Dog Progesterone Levels & Breeding Timing Chart: 2026 Guide

What is progesterone testing in dogs?

Dog progesterone testing is a blood test used to follow the hormone changes that occur during a female dog’s heat cycle. Progesterone begins near baseline, starts rising around the preovulatory LH surge and continues increasing through ovulation and the fertile period.

The purpose is not simply to obtain a number. The real value comes from comparing serial results over time. That trend helps the reproductive veterinarian estimate when the LH surge occurred, when ovulation likely followed and when the released ova should be mature enough for fertilization.

Serial timing becomes especially valuable when:

• The stud and female live in different states or countries.
• Fresh-chilled semen must be collected and shipped overnight.
• Frozen semen is being thawed for a narrow insemination window.
• The female has an irregular, early or late cycle.
• Previous breedings failed despite apparently normal fertility.
• A reproductive veterinarian is planning TCI or another insemination procedure.

Why progesterone timing matters for dog breeding

Some female dogs ovulate early, others late, and visible behavior does not always match the true fertile period. A female may flag, stand or attract males before the optimal window—or refuse to stand even when laboratory results show the cycle has advanced.

Improper timing is a common reason for conception failure. This risk increases when semen has reduced longevity after collection, chilling or freezing. Accurate ovulation timing can help:

• Reduce unnecessary travel, collections and repeat shipments.
• Match the insemination day to semen type and expected longevity.
• Coordinate the stud owner, collection clinic, carrier and receiving veterinarian.
• Identify abnormal or stalled cycles that require veterinary evaluation.
• Estimate gestational age more accurately than counting from the mating date alone.

When should dog progesterone testing start?

There is no universal first test day because the onset and length of proestrus vary. Many breeding programs obtain an early baseline after visible heat begins and repeat the test every 48 hours until the initial rise approaches. A veterinarian may start earlier for females with short, irregular or previously missed cycles.

Practical testing sequence

1. Notify the reproductive veterinarian at the first reliable sign of heat, such as vulvar swelling, bloody discharge or strong male interest.
2. Establish a baseline. This helps show that the female was tested before the meaningful rise.
3. Repeat approximately every 48 hours while progesterone remains near baseline, unless the veterinarian recommends a different interval.
4. Tighten the interval near the rise. Daily testing may be appropriate when the window is narrowing, the history is unusual or frozen semen is planned.
5. Keep the platform consistent. Avoid switching between laboratories or analyzers mid-cycle unless the veterinarian accounts for the change.

Dog progesterone levels chart: estimated stage and next step

The chart below is a breeder-facing reference—not a universal medical protocol. Merck Veterinary Manual notes that no single absolute progesterone value identifies every reproductive stage and that results from different methods are not necessarily comparable.

Canine ovulation timeline: LH surge to fertile window

The key is to count from the estimated LH surge or ovulation—not from the first day of bleeding.

This explains why “she ovulated today” does not automatically mean every insemination should occur that same day. Fresh sperm may survive long enough to wait for egg maturation. Frozen-thawed sperm generally provides far less margin, so placement is timed closer to mature ova.

How to read serial dog progesterone results

A single result is a snapshot. A series reveals the shape of the cycle.

Look for these four things

• Baseline: Was the female tested before the rise?
• Initial sustained increase: Did progesterone move clearly above baseline and continue rising?
• Rate of change: Is the value progressing normally, rising rapidly or appearing to stall?
• Days since the estimated LH surge: Where is the female in relation to expected ovulation and oocyte maturation?

A result of 5 ng/mL may mean something different when yesterday’s result was 1.8 than when a result three days earlier was already 4.8. The trend, interval and assay matter.

Breeding timing by semen type and insemination method

Semen type and placement method are related, but they are not the same thing. The reproductive veterinarian should choose the combination based on semen quality, shipping time, female history and the estimated stage of the cycle.

Example: turning progesterone results into breeding days

Illustrative series:

• Monday: 0.8 ng/mL
• Wednesday: 1.9 ng/mL
• Thursday: 3.6 ng/mL
• Saturday: 7.4 ng/mL

The Wednesday-to-Thursday increase may place the estimated LH surge around that period, while the Saturday result may be consistent with ovulation progression. The reproductive veterinarian would count forward from the estimated LH day, consider the analyzer and decide when mature ova and viable sperm are most likely to overlap.

A fresh-semen plan may allow multiple breedings across a broader period. A frozen-semen plan would generally be narrower and would require the veterinarian to select a precise post-ovulation appointment.

Progesterone testing vs. LH testing, vaginal cytology and vaginoscopy

LH testing

Direct LH testing can identify the central hormonal event used to time the cycle, but the surge may last only 12–24 hours and can be missed. Daily sampling is typically required. Progesterone is commonly measured alongside LH in case the brief surge is not captured.

Vaginal cytology

Cytology evaluates changes in vaginal epithelial cells and helps confirm that the female is progressing through estrus. It is useful for deciding when hormonal testing should intensify, but cytology alone does not pinpoint ovulation with the precision needed for high-stakes chilled or frozen semen.

Vaginoscopy

Vaginoscopy allows the veterinarian to evaluate changes in the vaginal mucosa, including crenulation associated with the fertile period. It can add valuable context but is best used with hormone testing and cytology.

