At What Age Can Dogs Get Pregnant?

December 16, 2021

at what age dog get pregnant








It’s hard for any pet parent to hear these words, but here it goes: young dogs have sex.

There, we said it. Heck – puppies will try and have sex, too!


Unfortunately, that also means they can get pregnant. 

And, since we don’t want lots of adolescent pups running around with swollen bellies, we’re here to tell you how young a dog can be and yet…still get pregnant. What signs should you look for when they’re pregnant, and, utmost importance, how to prevent unwanted dog pregnancies!

So, without too much more stalling, let’s get into it!

When do female dogs first go into heat?

Just as with humans, dogs have their own form of ovulation known as estrous cycles (also referred to as ‘heat’). Dogs first begin experiencing these estrous cycles when they reach puberty or sexual maturity. The question of when a dog will reach sexual maturity is largely dependent on the dog’s size and breed. 

It’s typical for most dogs to begin to sexually mature by the time they are between 6- and 9-months old. On the other hand, some giant breeds may not reach sexual maturity until they are between 12- and 15-months old.

Can female dogs get pregnant in their first heat?

At what age can Dogs get PregnantYes! Female dogs can get pregnant during their first heat, which can occur anytime between when they’re 6- and 15-months old. Yikes!

How often do female dogs go into heat?

Most female dogs will go into heat twice each year, although this can vary between breeds and individuals. Some small breeds may experience heat three times in a year, while some larger breeds may only come into heat once in a year.

It’s important to remember that, just like humans, it can take a little while for young female dogs to develop regular estrous cycles. In some cases, it can take two years or more for a young female dog to develop a regular cycle. That being said, just remember that puppyhood is kind of a topsy-turvy time of your dog’s life. So don’t fret if their body seems to be rapidly changing or if it changes with irregularity – it’s supposed to be that way! 

What are the signs of a dog going into heat?

Dogs who are going into heat will present with a variety of symptoms or signs that let you and their potential partner know they’re ready to mate, including:

  • A large, red, swollen vulva
  • Consistent licking of their hindquarters
  • Increased frequency of urination 


You may also notice that your dog behaves differently when they’re in heat. That’s natural! As your dog’s cycle progresses, their body begins releasing all kinds of hormones that are supposed to encourage mating. Dogs in heat may exhibit the following behavioral changes:

  • Being very friendly to other dogs
  • Enthusiastically pursuing male dogs
  • Humping or mounting of inanimate objects (or you!)
  • Anxiety or nervousness, which may manifest as malaise 

What happens when a dog is in heat?

at what age can a puppy get pregnantWhen a dog has come into heat, they will likely begin secreting a bloody discharge from their vagina. For most owners, this is the first sign that the dog is in heat. Over the course of the cycle, the discharge’s color and appearance changes considerably. What started as a bloody, red stream will eventually become watery and pink-to-red in color. 

As the dog’s discharge changes, so too does her urine. We know – we can’t believe how excited we are to keep talking about dog discharge and urine either. As her cycle progresses, the dog’s urine will become filled with different pheromones and hormones which act as signals to other dogs. The signal says something like “Hey! Hump me, instead of that pillow!” but we can’t be sure – we don’t speak dog urine. 

When are dogs most likely to become pregnant during heat?

Because sperm can survive for a week in a dog’s reproductive tract and still fertilize the eggs, a female dog can become pregnant during any stage of estrus. However, they are most likely to successfully become pregnant when her vaginal discharge is very watery as this is when the dog is ovulating. 

How long is a dog in heat for?

Though the time spent in heat can vary considerably between individual dogs, the average dog will be in heat for between 1 and 2 weeks. 

How to tell if your dog is pregnant?

