Can A Dog Get Pregnant In Silent Heat?

Photo by Nathalie SPEHNER on Unsplash

Oh, my God, I never thought of that! My dog getting pregnant without me having an idea she might be in silent heat? What is silent heat anyway and how come I never knew about this?

If you’re wondering about this, don’t worry you are not alone. Many other dog owners out there are facing the same dilemma. Sometimes it is impossible to tell if your female dog is in heat and leaving her for even a short time out of your sight is enough to get her in the family way and by the time you find out it’s too late.

All you can do is prepare yourself for a whole litter of puppies! Since this is not what you had in mind when you first got that dog you love so much, let’s talk things through and see how you can make sure this doesn’t happen to you – or your dog!

Understanding the fertility cycle of a female dog

Many pet owners like you decide to wait for their dog to go through one or two heat cycles before spaying her and most vets recommend this approach. Small and medium-sized dogs experience their first heat cycle at six months of age, while some breeds of bigger dogs can take as long as one year.

Female dogs normally have two heat cycles per year, but each dog differs in length of the heat, discharge amount and hormonal changes.

Female dogs are fertile when they bleed

One false assumption many people make is believing a dog’s heat cycle is just like a woman’s menstrual period. Wrong, they are quite the opposite. A woman is not fertile during her period, while dogs are very much so and basically sending out signals to all the male dogs in town to come and mate with her!

Yes, you might notice some behavioral changes, like the dog’s heart beating fast and shaking as she is anxiously waiting for her suitors, but the real signs are more subtle than that, and humans don’t get them.

The four stages of a dog’s fertility cycle

First, the part you’re most interested in. A female dog’s heat cycle lasts for an average of 21 days, quite a long time for the owner to be vigilant.

Proestrus stage – the first stage can last an average of 9 days and the most noticeable sign is the swelling of the vulva, which can be more or less obvious. If you don’t see that, you might notice a change in personality. Your dog will probably become more affectionate, even clingy – she knows she’s about to mate but she’s not ready for that yet.

Estrus Stage lasts for another 9 days on average and this is the dangerous time because the dog starts releasing eggs for fertilization and it is in her nature to call out to any dog who might take care of this problem. If she’s experiencing silent heat, she might not be very quiet. You will notice a rapid heart bit, shaking and panting – typical let-me-out behavior. The dog is fertile for the whole period!

Diestrus Stage means she is no longer in heat or fertile. The dog will experience a gradual disappearance of the vulva swelling and will lose interest in male suitors. This period lasts between 60 and 90 days. If someone made a mistake during the previous stage, this period will cover the dog’s pregnancy, which lasts around 60 days. If this was a planned thing and you want to breed her, congratulations!

Anestrus Stage is also known as the resting stage. It lasts between 100 and 150 days, a time when your dog couldn’t care less about males.

Yet, six months fly by easily and soon the cycle will begin again!

What is silent heat?

As a responsible pet owner waiting for the dog to go into heat you will be on the lookout for obvious signs, you know, textbook signs like the swelling of the vulva and a reddish discharge. And you wait and then wait a bit more, still, nothing happens. Is there a problem with my dog, should I see a vet?

Well, you probably should as there are some medical conditions which make a female dog have an abnormal fertility cycle, but there’s also the possibility she was in heat and you didn’t notice.

Basically, silent heat means you don’t notice the swelling of the vulva or the tell-tale discharge. It might be that the discharge is in fact very light and, well, maybe you have other things to do than watch your dog’s behind. Or it is quite possible that your dog is very fastidious about cleanliness and licks away the discharge so there’s nothing for you to see. Kinda gross, I know, but on the other hand, you wouldn’t want your dog wiping herself all over your carpet, would you?

So, the heat is silent – or better said invisible – to you. Well, don’t count your blessings because all the male dogs in your area got the message pretty fast.

Even if there are no visible signs, your dog has ovulated and is ready to be impregnated. No, scratch that, she is anxious to be impregnated and uses pheromones to advertise that. It is the smell of those pheromones that send out the message loud and clear – I’m here boys and I’m waiting!

Signs your dog might be in heat

So, you don’t see any bleeding and you certainly can’t smell the pheromones. What other signs are there? Some of the signs you might notice are that your dog might:

  • Urinate more often
  • Raise her leg differently while urinating or when a male dog happens to pass by
  • Pay more attention to male dogs
  • Become lazier or more aroused
  • Show signs of anxiety
  • Run away, to practice hiding from male dogs (Let’s hope this doesn’t happen to you!)

There’s no stopping an unneutered dog!

The unsuspecting clueless owner, you, I mean, will probably notice the dog is a bit restless. The anxiety manifests itself by the dog’s whining or crying. Or maybe the dog’s heart is beating fast and she is shaking. 

What can you do? Since the dog seems otherwise healthy you will probably assume she wants out and open the door to let her run around in the yard. Well, that’s a fatal mistake, my friend, for you I mean, not for the dog. Your dog will probably have a fun time with all the male dogs circling around the fence. 

When they sense a bitch in heat, male dogs can be very persistent and quite resourceful and they usually find a way to get to the irresistible female on the other side of the fence. 

Tip: Take this as a piece of friendly advice. If you go outside and catch the dogs in the act do not try to intervene. It’s not about you being considerate and all, trying to separate mating dogs can be very dangerous for them. How shall we put this? They’re in a pretty tight situation at that particular moment and efforts to separate might result in damaging both dogs’ reproductive parts. Plus, it might already be too late.

What to do when you don’t want puppies

If your dog is pregnant you will notice a few signs, such as weight gain, enlarged and discolored nipples, swelling of the abdomen

However, if you have reasons to believe the dog might be pregnant and you don’t want to deal with a litter, contact your vet as soon as you can.

What are your options? There are different ways a medical abortion can be performed during the first 30-40 days of the pregnancy. The vet can administer a shot or more to terminate the pregnancy and the procedure might require hospitalization.

There is also the possibility of spaying the dog while pregnant, which involves the removal of the uterus and the ovaries. It is the best option if you were going to spay her anyway, but it is also risky if the pregnant uterus is too enlarged with puppies. Removing the uterus at this stage could result in a dangerous hemorrhage.

Quick recap: What you need to keep in mind as a pet owner is that your female dog typically has two heat cycles per year. Even if you’ve done your research and know all the signs of heat, they might be missing. This is what silent heat means and the important thing is your dog is very much fertile during this time! If you notice any unusual sign or change in behavior around the time you think she should be in heat better don’t let her out of your sight if you don’t want puppies!