When I first looked into breeding dogs, I thought timing things would be kind of straightforward. Watch for signs of heat, maybe count some days, and just let nature do its thing.
But after seeing a few failed attempts and confusion about whether ovulation had even happened, it became clear, nature needs a little science. That’s where the progesterone test for dogs completely changed the game.
Understanding canine progesterone levels is like having a cheat code for successful breeding. You don’t need to guess when to mate or rely only on behavior, you can know exactly when ovulation happens and hit the sweet spot for conception.
Whether you’re a first-time breeder or just want to better understand your female’s cycle, tracking dog progesterone is the smartest move you can make.
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Dog Progesterone Level Chart for Breeding Timing
This Dog Progesterone Level Chart helps predict the fertile window by tracking hormone spikes before, during, and after ovulation. Once levels cross a certain point, you know it’s go-time for mating or artificial insemination.
| Progesterone Level (ng/mL) | Progesterone Level (nmol/L) | Reproductive Stage | Ovulation/Breeding Status | Recommended Action |
| <1.0 | <3.18 | Anestrus / Early Proestrus | Follicles developing | Begin testing every 2-3 days |
| 1.0-1.9 | 3.18-6.06 | Proestrus | Pre-ovulatory; LH surge imminent | Test every 1-2 days; monitor for behavioral changes |
| 2.0-3.9 | 6.36-12.42 | Proestrus → Estrus | LH surge occurs | Breeding Alert: Ovulation expected in 2 days |
| 4.0-7.9 | 12.73-25.15 | Early Estrus | Ovulation happening | Optimal breeding window opens (Breed in 2-3 days) |
| 8.0-15.0 | 25.47-47.75 | Peak Estrus | Eggs mature (peak fertility) | BREED NOW (Natural mating or AI) |
| >15.0 | >47.75 | Late Estrus → Diestrus | Post-ovulation; fertility declining | Last-chance breeding; fertility drops rapidly |
What Is Progesterone and Why It Matters
Dog progesterone is a hormone that plays a critical role in the reproductive cycle. In female dogs, it’s low before heat begins, then rises rapidly around ovulation, the exact moment when eggs are released and fertility peaks.
While outward signs of heat (like swelling or discharge) give rough clues, hormone testing gives precision.
That’s why dog breeding progesterone levels are tracked by vets before planning a mating session or insemination. It’s the most reliable way to avoid missed windows or failed attempts.
Progesterone Level Timeline – What to Expect Each Day
Every dog is different, so testing every 48 hours during the heat cycle gives the clearest picture. Here’s how the canine progesterone levels typically change across the heat cycle:
- Day 1–3 (Start of Heat): These days the levels are very low, usually up to 0–1 ng/mL. Your dog is not fertile during this time. This is proestrus.
- Day 4–7: Levels begin to rise slightly (1–2.5 ng/mL). Ovulation is getting close.
- Ovulation Day (Usually around 5–9): Sudden jump in levels (4–10 ng/mL). This signals ovulation.
- Best Breeding Days: Progesterone reaches 10–20 ng/mL within 1–2 days after ovulation. Fertility is at its highest.
- Post-ovulation (Day 10+): Levels remain high if pregnancy occurs. If not, they gradually drop.
How the Progesterone Test for Dogs Works
The progesterone test for dogs is a simple blood draw that measures the hormone level in nanograms per milliliter (ng/mL).
Most vet clinics or reproduction specialists offer this test and can deliver same-day results.
Some breeders also use in-house testing kits, but for accuracy and reliability, a vet is always the safer bet.
Multiple tests are usually needed to catch the sharp rise that indicates ovulation. Think of it as mapping out the cycle with data instead of guesswork.
When Is the Best Time to Breed Based on Progesterone?
The ideal time to breed is two days after ovulation, when dog progesterone levels are typically around 10–20 ng/mL.
This gives the eggs time to mature and the sperm a better chance of successful fertilization.
Here’s a quick breakdown:
- Below 2 ng/mL: Too early. No ovulation yet.
- 4–6 ng/mL: Ovulation likely started.
- 8–20 ng/mL: Best time to breed.
- Above 25 ng/mL: Past the ideal window. Fertility is lower.
Relying on behavior alone (like flagging or standing for mating) can lead to missed chances. Hormone levels are way more accurate.
Using Progesterone Testing with Artificial Insemination
If you’re doing artificial insemination (AI), precise timing becomes even more important.
Unlike natural mating, where sperm may be deposited multiple times, AI usually happens once or twice so catching that peak moment matters even more.
Vets often schedule AI based on repeated dog progesterone testing, making sure the levels are just right before going forward.
This is especially useful if shipping semen or using frozen samples, where timing is everything.
How Often Should You Test?
Start testing when signs of heat begin, usually when you see the first spotting or swelling. Then test every 2 days until progesterone hits at least 5 ng/mL. After that, daily or every 24 hours helps you catch the precise ovulation window.
On average, breeders do 3 to 5 tests per cycle, but this depends on your dog’s breed, previous cycle history, and how regular her heat is.
FAQs
What are normal progesterone levels in dogs?
Normal canine progesterone levels change depending on where your dog is in her heat cycle. Before heat starts, levels are very low, usually under 1 ng/mL.
Once heat begins and ovulation approaches, levels will start rising gradually. When ovulation hits, levels jump rapidly, typically to 4–10 ng/mL, which marks the fertile window.
After ovulation, they’ll continue to rise and stabilize anywhere from 10–30 ng/mL if pregnancy occurs. If no pregnancy happens, the levels will drop back down slowly during the next stage.
How long after a progesterone rise should I breed my dog?
The best time is usually 2 days after the progesterone reaches 5 ng/mL or more. This is when the eggs are most mature and the sperm has the best chance of fertilizing them.
Dog breeding progesterone levels around 10–20 ng/mL are considered ideal for timing.
Can you test progesterone at home?
Technically, yes, there are at-home progesterone test kits for dogs on the market, but they often require some practice and aren’t as reliable as the ones done at a veterinary clinic.
The results might not be as accurate, especially if you’re unfamiliar with how to draw blood or interpret the test.
Most breeders prefer getting their dog breeding progesterone tests done by vets or professional reproduction clinics because it ensures you’re working with the right data.
Is progesterone testing needed for every dog?
Not necessarily. Some breeders go by physical signs and behavior, but it’s not always accurate. For high-value litters, artificial insemination, or dogs with irregular cycles, progesterone test for dogs is highly recommended.
What happens if I miss the right progesterone window?
If you miss the timing especially if dog progesterone levels are already too high, the chances of a successful pregnancy drop significantly.
Eggs only stay viable for a short time after ovulation, and sperm has a limited lifespan too. Once the dog mating cycle window passes, the reproductive conditions just aren’t ideal anymore.
That doesn’t mean something is “wrong” with your dog, but it does mean you’ll likely have to wait for the next heat cycle and try again.