Dogs who are pregnant may display a number of symptoms, including:

  • Increased appetite (figures)
  • Weight gain
  • Increased nipple size
  • Swollen belly
  • Fatigued
  • More affectionate
  • More irritable

at what age can a female dog get pregnant

However, it can get a bit confusing how to tell for sure if your dog has gotten pregnant. After all, it’s not like you can just go to CVS pharmacy and pick up a test-kit. This means that you’ll need your dog to undergo formal diagnostic testing with a veterinarian if you want to be absolutely sure she’s pregnant.  

There are a number of different diagnostic methods available to discover whether or not your dog is pregnant


Ultrasounds can be administered between 25 and 35 days after the suspected date of gestation. During this procedure, the veterinarian will use an ultrasound to detect any signs of fetal heartbeats. This will allow you to know how many puppies your dog may be carrying.

Hormone Tests

This test can also be administered between 25 and 35 days after the suspected date of gestation. Your veterinarian will conduct a blood test to measure the concentration of the hormone Relaxin in your dog’s blood (although, as a potential grandparent to some puppies, we understand if you don’t feel like relaxin’). Relaxin is a hormone which is only produced during pregnancy, so a positive test is a relatively reliable indicator your dog is pregnant. 


X-rays are one of the simplest, most effective ways to determine whether or not your dog is pregnant. Unfortunately, x-rays are most reliable around 60 days after the suspected date of gestation because the puppies’ skeletons won’t show up until then. A positive x-ray test will allow you to understand how many puppies your dog is carrying. 

How can I prevent my dog from becoming pregnant ?

If you don’t want your dog to get pregnant, the best way to prevent this is to have her surgically sterilized or spayed. During this procedure your veterinarian will completely remove your dog’s reproductive tract, ovaries, and uterus. This will prevent your dog from ever being able to carry or birth puppies. 

When should you spay your dog?

when to spay your dogThis is a question which has been the subject of debate among veterinarians for many years now. The simple answer is that there likely isn’t a ‘best time’ to spay your dog. 

Some detractors of early spaying claim that spaying your puppy before she has her first estrus cycle may negatively impact her development. This is because most puppies’ growth plates don’t close until they’re between 9- and 12-months old and spaying heavily alters your puppy’s hormones. The fear is that the sudden alteration in hormone production while your puppy is still rapidly growing can negatively inhibit healthy bone growth. 

However, many veterinarians recognize these risks and continue to advocate for pet owners to spay their dogs. There is an abundance of unwanted dogs in the USA so we, at Banixx, advocate an earlier spay.  It’s either an earlier spay or the death of a litter of unwanted puppies.  Simple Truth. It is however much more commonplace nowadays to see animal scientists advocating for veterinarians to take a more holistic approach to assessing whether or not a dog is an appropriate age to be spayed. 

The American Kennel Club’s Canine Health Foundation has this to say about spaying: “Most dogs in the United States are spayed or neutered, and for years the procedures have been completed prior to maturity. The research suggests that veterinarians should be more cautious about the age at which they spay and neuter in order to protect the overall health of dogs.”.  However, this is a balancing act.  Females being spayed later in life, after first estrus, stand a chance of becoming pregnant.  Only careful, planned stewardship can prevent this.

Veterinarians are also split about whether or not spaying is a net benefit to the dog themselves. Laura J. Sanborn, M.S., wrote in her article titled “Long-Term Health Risks and Benefits Associated with Spay / Neuter in Dogs”: “An objective reading of the veterinary medical literature reveals a complex situation with respect to the long-term health risks and benefits associated with spay/neuter in dogs. The evidence shows that spay/neuter correlates with both positive and adverse health effects in dogs. It also suggests how much we really do not yet understand about this subject.”

Of course, we know that you’re going to do the responsible thing and do lots of research before deciding when to spay your dog. After all, we know you’re a good pet parent who’s always trying to find new, better ways to care for your four-legged friends – otherwise you wouldn’t be reading our blog! 

But nobody knows everything, right? Like…do you know how to treat a dog’s runny nose? Wipe it? Wrong.!  Only one way to find out…or, find out more about dog ear infections or simply just visit our Dog faqs




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