baby pool for a whelping box

The Top 5 Questions About Dog Pregnancy

In Animal Health, Dog Behavior, Dog CPR, Dogs, pet cpr, Pet First Aid, Pet Industry, Puppies, Uncategorized, veterinarian by Cara Armour2 Comments

First in order to discuss dog pregnancy let’s quickly break down some information needed beforehand such as how the female dog’s heat cycle works and plays a vital role in the production of puppies.

What Is the Heat Cycle?

On average, a female dog starts her first estrus, or heat cycle when she is around six months old. This can be earlier for some breeds and as late as 18-24 months for others- such as large breed dogs. Being “in heat” or “in season” are also common terms to describe this time in a dog’s reproductive cycle.

Obvious bodily changes occur such as enlarged nipples, swollen vulva and then eventually bloody discharge. The entire process lasts about 14-21 days, again, depending on the dog. Unlike humans, the discharge is not a sloughing of the uterine wall but a hormonal and pheromonal discharge that carries signals and smells to attract male dogs, communicating when the female is ready to breed.

In general, but certainly not always a good indicator and variable by each dog, the female is fertile when the discharge changes to be more watery or around day 10. However, sperm can hang for a little bit inside the female waiting for the eggs to drop so do not think that a dog in the early or even later stages of her cycle, can’t still get pregnant – she definitely could.

The good news is unlike humans, this cycle of being fertile generally on average only happens every six months. My girls tend to come in every eight to nine months.

When Can a Dog Get Pregnant?

Females can only get pregnant while they are in season and more often than not, this can be very obvious to people as to when. The dog’s body changes and often their behavior as well. They may tend to mark, or pee in smaller amounts in different places around your property. For some the changes are subtle and not so obvious, that is why it is crucial to check over your dog’s body completely at the very least once a week. Not only searching for injuries but checking out all their parts for growth or changes that may in fact lead to their heat cycle.

In general the female will know exactly when she is fertile and ready to accept a male. This is referred to as a standing heat because she will stand for the male. When she is not receptive she will walk away, sit or even snarl at the advancing male to say – back off! When she is ready, it’s pretty darn obvious.

Here is a video of my female dog in heat letting the white male Boxer know that she is ready. Fortunately she not only has panties on, but he lacks the bits that produce the semen to make the puppies. Even though my female should know that by smell, she is pretty certain he’s the one for her!

In general though it is safe to assume that dogs can get pregnant at any time during their heat cycle. Typically its when the hormone levels reach a certain point usually 10-12 days into the cycle but as with anything, this can vary. The dog’s semen may also remain fertile for a few days so just because it may seem early for them to mate, do not assume anything.

How Can I Prevent My Dog From Getting Pregnant?

This is actually much easier than many people make it sound. I have heard people claim that a dog from five miles away jumped an eight foot fence to mate with a dog in heat. While this could actually happen, preventing this is relatively easy.

Here are some ways I do it:

  • Panties are always on the female when she is ever off-leash in the house.  As illustrated in the video above. My females are around in tact males but for the entire three weeks of their estrus, they are never left out of sight loose. They are crated then closed behind a door or the male is.
  • The female is let out separately from the male, ALWAYS. She is attended in the yard, never left to roam on her own. It’s not just the in tact males in the neighborhood, she might want to go for a dander herself to find a boyfriend.
  • She is never brought to public places unless on leash and wearing panties. We still continue to train in agility during this time and there are in tact males in the building. She is only off leash with me in the ring but again – always wearing her pants.

female dog in panties

Veterinarians will have a very straight forward approach and will recommend spaying and neutering. That certainly is the 100% guaranteed way to prevent your dog from getting pregnant. This is not necessarily the healthiest option for all dogs and I would advise doing your homework, especially on the timing of the surgery. It is a major surgery where not only the reproductive organs are removed but valuable organs that are part of a hormone cycle that have been proven to help stave off cancers, promote proper growth in the animal and many more benefits.

As I mentioned in my post on how to find a good veterinarian, it is paramount that you feel comfortable with the advice and service your vet is providing. Consult with your breeder on their recommended timing for sterilizing if at all. In general it is safe to allow the female dog at least one heat cycle. This allows her body to mature and accept the full surge of the hormone cycle.

It does not go without saying that dealing with a female in heat is not the easiest thing in the world. I am extremely used to it and the first time I was caring for a client’s dog that was in heat I was a bit nervous. I educated myself on what was happening with their body and learned about the benefits of in tact natural dogs and thus have decided to keep my dogs reproductive systems whole.

