Veterinary drug · Drug monograph

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.

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

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.

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?