Progesterone
Canine Progesterone, commonly known as luteal hormone, is a natural pregnancy hormone secreted by the ovaries after maturity, and is one of the most accurate methods for determining the ovulation time in female dogs. By monitoring changes in progesterone levels in the blood, the optimal breeding period can be identified, with a pregnancy rate in female dogs exceeding 85%, thereby increasing the success rate of reproduction and litter size.
Estrus Cycle of Female Dogs
Under normal circumstances, female dogs will go into heat once before the age of 1. Afterward, they will go into heat twice a year, typically in the spring (March to May) and autumn (September to November). Each estrus cycle lasts for 5 to 12 days on average, with an average of 9 days, although some may last up to 21 days.
The estrus cycle of dogs can be divided into four stages: proestrus, estrus, diestrus (also known as “luteal phase”), and anestrus.
Proestrus
Average 9 days
(0-27 days)
Swelling of the vulva and red discharge attract males, but mating is not accepted.
Estrus
Average 9 days
(4-27 days)
During ovulation, the female dog accepts the male.
Diestrus
About 2 months
(56-100 days)
Depends on whether pregnant
Regardless of pregnancy, the ovaries produce a large amount of progesterone.
Anestrus
4-5 months
Until the next proestrus, the dog is sexually inactive.
Signs of Estrus in Female Dogs
Female dogs become more excited, active, restless, bark loudly, and their eyes become bright; the vulva swells, becomes red, and discharges red mucus with blood, and their appetite decreases. They urinate frequently, raise their tails, arch their backs, and like to approach male dogs.
Dog Breeders can judge and start progesterone testing based on the behavior of female dogs.
Factors Affecting Estrus in Female Dogs
Factors such as the age, physical condition, and living environment of female dogs will affect the variation of their estrus cycle to varying degrees. Each estrus cycle of the same female dog is different. If mating is desired, judging the estrus cycle based on changes in the color of the female dog’s external genitalia and vaginal secretions will result in a lower pregnancy rate.
Advantages of Progesterone Testing
- Progesterone testing is currently the most advanced and accurate method for determining the ovulation cycle of female dogs. It can determine the optimal breeding period and increase the number of litters in female dogs.
- It is not reliable to determine the optimal Canine breeding period by observing changes in the behavior of female dogs during estrus or inferring the days from previous cycles, as it is easily influenced by individual differences.
- Vaginal smears reflect changes in the morphology of vaginal epithelial cells as hormone levels change. However, only observing changes in vaginal epithelial cells often leads to delays, and there are differences in the subjective judgment of results by laboratory personnel. Therefore, vaginal cytology alone cannot be used to determine the timing of mating.
- Dog Progesterone testing is low cost, not limited by space, supports on-site and at-home testing, saves time and costs, and reduces the economic pressure on pet owners and the psychological pressure on dogs to go to clinics.
- Testing progesterone in dogs does not require extensive experience. The Haiweite Progesterone Test only requires 75μL of serum/plasma sample from the dog, and results can be obtained in 15 minutes, accurate, fast, and convenient!
How to Determine the Optimal Breeding Period with Progesterone Testing?
The follicles and corpus luteum in the ovaries are responsible for secreting estrogen and progesterone. When progesterone gradually increases and estrogen decreases, it stimulates the appearance of the LH (dog luteinizing hormone) peak, leading to the female dog accepting mating and showing signs of other estrus periods. As the follicles mature, rupture, and ovulation occur, followed by entering the “luteal phase,” the concentration of progesterone in the body will significantly increase. Generally, 2 days after the LH peak is the ovulation period, and thus the optimal conception period.