The heat cycle in brief
| Stage | Typical length | Fertile? |
|---|---|---|
| Proestrus (bleeding, swelling) | About 9 days, range 3 to 17 | No, she usually refuses males |
| Estrus (receptive) | About 9 days, range 3 to 21 | Yes. Ovulation happens early in this stage |
| Diestrus | About 2 months | No. Pregnant or not, hormones are high |
| Anestrus | About 2 to 3 months | No. Rest period |
Most dogs have a heat roughly every six months, with a normal range of four to twelve. Some giant breeds and many Basenjis cycle only once a year. Use the heat cycle calculator to estimate the next one.
The right age to breed
- She can get pregnant at her first heat, but most vets and kennel clubs advise waiting until she is fully grown and has finished at least one or two heats.
- Many breeders wait until about two years old, so hip, eye, heart and genetic tests can be done first.
- First litters after about six to seven years carry more risk, so talk to your vet if she is older.