# Midazolam: veterinary dose and monograph

> Midazolam is a veterinary sedative or anaesthetic agent. Water-soluble benzodiazepine — unlike diazepam it is reliably absorbed IM, is non-irritant, and mixes with most induction agents. Indications include co-induction with ketamine / propofol / alfaxalone; premedication in paediatric, geriatric or critically ill patients; status epilepticus (IV / IM / intranasal). This monograph lists 17 reference doses for dogs, cats, cattle, horses, sheep and pigs and 9 more species, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

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

## At a glance

- **Drug class:** Sedative / anaesthetic
- **Also known as:** Versed, Dormicum
- **Species with doses:** Dogs, Cats, Cattle, Horses, Sheep, Pigs, Birds, Rabbits, Ferrets, Guinea pigs, Chinchillas, Rats, Hedgehogs, Sugar gliders and Primates
- **General dose range:** 0.1–0.3 mg/kg IM once (premed) or CRI — check the species tables for the indication
- **Routes:** IV, IM
- **Last reviewed:** 1 October 2026

## Indications

- Co-induction with ketamine / propofol / alfaxalone
- Premedication in paediatric, geriatric or critically ill patients
- Status epilepticus (IV / IM / intranasal)
- Sedation in birds and exotics

## Midazolam 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

*Midazolam doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Co-induction / premed | 0.1–0.3 mg/kg | IV | once with an opioid ± ketamine | — |
| Status epilepticus | 0.2–0.3 mg/kg | IV | bolus; may repeat once; CRI 0.05–0.5 mg/kg/h if recurrent | — |

- Co-induction / premed: Papich 5e: 0.1–0.25 mg/kg IV or IM. Plumb’s p.837: 0.2–0.4 mg/kg IV or IM with an opioid (Day 2002); 0.1–0.5 mg/kg IV (Hellyer 2005); 50:50 v/v with ketamine at 1 mL per 9.1 kg (≈0.28 mg/kg midazolam + 5.5 mg/kg ketamine). Can cause excitement if given alone to healthy dogs. Reverse with flumazenil.
- Status epilepticus: Plumb’s p.837: 0.25 mg/kg IV (Knipe 2006); 0.2–0.4 mg/kg IV or IM, may repeat once — not per rectum (Hopper 2006); 0.07–0.2 mg/kg IV or IM, then CRI 0.05–0.5 mg/kg/h if seizures recur (Thomas 2010). Papich 5e: 0.1–0.2 mg/kg IV, or 0.2 mg/kg intranasally (5 mg/mL); CRI 0.1–0.3 mg/kg/h.

### Cats

*Midazolam doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Co-induction / premed | 0.1–0.3 mg/kg | IM | once | — |

- Co-induction / premed: Plumb’s p.837: 0.05–0.5 mg/kg, 0.3 mg/kg most effective mixed with ketamine for intubation (Reed 2002); 0.2–0.4 mg/kg IV or IM with an opioid. Papich 5e: sedation 0.05 mg/kg IV; induction 0.3–0.6 mg/kg IV with ketamine 3 mg/kg.

### Cattle

*Midazolam doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Calves — anaesthetic induction (with xylazine + ketamine) | 0.1 mg/kg | IV | once, at induction | — | Withdrawal NOT established — treat as extra-label |

- Calves — anaesthetic induction (with xylazine + ketamine): Plumb’s 10e p.883 (extra-label): calves — induced general anaesthesia with xylazine 0.05 mg/kg IV followed by ketamine 2 mg/kg and midazolam 0.1 mg/kg IV, which allows endotracheal intubation. This is the only cattle dose in Plumb’s 10e and applies to calves within that protocol; Papich 5e lists sheep only. Obtain a FARAD withdrawal.

### Horses

*Midazolam doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Anaesthetic adjunct (with ketamine) | 0.1 mg/kg | IV | once | — |
| Neonatal foal seizures | 0.04–0.2 mg/kg | IV | to effect; then CRI | — |

- Anaesthetic adjunct (with ketamine): Papich 5e: 0.1 mg/kg IV given with ketamine 2.2 mg/kg or other anaesthetics (e.g. xylazine). Reverse with flumazenil.
- Neonatal foal seizures: Papich 5e: 0.1–0.2 mg/kg (5–10 mg per foal) IV over 15–20 min or IM, then about 3 mg/h CRI. Plumb’s p.837: 2–5 mg TOTAL IV (or IM) for a 50 kg foal, repeated to effect; CRI 1–3 mg/h for a 50 kg foal (Bentz 2006). Rapid IV can cause apnoea and hypotension. (The previous 0.1–0.2 mg/kg/h CRI was several-fold too high.) (Plumb’s 2–5 mg per 50 kg foal = 0.04–0.1 mg/kg; Papich 0.1–0.2 mg/kg.)

### Sheep

*Midazolam doses for sheep*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Short-term sedation | 0.5 mg/kg | IV | once | — | Withdrawal NOT established — treat as extra-label |

- Short-term sedation: Papich 5e: sheep 0.5 mg/kg IV or IM for short-term sedation. Extra-label in a food animal — obtain a FARAD withdrawal.

