Dog Heat Cycle Calculator
Track your female dog's heat cycle and predict her next season. Plan for breeding or prevention.
Larger dogs typically have longer cycles
Understanding the Canine Heat Cycle
The heat cycle (estrus) is a natural reproductive process in intact female dogs. Understanding the phases helps you plan for breeding, prevent unwanted pregnancies, and provide appropriate care during this time.
Proestrus
7-10 days
Estrus
5-14 days (fertile)
Diestrus
60-90 days
Anestrus
4-5 months
Frequently Asked Questions
How often do dogs go into heat?
Most dogs go into heat twice a year (every 6 months). Smaller breeds may cycle 3-4 times per year, while giant breeds may only cycle once yearly. Cycles become regular after the first 1-2 years.
How long does a dog stay in heat?
A complete heat cycle lasts 2-4 weeks. The fertile period (estrus) is typically days 9-14, when the dog can become pregnant. Some dogs show signs for up to 4 weeks.
What are the signs my dog is in heat?
Signs include swollen vulva, bloody discharge, increased urination, behavioral changes (restlessness, clinginess), and attracting male dogs. Some dogs become more affectionate or irritable.
At what age do dogs first go into heat?
Most dogs have their first heat between 6-12 months. Smaller breeds often start earlier (6-9 months) while larger breeds may not start until 12-24 months.
Can I prevent my dog from going into heat?
Spaying (ovariohysterectomy) permanently prevents heat cycles and offers health benefits including reduced cancer risk. Discuss timing with your veterinarian.
When is the best time to breed a dog in heat?
The optimal breeding time is during estrus, typically days 9-14 of the cycle. Progesterone testing by a vet provides the most accurate timing for successful breeding.