# Alfaxalone: veterinary dose and monograph

> Alfaxalone is a veterinary sedative or anaesthetic agent. Neuroactive-steroid anaesthetic — a GABA-A agonist used for smooth IV induction and maintenance of general anaesthesia. Indications include induction of general anaesthesia (dog / cat); total intravenous anaesthesia maintenance (CRI); IM sedation in fractious cats / small patients. This monograph lists 8 reference doses for dogs, cats, pigs, rabbits and ferrets, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/alfaxalone · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Sedative / anaesthetic
- **Also known as:** Alfaxan
- **Species with doses:** Dogs, Cats, Pigs, Rabbits and Ferrets
- **General dose range:** 1–5 mg/kg IV to effect (induction) or CRI — check the species tables for the indication
- **Routes:** IV, IM
- **Last reviewed:** 1 October 2026

## Indications

- Induction of general anaesthesia (dog / cat)
- Total intravenous anaesthesia maintenance (CRI)
- IM sedation in fractious cats / small patients

## Alfaxalone 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

*Alfaxalone doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| IV induction | 1–3 mg/kg | IV | titrate slowly to effect over 60 s (lower if premedicated) | — |
| Maintenance CRI | 6–10 mg/kg/h | IV | CRI | — |

- IV induction: Papich 5e: 1.5–4.5 mg/kg IV if not premedicated; 0.2–3.5 mg/kg after premedication — titrate over 60 s; top-ups about 1–1.2 mg/kg (up to 2) per 10 minutes. Plumb’s p.49: 1–2 mg/kg IV slowly over 20–30 s; UK label 2–3 mg/kg. Apnoea possible — have intubation and oxygen ready.
- Maintenance CRI: Papich 5e: 6–10 mg/kg/h IV, suitable alongside other anaesthetic agents. Recovery after alfaxalone maintenance is longer than after inhalant.

### Cats

*Alfaxalone doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| IV induction | 2–5 mg/kg | IV | titrate to effect (lower end if premedicated) | — |
| IM sedation (fractious) | 2–3 mg/kg | IM | once, combined with an opioid ± dexmedetomidine | — |
| Deep sedation / light anaesthesia (IM) | 5–10 mg/kg | IM | once | — |

- IV induction: Papich 5e: 2.2–10 mg/kg IV (average 4 mg/kg) unpremedicated, 1–4 mg/kg after premedication; titrate over 60 s with 2 mg/kg top-ups. Plumb’s p.49: 2–5 mg/kg IV slowly (label 5 mg/kg); total 5–7 mg/kg for short procedures such as castration, 8–12 mg/kg for longer ones. CRI (Papich): 1.7 mg/kg IV then 7–10 mg/kg/h.
- IM sedation (fractious): Papich 5e: 2–3 mg/kg IM or IV for mild sedation, can be mixed with butorphanol 0.2 mg/kg in one syringe. Large IM volumes — split sites.
- Deep sedation / light anaesthesia (IM): Plumb’s p.49 (Alfaxan-CD RTU label, NZ): 5–10 mg/kg IM into the quadriceps; 10 mg/kg gives deep sedation or light anaesthesia for venepuncture or minor procedures (e.g. abscess drainage).

### Pigs

*Alfaxalone doses for pigs*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Miniature/pet pig — induction / sedation | 5–6 mg/kg | IM | once | — | Withdrawal NOT established — treat as extra-label |

- Miniature/pet pig — induction / sedation: Carpenter Exotic Animal Formulary 6th ed, Table 12-4 (p.662): miniature pigs 5–6 mg/kg IM, or 6 mg/kg IV; with dexmedetomidine 10 µg/kg IM gives smooth sedation (onset 3–4 min). Venous access in conscious pigs is difficult — IM route practical.

### Rabbits

*Alfaxalone doses for rabbits*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Anaesthesia induction | 6–9 mg/kg | IV | titrate to effect | — |

- Anaesthesia induction: Plumb's p.50: rabbits 6–9 mg/kg IV, or 9 mg/kg IM. ⚠ Apnoea is common — provide oxygen by facemask and be ready to intubate; prefer IM/premedicated induction unless confident with intubation. Alfaxalone is one of the better-tolerated rabbit induction agents.

### Ferrets

*Alfaxalone doses for ferrets*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Anaesthesia induction / sedation | 5–15 mg/kg | IV | titrate to effect | — |

- Anaesthesia induction / sedation: Carpenter's 6th ed (Ferret table): 5 mg/kg IV for induction; 5–15 mg/kg IM for sedation. Provide oxygen; monitor for apnoea.