### Pigs

*Midazolam doses for pigs*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Miniature/pet pig — sedation / premed | 0.1–0.5 mg/kg | IM | once | — | Withdrawal NOT established — treat as extra-label |

- Miniature/pet pig — sedation / premed: Carpenter Exotic Animal Formulary 6th ed, Table 12-4 (p.665–666): miniature pigs 0.1–0.5 mg/kg IM or IV; 0.2–0.4 mg/kg intranasal. Widely combined with ketamine/azaperone/dexmedetomidine. Reverse with flumazenil. Papich 5e: pigs up to 0.5 mg/kg IM, usually with ketamine.

### Buffalo

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

*Midazolam doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Calves — anaesthetic induction (with xylazine + ketamine) | 0.1 mg/kg | IV | once, at induction | — | Withdrawal NOT established — treat as extra-label |

- Calves — anaesthetic induction (with xylazine + ketamine): Plumb’s 10e p.883 (extra-label): calves — induced general anaesthesia with xylazine 0.05 mg/kg IV followed by ketamine 2 mg/kg and midazolam 0.1 mg/kg IV, which allows endotracheal intubation. This is the only cattle dose in Plumb’s 10e and applies to calves within that protocol; Papich 5e lists sheep only. Obtain a FARAD withdrawal.

### Birds

*Midazolam doses for birds*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication | 1–2 mg/kg | IM | once | — |

- Sedation / premedication: Plumb’s p.837: 1–2 mg/kg IM or IV with an analgesic (Clyde & Paul-Murphy 2000); 1 mg/kg IM premed for anxious birds (up to 6 mg/kg gives heavy sedation); with ketamine 10–30 mg/kg, midazolam 2–6 mg/kg (Morrisey 2010). Reverse with flumazenil 0.1 mg/kg.

### Rabbits

*Midazolam doses for rabbits*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication | 0.5–2 mg/kg | IM | once | — |

- Sedation / premedication: Plumb’s p.837: rabbits 1–2 mg/kg IM or IV (Ivey & Morrisey 2000); premedication 0.5–5 mg/kg IM or IV; IV induction adjunct 0.05–0.5 mg/kg to effect with pre-oxygenation and intubation (Vella 2009). Reverse with flumazenil.

### Ferrets

*Midazolam doses for ferrets*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication | 0.25–0.5 mg/kg | IM | once | — |

- Sedation / premedication: Carpenter's 6th ed (Ferret restraint/anaesthetic table): 0.25–0.3 mg/kg SC/IM, or 0.25–0.5 mg/kg SC/IM/IV — mild sedation/premedication. Combos: midazolam 0.2 mg/kg + butorphanol 0.2 mg/kg IM for minor procedures; or with ketamine 5–10 mg/kg IV for induction. Reversible with flumazenil.

### Guinea pigs

*Midazolam doses for guinea pigs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication | 1–2 mg/kg | IM | once | — |

- Sedation / premedication: Plumb’s p.837 (Adamcak & Otten 2000): hamsters, gerbils, mice, rats, guinea pigs and chinchillas 1–2 mg/kg IM; rodent premedication 3–5 mg/kg IM or IV.

### Chinchillas

*Midazolam doses for chinchillas*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication | 1–2 mg/kg | IM | once | — |

- Sedation / premedication: Plumb’s p.837 (Adamcak & Otten 2000): 1–2 mg/kg IM; rodent premedication 3–5 mg/kg IM or IV.

### Rats

*Midazolam doses for rats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication | 1–2 mg/kg | IM | once | — |

- Sedation / premedication: Plumb’s p.837 (Adamcak & Otten 2000): 1–2 mg/kg IM; rodent premedication 3–5 mg/kg IM or IV; injectable anaesthesia midazolam 5 mg/kg + ketamine 100 mg/kg + buprenorphine 0.05 mg/kg IP (Bennett 2009).

### Hedgehogs

*Midazolam doses for hedgehogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / anaesthesia (with ketamine) | 1 mg/kg | IM | once | — |

- Sedation / anaesthesia (with ketamine): Carpenter Exotic Animal Formulary 6th ed, Table 8-4 (p.516): hedgehogs — ketamine 30 mg/kg + midazolam 1 mg/kg IM; also part of midazolam-butorphanol ± ketamine sedation protocols. Preferred over diazepam for IM use. Reverse with flumazenil.

### Sugar gliders

*Midazolam doses for sugar gliders*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication | 0.1–0.5 mg/kg | IM | once | — |

- Sedation / premedication: Carpenter Exotic Animal Formulary 6th ed, Table 7-3 (p.500): sugar gliders 0.1–0.5 mg/kg SC/IM or intranasal. Combine with ketamine/butorphanol; give preemptively to reduce postsurgical self-mutilation. Reverse with flumazenil.

