath holding when animals are first exposed to irritating gas vapors has been reported. Depth of
anesthesia and effectiveness of analgesia is assessed by pinching the pinna with a small hemostat and lack
of a pedal withdrawal. As with other small rodents steps should be initiated to prevent hypothermia. Large
cecum can act as reservoir for anesthetics. Depending on drug solubility, the cecum can alter the
pharmacologic effect.
AGENT DOSAGE COMMENTS
Atropine sulfate 0.05-0.2 mg/kg SC Administer 15-30 minutes prior to
induction of anesthesia
Diazepam 1.0-5.0 mg/kg IP For sedation
Xylazine 5-10 mg/kg IP Mild sedation
Tiletamine/zolazepam
Xylazine
40 mg./kg IM
5 mg/kg IM
Duration of 90 min surgical anesthesia
(Buchanan, 1999).
December 21, 2010 Page 11
Tiletamine zolazepam
Medetomidine
40 mg/kg IM
0.5 mg/kg IM
Duration of can be as long as 3 h,
surgical anesthesia, us of reversal agent
my help to decrease time to recovery.
Buchanan (1999)
Ketamine + Xylazine 40 mg/kg IM + 5 mg/kg SC
25-40 mg/kg IM, SC + 5 mg/kg
SC, IM %
Duration and depth of anesthesia is
variable between animals.
Pentobarbital 15-30mg/kg IM
40 mg/kg IP
30mg/kg IP
30-45 mg/kg IV
Duration and depth of anesthesia is
variable between animals. Anesthesia
associate fatalities reported at dosages
over 50mg/kg
Isoflurane 2-5% induction, 0.25-4%
maintenance
Anesthetic of choice. Scavenge waste
anesthetic gases.
Analgesics
Buprenorphine 0.05 mg/kg SC, IV q8-12h
Flunixin meglumine 1-2 mg/kg SC
2.5-5.0 mg/kg SC q12-24h
Carprofen 1-2 mg/kg PO q12-24h
4 mg/kg SC q24h
Oxymorphone 0.2-0.5 mg/kg SC, IM q6-12h
Meloxicam 0.3-1 mg/kg PO, SC q12-24h Higher and more frequent dosing may
lead to anorexia
Buchanan et al (1999), Evaluation of injectable anesthetics for major surgical procedures in guinea pigs. Contemp. Top. Lab. Anim. Sci. 37(4):
58-63.
Hamsters
AGENT DOSAGE COMMENTS
Acepromazine 0.5-1.0mg/kg IM, SC Sedation prior to gas anesthesia
Atropine 0.1-0.4 mg/kg IM, SC
Glycopyrrolate 0.01-0.02 mg/kg SC Excess oral or respiratory mucus
Yohimbine 0.5-1 mg/kg IV Xylazine reversal
Ketamine + Diazepam 70 mg/kg + 2 mg/kg IP
Ketamine + Medetomidine 75 mg/kg + 1 mg/kg IP Reverse with atipamazole (1 mg/kg)
Ketamine + Xylazine 80 mg/kg + 5 mg/kg IM, IP
Telazol + Xylazine 30 mg/kg T + 10 mg/kg X IM,
IP
Pentobarbital 50-90 mg/kg IP Duration 60-70 min. respiratory
depression, variable depth of anesthesia
Isoflurane 2-5% induction, 0.25-4%
maintenance
Anesthetic of choice. Scavenge waste
anesthetic gases.
Analgesics
Buprenorphine 0.1 mg/kg SC q6-8h
Flunixin meglumine 2.5 mg/kg SC q12-24h
Carprofen 5 mg/kg SC q24h
Mouse
Preoperative evaluation of rodents should include careful review of the colony health history, age of the
animal and appearance of the animal. Parenteral administration of anesthetic agents is the most common
method of drug delivery in rodents. The volume of drug, site of administration and irritant properties of
the agent should be considered when injecting rodents. To minimize errors in IP injections, fasting the
animal for 4hand using a 20-22 gauge needle are recommended. During the procedure and recovery
period animals should be protected against hypothermia. Gas anesthesia can be used in mice, but
modification of equipment may be necessary to accommodate the small size of mice.
