Dexmedetomidine: veterinary dose and monograph

At a glance

Drug class

Sedative / anaesthetic

Also known as

Dexdomitor, Sileo, Precedex

Species with doses

Dogs, Cats, Horses, Ferrets, Reptiles, Hedgehogs and Primates

General dose range

0.005–0.04 mg/kg IV single / CRI — check the species tables for the indication

Routes

IM, IV, PO, SC

Last reviewed

1 October 2026

Indications

• Sedation for diagnostics and minor procedures
• Pre-anaesthetic premedication
• Co-induction agent (reduces propofol / alfaxalone induction dose 30–50%)
• Continuous rate infusion (CRI) for ICU sedation
• Sileo (oromucosal gel): noise-aversion / fireworks anxiety in dogs
• Cardiovascular stress reduction in HCM cats (controversial but used)

Dexmedetomidine dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Sedation / premedication (IM): Dosed by body-surface area — µg/kg falls as weight rises. Papich 5e: 125 µg/m² IM for premedication and minor sedation (≈9 µg/kg in small dogs to 3 µg/kg in large dogs); 500 µg/m² IM for deeper sedation. Plumb’s p.373: 125–375 µg/m² IM as a pre-anaesthetic; not accurate in dogs under 2 kg. Use the package-insert BSA table. Reverse with atipamezole. The calculator range (≈3–20 µg/kg) reflects the BSA doses across typical body weights — always check the package-insert BSA table.
• Sedation / analgesia (IV, 375 µg/m²): Papich 5e and Plumb’s p.373: 375 µg/m² IV for sedation and analgesia. This is about 22 µg/kg for a 5 kg dog and 11 µg/kg for a 40 kg dog — use the package-insert BSA table. Lower doses when combined with opioids/ketamine (Plumb’s, Ko 2009: 62.5–250 µg/m²). Calculator range ≈10–20 µg/kg.
• Sileo (noise aversion): Papich 5e: oromucosal gel 125 µg/m² applied to the gingiva between cheek and gum (ineffective if swallowed). Sileo label: give 30–60 min before the anticipated noise or at the first signs of anxiety; may repeat every 2 h up to 5 times per event. Plumb’s 10e pp.369–370 (label dosage): 125 µg/m² BSA onto the oral mucosa between cheek and gum using the Sileo dot syringe and weight-to-dots table (split doses over 6 dots between both sides); at least 2 hours between doses, no more than 5 doses per noise event; no food, treats or water for 15 minutes after dosing; gloves for the person dosing.
• Post-operative analgesia CRI: Plumb’s p.373 (Valtolina 2009): 25 µg/m² IV loading dose then 25 µg/m²/h for 24 h in critically ill dogs (roughly 0.7–1.5 µg/kg/h across 5–40 kg); about half needed rescue morphine.

Cats

• Sedation (IM, healthy): Papich 5e and Plumb’s p.373 (label): 40 µg/kg IM. Lower doses (10–25 µg/kg) for short-term sedation or with other agents, e.g. ketamine 3–5 mg/kg + dexmedetomidine 20 µg/kg, or butorphanol 0.2 mg/kg + dexmedetomidine 10 µg/kg IM. Reverse with atipamezole.
• Sedation (IV): Papich 5e: 5–20 µg/kg IV, sedation deepening with dose; may be combined with ketamine 5 mg/kg.
• Induction of vomiting: Papich 5e: 10 µg/kg IM; lower doses IV are also effective. Reverse with atipamezole once emesis is complete.

Horses

• Anaesthesia adjunct — IV bolus: Papich 5e: horses 5 µg/kg IV bolus during surgery, then CRI 8 µg/kg/h; perioperative analgesia 1.75–2 µg/kg/h IV.
• Anaesthesia / perioperative analgesia CRI: Papich 5e: 8 µg/kg/h IV during surgery after a 5 µg/kg bolus; 1.75–2 µg/kg/h IV for perioperative analgesia.

Ferrets

• Sedation (combination): Carpenter's 6th ed (Ferret table): 0.04–0.1 mg/kg IM — noted as an alpha-2 agonist not commonly used alone because of bradycardia; typically part of a ketamine ± butorphanol combination (dexmedetomidine at half the medetomidine dose). Pre-treat with atropine/glycopyrrolate; reverse with atipamezole.

Reptiles

• Sedation / antinociception (± ketamine): Carpenter's 6th ed (Reptile table): 0.1–0.2 mg/kg SC (ball pythons — thermal antinociception with minimal sedation); 0.2 mg/kg IM (tegus). Usually combined with ketamine for chelonian/squamate immobilisation. Reverse with atipamezole.

Hedgehogs

• Sedation (± ketamine): Carpenter Exotic Animal Formulary 6th ed, Table 8-4 (p.516): hedgehogs 0.02 mg/kg IM. Avoid in ill/debilitated animals (no safety/efficacy data). Reverse with atipamezole.

Primates

• Sedation (tamarins, macaques — with ketamine): Carpenter Exotic Animal Formulary 6th ed, Table 13-4 (p.693): tamarins/macaques 0.01 mg/kg IM (½ the medetomidine dose). Frequently combined with alfaxalone/ketamine. Reverse with atipamezole.

