Dog heat cycle chart: a printable heat log

What’s inside

• Your dog’s name, breed, date of birth, when her first heat came, and your vet’s phone number.
• “Heats at a glance”: six lines for the day each heat started and ended, how many days it lasted, the months since the start of the one before, and notes.
• “This heat, day by day”: date, day of the heat, bleeding or discharge, swelling, behavior, the stage if your vet named it, and notes. It goes on over page 2.
• A short how-to at the end, in US Letter and A4, with fields you can fill in on screen.

How to fill it in

1. Day 1 is the first day you notice bleeding or swelling. Write that date in “Heats at a glance” too.
2. Each day, note what you see: how much discharge, how swollen, how she behaves with other dogs. Short words are enough.
3. When it’s over, write the end date and count the days.
4. Count the months from the start of the previous heat to the start of this one.
5. Leave “Stage” empty unless your vet told you: the calendar alone can’t tell.

Why a record helps

The Merck Veterinary Manual gives 4 to 13 months between heats as normal, 7 months on average, and each of the first two stages lasts from 3 days to 3 weeks. That’s a wide range. Some dogs repeat their own interval to within 5 to 10 days, while in others it varies a lot (Concannon, 2011). Only her own dates show which kind of dog she is.

Young dogs need patience: their first cycles are often irregular, and it can take up to two years for them to settle (VCA Animal Hospitals). With two start dates, our calculator also uses her own rhythm to estimate the next heat.

• Dog heat cycle calculator