AGENT DOSAGE COMMENTS
Ketamine + Xylazine 100 mg/kg (K) + 5-16 mg/kg (X) IP.
80-100 mg/kg (K) + 10 mg/kg (X) IP
(Flecknell, 1996)
50 mg/kg + 5 mg/kg IP
Ketamine inhibits blinking, ocular
lubrication in needed to protect
against corneal ulceration. 60-100
min, anesthetic depth varies
(Wixson, 1994).
Ketamine + Xylazine +
Acepromazine
100 mg/kg (K) IP
20 mg/kg (X) IP
3 mg/kg (A) IP (Arras, 2001)
Excellent survivability and reliable
depth of anesthesia when
compared to other combinations.
Dose should be adapted to mouse
strain used.
Ketamine + Medetomidine with
Atipamazole reversal
Male: 50 mg/kg (K), 10 mg/kg (M) IP
Female: 75 mg/kg (K), 1-2.5 mg/kg
(M) IP
Combination produced light
anesthesia and good
immobilization (Cruz, 1998).
Isoflurane 2-5% induction, 0.25-4% maintenance Good general anesthetic with high
safety margin. Long procedures
require a precision vaporizer.
Scavenge waste anesthetic gases.
Analgesics
Buprenorphine 0.05-2.5 mg/kg SC, IP q6-12h
Takes 1 h to be effective so give
preemptively. For mild to
moderate pain. Duration of effect
3-5h (Gades, 2000). Combine with
NSAID.
Flunixin meglumine 0.3-2.0 mg/kg IM, IV, PO q12-24h
Carprofen 5 mg/kg SC q24h
Meloxicam 1-2 mg/kg PO, SC
Arras M, Autenried P, Rettich A, Spaeni D, Rülicke (2001) Optimization of intraperitoneal anesthesia in mice: drugs, dosages, adverse effects and anesthesia depth. Comp. Med. 51: 443-456
Cruz et al (1998). Observations on the use of Medetomidine/ketamine and its reversal with Atipamazole for chemical restraint in the mouse. Lab. Anim. Sci. 32(1): 18-22.
Gades et al (2000). The magnitude and duration of the analgesic effect of morphine, Butorphanol, and buprenorphine. Contemp. Top. Lab. Anim.
Sci. 39(2): 8-13. Wixson (1994). Anesthesia and analgesia. In: The Biology of the Laboratory Rabbit, 2nd ed. Manning et al eds., p 87-109, Academic Press, New
York.
December 21, 2010 Page 13
Pig
There is a documented variability of response to anesthetics between domestic and miniature swine. In
addition, there are response differences between breeds within both categories. Pigs are very sensitive to
restraint, anesthesia (particularly halothane) and excitement. In some cases these events can produce
malignant hyperthermia (MH). The first clinical sign is an elevation in end-tidal CO2. A rise of 5-10 mm
Hg above baseline is highly suspect. Other clinical signs of MH include muscle rigidity, tachypnea,
tachycardia and hyperthermia (rectal temperature up 108°F) followed by dyspnea, cardiac arrhythmias,
apnea and death. Dantrolene is the drug of choice for MH. The minimum effective dose for prophylaxis
is 3.5-5mg/kg
Preanesthetic preparation should include withholding feed, at least 12 hours, and withholding water, at
least 4-12 hours before anesthesia. Each pig should be evaluated before anesthesia; at a minimum, this
evaluation should include: rectal temperature, pulse, respiration rate, auscultation of the lung fields and
assessment of general health and attitude. If, extensive surgical procedures will be part of the project,
discuss with the veterinarian the need for additional preoperative testing.
Normal values: temperature 38.0-40.0oC (100.4-104.0
oF); heart rate 60-120/min; respiration rate 10-
12/min.
AGENT DOSAGE COMMENTS
Atropine
0.07-0.09 mg/kg IM Administer 15-30 min prior to
induction of anesthesia
Acepromazine 0.03-0.22 mg/kg IM, IV, SC
Glycopyrrolate 0.004-0.01 mg/kg IM Duration 30 min
Midazolam 100 µg/kg IM
0.5 mg/kg IM
Produces 20 min of sedation (Smith,
1991).
