Dog Progesterone Calculator
Select your testing machine
This is the single most important step. Each machine uses different calibration — the same blood sample gives different numbers on different machines. Pick yours to get accurate thresholds.
Breeding method
Timing recommendations differ significantly depending on semen type. Select your intended method.
Supports IDEXX Catalyst, Wondfo Finecare, Mini Vidas, Cube Vet, V200, and veterinary reference lab results. The single most important step is selecting the right machine — the same number means something completely different depending on what you tested with.
Understanding progesterone testing
Progesterone thresholds by machine
| Stage | IDEXX / V200 | Finecare / Mini Vidas | Cube Vet |
|---|---|---|---|
| Baseline | < 1.0 ng/mL | < 1.5 ng/mL | < 1.0 ng/mL |
| LH surge | 1.5–2.5 ng/mL | 2.5–5.0 ng/mL | 1.5–2.5 ng/mL |
| Ovulation | 4–8 ng/mL | 6–16 ng/mL | 3.5–8 ng/mL |
| Breeding window | 8–20 ng/mL | 16–40 ng/mL | 8–20 ng/mL |
| Post-ovulation | > 20 ng/mL | > 40 ng/mL | > 20 ng/mL |
Thresholds are approximate — individual variation occurs. Always confirm with serial readings.
Breeding method timing
| Method | Optimal timing | Viable window |
|---|---|---|
| Natural mating | 2–3 days post-ovulation | Several days (sperm survives 3–5 days) |
| Fresh-chilled AI | 2–3 days post-ovulation | Moderate (viable 24–48 hrs) |
| Frozen semen | 2.5–3 days post-ovulation | Very narrow (viable 12–24 hrs) |
Serial testing vs single readings
A single progesterone reading tells you where you are right now. Serial readings — taken every 48 hours then daily — tell you the trend, which is far more useful. A rising trend confirms the LH surge is real and ovulation is progressing. Some dogs have a false initial rise that drops back down before the true LH surge. Serial testing catches this and prevents premature breeding.
Progesterone testing FAQs
1Why do progesterone numbers differ between machines?
Different testing machines use different calibration standards. An IDEXX Catalyst is calibrated to the Immulite 1000 gold standard, while a Finecare or Mini Vidas is calibrated differently and reads higher values for the same blood sample. A reading of 5 ng/mL on an IDEXX has a completely different meaning to a 5 ng/mL on a Mini Vidas. Always use the threshold chart that corresponds to your specific machine.
2When should I start progesterone testing?
Start testing 5–7 days after the first sign of heat (vulval swelling or bloody discharge). Testing too early wastes money on low-value baseline readings, but starting too late risks missing the LH surge. Every 2–3 days initially, then daily once you see a significant rise.
3What progesterone level indicates ovulation?
On an IDEXX machine, ovulation occurs between approximately 4–8 ng/mL. On a Mini Vidas or Finecare, the equivalent is 6–16 ng/mL. On a Cube Vet, it's approximately 3.5–8 ng/mL. The critical point is that eggs are NOT immediately fertilisable after ovulation — they need another 48 hours to mature. The optimal breeding window begins about 2 days after ovulation.
4What is the LH surge and why does it matter?
The LH (luteinizing hormone) surge is the hormonal trigger that initiates ovulation. It typically occurs when progesterone rises to approximately 1.5–2.5 ng/mL on an IDEXX machine. Ovulation follows 48 hours later. The LH surge day is also used to calculate whelping dates — 65 days from the LH surge day is the most accurate whelping prediction method.
5How does timing differ for frozen vs fresh semen?
Fresh or fresh-chilled semen survives in the reproductive tract for several days, so breeding within a wider window around ovulation works well. Frozen semen has a very short viable window after thawing — typically less than 12–24 hours. This means frozen semen breeding must be timed with much greater precision, ideally on the exact days when eggs are mature. Surgical or TCI (transcervical insemination) is recommended for frozen semen to place it directly in the uterus.
6Can I compare my home machine results with my vet's lab results?
Only if both machines are calibrated to the same standard. IDEXX and V200 machines are calibrated to the Immulite 1000 reference, so their numbers are comparable. Finecare and Mini Vidas use different calibration and will give significantly higher numbers for the same sample. Always tell your vet which machine you are using so they interpret your results correctly.
7What if my dog was bred but didn't conceive?
The most common cause of failed breeding is incorrect timing — even a day or two off can make a difference, especially with frozen semen. Other causes include subclinical infections, poor semen quality, or anatomical issues. If a well-timed breeding fails, have both the stud and bitch evaluated. A progesterone-timed breeding with confirmed ovulation that still fails warrants a reproductive veterinary workup including uterine culture and semen analysis.
8How many times should a dog be bred per heat cycle?
For natural mating, most reproductive vets recommend breeding every other day during the fertile window — typically 2–3 breedings total. For fresh-chilled AI, two inseminations 24–48 hours apart are standard. For frozen semen, a single precisely timed surgical or TCI insemination is often sufficient because the semen is placed directly in the uterus. More breedings are not necessarily better — quality timing matters more than quantity.