# Dog Reproduction: Estrous Cycle, Ovulation, Breeding Time & Gestation in the Bitch

> Reproductive physiology of the bitch: puberty 6–24 months, monestrous with 6–7 month intervals, estrus 9 days (3–21), ovulation 1–3 days after estrus begins, breed day 2 after ovulation, gestation by reference event.

- Source page: https://wevet.in/reproduction/dog/
- Type: Reproduction
- Publisher: WeVet
- Updated: 2026-11-01
- Audience: veterinarians and veterinary students

Key reproductive figures for the dog from the MSD Veterinary Manual reproductive-cycle and gestation tables [1][2] and the Merck chapter on whelping and queening [3].

## Key figures

| Feature | Dog | Source |
|---|---|---|
| Age at puberty | 6–24 months; earlier in smaller breeds, later in larger breeds | [1] |
| Cycle | Monestrous all year; 6–7 months | [1] |
| Proestrus bleeding | Lasts 7–10 days | [1] |
| Duration of estrus | 9 days (3–21) | [1] |
| Ovulation | Usually 1–3 days after the onset of estrus; ova are shed before the first polar body has been extruded (primary oocyte) | [1] |
| Best time to breed | Day 2 after ovulation | [1] |
| First estrus after whelping | 4–5 months | [1] |

## Gestation depends on the reference event

| Counted from | Gestation | Source |
|---|---|---|
| Day of ovulation (determined by progesterone or LH monitoring) | 62–64 days | [2] |
| LH surge / initial rise in progesterone | 64–66 days | [3] |
| Breeding at an unknown stage of estrus | 58–72 days | [2] |
| First day the female permitted breeding | 58–72 days | [3] |
| First day of diestrus | 56–58 days | [3] |

## Frequently asked questions

### How often does a dog come into heat?

The bitch is monestrous all year, with cycles 6–7 months apart [1].

### When is the best time to breed a dog?

Day 2 after ovulation; ovulation usually occurs 1–3 days after the onset of estrus [1].

### How long is a dog pregnant?

62–64 days from the day of ovulation [2], 64–66 days from the LH surge [3] and 58–72 days from breeding at an unknown stage of estrus [2].

## References

[1] Features of the Reproductive Cycle (table) — MSD Veterinary Manual. https://www.msdvetmanual.com/multimedia/table/features-of-the-reproductive-cycle
[2] Approximate Gestation Periods (table) — MSD Veterinary Manual. https://www.msdvetmanual.com/multimedia/table/approximate-gestation-periods
[3] Whelping and Queening in Bitches and Queens — Davidson AP — Merck Veterinary Manual (reviewed 2025). https://www.merckvetmanual.com/management-and-nutrition/management-of-reproduction-dogs-and-cats/whelping-and-queening-in-dogs-and-cats

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Numbers in [brackets] cite the references above. For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.
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