Acepromazine: veterinary dose and monograph

At a glance

Drug class

Sedative / anaesthetic

Also known as

PromAce, Atravet, Acevet

Species with doses

Dogs, Cats, Cattle, Horses, Goats, Sheep, Pigs, Rabbits, Ferrets, Guinea pigs, Chinchillas, Hamsters, Rats and Mice

General dose range

0.01–0.1 mg/kg IM as needed — check the species tables for the indication

Routes

IM, PO, IV

Last reviewed

1 October 2026

Indications

• Pre-anaesthetic sedation / chemical restraint
• Anti-emetic (motion sickness in dogs)
• Adjunct for sedation protocols (with opioids)
• Equine standing sedation (low dose)

Acepromazine 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

• Pre-anaesthetic sedation: Papich 5e: anaesthetic protocols 0.01–0.05 mg/kg IV with other agents; single dose 0.025–0.1 mg/kg IM, IV or SC (most commonly 0.025 mg/kg); do not exceed 3 mg total. Plumb’s p.21: premedication 0.03–0.05 mg/kg IM (Hall & Clarke); with morphine 0.05 mg/kg IM (Pablo); anxiolysis in painful patients 0.05 mg/kg, max 1 mg (Carroll). No analgesia; hypotension — use low doses in giant breeds, sighthounds, MDR1 dogs and debilitated patients. Allow ≥15 min for onset IV.
• Sedation (oral): Papich 5e: 0.5–2.2 mg/kg q6–8h PO. Plumb’s p.21: label 0.55–2.2 mg/kg PO (considered by many up to 10× higher than needed); premedication 1–3 mg/kg PO at least 1 h before surgery (less reliable). Not an effective treatment for noise phobia alone.
• Restraint / sedation (IM): Plumb’s p.21 (Morgan 1988): restraint/sedation 0.1–0.25 mg/kg IM, maximum 3 mg total. Papich 5e: single dose 0.025–0.1 mg/kg IM, IV or SC (most common 0.025 mg/kg). No analgesia; hypotension possible. (The references do not list an anti-emetic indication.)

Cats

• Pre-anaesthetic sedation: Papich 5e: 0.025–0.1 mg/kg IM, IV or SC single dose; anaesthetic protocols 0.01–0.05 mg/kg IV. Plumb’s p.21: restraint/sedation 0.05–0.1 mg/kg IV, maximum 1 mg (Morgan); 0.11 mg/kg with atropine before ketamine (Booth). Oral sedation 1.1–2.2 mg/kg q6–8h (Papich).

Cattle

• Sedation / restraint: Not FDA-approved for food animals. Plumb's p.23: for extra-label use in food animals it is recommended to apply the Canadian withdrawal periods — meat 7 days, milk 48 hours. Contact FARAD for case-specific guidance. Dose: Plumb’s p.21 — 0.01–0.02 mg/kg IV or 0.03–0.1 mg/kg IM (Booth); 0.05–0.1 mg/kg IV, IM or SC (Howard). Papich 5e: 0.03–0.1 mg/kg IM, 0.01–0.02 mg/kg IV, 0.13–0.26 mg/kg PO.

Horses

• Standing sedation: Plumb’s p.21: label 0.044–0.088 mg/kg IV, IM or SC; mild sedation 0.01–0.05 mg/kg IV or IM — onset about 15 min IV, 30 min IM (Taylor); pre-anaesthetic 0.02–0.05 mg/kg (Booth); neuroleptanalgesia 0.02 mg/kg with buprenorphine or xylazine. Papich 5e: 0.04–0.1 mg/kg IM, preferably 36–48 h apart; perioperative 0.01–0.05 mg/kg. Penile prolapse/priapism risk in stallions. ARCI Class 3.

Goats

• Sedation: Plumb's p.21 (Hall & Clarke 1983): sheep & goats 0.05–0.1 mg/kg IM. Extra-label in food animals — FARAD withdrawal.

Sheep

• Sedation: Plumb's p.21 (Hall & Clarke 1983): 0.05–0.1 mg/kg IM.

