# PMSG / eCG (Pregnant Mare Serum Gonadotrophin): veterinary dose and monograph

> PMSG / eCG (Pregnant Mare Serum Gonadotrophin) is a veterinary drug. Equine chorionic gonadotrophin (eCG) extracted from pregnant mare serum. Indications include anoestrus in cattle / buffalo (follicular stimulation); superovulation for embryo transfer (cattle / buffalo days 8–13 of cycle); synchronisation after progestagen treatment (CIDR / PRID withdrawal). This monograph lists 4 reference doses for cattle and buffalo, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

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

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Folligon, Equine chorionic gonadotrophin, eCG
- **Species with doses:** Cattle and Buffalo
- **Routes:** IM
- **Last reviewed:** 1 October 2026

## Indications

- Anoestrus in cattle / buffalo (follicular stimulation)
- Superovulation for embryo transfer (cattle / buffalo days 8–13 of cycle)
- Synchronisation after progestagen treatment (CIDR / PRID withdrawal)
- Out-of-season breeding in sheep and goats

## PMSG / eCG (Pregnant Mare Serum Gonadotrophin) 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.

### Cattle

*PMSG / eCG (Pregnant Mare Serum Gonadotrophin) doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Anoestrus (cattle / buffalo) | 500–1000 IU per cow IM | IM | single | — | Withdrawal NOT established — treat as extra-label |
| Superovulation (embryo transfer) | 1500–3000 IU IM between days 8 and 13 of the cycle | IM | single (day 8–13 of cycle) | — | Withdrawal NOT established — treat as extra-label |
| Post-progestagen synchronisation | 300–750 IU IM at progestagen (CIDR/PRID) removal | IM | at end of progestagen treatment | — | Withdrawal NOT established — treat as extra-label |

- Anoestrus (cattle / buffalo): Label-sourced (Folligon, 1000 IU vial reconstituted to 200 IU/mL): 500–1000 IU IM (2.5–5 mL). eCG/PMSG has no monograph in Papich 5e or Plumb’s. Follow the local label.
- Superovulation (embryo transfer): Label-sourced (Folligon): 1500–3000 IU IM between days 8 and 13 of the cycle, followed by a prostaglandin 48 h later. Not in Papich 5e or Plumb’s.
- Post-progestagen synchronisation: Label-sourced (Folligon): 300–750 IU IM at progestagen (CIDR/PRID) removal. Not in Papich 5e or Plumb’s.

### Horses

*PMSG / eCG (Pregnant Mare Serum Gonadotrophin) doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — |

- No reference dose for this species: The previous row gave no dose (‘consult species-specific reference’). eCG/PMSG products such as Folligon are not labelled for mares, and neither Papich 5e nor Plumb’s has a PMSG monograph.

### Goats

*PMSG / eCG (Pregnant Mare Serum Gonadotrophin) doses for goats*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — |

- No reference dose for this species: No eCG/PMSG dose for goats is given in Papich 5e, Plumb’s or the product catalogue used; follow the local product label.

### Sheep

*PMSG / eCG (Pregnant Mare Serum Gonadotrophin) doses for sheep*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — |

- No reference dose for this species: No eCG/PMSG dose for sheep is given in Papich 5e, Plumb’s or the product catalogue used; follow the local product label.

### Buffalo

*PMSG / eCG (Pregnant Mare Serum Gonadotrophin) doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Anoestrus / follicular stimulation / synchronisation | 500–1000 IU IM for anoestrus; 300–750 IU at progestagen removal | IM | single | — | Withdrawal NOT established — treat as extra-label |

- Anoestrus / follicular stimulation / synchronisation: Folligon labels buffalo with cattle: 500–1000 IU IM for anoestrus/summer subfertility; 300–750 IU at progestagen (CIDR) withdrawal. Buffalo are seasonally anoestrous — PMSG is a common component of Indian buffalo breeding protocols.

## Contraindications

Hypersensitivity. Caution in animals with existing ovarian cysts (may worsen). Anti-PMSG antibodies form on repeated use — alternate with other gonadotrophins for chronic protocols.

