Understanding Progesterone Results
When you’re paying for stud fees, transport, chilled semen, and artificial insemination, you want to be sure that your bitch is 100% ready to breed. Here’s the best way to interpret progesterone test results.
The most difficult part about monitoring the canine reproduction system is that it is incredibly different to any other species. This makes it harder to apply concurrent aspects of our reproduction system, for example, to our pets. In fact, even some professionals do not understand the canine progesterone cycles; the information on this page is very valuable!
The Strous Cycle
The beginning period of the strous cycle is “Proestrus”. At this point, the estrogen levels of the bitch begin to rise. The actual progesterone levels are negligible, often less than 3ng/ml.
However, this point in time is still vital to testing a bitch; this is when a baseline test should take place. Our own research has found this to happen at around day 7/8 of a season, but can be as early day 4, and as late as day 20.
With a bitch of whom has started this cycle out of the blue, a progesterone test baseline should be gathered on day 6 or 7 of her season.
The Estrus Cycle
The next stage of the cycle is “Estrus”. It is at this point the bitch enters her fertile period – the stage at which she may be mated. Ideally, her progesterone levels should rise above the previous (3ng/ml) and she will likely garner much more interest from sexually active males. Sometimes, the bitch may also show interest in the stud dog.
You mustn’t confuse this short yet sharp rise with the true rise, of which is yet to come.
During this time, it is essential to follow the advice and guidance of the fertility specialist. Bitches are only fertile for a small amount of days during this period – not the entire time!
The progesterone levels should continue to rise above 3ng/ml, therefore continuous testing should also take place.
Here’s where it gets interesting; you may find a point where the bitch’s levels surface at around 2.5-3.5ng/ml.
Some may remain higher, some may remain lower.
Regardless, the key aspect you are looking for is a sharp rise. On average, this occurs at around 5ng/ml, but varies from dog to dog.
Once there is a sharp rise, the bitch’s ovary has released an egg. But this is not when you should mate the bitch.
Dogs have very different reproductive systems; upon ovulation in a bitch, the eggs are not mature. The maturing process happens over a couple of days – 48 hours to be exact.
This is a vital point to make as if you choose to use frozen or chilled sperm, it may not be viable if inseminated too early.
The breeding time must occur when the eggs have matured, as guessing how long semen will survive in the reproductive tract is very much a dangerous game.
Now, do note that some reproduction specialist may inquire for more tests. Although most bitches see a rise after 5ng/ml, some don’t.
Your bitch could level out at 5ng/ml then ris to 8ng/ml. It would be at this point that eggs have been released (but are not yet mature).
If you are opting to inseminate with chilled semen, you should delay insemination for at least 48 hours after ovulation. This is because chilled semen will statistically not last as long in the tract as fresh semen. Quality of sperm may also be lower, therefore it would be advised to maximise the chances of pregnancy.
After ovulation, a bitch’s progesterone levels will still continue to rise. Most testing machines will display “H”, indicating the testing parameters are too low to pick up on such a high progesterone level (which is often 50ng/ml+)
The next step would be to monitor any behavioural changes your bitch may incur. They are often very indicative of a successful mating and pregnancy.