Our professional dog heat cycle calculator is a valuable tool for breeders to predict and track the reproductive cycles of female dogs, and helps estimate crucial dates in a dog’s estrous cycle, including the onset of heat, fertile periods, and the end of the cycle.
If a Labrador Retriever’s last heat cycle began on March 1st, the calculator predict her next cycle to start around August 28th, considering an average cycle length of 180 days for the breed.
Dog Heat Cycle Calculator
| Breed | Last Heat Start | Avg. Cycle Length | Next Predicted Heat |
|---|---|---|---|
| Golden Retriever | April 5, 2024 | 187 days | October 9, 2024 |
| Chihuahua | February 20, 2024 | 205 days | September 12, 2024 |
| Siberian Husky | June 15, 2024 | 178 days | December 10, 2024 |
| Bulldog | March 30, 2024 | 210 days | October 26, 2024 |
| Labrador Retriever | March 1, 2024 | 180 days | August 28, 2024 |
| Beagle | May 10, 2024 | 192 days | November 18, 2024 |
| German Shepherd | June 1, 2024 | 220 days | January 8, 2025 |
| Poodle | July 1, 2024 | 180 days | December 28, 2024 |
| Dachshund | April 15, 2024 | 210 days | November 11, 2024 |
| Boxer | February 5, 2024 | 180 days | August 3, 2024 |
| Cocker Spaniel | January 25, 2024 | 210 days | August 23, 2024 |
| Rottweiler | March 20, 2024 | 230 days | October 5, 2025 |
| Shetland Sheepdog | May 1, 2024 | 180 days | October 28, 2024 |
Dog Heat Cycle Calculation Formula
The formula for calculating a dog’s heat cycle is:
Next Heat Start Date = Last Heat Start Date + Average Cycle LengthIf a Chihuahua’s last heat began on January 15th and her average cycle length is 200 days:
Next Heat Start Date = January 15th + 200 days = August 3rdFemale Dog Heat Cycle Chart
| Stage | Duration | Description |
|---|---|---|
| Proestrus | 7-10 days | Swelling of vulva, bloody discharge |
| Estrus | 5-10 days | Fertile period, discharge lightens |
| Diestrus | 60-90 days | Return to normal if not pregnant |
| Anestrus | 100-150 days | Reproductive inactivity |
Proestrus
Proestrus marks the beginning of the heat cycle and typically lasts 7-10 days. During this stage, the most noticeable physical change is the swelling of the vulva, accompanied by a bloody vaginal discharge. Female dogs may also urinate more frequently, marking their territory with pheromone-laden urine to attract males.
Estrus
Estrus is the fertile stage of the heat cycle, usually lasting 5-10 days. The physical signs during this period include a continuation of the swollen vulva, but the discharge typically becomes lighter in color, often described as straw-colored. The vulva also softens, preparing for potential mating. Behaviorally, this stage is marked by the female becoming receptive to male dogs.
Diestrus
Diestrus follows the fertile period and lasts approximately 60-90 days. During this stage, the physical signs of heat subside. The vulva returns to its normal size, and any discharge ceases. Behaviorally, the female dog is no longer receptive to males and will rebuff any mating attempts.
Anestrus
Anestrus is the final and longest stage of the heat cycle, typically lasting 100-150 days. This period is often referred to as reproductive inactivity, as there are no outward physical signs of any reproductive processes occurring. The dog’s behavior returns to normal, non-reproductive patterns. Hormonally, this is a quiet period with all reproductive hormones at baseline levels.
How do I calculate my dog’s heat cycle?
To calculate your dog’s heat cycle:
- Record the start date of her last heat cycle.
- Determine the average cycle length for your dog’s breed.
- Add the average cycle length to the last start date.
If your Beagle whose last heat started on May 10th, and Beagles typically have a 192-day cycle:
Next Heat Start = May 10th + 192 days = November 18thHow long after bleeding is a dog fertile?
A dog becomes fertile approximately 9-10 days after the onset of bleeding. The fertile period typically lasts about 5-7 days.
A German Shepherd started bleeding on June 1st, she might be most fertile around June 10th-16th.
How do you know when dog heat is over?
Discharge ceases: The bloody discharge diminishes and eventually stops.
Vulva returns to normal: The swelling of the vulva subsides.
Behavior changes: The dog becomes less receptive to male attention.
End of attraction: Male dogs lose interest in the female.
A Poodle’s heat cycle started on July 1st, you might expect these signs around July 21st-28th, signaling the end of her cycle.
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