Contraindications

Severe cardiac disease (DCM, advanced MMVD with low CO). Hypovolaemia, shock. Severe hepatic / renal disease. Diabetes mellitus (hyperglycaemia). Mechanical airway obstruction (sedation may worsen). Pregnant animals near term (uterine effects).

Species-specific warnings

Dogs: Standard pre-anaesthetic and procedural sedative. Atipamezole reversal at 10× the dex dose. Avoid in advanced cardiac disease.

Cats: Cats need ~2× canine dose. Vomiting ~50% — fast 4–6 h pre-administration. Standard component of "Kitty Magic".

Adverse effects

• Bradycardia (profound — often requires anticholinergic pre-treatment)
• Hypertension initially (alpha-1 vasoconstriction), then hypotension (central sympatholysis)
• Decreased cardiac output (~30%)
• Hyperglycaemia (insulin suppression)
• Diuresis followed by oliguria
• Hypothermia
• Vomiting (especially cats, ~50%)
• Decreased respiratory rate but maintained SpO2

Drug interactions

• Atipamezole: SPECIFIC REVERSAL agent — atipamezole dose = 10× dexmedetomidine dose (mg) IM
• Other CNS depressants: additive sedation — reduce other drug doses 30–50%
• Atropine / glycopyrrolate: routinely pre-administered to blunt bradycardia (controversial — may worsen myocardial workload)
• Sympathomimetics (epinephrine): severe hypertension at peak alpha-2 effect
• Halothane / isoflurane: reduces MAC 30–50%
• Insulin: dex causes hyperglycaemia — caution in diabetic patients

Pregnancy and lactation

Uterine effects similar to medetomidine — caution in late pregnancy (may induce parturition). Crosses placenta. Generally avoided in pregnancy.

Monitoring

• Heart rate, blood pressure, mucous membrane colour
• SpO2 — supplemental oxygen if <95%
• Body temperature — hypothermia common
• Recovery — quiet environment, avoid stimulation
• Cats: vomiting in ~50% — fast 4–6 h pre-administration
• Pre-procedure: ECG in suspected cardiac disease patients

Toxicity and overdose

Profound bradycardia / hypotension can be fatal in cardiac patients. Hypoxia from decreased respiratory drive (less than xylazine but real). Hyperglycaemia. Vomiting common in cats. Recovery prolonged in hepatically-compromised patients.

Management: ATIPAMEZOLE 10× the dexmedetomidine dose (mg) IM is the specific reversal. Supportive: IV fluids, oxygen, atropine for bradycardia, active warming. Re-sedation possible — monitor for 4–6 h after reversal.

Clinical pearls

• DOSE: half the medetomidine dose (dex is the active enantiomer)
• Canine sedation IM: 5–20 µg/kg with butorphanol 0.2 mg/kg + atropine 0.02 mg/kg = excellent restraint for 30 min
• "Kitty Magic" (cat sedation): dexmedetomidine 5 µg/kg + ketamine 5 mg/kg + butorphanol 0.2 mg/kg IM = 30-min anaesthesia
• Co-induction: 1–3 µg/kg IV before propofol/alfaxalone — reduces induction dose 30–50%
• CRI for ICU: 0.5–3 µg/kg/h — gentle sedation without prolonged recovery
• REVERSAL: atipamezole 10× the dexmedetomidine dose (mg) IM — fully reverses sedation in 5–10 min
• Sileo gel for noise phobia: apply to gum 30 min before fireworks/storm — onset 30 min, duration 2 h
• NEVER mix with epinephrine (severe hypertension)
• Avoid in DCM, advanced MMVD — reduced cardiac output may decompensate

Mechanism of action

Highly selective alpha-2 adrenergic agonist (1620:1 alpha-2:alpha-1 selectivity ratio — vs. xylazine 160:1). Stimulates pre-synaptic alpha-2 receptors in the locus coeruleus, reducing noradrenaline release → sedation, analgesia, anxiolysis. Peripheral alpha-1 effects: initial vasoconstriction → bradycardia. Central sympatholysis → sustained hypotension. Fully reversible with atipamezole.

Formulations and products

• Dexdomitor 0.5 mg/mL injectable (small animal)
• Dexdomitor 0.1 mg/mL injectable (low concentration)
• Sileo 0.1 mg/mL transmucosal oromucosal gel
• Precedex 100 µg/mL human IV (CRI)
• Dexdomitor (Zoetis) — 0.5 mg/mL, Injection (small animal)
• Sileo (Zoetis) — 0.1 mg/mL, Oromucosal gel
• Precedex — 100 µg/mL, IV concentrate (human-label)

Storage

Injectable: 15–25 °C, protect from light. Sileo gel: 15–25 °C. Multidose vial: discard 28 days after broaching.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Other sedatives and anaesthetics

• Acepromazine
• Alfaxalone
• Azaperone
• Detomidine
• Diazepam
• Etomidate
• Guaifenesin (GGE)
• Isoflurane

Frequently asked questions