31st March 2026
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Timing is often the most important and stressful part of dog breeding. The DOD2 – Dog Ovulation Detector was designed to remove uncertainty and reduce unnecessary mating attempts to ensure breeders have clear and reliable insight into a bitch’s fertile window.
Recently, we were contacted by a customer who felt confused by the pattern of readings from her DOD2. The values did not look exactly like the example shown in the manual, which led her to question whether the device was truly adding value. This is a very understandable concern and one that highlights an important truth about canine reproduction. We contacted our friend and expert, Karen Abbott (of ViiSona in Canada) who came back with an excellent explanation of what was going on and how to interpret readings from the Draminski detector; it’s thanks to her that we can give the details below…
One of the most important things to understand about ovulation detection is that there is no universal or correct set of numbers. Every bitch is different, and even the same bitch can show different values from one season to the next.
The charts shown in manuals are intended only as illustrative examples. They demonstrate a typical pattern, not a fixed template that every cycle must follow.
What truly matters is recognising the overall profile of the cycle. This consists of a gradual rise in readings, a clear maximum peak, and a subsequent decline. This sequence is the biological signal that ovulation has been triggered.
Graph above created by Karen Abbott founder of ViiaSona in Canada
In this example, the readings began at a lower level early in the cycle, with values such as 190 on Day 2 and 330 on Day 3, followed by some natural fluctuation over the next few days. By Day 6 the reading had risen to 350, and on Day 7 a higher value of 480 was recorded in the morning before dropping slightly later the same day. This gradual upward movement is a typical sign that the bitch was approaching ovulation.
A clear maximum value was then recorded on Day 8 in the morning, when the reading reached 600. This was the highest value seen during the entire cycle and represents the true peak. No subsequent readings exceeded this level.
On Day 9, the reading dropped sharply to 310. This sudden decline following the peak is the critical indicator breeders should look for, as it confirms that ovulation has been triggered and that the bitch is entering her fertile window.
Once this drop takes place, the optimal breeding period is typically within 24 to 48 hours. Based on this pattern, the most fertile window fell around Days 9 to 10.
In this case, the breeder chose to carry out the first mating on Day 8, immediately after the peak reading was identified. This is a common and sensible approach, particularly when working with a strong, clear peak. Importantly, mating on Day 8 was still entirely appropriate, as canine semen can survive for several days within the reproductive tract and remain viable until ovulation has fully occurred.
Breeding strategies often fall into three simple categories. An early mating takes place at or just after the peak reading, allowing sperm to be present and waiting when ovulation occurs. An optimal mating is carried out after the post-peak decline, usually within 24 to 48 hours, when the eggs are maturing and fertility is at its highest. A later mating may follow if readings remain supportive, helping to cover any individual variation in timing. Using the DOD2 allows breeders to plan these matings with intention rather than guesswork.
The readings that followed, ranging between the mid-300s and low-400s from Days 10 to 15, show the steadier, post-ovulation phase of the cycle. This is exactly what is expected once the fertile window has passed.
When viewed as a complete sequence rather than as isolated numbers, these readings form a clear and reliable ovulation profile and demonstrate how the DOD2 is intended to be used.
Breeders sometimes become concerned when values rise and fall slightly from day to day. This is completely normal. Ovulation is a biological process rather than a mechanical one, and small fluctuations do not indicate a fault with the device.
The DOD2 measures changes in the electrical resistance of vaginal mucus near the cervix. These changes reflect natural hormonal shifts within the bitch’s body. The individual numbers themselves are less important than the trend they form over time.
Some bitches reach their peak at lower values, while others peak much higher. There is no correct number. What matters is the recognisable rise, peak, and decline.
Questions are sometimes raised about the need for a professional ovulation detector when lower-cost alternatives are readily available online. The difference lies in accuracy, reliability, and consistency.
The DOD2 is a medical-grade instrument designed specifically for canine ovulation detection. It is calibrated, durable, and engineered to provide repeatable results when used correctly. Lower-priced imitation devices may look similar, but they often rely on inferior sensors and uncalibrated electronics. This frequently leads to inconsistent readings and, in many cases, missed breeding opportunities.
For breeders, losing a cycle due to unreliable information can be far more costly than investing in a proven, long-lasting instrument.
In addition to accuracy, the DOD2 is designed with practical day-to-day use in mind. It allows breeders to pinpoint the optimal time for mating, reducing unnecessary travel and repeated attempts. It is capable of detecting silent oestrus and identifying potential reproductive irregularities.
The device features a clear 2.4 inch LCD screen with energy-saving backlighting, making results easy to read and interpret. Its internal memory stores data for up to 100 dogs and 200,000 measurements, each recorded with the date and time.
Powered by four AA batteries, the DOD2 offers approximately 150 hours of continuous operation. It does not require periodic calibration, is safe and straightforward to clean between uses.
When used consistently, at the same time each day, inserted to the correct depth, and cleaned properly, the readings become clear and highly informative rather than confusing.
The accompanying graph above illustrates this cycle clearly, showing a strong rise in values, a definitive peak, and a sharp decline that marks the fertile window. By focusing on the overall pattern rather than individual numbers, breeders can confidently identify important markers.
The DOD2 – Dog Ovulation Detector is not about matching exact numbers or following textbook charts. It is about understanding each dog’s unique cycle and identifying the key moment when ovulation has occurred.
For breeders seeking greater efficiency, reduced stress, and confident, informed breeding decisions, the DOD2 remains an invaluable tool, supporting successful outcomes season after season.
If uncertainty ever arises when interpreting readings, support is always available. Often, taking a step back and looking at the complete pattern is all that is needed.
