Progesterone Timing


One of the most important things to test for when breeding your bitch is progesterone/ovulation timing. Regardless of the method of breeding or type of semen used, ovulation timing is the most crucial aspect of a successful breeding.

In order to successfully time ovulation, you must:

  • Know when your bitch has come into season (Day 1 of the cycle)
  • Test for progesterone levels beginning on Day 5 or 6
  • Test LH levels (if necessary)
  • Get a vaginal cytology done, to confirm the timing physically through cell shape along with the progesterone levels

One major benefit we have at All Pets is that we have a top of the line machine made by TOSOH called the AIA-360 in our reproductive center. This on site machine is excellent in testing progesterone levels and is measured in nanograms/mL. The biggest benefit of having this machine is that daily tests can be run when your bitch comes into season and we can have the results in under an hour and a half. This is advantageous because many progesterone tests need to be sent to an outside lab, where the results would be received the next day. In cases like this, the progesterone levels of your bitch could change drastically in the amount of time that you are waiting for these results. This means that the window of time to breed could have already passed before you have received the results!

Progesterone tests help us determine when the LH surge occurs, when ovulation occurs and when the most fertile time in the cycle is. These tests should be run every other day to determine the LH surge. When the progesterone values double or the levels are between 2.0-4.0 ng/ml on the AIA-360, this should correlate with the LH surge.

Ovulation generally occurs between 48-72 hours after the LH surge. The eggs should be fertilized 48 hours post ovulation and are only viable for fertilization for another 48-72 hours.

After the LH surge is determined, consider that day 0 of the cycle. Four days from day 0, is when the first day of a natural breeding or chilled semen can be implanted. During this time the progesterone level using the AIA-360 is approximately 12.0-27.0 ng/mL

Please note: Every cycle is different. The cycle is never truly the same, and varies dog to dog, and with each new cycle.This is why it is so important to do ovulation timing, so that we can determine the most fertile period for breeding.

In addition to this, before breeding, you will need to determine both the type of semen you intend to use and the method of insemination.

For more information: Please refer to the Artificial Insemination Section of our website.