Pigs

• Sedation / restraint: Plumb’s p.21: 0.1–0.2 mg/kg IV, IM or SC (Howard); 0.03–0.1 mg/kg (Hall & Clarke); 0.5 mg/kg IM then ketamine 15 mg/kg IM 30 min later for brief immobilisation (Lumb & Jones). Papich 5e: adults 0.03–0.2 mg/kg IV, IM or SC. Not FDA-approved for food animals — Plumb’s suggests the Canadian 7-day meat withdrawal; contact FARAD.

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Sedation / restraint: Not FDA-approved for food animals. Plumb's p.23: for extra-label use in food animals it is recommended to apply the Canadian withdrawal periods — meat 7 days, milk 48 hours. Contact FARAD for case-specific guidance. Dose: Plumb’s p.21 — 0.01–0.02 mg/kg IV or 0.03–0.1 mg/kg IM (Booth); 0.05–0.1 mg/kg IV, IM or SC (Howard). Papich 5e: 0.03–0.1 mg/kg IM, 0.01–0.02 mg/kg IV, 0.13–0.26 mg/kg PO.

Rabbits

• Tranquillisation / premedication: Plumb's p.21 (Ivey & Morrisey 2000): rabbits 1 mg/kg IM (onset ~10 min, lasts 1–2 h); premed 0.25–2 mg/kg IV/IM/SC. No analgesia; may cause hypotension/hypothermia.

Ferrets

• Tranquillisation: Plumb's p.21 (Finkler 1999): 0.25–0.75 mg/kg IM/SC (used safely in pregnant jills); or 0.1–0.25 mg/kg IM/SC (Williams 2000). May cause hypotension/hypothermia — caution if dehydrated.

Guinea pigs

• Tranquillisation: Plumb's p.21 (Adamcak & Otten 2000): Mice/Rats/Hamsters/Guinea pigs/Chinchillas 0.5 mg/kg IM. ⚠ Do NOT use in gerbils.

Chinchillas

• Tranquillisation: Plumb's p.21 (Adamcak & Otten 2000): 0.5 mg/kg IM.

Hamsters

• Tranquillisation: Plumb's p.21 (Adamcak & Otten 2000): 0.5 mg/kg IM.

Rats

• Tranquillisation: Plumb's p.21 (Adamcak & Otten 2000): 0.5 mg/kg IM.

Mice

• Tranquillisation: Plumb's p.21 (Adamcak & Otten 2000): 0.5 mg/kg IM.

Contraindications

CONTRAINDICATED in boxers, giant breeds, brachycephalic breeds, and sighthounds (exaggerated hypotension, prolonged recovery, collapse). Hypovolaemia / shock / dehydration — severe hypotension risk. Seizure history (lowers seizure threshold). Liver disease (hepatically metabolised). Organophosphate exposure. Tetanus. Very young (<12 wk) or very old / debilitated animals. MDR1-mutation breeds — use reduced dose (25–50%). Do NOT use to control aggression in frightened animals — may disinhibit.

Species-specific warnings

Dogs: BOXERS: traditionally avoided — idiosyncratic syncope/bradycardia reported. Low-dose (0.005–0.01 mg/kg) likely safe. NEVER in epileptic dogs.

Cats: Cats more resistant to ACP sedation — often disappointing as monotherapy. Combine with opioid for cooperative restraint.

Horses: STALLIONS: PROHIBITED — penile prolapse / priapism (often permanent). Use detomidine for stallions instead. Geldings, mares, foals: standard tranquilliser.

Cattle: Used in cattle for restraint at 0.05–0.1 mg/kg IM. Hypotension can be problematic in dehydrated patients — pre-treat with IV fluids.

Adverse effects

• Hypotension (alpha-1 blockade) — most common and clinically significant
• Bradycardia (reflex or vagal)
• Hypothermia (loss of thermoregulation)
• Penile paraphimosis / priapism (horses, rare but serious)
• Lowered seizure threshold
• Paradoxical excitement (rare, more common in cats and horses)
• Protracted recovery in sighthounds, boxers, giant breeds

