# Yohimbine: veterinary dose and monograph

> Yohimbine is a veterinary drug. Alpha-2 adrenergic ANTAGONIST used as a reversal agent — it rapidly antagonises xylazine (and other alpha-2 agonist) sedation/anaesthesia, and is the classic antidote for amitraz (the alpha-2-agonist tick dip/collar) toxicosis. Indications include reversal of xylazine sedation/anaesthesia (dogs, ruminants, horses, wildlife); amitraz toxicosis — antidote (reverses CNS depression, bradycardia, hyperglycaemia); reversal of other alpha-2 agonist overdose (alternative to atipamezole). This monograph lists 8 reference doses for dogs, cats, cattle, horses, sheep and birds and 2 more species, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

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

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Yobine, Antagonil, Yohimbine hydrochloride
- **Species with doses:** Dogs, Cats, Cattle, Horses, Sheep, Birds, Rabbits and Camelids
- **General dose range:** 0.1–0.125 mg/kg IV single dose (repeat if needed) — check the species tables for the indication
- **Routes:** IV
- **Last reviewed:** 1 October 2026

## Indications

- Reversal of xylazine sedation/anaesthesia (dogs, ruminants, horses, wildlife)
- Amitraz toxicosis — antidote (reverses CNS depression, bradycardia, hyperglycaemia)
- Reversal of other alpha-2 agonist overdose (alternative to atipamezole)

## Yohimbine 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

*Yohimbine doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Xylazine reversal / amitraz toxicosis | 0.1–0.11 mg/kg | IV | single dose (repeat per amitraz protocol) | — |

- Xylazine reversal / amitraz toxicosis: Papich 5e: 0.11 mg/kg IV, or 0.25–0.5 mg/kg SC or IM. Plumb’s p.1179: xylazine reversal 0.1–0.11 mg/kg IV slowly (label); medetomidine 0.11 mg/kg IV; amitraz — 0.1 mg/kg IV repeated as needed (Manning; Hillier), or 0.11 mg/kg IV / 0.25 mg/kg IM with atipamezole 50 µg/kg IM (Torres 2007).

### Cats

*Yohimbine doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Xylazine reversal | 0.11 mg/kg | IV | single dose | — |

- Xylazine reversal: Papich 5e (dogs and cats): 0.11 mg/kg IV slowly, or 0.25–0.5 mg/kg SC or IM. (The previous 0.1–0.5 mg/kg IV mixed the IV and IM doses.)

### Cattle

*Yohimbine doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Xylazine reversal | 0.1–0.2 mg/kg | IV | single dose | — | Withdrawal NOT established — treat as extra-label |

- Xylazine reversal: Papich 5e: cattle and sheep 0.125–0.2 mg/kg IV to reverse xylazine or medetomidine. Plumb’s p.1179: 0.125 mg/kg IV (Gross & Tranquilli); IM preferred except in emergencies (less excitement), 0.1 mg/kg IV in emergencies — wait 30–45 min after IM ketamine/Telazol before reversing (Anderson & Abrahamsen 2008). Obtain a FARAD withdrawal.

### Horses

*Yohimbine doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Xylazine reversal | 0.075–0.125 mg/kg | IV | single dose | — |

- Xylazine reversal: Plumb’s p.1179 (Gross & Tranquilli): 0.075 mg/kg IV. Papich 5e: 0.125 mg/kg IV for xylazine, 0.2 mg/kg IV for detomidine; the full dose may not be needed. Give slowly. ARCI Class 2.

### Sheep

*Yohimbine doses for sheep*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Xylazine reversal | 0.125–0.2 mg/kg | IV | single, slow | — | Withdrawal NOT established — treat as extra-label |

- Xylazine reversal: Papich 5e: cattle and sheep 0.125–0.2 mg/kg IV to reverse xylazine or medetomidine. Give slowly; atipamezole is an alternative.

### Buffalo

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

*Yohimbine doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Xylazine reversal | 0.1–0.2 mg/kg | IV | single dose | — | Withdrawal NOT established — treat as extra-label |

- Xylazine reversal: Papich 5e: cattle and sheep 0.125–0.2 mg/kg IV to reverse xylazine or medetomidine. Plumb’s p.1179: 0.125 mg/kg IV (Gross & Tranquilli); IM preferred except in emergencies (less excitement), 0.1 mg/kg IV in emergencies — wait 30–45 min after IM ketamine/Telazol before reversing (Anderson & Abrahamsen 2008). Obtain a FARAD withdrawal.

### Birds

*Yohimbine doses for birds*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Alpha-2 agonist reversal | 0.1 mg/kg | IV | once | — |

- Alpha-2 agonist reversal: Plumb’s p.1179 (Clyde & Paul-Murphy 2000): 0.1 mg/kg IV.

