Dog Pregnancy: What To Expect When Your Dog Is Expecting

By Chyrle Bonk, DVM December 29, 2020

There are few things in the world more joyful than a puppy, unless it’s a whole litter of puppies! Even though dogs have been having those litters of puppies without the aid of humans for many, many years, if your dog is bred or you’re thinking about having her bred, then there are some important things for you to know that could help her.

What Is A Dog’s Heat Cycle?

The heat, or estrous, cycle consists of four phases each characterized by different hormonal, behavioral, and physiological changes. This cycle preps the body for a potential pregnancy, supports that pregnancy if applicable, and then clears things out to get ready for the next one. Now, for a little more on the heat cycle of a dog:

  • What age do dogs start going into heat?

Female pups will have their first heat when they reach puberty. When this happens depends on a dog’s size and breed, and to some extent the time of year (we’ll get more into that later). As a general rule, this is around six months of age. Smaller breeds tend to start younger, and some large breeds might not have their first heat until they’re 18 months old.

  • What age do dogs stop going into heat?

Dogs don’t go through a typical menopause like humans do. Rather, they stay fertile their entire life. That means your 16-year-old best friend can still have a litter of puppies. However, as a female dog ages, her heat cycles tend to become fewer and further in between, instead of the set twice a year that younger dogs are used to.

  • How often do dogs go into heat?

Most females will go into heat twice a year. There’s no real set timing for this, but most dogs follow a spring and fall schedule. Some breeds, such as Basenjis, only cycle in the spring, (this brings us back to the time of year comment from above) and some smaller breeds will cycle three times a year while larger breeds may only go into heat once per year. Young pups will be more irregular than those seasoned females as it may take a few years for them to hit their regularity stride.

  • How long does a dog stay in heat?

A dog will stay in heat, or be receptive to a male and able to become pregnant, for about 1.5 to 2 weeks. It varies for each individual pup and can last as long as three weeks.

  • What are the stages of the heat cycle?

The four stage of estrous are: proestrus, estrus, diestrus, and anestrus.

Proestrus is when the body is preparing for heat. Follicles are developing, estrogen is increasing and males are starting to get interested.

Estrus is the “true heat” stage when a female is receptive to a male and when ovulation of the eggs occurs. Estrogen decreases and progesterone increases.

Diestrus is the two-month period following estrus when the female no longer wants anything to do with the male and progesterone peaks and then starts to decline. This phase is basically the same hormonally regardless of whether a dog is pregnant or not.

Anestrus is the period after diestrus until proestrus begins again. It can last as little as four months or longer for those large breed dogs. This is the time when there is not a lot going on except the uterus is regrouping and preparing for the next go-around.

How Long Are Dogs Pregnant?

Pregnancy in dogs lasts about nine weeks, or 63 days. As with any gestation length, there is going to be variability between each pup, and it may be shorter or longer. An interesting note is that the diestrus phase is the same length and hormonal profile as a pregnancy, causing some dogs to have a ‘false pregnancy’ when their body thinks that they are pregnant even though they aren’t. Some dogs will go through a nesting phase, treating their toys, your socks, or other pets as their puppies and some will even go as far as to produce milk.

What Are the Signs That A Dog Is Pregnant?

Early on in the pregnancy, your dog is going to be pretty secretive and not show many outward signs. Some dogs may experience a little nausea due to hormonal changes and may not eat as much or even vomit a little. Some dogs may be a little more tired than usual.

As the pregnancy progresses, she will start to put on weight and may have an increased appetite. Your vet will be able to find puppies on an ultrasound at about three weeks into the pregnancy. By the fourth week, you will be able to feel the puppies palpating inside your dog’s belly.

At around six weeks along, you may start to notice nipple enlargement and even some milky discharge from them. Her tummy should be pretty noticeable by now as well. Six to seven weeks of gestation is when an x-ray can be done to evaluate the puppies’ bony structure and head sizes, which is especially important in small, brachycephalic breeds.

The last two weeks will show more belly growth and you may even be able to see the puppies move when your dog is resting. The mammary glands should fill as well and the momma-to-be will probably be pretty uncomfortable and restless.

