This Is How Dogs Reproduce

You've surely seen two dogs mating at some point, or a dog trying to mount its owner's leg... These are common acts in the canine world, as natural as life itself.

Let's look at how and when our four-legged furry friends reproduce.

Reproductive Maturity in Female Dogs

Actually, this varies a lot depending on breed, dog size, and environment, as incredible as that might sound. Females belonging to small dog breeds reach sexual maturity from around seven or eight months old, which is when they usually have their first heat.

That said, females belonging to large dog breeds delay this maturity until around nineteen months old, also having their first heat around then.

The truth is there's no exact set date, but the ones we've mentioned are the most common, so if your female is a month early or two months late having her first heat compared to these dates, there's no need to worry.

Males, on the other hand, mature sexually earlier, and generally from around seven months old they're able to mount, though this isn't recommended at all. Ideally, we'd wait until our dog is two years old for its first mounting.

Heat in Female Dogs

Female dogs typically go into heat a couple of times a year, though each cycle can even last months... Usually the duration is shorter, with about thirty days being typical.

During this period, the female goes through different stages of heat, divided into Proestrus and Estrus.

• Proestrus is the stage where the female starts her heat — her vulva swells slightly, and the typical heat bleeding begins. This stage usually lasts around ten days, and although some males may be attracted to the female, she won't let them mount her yet.
• Estrus is the second stage of heat, where bleeding decreases considerably and the vulva swells. This is the phase when the female is most receptive to mounting, and for a few days she'll be very receptive to males courting her. Estrus lasts around ten days.

After these twenty days of intense heat, the phase called "Diestrus" begins, when the female starts refusing to be mounted by males again, and her heat gradually fades completely.

Canine Reproduction

When we have a sexually mature female in the "Estrus" phase and pair her with a sexually mature male, the courtship stage begins. This is a stage where the male flirts with the female, smells her (the female releases pheromones very attractive to the male), they get to know each other a bit, and after some preliminaries, mounting begins.

Mounting is the second stage of reproduction — this is when the male places his front paws on the female's back and tries to penetrate her. After a few attempts, copulation and the turn will begin, which is the third phase.

During copulation and the turn, the male has already inserted his penis into the female's vagina, and it's swollen, making it impossible to withdraw. The male then turns one of his back legs, resulting in the well-known "turn," when both dogs end up locked together by their private parts, entering the tie phase.

The tie is that period of time when both are joined without being able to separate — it usually lasts between twenty and sixty minutes, and it's very important not to try to separate them under any circumstances (or you could cause both serious injuries). It's during this phase that the male ejaculates forcefully, likely getting the female pregnant.

When the male relaxes, his penis deflates, and they finally manage to separate, ending the tie.

How Long Does Mating Last?

Assuming both dogs are ready for it, mating can happen at any time. Keep in mind it can last between half an hour and an hour and a half, so you need patience and, above all, let them proceed calmly.

Females don't tend to be very selective when receptive, so they can be mounted by several different males during the same heat cycle.

How to Prevent a Female Dog From Going Into Heat or Getting Pregnant

Today, we have many options to prevent our female dog from getting pregnant, with full spaying being the most recommended.

If we spay our female, we'll not only prevent pregnancy — we'll also prevent her from going into heat again and avoid her developing certain illnesses like uterine or mammary cancer.

On another note, there's also the option of using contraceptive injections at your vet clinic, so even if she's mounted, she won't get pregnant. This option is simpler but doesn't eliminate her heat — it's just a temporary fix to prevent puppies.

Lastly, the simplest but least reliable option, since sooner or later something could go wrong, is not letting your female mix with male dogs during her heat. This is somewhat cruel, since she'll be receptive for a few days, but it's another way to prevent pregnancy.