In the Yucatan micropig significant
cardiovascular changes reported
(Goodrich, 2001)
Ketamine 11-33 mg/kg IM Duration 30 min, immobilization with
poor muscle relaxation
Ketamine + Acepromazine 33 mg/kg + 1.1 mg/kg IM Duration 30 min, mild cardio-
depressant
Ketamine + Diazepam or
Azaperone
15 mg/kg + 2 mg/kg or 2 mg/kg
IM
Similar to ketamine + acepromazine.
Diazepam and azaperone should be
given 15-20 min prior to ketamine.
Ketamine + Midazolam 33 mg/kg + 500 µg/kg Hypothermia and 1-4h recovery.
Endotracheal intubation possible.
Ketamine + Xylazine 20 mg/kg + 2 mg/kg IM Anticholinergics recommended to
overcome cardiodepression due to
xylazine. Endotracheal intubation
possible.
Telazol 2-8.8 mg/kg IM 20 min of immobilization, hypothermia
and cardiac depression
Telazol + Xylazine 4.4 mg/kg + 2.2 mg/kg Cardiopulmonary depression, 20 min
duration of anesthesia, endotracheal
intubation possible.
Pentobarbital 20 mg/kg IV
5-15 mg/kg/h continuous IV
infusion (non survival studies)
20-30 min duration, metabolized by the
liver, more cariodepressant than
thiopental, prolonged recovery. Often
easier to immobilize with ketamine
hydrochloride prior to IV
administration of barbiturate to effect
(reduces barbiturate dose). Inject half
rapidly, rest to effect. Perivascular
infiltration can cause tissue sloughing.
Propofol Induction with 0.83-1.66 mg/kg
IV followed by incremental IV
boluses at 14-20 mg/kg/h
Induction with azaperone and
thiopental is recommended (Foster,
1992). Useful in cardiovascular
protocols.
Isoflurane 1-3% Scavenge waste anesthetic gases. Can
cause malignant hyperthermia
Analgesics
Carprofen 2-4 mg/kg IV, SC q24h
5 mg/kg IM q24h
Flunixin meglumine 2-2.2 mg/kg IV, SC q12-24h
Phenylbutazone 1mg/kg IM
Buprenorphine 0.01 mg/kg IV q6h
0.02 mg/kg IV q10h (Rodriguez,
2001)
0.005- 0.1 mg/kg IM, IV q6-12h
Less effective in treating pain due to
inflammation, organ failure or systemic
disease. Higher dosages recommended
for major surgical procedures.
Fentanyl 0.05 mg/kg IM q2h
50-100 µg/kg/h IV
50 µg/h patch for 25-30 kg pig
up to 72 h (Harvey-Clark, 2000)
Infusion is preferred because of the
short half life in swine. Transdermal
patches have been tried in miniature
swine (Wilkinson, 2001)
Tramadol 2-4 mg/kg PO
Lidocaine and prilocaine
(EMLA cream)
Topical, apply 2 mm of cream to
skin 45 min prior to procedure
Effective in preventing pain associated
with blood sampling or injection of the
ear veins
Phenylbutazone 1 mg/kg q24h IM
Ketoprofen 1-3 mg/kg PO q12h NSAID, potent, non-selective inhibitor
of COX enzymes, good analgesic agent
and anti-inflammatory.
Goodrich et al (2001). Non-invasive measurement of blood pressures in the Yucatan micropig (Sus scrofa domestica), with and without
Midazolam-induced sedation. Comp. Med. 51(1): 13-15. Harvey-Clark et al (2000). Transdermal fentanyl compared with parenteral buprenorphine in post-surgical in swine: a case study. Lab. Anim.
34(4): 386-398.
Foster PS, Hopkinson KC, Denborough MA (1992). Propofol anesthesia in malignant hyperthermia susceptible swine. Clin. Exp. Pharmacol. Physiol. 19: 183-186.
