Cloprostenol Sodium
Cloprostenol sodium
Also known as: Estrumate Β· estroPLAN Β· ICI-80996
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
π NA β North Americaπ EU β Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Adjunctive treatment of open cervix pyometra | 1-5 micrograms/kg (0.001-0.005 mg/kg) | Not specified | once per day | Up to 2-3 weeks | π NA |
| Adjunctive treatment of open cervix pyometra | 1 microgram/kg | SC | every 5 days | for 15 days (if not cured earlier) | π NA |
| Pregnancy termination | 1-2.5 micrograms/kg | SC | once daily | for 4-7 days | π NA |
| Pregnancy termination | 1-2.5 micrograms/kg | SC | every 48 hours | for three doses | π NA |
- Adjunctive treatment of open cervix pyometra: When starting treatment, start with one-half the normal dosage and gradually achieve the full dose within 2-3 days.
- Adjunctive treatment of open cervix pyometra: Give not during feeding. Use with aglepristone at 10 mg/kg SC every 5 days until cured. Give Clavamox (12.5 mg/kg PO twice daily) and supportive hydration throughout protocol.
- Pregnancy termination: Successful in terminating pregnancy in dogs after 30 days gestation.
- Pregnancy termination: At higher dose (2.5 mg/kg); appears very effective starting at 30 days of pregnancy. Anticholinergic drug administration (e.g., atropine) 15 minutes prior to dosing appears to lessen adverse effects.
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| To cause abortion prior to the twelfth day of gestation | 100 micrograms | IM | once | β | π NA |
| For luteolysis and to stimulate uterine contractions | 250 micrograms (total dose) | IM | once | β | π NA |
| For luteolysis | 25-250 micrograms (0.1-1 mL) | IM | once | β | π NA |
| As an ecbolic | 250 micrograms (1 mL) | IM | q24h | β | π NA |
- To cause abortion prior to the twelfth day of gestation: Most effective day 7 or 8 post estrus. Mare will usually return to estrus within 5 days.
- For luteolysis and to stimulate uterine contractions: Research has shown that 1/10th of a dose can still cause luteolysis and if given on once or on two consecutive days can avoid side effects.
- For luteolysis: Should not be used more than one day after ovulation because it can damage the corpus luteum and reduce progesterone.
Cattle
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For treatment of pyometra | 500 micrograms | IM | once | β | π NA |
| For pyometra or chronic endometritis, mummified fetus, luteal cysts | 500 micrograms | IM | once | β | π NA |
| For unobserved or undetected estrus in cows with continued ovarian cyclicity and a mature corpus luteum | 500 micrograms | IM | once | β | π NA |
| For abortion, from one week after mating to approximately the 150th day of gestation | 500 micrograms | IM | once | β | π NA |
| For controlled breeding (Single injection method) | 500 micrograms | IM | once | β | π NA |
| For controlled breeding (Double injection method) | 500 micrograms | IM | Repeat dose 11 days later | β | π NA |
- For treatment of pyometra: Up to 97% efficacy.
- For pyometra or chronic endometritis, mummified fetus, luteal cysts: Manual assistance may be required to remove mummified fetus from vagina.
- For unobserved or undetected estrus in cows with continued ovarian cyclicity and a mature corpus luteum: Estrus should commence in 2-5 days at which time the animal may be inseminated. If estrus detection is not possible, inseminate twice at 72 and 96 hours post injection.
- For abortion, from one week after mating to approximately the 150th day of gestation: Abortion generally takes place in 4-5 days after injection.
- For controlled breeding (Single injection method): Use only animals with mature corpus luteum. Inseminate at usual time after detecting estrus, or once at 72 hours, or twice at 72 and 96 hours post injection.
- For controlled breeding (Double injection method): Estrus should occur in 2-5 days after second injection.
Swine
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| To induce parturition in sows | 175 micrograms | IM | once | β | π NA |
- To induce parturition in sows: Give 2 days or less before anticipated date of farrowing. Farrowing generally occurs in approximately 36 hours after injection.
Goats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| To induce parturition in does | 62.5-125 micrograms | IM | once | β | π NA |
| To treat pseudopregnancy (hydrometra/mucometra) | 125 micrograms | IM | once | β | π NA |
- To induce parturition in does: Give at 144 days of gestation in early morning. Deliveries will peak at 30-35 hours after injection. Maintain goat in usual surroundings and minimize outside disturbances.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Cloprostenol sodium is a synthetic prostaglandin F2Ξ± (PGF2Ξ±) analogue widely used in veterinary medicine primarily for its potent luteolytic properties. It is structurally related to naturally occurring dinoprost but is significantly more potent and has a longer duration of action.
