Dog heat cycles: timing, signs and tracking

A bitch’s heat (her season, or oestrus cycle) is the time she can fall pregnant. Knowing her pattern helps you plan matings, book progesterone tests and your stud, and spot a season that’s running late.

How often does a dog come into season?

Most bitches come into season about every 7 months, but anything from 4 to 13 months can be normal. Small breeds may cycle three times a year and giant breeds once a year. Most dogs have no set breeding season, but Basenjis and sled-dog breeds usually cycle in spring.

The first season usually comes at about 6 months old, earlier in small breeds. Large and giant breeds may not cycle until 18 to 24 months. Early cycles are often irregular, and it can take up to 2 years for her cycle to settle.

How long does a heat last?

A whole season usually lasts about 2 to 3 weeks. It has two parts you’ll notice:

• Pro-oestrus, about 9 days (anywhere from 3 days to 3 weeks): her vulva swells and there’s a bloody discharge. Males are interested, but she won’t let them mate.
• Oestrus, about 9 days (again 3 days to 3 weeks): the discharge usually turns watery and pink or salmon-coloured, and she’ll stand for a male. This is her fertile time.

Signs she’s coming into season

• A swollen vulva (not always obvious).
• A bloody discharge, which is usually the first thing owners notice.
• Weeing more often and marking.
• Males taking a sudden interest in her.

Most bitches won’t accept a male until about day 7 to 10 of their season.

When does she ovulate?

Many bitches ovulate around day 11 of their season, but it can be as early as day 3 or as late as day 18, so counting days is a poor guide. Your vet can time ovulation with progesterone blood tests, often repeated over several days, and vaginal smears. Tests sent to an outside laboratory are more accurate than in-clinic tests.

Vets usually count from the first rise in progesterone. Natural mating or AI with fresh semen is often planned for 3 to 6 days after that rise, and frozen semen for day 5 or 6. Your vet will give you the exact days for your bitch.

Logging a heat in WhelpHQ

1. 1Go to Breeding → Heat → Log Heat and pick her.
2. 2Enter the Date first noticed and the First sign you saw, for example Bleeding / spotting.
3. 3WhelpHQ suggests a day of her heat for that sign (day 1 for swelling, day 2 for bleeding, day 4 for males showing interest, day 10 for standing). Change it if you know better, and WhelpHQ counts back to her real first day.
4. 4Add how long it lasted and how strong it was if you know, then tap Log Heat.

How WhelpHQ predicts her next heat

Once she has two or more heats on record (including heats worked out from her past litters), WhelpHQ uses her own average gap between seasons, leaving out gaps under 3 months or over a year. Until then it uses 180 days, because most dogs come into season about twice a year. Her page shows the predicted date and a window to watch, because no bitch is exactly on time, and you get a reminder just before it.

After a litter, her next heat is counted from the heat she was mated on. If you didn’t log that heat, WhelpHQ asks when she was in heat. Until you tell it, her page works it out from the birth date, and her next-heat reminder is set for about 120 days after the birth.

When her season is late

Open Breeding → Heat. Under Upcoming heats, tap Still waiting to be reminded again in a week without changing her prediction, or No heat seen to record a season you expected but didn’t see. Only use No heat seen once you know she isn’t in pup.

Progesterone results

On the Heat tab, tap the droplet icon (Progesterone tracking) on her heat to record each blood test result in ng/mL. WhelpHQ charts the readings so you and your vet can see the rise. It doesn’t work out ovulation for you: your vet reads the results.