When a friend of mine adopted her first female dog, she had no idea what the heat cycle would actually entail. She thought it was just one or two days of bleeding and then the endless questions began.
“Why is she licking herself so much?”, “Is it normal she’s crying at night?”, “Do I need to keep her away from every male dog for a month?”
The truth is, the dog heat cycle is way more complex than most first-time owners expect. And when you’re not prepared, it can feel overwhelming, especially if you’re considering breeding or just trying to prevent accidental mating.
Knowing the full dog breeding cycle and what your dog’s body is going through can help you alot.
Table of Contents
Canine Heat Cycle (Estrus) Stages & Timeline
The Dog Heat Cycle Chart is a week-by-week breakdown of what female dogs go through during their reproductive window.
It typically lasts 2 to 4 weeks and includes hormonal changes, behavior shifts, and physical symptoms.
| Stage | Duration | Physical Signs | Behavior Changes | Fertility Status | Key Risks |
| Proestrus | 7-10 days | • Swollen vulva • Bloody discharge • Male attraction | Restless, nervous Appetite changes | Not fertile (Males attracted but female unreceptive) | Pyometra risk begins |
| Estrus | 5-9 days | • Discharge lightens (straw-colored) • Softened vulva • “Flagging” tail posture | Receptive to males Increased urination | Highly fertile (Ovulation occurs) | Accidental pregnancy Mating injuries |
| Diestrus | 60-90 days | • Discharge stops • Vulva returns to normal size | Rejects males Possible false pregnancy | Fertility ends | Pyometra (25% risk in unspayed females) Mammary tumors |
| Anestrus | 3-5 months | No signs | Normal behavior | Non-fertile | N/A |
Female Dog Heat Cycle Chart
The female dog cycle chart gives a clear visual of each phase: proestrus, estrus, diestrus, and anestrus. It’s essential for pet parents whether you’re looking to breed or simply want to keep your dog safe and comfortable during her cycle.
Hormones fluctuate heavily, and even small changes in behavior or discharge can tell you what phase she’s in.
| Stage | Duration | What Happens | Discharge | Behavioral Signs | Fertile? |
| Proestrus | ~7–10 days | Vulva swells, hormone levels rise, males are attracted but female isn’t receptive | Bloody to pinkish | Clingy, restless, starts licking genital area | No |
| Estrus | ~5–9 days | Ovulation occurs, female is receptive to mating | Lighter, straw-colored | “Flagging” tail, flirty with male dogs | Yes |
| Diestrus | ~60 days (if not pregnant) | Hormones drop, female no longer receptive | Discharge ends | Back to normal behavior, possible false pregnancy | No |
| Anestrus | ~4–5 months | Resting stage before next heat begins | None | Normal behavior resumes | No |
Male Dog Heat Cycle Chart
While male dogs don’t experience a cycle in the same way, understanding the male dog heat cycle chart is still useful especially if you have both genders in your home.
Males can detect a female in heat from miles away and may show obsessive behaviors, marking, restlessness, and even aggression. Their behavior aligns closely with nearby females’ heat cycles.
| Female Stage | Male Response Behavior | Risk of Mating | Notes |
| Proestrus | High interest, sniffing, marking territory | Low | Male attracted to scent, but female won’t allow mounting |
| Estrus | Obsessive behavior, constant attempts to mate | High | Female allows mating, males can detect her from miles away |
| Diestrus | Reduced interest, confused behavior | Very low | Mating rarely occurs, but some males may still try |
| Anestrus | No reaction, normal behavior | None | No hormonal signals from the female, males are indifferent |
Dog Heat Cycle by Age – When Does It Start?
It depends on many factors. Small breeds often cycle earlier, while larger breeds might take up to 18 months.
The timing of the first cycle depends on genetics, breed, and overall health. Once it begins, your dog will continue cycling about every six months.
So when you’re tracking the dog heat cycle by age, it’s really about spotting that first heat and counting forward in half-year increments.
Dogs don’t have a menopause stage, they can technically go into heat their whole life, although fertility and egg quality drop with age.
Dog Heat Cycle by Week – What Happens When?
The dog heat cycle by week looks like this:
- Week 1 (Proestrus): Swelling begins, bloody discharge appears, male dogs show interest but she’s not ready to mate yet. Behavior can be moody or clingy.
- Week 2 (Estrus): This is the fertile stage. Discharge lightens in color, she may “flag” (move tail to the side) and accept males. This is the core dog breeding heat cycle phase.
- Week 3 (Diestrus): Fertility ends, behavior normalizes. The uterus prepares for pregnancy if mating occurs. False pregnancy can also happen.
- Week 4+ (Anestrus): A rest period before the next cycle begins. Hormones settle. No signs of heat or fertility here.
Tracking the female dog heat cycle dog progesterone level during this time especially during breeding is crucial.
Progesterone testing tells you exactly when ovulation occurs and can pinpoint the best time for mating or insemination.
Understanding the Dog Breeding Cycle
If you’re planning to breed, knowing the full dog breeding cycle timeline is key. Timing is everything. Breeding too early or too late can result in failed attempts or small litters.
Ovulation doesn’t happen the day bleeding starts, it usually happens several days into the estrus stage.
Many breeders rely on progesterone testing to align mating with peak fertility. If your vet offers this service, you can get highly accurate results on when to mate.
Once pregnancy is confirmed, it typically lasts 63 days. During that time, nutrition, activity, and health monitoring become top priorities.
But even before that, understanding the dog mating cycle makes all the difference.
Hormones & Progesterone Levels
Tracking the female dog heat cycle dog progesterone level isn’t just for breeders, it’s a helpful tool for anyone trying to figure out where their dog is in her cycle.
Progesterone levels rise sharply during ovulation, and testing can help determine:
- The exact day of ovulation
- Whether she’s likely to become pregnant
- If it’s time to mate or wait
- The best date range for conception
This testing is often done via simple bloodwork, and many vets can provide a same-day result.
FAQs
How often do dogs go into heat?
Most dogs go into heat every six months, or about twice a year.
Smaller breeds might cycle more often, while giant breeds may only have one heat per year. Tracking with a dog heat cycle chart helps you stay ahead of the timeline.
At what age does a dog start her heat cycle?
Dogs usually experience their first heat between 6 to 12 months of age. Some large breeds may take up to 18 or even 24 months.
It’s important to track the dog heat cycle by age so you’re ready when it happens and can avoid accidental pregnancies early on.
Can male dogs sense a female in heat?
Absolutely. Male dogs can detect a female in heat from several miles away thanks to scent. They may become obsessed, vocal, or even try to escape to find her. Understanding the dog mating cycle helps prevent unwanted behavior and breeding.
Is there a difference between the heat cycle and the breeding cycle?
Yes. The dog heat cycle refers to the full hormonal and physical process a female dog goes through.
The dog breeding cycle focuses on the window when she is fertile and ready to mate. That fertile period happens during the estrus stage and typically lasts 5 to 9 days.