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Dog Progesterone & Ovulation Timing Calculator
Enter your bitch’s serial progesterone (P4) results and get the estimated LH surge, ovulation day, optimal breeding window for fresh or frozen semen, predicted whelping date, and elective C-section timing, built on standard canine reproduction protocols.
Progesterone results
Enter each blood test by date. Serial results (3+) give the best estimate, test every 24-48 hours.
Your readings are saved on this device only, come back as you test and your series will be waiting. Nothing is uploaded.
Fresh & fresh-chilled sperm survive several days, breed across the window, ~48 hours apart.
Current phase
Awaiting results
Add at least one dated result to plot the progesterone curve.
Enter your progesterone results
Add each dated progesterone test above. Once readings cross ~2 ng/mL, the calculator estimates the LH surge, ovulation, breeding window, and whelping date.
Educational estimate only, not veterinary advice. P4 thresholds are lab- and assay-dependent; trend results from the same laboratory and confirm all breeding and C-section decisions with your reproductive veterinarian.
The protocol
How progesterone times a breeding
In the bitch, progesterone rises in a predictable pattern through proestrus and estrus. Anchoring to the LH surge, when P4 climbs through about 2 ng/mL, lets you count forward to every decision that follows.
Baseline & proestrus
< 2 ng/mLProgesterone sits low. Begin serial testing as standing heat approaches so you capture the rise.
LH surge, Day 0
≈ 2 ng/mLThe reproductive anchor point. Everything else is counted from here. Watch for a sustained rise (a single brief bump can be spurious).
Ovulation, LH + 2 days
≈ 5 ng/mLEggs are released about 48 hours after the LH surge, then take ~2 more days to mature before they can be fertilized.
Optimal breeding window
≈ 8-20+ ng/mLNatural / fresh: 2-4 days after ovulation (breed ~48h apart). Frozen: 3-4 days after ovulation, a single, well-timed AI, placed later because thawed sperm are short-lived.
Predicted whelping
LH + 65 daysGestation averages 65 days from the LH surge (≈63 from ovulation), far more reliable than counting from the mating date.
Elective C-section
Ovulation + 63 daysScheduled from ovulation, never before ~62-63 days. A pre-op P4 drop toward < 2 ng/mL helps confirm fetal readiness.
Methodology & sources
Built on established protocols
The thresholds and day-offsets above are drawn from peer-reviewed canine theriogenology and major veterinary references, cross-checked across sources. This tool is educational and does not replace your reproductive veterinarian.
- De Cramer KGM. Simplifying the Canine Reproductive Cycle Using the Concentration of Progesterone (IDEXX, 2019), reference tables for ovulation, gestation length, and pre-partum progesterone.
- American Kennel Club & AKC Canine Health Foundation, ovulation timing guidance for breeders.
- Merck Veterinary Manual, Breeding Management of Bitches; Whelping in Bitches.
- WSAVA, Breeding Management and Ovulation Timing in the Bitch.
- Fontaine E, DVM, Canine Ovulation Timing: Beyond the Progesterone Number.
- Greer M, DVM, JD (Society for Theriogenology / Revival Animal Health), frozen-semen timing guidance.
Important: Progesterone is an aid to ovulation timing, not a guarantee of conception or whelping date. Absolute P4 thresholds vary by lab and assay, so trend results from the same laboratory. Confirm all breeding and elective C-section decisions with a reproductive veterinarian, ideally a Diplomate of the American College of Theriogenologists (ACT).
Frequently asked questions
Keep exploring
Related tools and guides
Once you have your breeding window, these tools and guides cover the rest of the cycle, from due date to whelping day.
Keep every cycle in one place
BreedTracker logs progesterone results, heat cycles, whelping, and puppy weights across every dam, so the timing you calculate here is saved, trended, and never lost in a text thread.
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