Common progesterone and breeding-timing mistakes

1. Starting too late. Without a baseline, it becomes harder to identify when the initial rise occurred.
2. Stopping after one test. A single number cannot show direction, rate of change or a stalled cycle.
3. Switching machines mid-cycle. Different methods may create an artificial jump or drop.
4. Counting from bleeding alone. The first day may have been missed, and female cycles vary.
5. Shipping chilled semen before progression is confirmed. Early arrival can use up viability before the fertile period.
6. Treating ovulation as immediate peak fertility. Canine ova need time to mature.
7. Using fresh-semen timing for frozen semen. Frozen-thawed sperm generally requires a much tighter window.
8. Ignoring semen quality. Perfect timing cannot compensate for an inadequate dose or severely compromised motility.
9. Waiting to locate a repro clinic. TCI appointments, weekends and shipping cutoffs should be addressed before the window arrives.
10. Assuming a female’s cycles are identical. Prior history is useful, but one heat may differ from the next.

Semen quality: the other half of breeding success

Accurate timing is only one part of a successful breeding. The collection and receiving clinics should evaluate whether the dose is suitable for the planned method.

Important semen measurements

• Motility: the percentage and quality of forward-moving sperm.
• Concentration: the number of sperm within the sample.
• Total motile sperm: a more useful dose-level measure than concentration alone.
• Morphology: the percentage and types of structurally abnormal sperm.
• Post-thaw quality: critical when evaluating frozen doses.
• Collection fraction and contamination: handling affects the final usable sample.

For shipped semen, quality should be evaluated at collection and again at the receiving clinic when practical. The receiving report helps distinguish a timing problem from a collection, extender, transit or dose problem.

What Venomline has learned from shipped-semen breedings

A successful outside-stud breeding is a coordinated medical and logistics process—not simply “shipping a box.” The female owner, stud owner, collection clinic, carrier and receiving veterinarian all affect the outcome.

Before the female enters heat

• Select the stud and complete the breeding agreement.
• Confirm where the stud will be collected and who will prepare the shipment.
• Choose a receiving veterinarian that performs the intended insemination method.
• Ask which progesterone analyzer the clinic uses and how quickly results return.
• Review weekend, holiday and weather-related shipping limitations.
• Confirm whether a backup collection or second shipment is possible.

During the heat cycle

• Send every progesterone result—not only the newest number—to the receiving veterinarian.
• Include the date, time and analyzer with each result.
• Do not schedule collection solely from standing behavior.
• Confirm the receiving clinic will be open and prepared when the shipment arrives.
• Track the package and keep the collection clinic, breeder and receiving clinic informed.

After delivery

• Record the arrival time and package condition.
• Have the receiving clinic evaluate the dose when appropriate.
• Document the insemination date, method and female’s progesterone timeline.
• Schedule pregnancy confirmation based on the veterinarian’s recommendation.

Frozen-semen case study: 10 puppies from one King Koopa dose

Frozen semen can produce an exceptional result when the stored dose, thaw procedure, female timing and veterinary placement are aligned. This historical case is presented as an outcome record, not a recommendation of one procedure over another; current options, welfare standards and local law should be reviewed with the treating reproductive veterinarian.

• Client: Evolved Bullies, Australia
• Stud: Venomline’s King Koopa
• Semen: Frozen
• Documented method: Surgical insemination
• Outcome: 10 healthy puppies from one dose

The lesson is not that every frozen dose will produce ten puppies. It is that frozen semen is not inherently ineffective; it is simply less forgiving. Storage, thaw quality, timing, dose and veterinary technique all matter.

Can progesterone testing predict a dog’s due date?

Progesterone timing can help establish a more reliable reproductive timeline than counting from a mating or insemination date. This matters because sperm can survive before fertilization, multiple breedings may occur, and the breeding date is not necessarily the conception date.

Merck Veterinary Manual describes parturition as typically occurring about 64–66 days after the LH peak. The veterinarian may combine the estimated LH surge, ovulation timing, ultrasound findings, radiographs, clinical signs and late-gestation progesterone testing when planning delivery or a medically necessary C-section.

How much does dog progesterone testing cost?

Pricing varies by region, clinic, analyzer, laboratory fees, number of samples and whether interpretation is included. Ask the clinic:

• Is the blood draw included?
• Is the test run in-house or sent to an outside laboratory?
• How quickly are results available?
• Which analyzer or method is used?
• Does the fee include vaginal cytology or reproductive consultation?
• Is after-hours or weekend testing available?

Serial testing costs more than one test, but it can protect a much larger investment in stud fees, overnight semen shipping, frozen-dose transfer and insemination procedures.

Download the dog progesterone timing chart

Print the timeline and bring it to the reproductive clinic so the breeder, stud owner and veterinarian are working from the same documented plan.

Veterinary references

This guide combines Venomline’s practical shipped-semen experience with veterinary reproduction references. Medical decisions should be made by the treating veterinarian.

1. UC Davis School of Veterinary Medicine — Ovulation Timing in the Dog
2. Merck Veterinary Manual — Breeding Management of Bitches
3. Cornell University College of Veterinary Medicine — Canine Reproductive Function Tests
4. American Kennel Club — Fresh and Chilled Semen Breeding Guidance

Continue planning your breeding

• How American Bully Stud Service Works
• Available American Bully Studs & Fees
• Documented Venomline Client Litters
• How to Become a Successful American Bully Breeder
• The Pocket Bully Breeder’s Blueprint
• Linebreeding, Inbreeding & Outcrossing
• Foundation Females in American Bully Breeding