Riebold (1995)
Rodriguez NA, Cooper DM, Risdahl JM (2001). Antinociceptive activity of and clinical experience with buprenorphine in swine (2001). Contemp Top Lab Anim Sci 40(3): 17-20.
Smith AC, Zellner JL, Spinale FG, Swindle MM (1991). Sedative and cardiovascular effects of Midazolam in swine. Lab Anim Sci 41: 157-161.
Wilkinson AC, Thomas ML, Morse BC (2001). Evaluation of transdermal fentanyl system in Yucatan miniature pigs. Contemp Top Lab Anim Sci 40(3): 12-16.
December 21, 2010 Page 15
Rabbit
Rabbits are prone to hypoxia due to their small lung capacity and restricted nasopharynx, especially in
short nosed breeds. Their tidal volume is 4-6 ml/kg2. Rabbits should be evaluated for signs of disease (i.e.
respiratory noises, sneezing, appetite, consistency of feces, skin turgor, and moistness of mucus
membranes) before anesthesia is administered. Anesthetic drug dosages in the rabbit are higher than
similar sized cats or dogs. Animals should be weighed prior to the administration of drugs. The large
intestinal tract can lead to over estimation of lean body mass. In addition the cecum can act as a reservoir
for anesthetics and alter drug effects. It may be beneficial to calculate the drug dose based on metabolic
body size (Wkg0.75
)3. In addition age, sex, breed and strain, body weight and time of day may affect the
response to anesthetic agents. Drugs given intravenously should be given to effect. When giving
intramuscular injections start at the lower end of the dose range. Fasting is not required because rabbits
have a high metabolic rate and a low risk for vomiting.
Endotracheal intubation should be used in prolonged procedures. Tube sizes range from 2.0 mm to 4.0
mm inner diameter. The blind placement of the endotracheal tube works well for many operators and is
easy to master. Prior to intubation, a few drops lidocaine should be applied directly to the larynx to
prevent laryngospasm. A non-rebreathing circuit (e.g. Ayers’s T-tube, Bain system) should be used with
rabbits on gas anesthesia. In addition, supplementary oxygen is recommended in animals given
barbiturates, or other injectable agents that reduce respiratory function. Use of a pulse oximeter is
recommended anesthesia because anesthesia and a large gastrointestinal tract can decrease tidal volume
and compromise respiratory function.
The depth of anesthesia is best indicated by response to ear pinch. The reliability of accepted reflex tests
as indicators of anesthesia level has been rated (most to least) as follows: pinna, pedal, corneal, palpebral
reflex (Borkowski, 1990)4.
Rabbits have high levels of circulating catecholamine. The sudden awareness of pain can lead to breath
holding which further increases circulating catecholamines, and the possibility of fatal cardiac
arrhythmias.
AGENT DOSAGE5 COMMENTS
Atropine 0.1-0.5 mg/kg SC, IM Some rabbits produce an atropine
esterase, which can inactive atropine.
Glycopyrrolate 0.01-0.02mg/kg SC
Duration 60 min. Glycopyrrolate has
been shown to be effective and is the
recommended anticholinergic agent in
rabbits.
Acepromazine 0.25-1.0 mg/kg IV,IM or SC
1-5 mg/kg SC, IM
Duration 15-30m. Useful as mild
tranquilizer to reduce handling stress,
activity as a vasodilator is beneficial in
blood collection procedures.
At this dosage will increase the duration
and depth of anesthesia of ketamine-
xylazine
2 Harcout-Brown, F (2002). Textbook of Rabbit Medicine, Butterworth Heinmann, Edinburgh
3 Aeschbacher, G (1995). Rabbit Anesthesia. Compendium on Continuing Education, 17:1003-1011.
4 Borkowski, GL, Danneman PJ, Russell GB, Lang CM (1990). An evaluation of three intravenous anesthetic
regimens in New Zealand rabbits. Lab. Anim. Sci. 40: 270-276. 5 May need to decrease dosages by up to ½ for small breed e.g. Dutch-Belted.