### Primates

*Midazolam doses for primates*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Sedation / premedication (monkeys) | 0.05–0.3 mg/kg | IM | once | — |

- Sedation / premedication (monkeys): Carpenter Exotic Animal Formulary 6th ed, Table 13-4 (p.697): monkeys 0.05–0.1 mg/kg IM/slow IV; brown lemurs/prosimians 0.1–0.3 mg/kg IM/IV; with ketamine helps prevent seizures in lemurs. Reversible with flumazenil.

## Contraindications

Sole sedative in healthy excitable adults (can cause paradoxical excitation). Severe hepatic impairment (prolonged effect). Reverse with flumazenil if needed.

## Adverse effects

- Paradoxical excitation / dysphoria when used alone in healthy animals
- Mild respiratory depression (additive with opioids)
- Minimal cardiovascular effect (a benzodiazepine advantage)

## Drug interactions

- Inhalational anaesthetics: midazolam DECREASES the dose required
- Thiopental: midazolam decreases the dose required
- Azole antifungals (ketoconazole, itraconazole, fluconazole): may INCREASE midazolam levels
- Calcium-channel blockers (diltiazem, verapamil): may increase midazolam levels
- Macrolides (erythromycin, clarithromycin): may increase midazolam levels
- Cimetidine: may increase midazolam levels
- Other CNS depressants: increased risk of respiratory depression
- Opiates: may increase the hypnotic effect of midazolam; hypotension has been reported with meperidine (pethidine)
- Phenobarbital: may DECREASE peak levels and AUC of midazolam
- Rifampin: may decrease peak levels and AUC of midazolam
- Propofol: synergistic — midazolam plasma concentrations may rise by up to 20% (Plumb's propofol monograph)

## Pregnancy and lactation

Crosses the placenta; reserve for when benefits outweigh risks. Reversible with flumazenil.

## Toxicity and overdose

Plumb's p.836: very limited information. The IV LD50 in mice is reported as 86 mg/kg. Accidental overdoses should be managed supportively, as for diazepam. FLUMAZENIL can antagonise midazolam, but because midazolam is short-acting and flumazenil is expensive, supportive therapy is usually more appropriate for all but the largest overdoses. The practical hazard is respiratory depression, especially when stacked with opioids or other CNS depressants.

## Clinical pearls

- Reliable IM absorption and non-irritant — the benzodiazepine of choice when IV access is difficult
- Best combined with an opioid or dissociative — alone in healthy adults it can cause dysphoria, not sedation
- Excellent cardiovascular stability makes it ideal for sick / cardiac patients

## Mechanism of action

Plumb's p.836: benzodiazepine. Depresses the subcortical CNS — primarily limbic, thalamic and hypothalamic levels — producing anxiolysis, sedation, skeletal muscle relaxation and anticonvulsant activity. The exact mechanism is unknown; postulated contributions are antagonism of serotonin, increased release and/or facilitation of GABA activity, and diminished release or turnover of acetylcholine in the CNS. Benzodiazepine-specific receptors are found in mammalian brain, kidney, liver, lung and heart, and are absent from white matter in every species studied. Midazolam's distinguishing property is its solubility: water-soluble in the vial but LIPID-soluble at body pH, which gives a very rapid onset after injection, and it has roughly TWICE the benzodiazepine-receptor affinity of diazepam.

## Formulations and products

- Midazolam 5 mg/mL injection
- Midazolam 1 mg/mL injection

## 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.

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- [Propofol](https://vetmasterji.com/drugs/propofol)
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## Frequently asked questions

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

Reference doses for Midazolam in dogs: 0.1–0.3 mg/kg IV once with an opioid ± ketamine (Co-induction / premed); 0.2–0.3 mg/kg IV bolus; may repeat once; CRI 0.05–0.5 mg/kg/h if recurrent (Status epilepticus). Confirm against the label and the patient before use.

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

Reference doses for Midazolam in cats: 0.1–0.3 mg/kg IM once (Co-induction / premed). Confirm against the label and the patient before use.

### What is the dose of Midazolam for cattle?

Reference doses for Midazolam in cattle: 0.1 mg/kg IV once, at induction (Calves — anaesthetic induction (with xylazine + ketamine)). Confirm against the label and the patient before use.

### What is the withdrawal period for Midazolam?

Cattle, IV (Calves — anaesthetic induction (with xylazine + ketamine)): Withdrawal NOT established — treat as extra-label; Sheep, IV (Short-term sedation): Withdrawal NOT established — treat as extra-label; Pigs, IM (Miniature/pet pig — sedation / premed): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Midazolam not be used?

Sole sedative in healthy excitable adults (can cause paradoxical excitation). Severe hepatic impairment (prolonged effect). Reverse with flumazenil if needed.

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

Paradoxical excitation / dysphoria when used alone in healthy animals; Mild respiratory depression (additive with opioids); Minimal cardiovascular effect (a benzodiazepine advantage).

## Sources

- Plumb's Veterinary Drug Handbook
- Carpenter's Exotic Animal Formulary 6th ed — Ferret chemical restraint/anaesthetic agents (Table 11-5); Primate (Table…
- Papich, Papich Handbook of Veterinary Drugs, 5th edition
- Carpenter, Exotic Animal Formulary

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