### Rabbits

*Yohimbine doses for rabbits*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Xylazine reversal | 0.2 mg/kg | IV | as needed | — |

- Xylazine reversal: Plumb’s p.1179 (Huerkamp 1995): rabbits 0.2 mg/kg IV as needed; also partially antagonises ketamine and acepromazine. Mice/rats 0.2 mg/kg IP.

### Camelids

*Yohimbine doses for camelids*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Xylazine reversal | 0.25 mg/kg | IV | once | — |

- Xylazine reversal: Plumb’s p.1179 (Fowler 1989): llamas 0.25 mg/kg IV or IM.

## Contraindications

Known hypersensitivity. Caution in seizure disorders, significant cardiac disease and hypertension (alpha-2 blockade raises sympathetic outflow → tachycardia, hypertension, excitement). Renal disease. Avoid rapid IV (transient excitement/cardiovascular effects).

## Species-specific warnings

> **Caution:** Cattle: Ruminants are exquisitely sensitive to xylazine; yohimbine is useful to hasten recovery from over-sedation.

## Adverse effects

- Transient excitement/apprehension, muscle tremor
- Tachycardia, hypertension
- Hypersalivation
- Rapid reversal can unmask pain (if the alpha-2 was providing analgesia)

## Drug interactions

- Alpha-2 agonists (xylazine, medetomidine, amitraz, clonidine): directly antagonised (the intended action) — reverses their effects
- Other sympathomimetics/stimulants: additive excitation, tachycardia, hypertension
- Tricyclic antidepressants/MAOIs: enhanced pressor effects

## Pregnancy and lactation

Limited data; use when reversal is clinically needed. Rapid reversal in a pregnant animal should be balanced against the cardiovascular surge it produces.

## Monitoring

- Recovery from sedation (arousal, posture, gait)
- Heart rate, rhythm and blood pressure (watch the post-reversal surge)
- For amitraz toxicosis: re-emergence of CNS depression/bradycardia (amitraz outlasts yohimbine — re-dose) and blood glucose
- Pain status if the alpha-2 was providing analgesia

## Toxicity and overdose

Overdose causes sympathetic overstimulation — excitement/agitation, muscle tremor, tachycardia, hypertension and potentially seizures. Effects are generally short-lived because yohimbine is rapidly metabolised (which is also why repeat dosing is needed for the longer-acting amitraz).

Management: No specific antidote. Supportive — keep calm/quiet, IV fluids, and manage tachyarrhythmia/hypertension and seizures (benzodiazepines) as needed. Effects wane quickly with the drug's short half-life.

## Clinical pearls

- The classic reverser for XYLAZINE — and the go-to antidote for AMITRAZ (tick dip/collar) toxicosis
- Amitraz lasts longer than a single yohimbine dose — expect signs to recur and be ready to re-dose plus give supportive care
- For medetomidine/dexmedetomidine, atipamezole is the more selective, usually preferred reversal agent
- Give slowly IV — rapid injection causes transient excitement, tachycardia and hypertension
- Reversal also reverses the alpha-2's analgesia — provide alternative pain relief if a painful procedure was performed

## Mechanism of action

Competitive antagonist at alpha-2 adrenoceptors. By blocking central (pre-synaptic) alpha-2 receptors it removes the negative feedback on noradrenaline release, increasing central sympathetic outflow and arousal — thereby reversing the sedation, bradycardia and CNS/respiratory depression produced by alpha-2 agonists such as xylazine and amitraz. It also has some peripheral alpha-2-blocking and serotonergic activity.

## Formulations and products

- Injection 2 mg/mL
- Yobine / Antagonil (Lloyd / various) — 2 mg/mL, Injection

## Storage

Injection: 15–30 °C, protect from light.

## 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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## Frequently asked questions

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

Reference doses for Yohimbine in dogs: 0.1–0.11 mg/kg IV single dose (repeat per amitraz protocol) (Xylazine reversal / amitraz toxicosis). Confirm against the label and the patient before use.

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

Reference doses for Yohimbine in cats: 0.11 mg/kg IV single dose (Xylazine reversal). Confirm against the label and the patient before use.

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

Reference doses for Yohimbine in cattle: 0.1–0.2 mg/kg IV single dose (Xylazine reversal). Confirm against the label and the patient before use.

### What is the withdrawal period for Yohimbine?

Cattle, IV (Xylazine reversal): Withdrawal NOT established — treat as extra-label; Sheep, IV (Xylazine reversal): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Yohimbine not be used?

Known hypersensitivity. Caution in seizure disorders, significant cardiac disease and hypertension (alpha-2 blockade raises sympathetic outflow → tachycardia, hypertension, excitement). Renal disease. Avoid rapid IV (transient excitement/cardiovascular effects).

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

Transient excitement/apprehension, muscle tremor; Tachycardia, hypertension; Hypersalivation; Rapid reversal can unmask pain (if the alpha-2 was providing analgesia).

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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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.