- βLarge Animals:β It is a staple in bovine, equine, and swine reproduction for estrus synchronization, inducing parturition, and managing reproductive pathologies such as luteal cysts, mummified fetuses, or chronic endometritis.
- βSmall Animals:β In dogs, it is used off-label for pregnancy termination and the medical management of open-cervix pyometra.
βClinical Pearl:β Because it is a synthetic analogue, cloprostenol often exhibits fewer systemic side effects in horses compared to natural PGF2Ξ± (dinoprost), though dogs may still experience significant cholinergic-like adverse effects (which can be mitigated by pre-treatment with anticholinergics like atropine).
Mechanism of action
Cloprostenol acts as a potent agonist at prostaglandin F (FP) receptors.
- βLuteolysis:β Binds to FP receptors on the βcorpus luteum (CL)β β induces rapid functional and structural regression (luteolysis) β sharp decline in progesterone production. This drop in progesterone removes the negative feedback on the hypothalamus/pituitary, allowing a return to estrus, or induces abortion/parturition depending on the stage of gestation.
- βMyometrial Contraction:β Directly stimulates FP receptors on uterine smooth muscle β increases intracellular calcium β powerful, rhythmic uterine contractions (ecbolic effect).
- βCervical Relaxation:β Concurrently promotes relaxation and dilation of the cervix, facilitating the expulsion of uterine contents (e.g., fetus, purulent material in pyometra).
Safety & warnings
Contraindications
- Pregnancy (when abortion or induced parturition are not desired)
- Intravenous (IV) administration
Adverse effects
- Increased salivation (dogs)
- Tachycardia (dogs)
- Increased urination and defecation (dogs)
- Gagging and vomiting (dogs)
- Ataxia and mild depression (dogs)
- Sweating (horses)
- Cramping and loose stools (horses)
- Increased risk of dystocia if used after 5th month of gestation (cattle)
Precautions
Women of child-bearing age, pregnant women, and persons with asthma or other respiratory diseases should use extreme caution when handling cloprostenol, as the drug may induce abortion or acute bronchoconstriction. Cloprostenol is readily absorbed through the skin and must be washed off immediately with soap and water. βDo not administer IV.β
Drug interactions
Activity may be enhanced by cloprostenol
Monitoring
- Resolution of clinical signs (e.g., clearance of pyometra)
- Estrus behavior and timing
- Confirmation of pregnancy termination/abortion
- Adverse cholinergic effects in dogs (salivation, vomiting, heart rate)
Pharmacokinetics
Absorption
Readily absorbed through the skin.
Overdose
In cattle, doses of 50 and 100 times those recommended may cause signs of uneasiness, slight frothing, and milk let-down.
In small animals, overdoses of cloprostenol or other synthetic prostaglandin F2Ξ± analogs reportedly can result in severe shock and death.
Available products
Formulations
- Injection (250 micrograms/mL)
Veterinary
- Cloprostenol Sodium Injection equivalent to 250 micrograms/mL cloprostenol in 20 mL vials (Estrumate, estroPLAN)
Human-labeled
- None
Regulatory status
No regulatory data for: πΊπΈ US Β· πͺπΊ EU Β· π¬π§ UK Β· ππ° HK Β· πΉπΌ TW Β· π―π΅ JP Β· π°π· KR Β· π¦πΊ AU
Storage & stability
Store at room temperature (15-30Β°C); protect from light.
Client information
βCRITICAL HUMAN SAFETY WARNING:β Cloprostenol is readily absorbed through the skin and can cause severe adverse effects in humans.
- Pregnant women, women of child-bearing age, asthmatics, and individuals with bronchial diseases must use extreme caution or avoid handling this product entirely. Accidental exposure can induce abortion or acute bronchospasm (asthma attack).
- If accidental skin exposure occurs, wash the area immediately with soap and water.
- This medication should only be handled and administered by individuals fully familiar with its use and safety precautions.
- In dogs, you may notice side effects like drooling, vomiting, increased urination/defecation, or panting shortly after administration. Your veterinarian may prescribe an additional medication to help minimize these effects.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerβs current label.