What Are Ways to Care For Your Dog During Pregnancy?

Fortunately, your dog is going to do most of the work when it comes to her pregnancy. However, there are some areas where you can help. First of all, make sure she is eating a high-quality dog food. For recommendations on this, speak with your vet. For the early part of pregnancy, you won’t really need to adjust the feeding amounts unless your vet recommends it based on your dog’s weight and weight gain. When she gets into the final four to five weeks, you can gradually start to increase her food until she’s eating about 1.5 times her normal food intake. Again, this may be different due to recommendations from your vet based on her weight gain.

See your veterinarian throughout the pregnancy. Just like a pregnant woman should have regular prenatal appointments, pregnant dogs should as well. This will help your vet keep track of your dog’s weight, keep tabs on the size of the puppies and help you prepare for whelping.

You should also try to keep her stress to a minimum. If she’s a working dog, give her some time off. Make sure she has a comfortable bed and a safe space where she can go and relax without distractions. You may also give her separate feeding times if you have other dogs that make mealtime a rush job.

What Is The Average Size Of Puppy Litters?

A rough average is five to six puppies per litter. How many puppies your dog ends up with will depend a lot on her breed and if she’s been through this before. In general, smaller breeds have fewer puppies per litter simply because their belly run out of room. Larger breeds tend to have more puppies. Younger females, especially if it’s their first litter, may have fewer puppies than they do in later litters down the road. It’s not really uncommon for a Yorkie to have a single and a Lab to have 11!

How To Care For Your Dog and Puppies

Once the puppies arrive, it’s not uncommon for your girl to be a little off for a day or two. Her appetite may be variable and she may be reluctant to leave those new babies. Some dogs will go right back to normal. Nursing puppies take a lot out of a mother, so feed her all she wants to eat, preferably a higher calorie food, such as a puppy formula. You may also add some canned food in there to boost her water intake and make sure there is always clean water available.

There will also be some vaginal discharge that may be blood tinged or even a dark greenish color for a couple of weeks. Just make sure that it doesn’t have a foul odor or a lot of fresh blood.  You should also check her mammary glands every day for extra firmness, lumpiness, pain, or heat as these could all be signs of mastitis.

As for the little ones, make sure that each puppy eats every day, multiple times. The smaller puppies may have a harder time getting their fill, especially if it’s a large litter so pay special attention to them. You can use a small food scale to weigh each one to make sure they are gaining weight. You’ll also want to check the umbilical cords as some mommas can get a little aggressive and nibble them too close to the body.

If you need to have your puppies’ dewclaws removed or tail docked, please discuss the procedures with your veterinarian during that first week. Even if you don’t need these procedures performed, you should see your vet in the first week to make sure everything is okay.

The Importance of Spaying and Neutering

So, we’ve talked a lot about pregnancy and puppies in this article, but the question you should be asking yourself is if your dog should be pregnant in the first place. Puppies are great, but not every dog should have them. There are a lot of unwanted dogs out there, more than there should be. This is due to accidental breeding and unwanted litters. Spaying and neutering are great ways to prevent your dog from having unwanted puppies, and it also helps keep the stray and homeless dog population down.

Unwanted puppies aside, spaying and neutering is also important from a medical standpoint. Neutering completely removes the possibility of a male getting testicular cancer and prostate problems later on in life. Spaying makes uterine infections nonexistent and drastically decreases the possibility of mammary cancer.

On the behavioral side, removing the reproductive organs also removes the reproductive hormones that make a dog wander and cause male dog aggression. It also stops the biannual heat cycles that brings all of the neighborhood males to your doorstep.

One final note:  there has been a lot of research lately about the possible benefits of delaying spaying and neutering until after puberty. This may decrease the likelihood of ligament injuries and some forms of cancer down the road. Always speak with your veterinarian about when it’s best to have your dog spayed or neutered.


If you have an expectant mother or are thinking about having your dog bred, speak with your veterinarian first. They will be able to help you decide if having puppies is right for your dog and when and how you should go about it. They will also be there to help make sure your dog has the healthiest pregnancy that they can.

Petozy is a brand dedicated to pet and pet parent happiness. Learn more about us here.