The mating process is different for dogs than for other species. Dogs can only get pregnant when they come into heat. Their heat cycles are fairly regular; they can occur as often as every several months or just once a year. If you are looking to breed your dog, you must become familiar with the different stages of the heat cycle so you know the best time to breed.
There are four heat stages in dogs. The first one, proestrus, can last up to 20 days, although 7-10 days is normal. During this stage, the vulva swells up and bloody discharge is released. You may notice male dogs hanging around the female. The day you notice the discharge is considered “Day 1.” Be sure to make a note of this, as this is important for breeding purposes. The female is not ready to breed at this time, but males will still want to try, so you may want to protect your dog by keeping her locked up or covered with underwear or a diaper.
The next stage, estrus, occurs when the discharge pales in color. It may turn pink or straw-colored. The dog will whine more often and shift her tail to the side to show male dogs that she is ready to breed. This stage lasts anywhere from 5-14 days. A female can become pregnant at this time, so watch her closely. If you want to breed her, now is the time to take her to the stud. If not, keep her at home, preferably inside the house or in a tightly-fenced area. Pregnancies can still occur through chain-link fences and kennels.
The third stage, diestrus, occurs at around the 24th day. This stage can last 2-3 months. The bleeding has stopped and the female is no longer fertile at this stage, but she still has a scent that may attract males.
Anestrus is the final stage, the point where the female is back to normal and unable to become pregnant. This lasts about 2-3 months, after which the dog will emit bloody discharge and start the heat cycle again.
Females are ready to mate at around Day 10 of their heat. This process can be hard for some dogs. The female will show her interest by playing with the male and shifting her tail to the side. If she is not ready, she may growl or snap. An inexperienced male may need some time to find the female’s vulva, so expect many breaks. Keep fresh water on hand, as they will be panting from the excitement.
The male will start humping and then mount the female by approaching her from behind and pulling her body toward him. After he penetrates the vagina, he will start thrusting. The penis of a dog has a bone and tissue called bulbus glandis, which swells when inside the female. This locks the dogs together in what is known as a tie.
The tie can last 5-30 minutes. During the tie, the male will move around the female until both rear ends are touching. The dogs are safe to untie when the swelling goes down. It is advised to never try to untie the dogs, as this can seriously injure both.
The process can continue every other day until the female is no longer receptive, which could be after a week or so.
It is not always necessary for the dog to tie in order for a pregnancy to occur. In some cases – inexperience on the part of the male or situations when the female refuses to say still long enough – the male may not tie with the female but still ejaculate in a process called slip mating. The richest part of the sperm is released while the male is thrusting. By the time the dogs tie, the female should already have sperm in her. Therefore, a litter is still possible. Many puppies have been born through slip mating.
If there are reasons why natural breeding would be impossible – such as long distances – it is acceptable to use artificial insemination. The semen can be fresh or frozen and still comply with AKC rules. However, there are other procedures that must be followed, so be sure to read them thoroughly before impregnating your dog through this method.