So often, timing is everything, and in the case of canine breeding, success depends on ovulation timing. While most mammals ovulate when the estrogen in their blood is increasing, canines ovulate when the estrogen level in their blood is declining and the progesterone level is increasing. In order to reduce the number of breedings required and increase maximal pregnancy rates and litter size, it’s important that breeding attempts be made when progesterone levels are high.
Why are progesterone levels important?
Progesterone levels initially rise at the beginning of a canine’s ovulation (or fertile) period. Ovulation occurs when progesterone levels are between 4 to 10 ng/ml and can reach levels of 10 to 15 ng/ml by the end of the fertile period. Breedings should be planned four to six days after the initial rise, and two to four days after the ovulation begins. Baseline or initial progesterone levels can vary from one canine to another, so it’s important to start progesterone testing early enough to define baseline levels.
Following ovulation, it takes eggs two days to mature and be ready for fertilization. Once the eggs have matured, they are capable of being fertilized for about two days. In other words, the fertile period in a canine begins two days after ovulation and lasts for the next three to four days. Progesterone levels rise between 4 and 10 ng/ml at the time of ovulation. While progesterone rises slowly before ovulation, progesterone levels rise rapidly after ovulation. A rise of about 3 to 4 ng/ml in a 24-hour period, after progesterone levels have already reached a baseline of 4 ng/ml, is confirmation of ovulation.
How are progesterone levels tested?
Progesterone levels are not species specific, which means that the test can be run in almost any veterinary lab, or in even human labs. Results should also be available in less than 24 hours, which is important when working in a tight timeframe for breeding.
A canine’s progesterone levels can be tested every two to three days starting about three to five days into the ovulation period. There are two ways to measure progesterone, whether in-house at your local animal hospital in Phoenix, AZ or in a laboratory:
- In-house tests: These tests typically come in packs of five to 10 and must be refrigerated. These tests are semiquantitative enzyme-linked immunosorbent assay (ELISA) tests. These tests are most accurate when two progesterone standards are run alongside a sample. In-house tests are easy to do and will give results within 30 minutes, but they do require accuracy in timing and handling.
- Laboratory tests: These tests are more complicated, but also more accurate. Laboratory tests are either radio immunoassays or chemiluminescence assays. Laboratory tests are reported in ng/ml, which means predictions can be made more accurately.
Where can you get your canine’s progesterone levels tested?
Testing your canine’s progesterone levels can help decrease the number of breedings required and also increase pregnancy rates and litter sizes. If you are looking to test your canine’s progesterone levels for breeding purposes, Christown Animal Hospital, your local animal hospital in Phoenix, AZ, can help. To learn more about our services, contact us today!
Categorised in: Animal Hospital
This post was written by Writer