Understanding the Canine Reproductive Cycle and Mating
Breeder Information Series
As a dog breeder, having a comprehensive understanding of the canine reproductive cycle is crucial for successful breeding practices. This knowledge not only ensures the health and well-being of the breeding dogs but also contributes to the production of healthy litters.
When does a dog become sexually mature?
Dogs usually attain puberty 2 to 3 months after reaching their adult size, which will be sooner for small breeds compared to large breed dogs. The average puberty occurs between 6 to 12 months but can take up to 24 months! The first reproductive cycle, known as the estrous cycle or heat, can be abnormally prolonged or split, and may occur sooner in dogs housed together with other dogs in heat. While most dogs cycle every 6 to 7 months, some breeds such as the Basenji and sled dogs will cycle once a year, while other breeds may cycle up to three times a year.
The Canine Reproductive Cycle
The reproductive cycle of a dog, also known as the estrous cycle, is divided into four distinct stages:
Proestrus: This stage marks the beginning of the heat cycle and lasts from 3 days to 3 weeks, with 9 days average. During proestrus, female dogs (bitches) start to attract males, but they are not yet receptive to mating. Under the influence of a gradually increase in estrogen, physical signs include a swollen vulva and a bloody vaginal discharge. Behavioral changes may also be observed. This can include:
Being more friendly to other dogs, particularly males, and prone to wandering to seek out males.
Mounting or humping other dogs, pets, and toys, or gathering toys into a sleeping area.
Moving her tail to one side (flagging) when touched or when around male dogs, while some dogs may protect their rear end.
Being anxious, clingy, or nervous, and possibly eating less.
Marking her territory with urine, even lifting her leg like a male.
Estrus: Lasting about 5-10 days, this is the stage where the female is receptive to the male and is characterized by maximum estrogen levels. Ovulation normally occurs during the earlier part of this period. The vaginal discharge decreases and changes in color from red to a straw-like color. It's the optimal time for breeding. (See determination of ovulation and ideal breeding timing).
Diestrus: This phase follows estrus and signifies the end of the female's receptiveness to the male. Diestrus lasts about 60-90 days, regardless of whether the female is pregnant or not and is characterized by high levels of progesterone required for a successful pregnancy. Length of pregnancy and the estimated whelping date is most accurately determined as the time from ovulation, not from the start of the estrous cycle nor from the dates of breeding (see here for calculation whelping dates) (see here for pregnancy diagnosis)
Anestrus: The final stage is a period of sexual hormonal inactivity, lasting about 4-5 months, before the cycle starts again. Both estrogen and progesterone levels remain low during this period.
Timing of Mating
The timing of mating is critical for successful conception. Ovulation typically occurs in the early to middle of the estrus phase, but this can vary. Progesterone tests and vaginal cytology can help determine the best breeding time. Generally, mating is recommended a few days after the onset of estrus when ovulation is not known, but mating timing can be improved with knowledge of the timing of ovulation (see here for information on timing for ovulation and breeding).
Mating Process
Natural mating should be supervised to ensure the safety and comfort of both dogs. The male will mount the female, and a 'tie' occurs, where the male and female are locked together for 5-20 minutes. During mating, part of the male’s penis known as the bulbis glandis swells within the female vaginal tract, physically locking the dogs together. This is a normal part of canine mating and should not be interrupted as it increases the chances of successful fertilization.
Considerations for Breeders
Health and Behaviour Screening: Both male and female dogs should be health screened to avoid the transmission of genetic diseases and the dogs’ behaviours considered to ensure they are fit for breeding. In addition, breeding dogs should be up to date on vaccinations and free of parasites and infectious disease. (See here for advice on health screening).
Age of Breeding: Females should not be bred during their first heat cycle. It's generally recommended to wait until they are at least in their second or third cycle, depending on their size and breed. Males can begin breeding once they reach sexual maturity, but it's often advised to wait until they are physically and mentally mature.
Nutrition and Care: Proper nutrition and care are essential during the breeding process. This includes a balanced diet, regular exercise, and a stress-free environment. (See here for advice on nutrition during pregnancy).
Professional Guidance: Consulting with a veterinarian, especially one with expertise in canine reproduction, is invaluable. They can provide guidance on health screenings, timing of mating, and care during pregnancy.
Conclusion
Successful dog breeding requires a deep understanding of the canine reproductive cycle and a commitment to the health and well-being of the dogs involved. By ensuring that both the male and female are healthy, understanding the timing of mating, and providing appropriate care throughout the process, breeders can contribute to the birth of healthy puppies and the welfare of the breeding dogs. Always remember, responsible breeding practices not only benefit the dogs but also enhance the reputation and success of your breeding program.