Doxopram 5 mg/kg IM, IV Respiratory stimulant. Duration 15 min
Diazepam 1-5 mg/kg IV, IM Cardiovascular side effects are minimal
when used alone. Can reverse with
flumenzanil (0.01-0.1 mg/kg)
Midazolam 1-2 mg/kg IM, IV More potent than diazepam. Can mix
with other solutions or drugs. Free from
propylene glycol. May be better for
cardiovascular research.
Medetomidine 0.1-0.5 mg/kg IM Sedation or premedication
Ketamine 20-50 mg/kg IM Good for restraint and minor
procedures.
Ketamine + Diazepam 10-15 mg/kg + 0-2 -0.5 mg/kg
IV
Follow with Isoflurane for anesthesia
Ketamine + Xylazine 30-40 mg/kg + 3-5 mg/kg IM
10 mg/kg + 3 mg/kg IV
IV infusion: 25 mg/kg + 5
mg/kg. Give the first ⅓ over 1
min, and the remainder slowly
over the next 4 min.
Better combinations available.
Respiratory depression, hypotension
and hypoxemia common. Light plane of
anesthesia not suitable for
intraabdominal or intrathoracic
procedures. IM injection can cause
local irritation and amputation of the
digits on the injected legs. Dilution with
saline will limit this effect. Duration
20-30 min
IV infusion has good muscle relation
and analgesia, with moderate
depression of respiratory and heart rate
and severe hypotension.
Ketamine + Xylazine +
Acepromazine
35 mg/kg + 5 mg/kg + 0.75
mg/kg IM
Longer anesthesia than with ketamine
plus xylazine. Use with an
anticholinergic. More hypotension and
hypothermia than ketamine plus
xylazine.
Ketamine + Xylazine +
Butorphanol
35 mg/kg + 5 mg/kg + 0.1
mg/kg IM
Longer loss of reflexes than with
ketamine plus xylazine. Less
hypotensive effects compared to
ketamine plus xylazine plus
acepromazine.
Ketamine + Medetomidine 20 mg/kg + 0.1 mg/kg IM Wait 15 min after Medetomidine before
giving ketamine. Duration 90-180 min.
low mortality.
Ketamine + Medetomidine +
Butorphanol
10 mg/kg + 0.2 mg/kg + 0.05
mg/kg SC
Induction. Can be mixed in same
syringe. Duration 30-40 min
Yohimbine 0.2-1.0 mg/kg IV Will cut in ½ the duration of ketamine
plus xylazine anesthesia.
December 21, 2010 Page 17
Propofol 7.5-10 mg/kg IV Lower dosage safest for repeat
administration. Anesthesia time 2-3 min
at lower dosage increases to 3.5 min at
higher dosage. Respiratory support
equipment should be available to treat
respiratory depression (Labreck, 1998)
Propfol + medetomidine +
midozolam + atropine
0.25 mg/kg medetomidine + 0.5
mg/kg midazolam+ 0.5 mg/kg
atropine IM + 4.0 mg/kg
propofol IV
Average length of ear pinch reflex loss
was 37 min. sufficient anesthesia for
endotracheal intubation, induction, and
short term anesthesia.
Isoflurane 1-5%. MAC = 2.05 Premedication is advised to reduce
stress of induction. Gradually increase
the percentage of gas being delivered to
prevent high initial exposure to the
agent if the animal holds it breath.
Scavenge waste anesthetic gases.
Analgesics
Buprenorphine 0.01-0.05mg/kg SC, IV Duration 6-12 h Partial -agonist,
recommended for moderate pain.
Flunixin meglumine 1.1 mg/kg SC, IM q12-24h Not to exceed 3 days
Carprofen 1.5 mg/kg PO q12h
2-4 mg/kg SC q24h
Meloxicam 0.5-2.0 mg/kg PO, SC q12h Palatable oral form; wide safety
margin; very effective when combined
with Buprenorphine for severe (i.e.
surgical) pain
Lidocaine and prilocaine
(EMLA cream)
Topical, apply 2mm of cream
to skin 45 min prior to
procedure.
Local anesthetic, full-skin thickness
analgesia, which reduced the
discomfort associated with ear
venipuncture Not documented
LaBreck JC, An YH, Friedman RJ (1998). Chronic use of propofol for multiple minor procedures in the rabbit. Contemp. Top. Lab. Anim. Sci.
