# Clenbuterol: veterinary dose and monograph

> Clenbuterol is a veterinary drug. Beta-2 agonist bronchodilator for equine asthma (recurrent airway obstruction); also a uterine relaxant (tocolytic). Indications include equine asthma / recurrent airway obstruction; uterine relaxation in dystocia (mares). This monograph lists 2 reference doses for horses, each with route, frequency and source.

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

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Clenbuterol HCl, Ventipulmin
- **Species with doses:** Horses
- **General dose range:** 0.0008–0.0032 mg/kg PO q12h — check the species tables for the indication
- **Routes:** PO, IV
- **Last reviewed:** 1 October 2026

## Indications

- Equine asthma / recurrent airway obstruction
- Uterine relaxation in dystocia (mares)

## Clenbuterol 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.

### Horses

*Clenbuterol doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Recurrent airway obstruction (stepwise) | 0.0008–0.0032 mg/kg | PO | q12h | up to 30 days, then reassess |
| Dystocia — uterine relaxation | 300 µg per 500 kg mare slowly IV (where an injectable is available), or 10 mL of syrup PO on arrival | IV | single dose | — |

- Recurrent airway obstruction (stepwise): Papich 5e and Plumb’s p.289 (label): start 0.8 µg/kg twice daily for 3 days; if no response increase to 1.6, then 2.4, then 3.2 µg/kg twice daily, each for 3 days (0.5 mL of syrup per 100 lb per 0.8 µg/kg step); discontinue if no response at 3.2 µg/kg. Duration of effect 6–8 h. ARCI Class 3.
- Dystocia — uterine relaxation: Plumb’s p.289: 300 µg per 500 kg IV slowly (Card — injectable not available in the USA); 10 mL of syrup orally as the mare arrives (McCafferty). Xylazine or detomidine may potentiate uterine relaxation.

## Contraindications

Pregnant mares near term (tocolytic — delays parturition) unless intended; cardiac disease/tachyarrhythmias. Food-producing animals where prohibited.

## Adverse effects

- Tachycardia
- Sweating, muscle tremors, restlessness
- Urticaria

## Formulations and products

- Oral syrup 72.5 µg/mL

## 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 Clenbuterol for horses?

Reference doses for Clenbuterol in horses: 0.0008–0.0032 mg/kg PO q12h for up to 30 days, then reassess (Recurrent airway obstruction (stepwise)); 300 µg per 500 kg mare slowly IV (where an injectable is available), or 10 mL of syrup PO on arrival IV single dose (Dystocia — uterine relaxation). Confirm against the label and the patient before use.

### When should Clenbuterol not be used?

Pregnant mares near term (tocolytic — delays parturition) unless intended; cardiac disease/tachyarrhythmias. Food-producing animals where prohibited.

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

Tachycardia; Sweating, muscle tremors, restlessness; Urticaria.

## Sources

- Plumb's Veterinary Drug Handbook
- Papich 5e — Clenbuterol
- 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.