## Species-specific warnings

> **Caution:** Cattle: Superovulation doses (1500–3000 IU) carry hyperstimulation risk — confirm reproductive history and follicular status first.

> **Caution:** Sheep: Standard tool for out-of-season breeding alongside progestagen sponges.

> **Caution:** Goats: Same protocol as sheep — 250–500 IU IM at sponge removal.

## Adverse effects

- Risk of ovarian hyperstimulation if dose is excessive
- Anti-PMSG antibodies on repeated use — diminishing response over time

## Pregnancy and lactation

Not given to pregnant animals — purpose is to stimulate cyclic activity. Zero milk / meat withdrawal per catalogue.

## Monitoring

- Trans-rectal ultrasound at 24–48 h post-injection to assess follicular response
- Track oestrus expression in ewes / does within 24–60 h after sponge removal
- Watch for hyperstimulation if higher superovulation doses are used

## Clinical pearls

- Sheep / goat out-of-season breeding: 250–500 IU IM at sponge removal works in most flocks
- Cattle superovulation for embryo transfer: 1500–3000 IU IM between days 8–13 of cycle, followed by PGF2α at day 12–13
- Anti-PMSG antibodies build up over repeated cycles — alternate with FSH-only preparations for chronic donor cows
- Zero milk / meat withdrawal makes PMSG production-friendly

## Mechanism of action

Glycoprotein hormone with prolonged FSH-like activity and weaker LH-like activity. Long plasma half-life (~24–48 h) — a single injection drives follicular recruitment and growth over several days. The FSH:LH bias is what makes PMSG/eCG the gonadotrophin of choice for superovulation and out-of-season induction.

## Formulations and products

- Folligon 1000 IU lyophilized vial (MSD) — reconstitute to 5 mL = 200 IU/mL
- Folligon (MSD Animal Health) — 1000 IU per vial (lyophilized), Lyophilized injection — reconstitute with 5 mL solvent → 200 IU/mL

## Storage

Lyophilized vials: 2–8 °C, protected from light. Reconstituted solution: refrigerate, use within 24 h.

## 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 PMSG / eCG (Pregnant Mare Serum Gonadotrophin) for cattle?

Reference doses for PMSG / eCG (Pregnant Mare Serum Gonadotrophin) in cattle: 500–1000 IU per cow IM IM single (Anoestrus (cattle / buffalo)); 1500–3000 IU IM between days 8 and 13 of the cycle IM single (day 8–13 of cycle) (Superovulation (embryo transfer)); 300–750 IU IM at progestagen (CIDR/PRID) removal IM at end of progestagen treatment (Post-progestagen synchronisation). Confirm against the label and the patient before use.

### Can PMSG / eCG (Pregnant Mare Serum Gonadotrophin) be given to horses?

Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species (No reference dose for this species).

### Can PMSG / eCG (Pregnant Mare Serum Gonadotrophin) be given to goats?

Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species (No reference dose for this species).

### What is the withdrawal period for PMSG / eCG (Pregnant Mare Serum Gonadotrophin)?

Cattle, IM (Anoestrus (cattle / buffalo)): Withdrawal NOT established — treat as extra-label; Cattle, IM (Superovulation (embryo transfer)): Withdrawal NOT established — treat as extra-label; Cattle, IM (Post-progestagen synchronisation): Withdrawal NOT established — treat as extra-label; Buffalo, IM (Anoestrus / follicular stimulation / synchronisation): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should PMSG / eCG (Pregnant Mare Serum Gonadotrophin) not be used?

Hypersensitivity. Caution in animals with existing ovarian cysts (may worsen). Anti-PMSG antibodies form on repeated use — alternate with other gonadotrophins for chronic protocols.

### What are the side effects of PMSG / eCG (Pregnant Mare Serum Gonadotrophin) in animals?

Risk of ovarian hyperstimulation if dose is excessive; Anti-PMSG antibodies on repeated use — diminishing response over time.

## Sources

- MSD Animal Health Blue Cross Book 31/2015 — Folligon, p. 115
- Plumb's Veterinary Drug Handbook
- 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.