This page is an educational reference for veterinarians and veterinary students. It does not replace a thorough examination, clinical judgment, or the attending veterinarian's final decision. Doses are for adult animals, per kilogram; the amount and volume of each drug for a patient, and the doses for neonates and seniors, are calculated in the tool itself.
Step by step
per kilogram of body weight
1 Preanesthetic preparation Before the injection
Healthy animal: allow free access to water; withhold food for 4–6 hours before anesthesia.3
Animal under 8 weeks or under 2 kg: withhold food for no more than 1–2 hours, monitor blood glucose before, during and after induction, and schedule it as the first patient of the day.3
Animal with a history or risk of regurgitation: withhold food and water for 6–12 hours.3
Vomiting is common with dexmedetomidine; pretreatment with an antiemetic such as maropitant reduces it.3,4
This range is for moderate sedation before induction, and it stays the same with an opioid.1,5
Give a nervous, aggressive or excited animal time to settle before the injection.2
Effects of this drug
Produces sedation and analgesia; their depth and duration depend on the dose.2,4
Less induction agent is needed: the propofol requirement falls by about 30% in dogs and about 50% in cats.2
Lowers heart rate and cardiac output and constricts peripheral vessels; mucous membranes may look pale or bluish even though arterial oxygenation is normal.2,4
Vomiting is common, usually 5–10 minutes after injection; more common in cats and at higher doses.2,4
Its effects, including analgesia, are reversed by atipamezole.1,6
3 Wait and prepare 15–30 minutes
Premedication is usually given 15–30 minutes before induction.1
In dogs, give dexmedetomidine about 20 minutes before induction.2
Brief apnea and hypotension at induction are very common: inject slowly, and have intubation equipment, oxygen and assisted ventilation ready.5,7
Prepare the syringe with the volume of the range, but you need not inject it all: inject slowly IV to effect, until the depth of anesthesia is enough for intubation.5,7
Give the induction dose over about 10–40 seconds; injecting very slowly may not produce enough depth.7
Start at the low end. After the first portion, allow time for the drug to act and assess the animal; if needed, give further portions in small increments. Do not make the first portion too small, because a very small dose may cause excitement.4,5
After an alpha-2 premedication such as dexmedetomidine, dogs need about 3 mg/kg on average, sometimes much less; dexmedetomidine lowers the propofol requirement in dogs by about 30%. Each animal's need may be much lower or higher than the average.2,7
If the animal is moderately sedated after premedication, expect the low end of the range.5
After an alpha-2 premedication such as dexmedetomidine, cats need about 2 mg/kg on average, the low end of the range, sometimes much less; dexmedetomidine lowers the propofol requirement in cats by about 50%. Each animal's need may be much lower or higher than the average.2,7
Effects of this drug
Produces rapid, short anesthesia with a rapid recovery.7
Its effect starts quickly and is short, so it is easy to give to effect, and it can be repeated during the same anesthetic.5
Depresses breathing and circulation in a dose-dependent way. Brief apnea and mild hypotension at induction are very common; rapid injection causes apnea, bradycardia and hypotension.5,7
It relaxes muscle more than ketamine and midazolam; paddling, muscle twitching or nystagmus are sometimes seen at induction.1,7
5 Intubation, oxygen and eye protection Immediately after induction
Place the endotracheal tube as soon as possible and give oxygen.5,7
If breathing stops or is weak, provide assisted ventilation with oxygen.1,7
Apply a corneal lubricant ointment or drops and repeat every 2–4 hours.5
In cats, the larynx goes into spasm when stimulated: before intubation, drip no more than 0.2 mL of 2% lidocaine without epinephrine onto the arytenoid cartilages from a 1 mL syringe without a needle, and wait 60–90 seconds with oxygen. A spray with a nozzle may damage the laryngeal mucosa.4
In cats, if laryngospasm occurs, stop, give oxygen and check the depth of anesthesia; wait 60–90 seconds before trying again. Laryngospasm usually resolves on its own.4
6 Anesthesia 5–10 minutes
A single dose of propofol provides about 5–10 minutes of anesthesia.1
For a few more minutes, inject one-third to one-half of the induction dose again, slowly, to effect.1,5
For a longer procedure, maintain anesthesia with an inhalant.1
In cats, do not continue propofol for more than 30 minutes; cats eliminate it more slowly, and longer use prolongs recovery.4,7
7 Recovery After anesthesia ends
Recovery from propofol is rapid: the animal wakes as the drug redistributes from the brain to other tissues.7
The percentage on each side is not a measurement but a qualitative grade from the sources: full 100, good 75, partial 50, low 25, none zero. It refers to the peak effect after induction, not the whole duration.