37(2): 71-72.
Rat
AGENT DOSAGE COMMENTS
Acepromazine 0.5-1.0 mg/kg IM In combination with ketamine.
Sedation.
Atropine 0.05-0.1 mg/kg SC
0.1-0.4 mg/kg SC, IM
Some rats possess serum
atropinesterase
Glycopyrrolate 0.01-0.02 mg/kg SC Excess oral or respiratory mucus
Diazepam 3-5 mg/kg IM
Sedation and anesthesia. Dilute
1:100 to reduce injection site
irritation.
Ketamine 25-40 mg/kg IM Heavy sedation at higher doses
Ketamine + Xylazine 75-95 mg/kg (K) + 5 mg/kg (X)
IM, IP
Anesthesia. IM can cause tissue
necrosis.
Ketamine + Acepromazine 75 mg/kg (K) + 3 mg/kg (A) IP Anesthesia
Ketamine + Medetomidine 75-90 mg/kg (K) + 0.5 mg/kg (M)
IP
Anesthesia, 20-20 min
Medetomidine 0.03-0.1 mg/kg SC Light to moderate sedation
Pentobarbital 60 mg/kg IP Duration of effect highly variable
between sex, strain and age
Tiletamine + Zolazepam (Telazol) 20-40 mg/kg IM Anesthesia
Propofol 7.5-10 mg/kg IV Anesthesia, induction
Atipamazole 1 mg/kg SC Medetomidine reversal
Yohimbine 0.5-1.0 mg/kg IV Xylazine reversal
Isoflurane 2-5% induction, 0.25-3%
maintenance
Good general anesthetic. Long
procedures require precision
vaporizer. Scavenge waste
anesthetic gases.
Analgesics
Buprenorphine 0.02-0.5 mg/kg SC, IV, IP, IM
0.05 mg/kg SC, IM + Carprofen 5-
10 mg/kg PO
6-12h duration
Butorphanol (Torbugesic) 0.2-2 mg/kg SC, IP 2-4h duration
Flunixin meglumine (Banamine) 1.1-2.5 mg/kg SC q12-24h
Carprofen (Rimadyl) 5-10 mg/kg SC, PO q12-24h Can combine with buprenorphine
0.05 mg/kg
Meloxicam 1-2 mg/kg PO, SC q24h
Ketoprofen 5 mg/kg SC, IM, PO q24h NSAID
Oxymorphone 0.2-0.5 mg/kg SC, IM q6-12h
Bupivicaine 1-2 mg/kg SC
MAINTENANCE OF ANESTHETIC MACHINES AND VAPORIZERS
As with all equipment, anesthetic machines and vaporizers need experience normal wear and tear and to
be serviced periodically to ensure that they are working safely and effectively. Vaporizers should be
calibrated to ensure that they are delivering the correct amount of anesthetic agent. Typically calibrations
can be done in house by a trained technician. Please contact Laboratory Animal Resources or the Animal
Care Program coordinator for assistance with this aspect. The IACUC requires that vaporizers be
calibrated at least every 2 years, or immediately if the equipment does not operate optimally. See “Policy
on Maintenance of Anesthetic Vaporizers” at http://web.research.colostate.edu/ricro/acuc/policies.aspx.
The unit also needs to be cleaned and serviced. This is more involved, and often requires the unit to be
shipped to the original manufacturer or company specialized in performing those procedures. The
frequency of servicing will depend on the volatile anesthetic agent being used, how often the equipment is
used, whether the unit is mobile or stationary. Please check with the manufacturer of your unit for the
recommended schedules for servicing the unit, which may range from every 1-3 years or longer.
December 21, 2010 Page 19
The hoses, fittings and connections should be checked routinely for leakage of anesthetic gases; and for
proper functioning. A properly functioning scavenging system should be in place to avoid exposing
personnel to waste anesthetic gases which can present an occupational hazard. Additional information is
available at http://web.research.colostate.edu/ACP/OHP_Waste.aspx and http://vam.anest.ufl.edu/.
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