Can a female dog get pregnant while bleeding during the heat?

Can a dog become pregnant when she is bleeding? There is a widespread belief that dogs cannot get pregnant during the first days of the heat. We see from where this is coming.

Two dogs on a date.
Photo by Carlos Moron Villar

For one thing, it’s easy to assume that first days it’s all just starting up, so there’s no need to worry. The second source is that we like to compare the bleeding of dogs to menstruation in humans. However, it’s a fundamentally different thing. We’ll get to it later.

Your dog can become pregnant while bleeding. That is, even if copulation occurred on the first day of the heat. Here are several reasons why:

  • Red discharge of dogs is not the same as menstruation for women. Human menstruation means that the ova did not get fertilized and is now extracted from the body. It happens right after the fertile days and woman cannot get pregnant during this time. However, so-called “bleeding” in dogs is not the same thing; it happens before, not after the fertile days. This means, when your dog is bleeding, you have to become careful to avoid unwanted pregnancy.
  • It’s hard to predict ovulation. Technically the first days of the heat are safer. Insemination will not occur during the early days, because it cannot happen before the ovulation. Ovulation is triggered by hormones several days after the beginning of the heat. While on average, dogs ovulate in the nith day of the heat, it can occur anywhere from the third and seventeenth day. Three days is not much, and it’s even worse if you do not know when the heat started.
  • It’s easy to miss the beginning of the heat. The first sign of the heat is a bloody discharge from the vulva, often incorrectly labelled as bleeding. But what if the discharge is not red, but pink or yellow, or the dog is very clean about herself? Noticing the beginning of the heat is hard. Therefore you can’t quite know form when to start counting the days. And even if you take blood tests to monitor ovulation, there is one more thing why copulation before it isn’t safe.
  • Sperm may survive up to seven days inside the uterus. This works as evolutionary insurance since sex in nature is not that predictable. It happens when two dogs meet, not when the ovulation occurs. That’s why a male dog’s sperm is remarkably viable and can survive in the uterus of female for several days. This means, forget about potential three days that might be safe at the beginning of the heat. They are not.

Therefore, a dog can become pregnant while bleeding. Foremost, bleeding in dogs is not menstruation. It signifies the beginning of the fertile days, not the end of them as for humans. And, even if we consider the first days of the heat as a warm-up phase, you cannot get rested. Things will get wild rapidly.

You can learn more about the heat cycle in female dogs here.