HypnosisLoss of consciousness — 100% (Full)
Propofol produces rapid, predictable, short anesthesia and is given to effect.1,7
Dexmedetomidine lowers the propofol dose needed.2,7
AnalgesiaPain control — 25% (Low)
Dexmedetomidine provides analgesia, but it is supportive and shorter than its sedation.8
Propofol provides no analgesia: if the procedure is painful, the animal will feel the pain after it wakes.7,8
Muscle relaxationRelaxed muscle tone — 75% (Good)
Propofol produces more muscle relaxation than ketamine and midazolam.1
Paddling, muscle twitching or nystagmus are sometimes seen at induction.7
Blood pressure: First high, then normal or low
Dexmedetomidine raises blood pressure first, then brings it back to normal or below, and propofol lowers it at induction; after induction, blood pressure may fall. The heart rate is slow.2,7,8
Dexmedetomidine ↑↓ Rises, then falls: Raises blood pressure first, then brings it back to normal or below; slows the heart rate.2
Propofol ↓ Lowers: Lowers blood pressure in a dose-dependent way; rapid injection increases hypotension and bradycardia.5,7
Before you start: contraindications
Contraindication Do not give dexmedetomidine in: cardiovascular disease, severe systemic disease, moribund animals, or hypersensitivity to the drug.2
Contraindication Do not give propofol to an animal hypersensitive to propofol or to the components of its emulsion.7
Cautions and notes
Caution Dexmedetomidine's analgesia is limited and short, and propofol provides none: for surgery or any painful procedure, also choose an opioid.7,8
Caution This protocol is for healthy animals. In sick or debilitated animals, give dexmedetomidine only after weighing the risks and benefits.2
Caution Dexmedetomidine, especially before propofol, slows the heart and may make its rhythm irregular; monitor heart rate and rhythm.2,8
Caution Do not give atropine or another anticholinergic with dexmedetomidine unless bradycardia and hypotension occur together; blood pressure may rise very high.2,4,8
Caution If the premedication does not sedate enough, more propofol is needed, and cardiovascular and respiratory side effects increase.5
Caution Give dexmedetomidine with caution in diabetes, liver or kidney disease, low or high blood pressure, and after trauma.8
Caution Use caution in heart, lung, liver or kidney disease, hypovolemia, hypoproteinemia and hyperlipidemia, and in very thin, debilitated or senior animals; a lower dose may be enough.5,7
Caution Monitor body temperature and keep the animal warm during anesthesia and recovery.2
Caution Do not inject dexmedetomidine again; for a longer procedure, maintain anesthesia with an inhalant.1,2
Caution Dexmedetomidine is not recommended during pregnancy and lactation; the safety of propofol in the fetus, in neonates and during lactation has not been established.2,7
Caution Propofol contains no antimicrobial preservative: draw it up aseptically, use it immediately after opening, and discard the remainder. Do not use it if the emulsion stays separated after gentle shaking.7
Caution In sighthounds (such as Greyhounds), propofol is eliminated more slowly and recovery may be slightly longer.1,7
Note Dexmedetomidine and the opioid can be drawn up in one syringe. Do not mix propofol with another drug in one syringe; it is compatible only with dextrose or saline solutions.1,7
Note Chloramphenicol, ketoconazole and loperamide slow the elimination of propofol and prolong recovery.7
Caution In cats, repeated propofol anesthetics may lead to red cell damage (Heinz body anemia), anorexia, diarrhea and prolonged recovery; if the cat must be anesthetized again, an interval of more than 48 hours reduces this risk.7
If needed, give it IM at the end of the procedure, or if the effects of dexmedetomidine become life-threatening. The sedation, analgesia and cardiorespiratory effects of dexmedetomidine are reversed, and the animal usually wakes and stands within 15 minutes.2,6
If the procedure was painful, treat the pain separately, because the analgesia of dexmedetomidine is reversed too. After the injection, leave the animal in a quiet place; in dogs, transient hypotension has been seen in the first 10 minutes.6,8