Drug interactions

• Opioids (morphine, methadone, butorphanol): SYNERGISTIC — "neuroleptanalgesia" classic combo (ACP 0.05 mg/kg + opioid IM)
• Alpha-2 agonists (xylazine, dexmedetomidine): additive sedation + cardiovascular depression — reduce doses
• Hypotension-inducing drugs (vasodilators, ACE-I, furosemide): additive hypotension — caution
• Epinephrine: PARADOXICAL HYPOTENSION (alpha-1 blocked, beta-2 vasodilation unopposed) — use NOREPINEPHRINE for ACP-induced hypotension
• Organophosphates: ACP enhances toxicity — avoid in OP exposure
• CNS depressants (anaesthetics, barbiturates, benzodiazepines): additive depression
• Phenobarbital / antiepileptics: ACP LOWERS SEIZURE THRESHOLD — avoid in epileptic patients

Pregnancy and lactation

Crosses placenta. Neonatal depression possible at delivery. Avoid as routine sedation in pregnant animals near term. Occasionally used in pregnant mares for behavioural restraint at lowest dose.

Monitoring

• Blood pressure — most clinically significant effect; pre-treat hypovolaemia with IV fluids before ACP
• Heart rate — bradycardia possible (especially with concurrent opioid)
• Body temperature — hypothermia in cool environment is rapid
• Sedation depth — onset 15–30 min IM, 30–60 min PO; peak 30–60 min IV
• Boxers: monitor closely if used; recent low-dose (0.005–0.01 mg/kg) protocols are safer than historical higher doses

Toxicity and overdose

BOXER DOGS: idiosyncratic SYNCOPE / bradycardia / collapse after ACP — historical recommendation to AVOID in Boxers; recent studies suggest low-dose ACP (0.005–0.01 mg/kg) is safe but caution persists. Profound hypotension — most significant cardiovascular effect; avoid in hypovolaemic, shock, anaemia. Penile prolapse / priapism in stallions (uncommon but irreversible — CONTRAINDICATED in breeding stallions). Lowers seizure threshold — avoid in epileptics. Hypothermia common (vasodilation). Prolonged effect in old patients / hepatic compromise.

Management: No specific antidote. Supportive: IV fluids for hypotension, ACTIVE WARMING for hypothermia. AVOID epinephrine (paradoxical hypotension) — use NOREPINEPHRINE 0.1–0.5 µg/kg/min CRI for refractory hypotension. Beta-2 vasodilation can be helped by alpha-1 agonists (phenylephrine 1–2 µg/kg/min). Reversal of priapism in stallions: pre-empt by using lowest effective dose; once established, surgical intervention often needed.

Clinical pearls

• Pre-anaesthetic tranquilliser: 0.025–0.05 mg/kg IM (dogs), 0.05 mg/kg IM (cats), 0.03–0.05 mg/kg IM (horses) — 30 min before induction
• Neuroleptanalgesia: ACP 0.05 mg/kg + butorphanol 0.2 mg/kg IM — classic small-animal cooperative restraint
• Travel anxiety / fireworks: 1–2 mg/kg PO 1–2 h before event (dogs) — gabapentin or trazodone usually preferred now
• Stallions: PROHIBITED in breeding stock — penile prolapse / priapism (often permanent)
• BOXERS: traditionally avoided — recent data suggests low dose (0.005–0.01 mg/kg) is safe but use cautiously
• NEVER use in epileptic dogs — lowers seizure threshold
• ACE-induced hypotension: NOREPINEPHRINE, not epinephrine (paradoxical hypotension with alpha-1 blocked)
• Long duration (4–8 h) — over-tranquillisation can delay recovery; use lowest effective dose
• No analgesia — always combine with opioid / NSAID for painful procedures

Mechanism of action

Phenothiazine tranquilliser. Antagonises D2 dopamine receptors (sedation, anti-emetic action), alpha-1 adrenergic receptors (vasodilation → hypotension), H1 histamine receptors (mild antihistaminic), and 5-HT receptors. Produces tranquillisation without analgesia. No analgesia — MUST pair with opioid / NSAID / alpha-2 for painful procedures. Antiarrhythmic (decreases ventricular ectopy in some settings). Long duration of action (4–8 h in dogs, can be 12+ h).

Formulations and products

• PromAce injection 10 mg/mL
• Tablet 10 mg
• Tablet 25 mg

Storage

Tablets: 15–25 °C, dry, protected from light. Injection: 15–25 °C, protect from light (yellow → colorless on degradation — discard if discoloured). Multidose vial: discard 28 days after broaching. Schedule IV controlled substance in some jurisdictions.

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

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

Frequently asked questions