How Long After Mating Can You Ultrasound Scan my Dog?

More accurate puppy counts are possible when you bring your dog for a scan 28-32 days after last mating. 

What Is A Progesterone Test For Dogs?

A progesterone test analyses a blood sample for circulating progesterone, in dogs it is the hormone that indicates ovulation and helps maintain a pregnancy. 

By testing progesterone levels, you are able to pinpoint the day of ovulation and plan matings that are more likely to result in success.


The progesterone test that we offer is run on the state of the art MiniVidas Blue; it provides quantitative results meaning it will provide an accurate numerical value of circulating progesterone (not a colour change/PreMate, that is inaccurate) and is therefore able to pin point ovulation and subsequently the best day to mate your dog. 

Why Progesterone Test?


It is recognised that in the dog up to 75% of failures to conceive can be attributed to incorrect timing of breeding. ¹

More precise timing of the breeding events is required when:

  • There is limited access to the stud

  • When artificial reproductive techniques are going to be used

  • When the quality of the semen is questionable.


The ability to accurately time breeding is of practical and economic importance to breeders. Optimal timing helps breeders:

  • Maximise pregnancy rates and litter size (Semen and stud fees are expensive.)

  • Plan travel for matings

  • Optimise of time for assisted breeding techniques (artificial insemination using fresh, chilled, or frozen


  • Optimise the timing of breeding when access to the stud is limited to one or two matings

  • Prevent unnecessary use of male

  • With the planning of matings when the same male is used on two bitches simultaneously

  • Optimise the time for breeding in bitches that have a history of non-receptivity or show silent heats

  • Estimate expected whelping dates more accurately based on a known ovulation date.


Successful fertilisation typically occurs between 3–4 days before the end of estrus. By simply observing a bitch during her heat cycle, there is no way of knowing when the end of estrus will be. To complicate matters, some bitches may bleed throughout their entire heat period, whereas other may not, some bitches may stand for a stud willingly, even long before there are eggs available for fertilisation, whilst others may only be receptive for a day or two.  There are many other variations and idiosyncratic behaviors that can confuse the breeder, all contributing to a missed opportunity to breed the bitch successfully.

The ovulation test is most commonly used by breeders who are subject to large stud fees and require some sort of guarantee that their bitch had the correct progesterone levels; if their bitch does not become pregnant, but had the correct progesterone levels, the fault is usually the stud dog.

It is a common misconception among breeders that the heat cycle and the point at which a bitch will allow mating replicates itself in each repeating heat cycle of each individual bitch. The breeder then uses the data from a previous cycle and applies it to the next cycle. For instance, because a bitch was previously successfully bred on day 10 (starting from first signs of heat), the breeder will keep on mating that specific bitch on day 10. While this might work in some cases, it most certainly won’t work in all cases. Similarly, it is not always true that the stud can sniff out exactly when the bitch is at her peak (optimum time for fertilization).

Hormones of a Bitches Cycle

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Progesterone starts to rise just before ovulation, toward the last week of the heat cycle. It is well established that as soon as the progesterone levels are around 2 ng/mL, luteinising hormonepeaks and ovulation takes place when the progesterone levels are around 5–8 ng/mL. From this point, eggs require 48 hours to mature, and by that time the progesterone levels usually average 10 ng/mL or above.

When Should I Start Testing My Dog's Progesterone Levels?

We recommend taking an initial sample at day 9 following your dog showing the first signs of bleeding. Subsequent tests/advice will depend on this initial result. 


Small How Many Blood Samples will we Need to Run?

We try and limit the number of tests required to accurate predict ovulation. It is better to take an initial sample and retest 3/4 days after than to completely miss ovulation. Typically two or 3 tests are required. 

References and additional resources

  1. Johnston SD, Kustritz MVR, Olson PNS. Canine and Feline Theriogenology. Philadelphia, PA: WB Saunders; 2001.