This is a choice, many rescues will not adopt out a dog until it has been sterilized and that makes perfect sense. Typically dogs in rescues are considered homeless and could contribute to the population of stray dogs. It makes complete sense to spay and neuter these animals as they are not intended for breeding programs. For those that are continuing on the legacy of the purebred dog, spaying and neutering certain dogs should be considered with great care.

How Long Are Dogs Pregnant?

Dogs are pregnant for about two months, usually between 61-65 days, again depending on the dog, the breed etc. Pregnancy is very hard to confirm any earlier than three weeks into it so you will have to bite your nails until you can get into a vet for an ultrasound. Skulls and bones don’t start to harden until six weeks so that is when most people can feel them but three weeks is the earliest time to be detect by ultrasound.

pregnant dog

Debbie mere days from whelping

Do not base it on weight or body changes. Many dogs have what are known as false pregnancies, they’re bodies hormonally assume they are pregnant and may even produce milk. Weight gain is very normal as are enlarged nipples. These are not guaranteed signs that a dog is pregnant.

My girls experience false pregnancies for every heat they are not bred and they look completely pregnant! Their bodies even go as far as producing milk!

My Dog is Confirmed Pregnant, What Now?

If the pregnancy is unplanned then the prior weeks to breeding and the nutritional consideration for that have passed, BUT you can still provide better nutrition in the final 5-6 weeks to help your dog and the puppies on the way. Consult with your veterinarian on the amounts and type of food your pregnant dog should receive for optimal growth of the pups and to maintain the best health of your dog. We follow a strict diet regimen for our pregnant girls that they do not seem to mind considering their meal size doubles in quantity and frequency! We also supplement and remove certain parts of their diet based on their breed, size and personal needs.

You will want to build out a section of your home for the mom to have her puppies. This should be a quiet area not in the center of the hustle and bustle of the home. A quiet corner where temperature can be easily regulated and she can build a nice den, which technically you will build for her.

Whelping Box

Debbie in her den (also called a whelping box) just before she had her puppies

These dens in breeding terms are referred to as whelping boxes. Their size is based on your dog’s size and should be adequate for delivering puppies, lying completely flat-out and have an area where the puppies will start to go potty once the mom stops cleaning. Some people have used baby pools or built their own and often people place in them what is known as a pig-rail. This allows the puppies an area to crawl away from the mother and not get squished by her – moving around 5-10 puppies in tight quarters can be tough on a mom.

As the puppies aged and I wanted to get sleep in my own bed, I set up a puppy pool as a second den for everyone to sleep. When puppies get about 2-3 weeks old, they are taught to eliminate outside of the sleeping area, hence my litter box setup

There are TONs of other supplies that should be available for pregnant pups for various reasons but the most important are going to be fresh clean towels, a thermometer to check her temperature to plan for delivery as well as monitor any signs of fever and more towels! While some use newspaper because it is inexpensive and easy to throw away, new studies are showing it can cause hip and knee issues for the puppies as their feet frequently slide out from underneath them. If left to their own, most mother dogs would head under a porch or build their own den dug out of dirt which as you can imagine has a much better grip for tiny puppy toes.


I hope that you take away a few key points from this post.

  1. A better understanding of a dog’s natural season and it’s importance to their body
  2. The knowledge that keeping a dog from getting pregnant does take responsibility but doesn’t always warrant the removal of organs
  3. How to find out if your dog is pregnant
  4. Dogs are not pregnant long so whether planned or not, there are many things as the animal’s guardian that you can do to help make the puppies entry into the world as safe for them and their mom as possible.

One of the best things you can do is to understand your dog’s health to the best of your ability. Learn what their normal temperature is, how to take and what to look for in physical changes during hormone cycles and in general what abnormalities to keep an eye on. This and much more is taught in our pet first aid and CPR class especially on how to perform CPR as well as rescue breathing on a puppy, of which I have done both.

Do you have a dog pregnancy story or one about helping deliver puppies? Please share it with us in our submit your story section.

puppies in a whelping box





  1. Where and what do you use for a litter box for the puppies to go to the bathroom in?

    1. Author

      I received great advice from a long-time breeder. Stores like Lowe’s carry wood pellets for stoves that are just compressed wood shavings. They say “safe for animal and human consumption” do not get the ones that are not. I have two litter boxes that I place them in starting with a small tray (boot tray) at first in the whelping box around 2.5/3 weeks. They learn very quickly to use them, they’re nice and clean. Poops fall to the bottom and can be scooped out and the pee causes the pellets to turn to dust that you dump or can scoop as well.

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