## Contraindications

Use reduced doses in cardiovascular / respiratory compromise and in shock. Always titrate to effect; have airway support ready. Caesarean use possible but titrate carefully.

## Adverse effects

- Dose-dependent respiratory depression / apnoea (especially with rapid injection)
- Hypotension at higher doses
- Excitement / paddling during recovery if unpremedicated or recovered in a noisy area

## Drug interactions

- Additive CNS / respiratory depression with opioids, benzodiazepines, alpha-2 agonists and inhalants — reduce the induction dose after premedication
- No significant metabolic drug interactions reported

## Pregnancy and lactation

Crosses the placenta but is rapidly cleared; widely used for caesarean induction — titrate to the lowest effective dose and ventilate the dam.

## Monitoring

- Respiratory rate / apnoea — preoxygenate and be ready to ventilate
- Blood pressure
- Recovery quality (recover in a quiet area)

## Toxicity and overdose

Overdose or a rapid bolus causes apnoea, hypoventilation and hypotension. There is no antidote; the short duration means support until redistribution is usually sufficient.

Management: Secure the airway, give oxygen and assisted / mechanical ventilation for apnoea, and IV fluids ± vasopressors for hypotension until the patient lightens (rapid clearance).

## Clinical pearls

- Give the induction dose slowly over ~60 seconds and titrate — a fast bolus is the usual cause of apnoea
- Premedicate and recover patients somewhere quiet; rough recoveries are almost always under-premedication
- The ability to dose IM makes it a friend for cats you cannot place a catheter in awake

## Mechanism of action

Neuroactive (synthetic) steroid anaesthetic. Positively modulates GABA-A receptors in the CNS, enhancing chloride conductance to produce dose-dependent sedation, hypnosis and anaesthesia. Rapidly redistributed and metabolised (non-cumulative), giving fast, clear recoveries.

## Formulations and products

- Alfaxan 10 mg/mL injection
- Alfaxan (Jurox / Dechra) — 10 mg/mL, IV / IM injection

## Storage

Store at 15–25 °C. The preservative-free formulation is single-use — discard opened vials per label; preserved (multidose) versions allow up to ~28 days.

## Before you use this dose

> **Caution:** 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](https://vetmasterji.com/drugs/acepromazine)
- [Azaperone](https://vetmasterji.com/drugs/azaperone)
- [Detomidine](https://vetmasterji.com/drugs/detomidine)
- [Dexmedetomidine](https://vetmasterji.com/drugs/dexmedetomidine)
- [Diazepam](https://vetmasterji.com/drugs/diazepam)
- [Etomidate](https://vetmasterji.com/drugs/etomidate)
- [Guaifenesin (GGE)](https://vetmasterji.com/drugs/guaifenesin)
- [Isoflurane](https://vetmasterji.com/drugs/isoflurane)

## Frequently asked questions

### What is the dose of Alfaxalone for dogs?

Reference doses for Alfaxalone in dogs: 1–3 mg/kg IV titrate slowly to effect over 60 s (lower if premedicated) (IV induction); 6–10 mg/kg/h IV CRI (Maintenance CRI). Confirm against the label and the patient before use.

### What is the dose of Alfaxalone for cats?

Reference doses for Alfaxalone in cats: 2–5 mg/kg IV titrate to effect (lower end if premedicated) (IV induction); 2–3 mg/kg IM once, combined with an opioid ± dexmedetomidine (IM sedation (fractious)); 5–10 mg/kg IM once (Deep sedation / light anaesthesia (IM)). Confirm against the label and the patient before use.

### What is the dose of Alfaxalone for pigs?

Reference doses for Alfaxalone in pigs: 5–6 mg/kg IM once (Miniature/pet pig — induction / sedation). Confirm against the label and the patient before use.

### What is the withdrawal period for Alfaxalone?

Pigs, IM (Miniature/pet pig — induction / sedation): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Alfaxalone not be used?

Use reduced doses in cardiovascular / respiratory compromise and in shock. Always titrate to effect; have airway support ready. Caesarean use possible but titrate carefully.

### What are the side effects of Alfaxalone in animals?

Dose-dependent respiratory depression / apnoea (especially with rapid injection); Hypotension at higher doses; Excitement / paddling during recovery if unpremedicated or recovered in a noisy area.

## Sources

- Plumb's Veterinary Drug Handbook
- Papich, Papich Handbook of Veterinary Drugs, 5th edition
- Carpenter, Exotic Animal Formulary

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.